280 results on '"Slater, JD"'
Search Results
2. Rapid evolution of virulence and drug resistance in the emerging zoonotic pathogen Streptococcus suis.
- Author
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Ratner, AJ, Holden, MTG, Hauser, H, Sanders, M, Ngo, TH, Cherevach, I, Cronin, A, Goodhead, I, Mungall, K, Quail, MA, Price, C, Rabbinowitsch, E, Sharp, S, Croucher, NJ, Chieu, TB, Mai, NTH, Diep, TS, Chinh, NT, Kehoe, M, Leigh, JA, Ward, PN, Dowson, CG, Whatmore, AM, Chanter, N, Iversen, P, Gottschalk, M, Slater, JD, Smith, HE, Spratt, BG, Xu, J, Ye, C, Bentley, S, Barrell, BG, Schultsz, C, Maskell, DJ, Parkhill, J, Ratner, AJ, Holden, MTG, Hauser, H, Sanders, M, Ngo, TH, Cherevach, I, Cronin, A, Goodhead, I, Mungall, K, Quail, MA, Price, C, Rabbinowitsch, E, Sharp, S, Croucher, NJ, Chieu, TB, Mai, NTH, Diep, TS, Chinh, NT, Kehoe, M, Leigh, JA, Ward, PN, Dowson, CG, Whatmore, AM, Chanter, N, Iversen, P, Gottschalk, M, Slater, JD, Smith, HE, Spratt, BG, Xu, J, Ye, C, Bentley, S, Barrell, BG, Schultsz, C, Maskell, DJ, and Parkhill, J
- Abstract
BACKGROUND: Streptococcus suis is a zoonotic pathogen that infects pigs and can occasionally cause serious infections in humans. S. suis infections occur sporadically in human Europe and North America, but a recent major outbreak has been described in China with high levels of mortality. The mechanisms of S. suis pathogenesis in humans and pigs are poorly understood. METHODOLOGY/PRINCIPAL FINDINGS: The sequencing of whole genomes of S. suis isolates provides opportunities to investigate the genetic basis of infection. Here we describe whole genome sequences of three S. suis strains from the same lineage: one from European pigs, and two from human cases from China and Vietnam. Comparative genomic analysis was used to investigate the variability of these strains. S. suis is phylogenetically distinct from other Streptococcus species for which genome sequences are currently available. Accordingly, approximately 40% of the approximately 2 Mb genome is unique in comparison to other Streptococcus species. Finer genomic comparisons within the species showed a high level of sequence conservation; virtually all of the genome is common to the S. suis strains. The only exceptions are three approximately 90 kb regions, present in the two isolates from humans, composed of integrative conjugative elements and transposons. Carried in these regions are coding sequences associated with drug resistance. In addition, small-scale sequence variation has generated pseudogenes in putative virulence and colonization factors. CONCLUSIONS/SIGNIFICANCE: The genomic inventories of genetically related S. suis strains, isolated from distinct hosts and diseases, exhibit high levels of conservation. However, the genomes provide evidence that horizontal gene transfer has contributed to the evolution of drug resistance.
- Published
- 2009
3. Invasive disease and toxic shock due to zoonotic Streptococcus suis: an emerging infection in the East?
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Sriskandan, S, Slater, JD, Sriskandan, S, and Slater, JD
- Abstract
Sriskandan and Slater discuss the implications of Tang and colleagues' report of the largest known zoonotic outbreak of S. suis, which occurred in Sichuan Province, China, in 2005.
- Published
- 2006
4. SU-E-T-333: Immobilization for Proton Therapy - How Is It Different to Photon Therapy?
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Wroe, A, primary, Schulte, R, additional, Slater, JD, additional, and Slater, JM, additional
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- 2012
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5. MO-A-213AB-10: Scattering System Optimization for Proton Therapy
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Wroe, A, primary, Schulte, R, additional, Barnes, S, additional, McAuley, G, additional, Slater, JD, additional, and Slater, JM, additional
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- 2012
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6. Asymmetric scalp electromyogram: a common and accurate lateralizing sign in motor seizures.
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Kalamangalam GP, Tandon N, Saria HY, and Slater JD
- Published
- 2011
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7. Partial Breast Irradiation Delivered With Proton Beam: Results of a Phase II Trial.
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Bush DA, Slater JD, Garberoglio C, Do S, Lum S, and Slater JM
- Published
- 2011
8. A technique of partial breast irradiation utilizing proton beam radiotherapy: comparison with conformal X-ray therapy.
- Author
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Bush DA, Slater JD, Garberoglio C, Yuh G, Hocko JM, and Slater JM
- Abstract
PURPOSE:: To develop a breast immobilization system and clinical technique to deliver partial breast irradiation with a proton beam and compare dose distributions using proton therapy and conformal x-rays. METHODS:: A clinical technique to provide reproducible breast immobilization was developed. Breast immobilization begins by fitting each patient with a treatment brassiere. Patients are placed prone in a cylindrical polyvinyl chloride shell with the upper and lower body being supported and immobilized with Vac-Lok foam bead cushions. The upper chest and breast areas are immobilized with two-part expandable foam. After a treatment planning computed tomography scan, the lumpectomy cavity is outlined, and a clinical target volume is generated by adding 1cm in all dimensions. A three-dimensional treatment plan is developed with treatment typically given with 2 to 4 separate proton beams. The dose administered is 40 cobalt Gray equivalents (CGE) delivered in 10 daily fractions of 4 CGE with multiple fields treated each day. Proton and conformal x-ray plans were compared using dose-volume histogram analysis to determine volumes of normal breast tissue and skin treated with each technique. RESULTS:: An institutional review board-approved clinical trial was developed using this technique, and 20 patients have completed treatment. All subjects were able to undergo the immobilization procedure and daily treatments without significant discomfort, and no treatment interruptions were encountered. There was no evidence of respiratory motion identified on treatment planning CT images or on daily set-up radiographs. Acute toxicity has been limited to occasional radiation dermatitis (Radiation Therapy Oncology Group grade 1-2). Proton plans were compared with 2 methods of photon partial breast irradiation, including reduced tangential fields and five-field conformal techniques. Ten treatment plans with dose-volume histogram analysis revealed that the use of proton beams provided a significant reduction in doses to the ipsilateral breast and skin while eliminating doses to the heart and lung tissues. CONCLUSIONS:: A simple immobilization procedure provides accurate and reproducible breast positioning while simultaneously eliminating respiratory motion. The procedure has been well tolerated by the first 20 patients. Protons can provide substantial normal tissue protection compared with the use of conformal x-rays when used for partial breast treatment. We plan to continue enrollment and analyze long-term toxicity, local control, and survival. [ABSTRACT FROM AUTHOR]
- Published
- 2007
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9. Fractionated proton radiation treatment for pediatric craniopharyngioma: preliminary report.
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Luu QT, Loredo LN, Archambeau JO, Yonemoto LT, Slater JM, and Slater JD
- Abstract
This retrospective preliminary review evaluated the efficacy and toxicity of fractionated proton radiotherapy in the management of pediatric craniopharyngioma. METHODS: Sixteen patients, aged 7-34 years, were treated with proton-beam radiation. All had undergone at least one tumor resection. Seven patients underwent repeat resection for recurrence; one had previous x-ray radiotherapy. A daily dose of 1.8 cobalt gray equivalent was used to give a total dose in the range of 50.4-59.4 cobalt gray equivalent. RESULTS: Local control was achieved in 14 of 15 patients. Twelve of 15 patients survived. There were few acute side effects. Long-term complications included newly diagnosed panhypopituitarism, a cerebrovascular accident from which the patient fully recovered, and an out-of-proton-field meningioma in the single patient who received previous radiotherapy. DISCUSSION: Fractionated proton radiotherapy is an effective treatment for children with craniopharyngioma. Longer follow-up is needed to evaluate late complications. [ABSTRACT FROM AUTHOR]
- Published
- 2006
10. Reduced Activation and Affinity of Renin during Pregnancy and Oral Contraception: Determination of Kinetic Parameters by a Fully Autologous Plasma Renin Assay
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Daniels Cr, Slater Jd, and Eisen
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Plasma osmolality ,medicine.medical_specialty ,Endocrinology ,Blood pressure ,Renal sodium reabsorption ,Chemistry ,Internal medicine ,Renal blood flow ,Renin–angiotensin system ,Body water ,Extracellular fluid ,medicine ,Angiotensin II - Abstract
In healthy normotensive pregnancy, a complex functional network develops between the cardiovascular system, the volume and composition of the extracellular fluid and the renin-angiotensin system (RAS). Cardiac output and heart rate increase, but blood pressure is reduced. The kidneys increase in size and both the glomerular filtration rate and renal blood flow increase early. Renal tubular water and sodium reabsorption is even more enhanced, so that the total body water of mother and foetus rises in the course of pregnancy by 6-8 litres. Plasma osmolality falls by about 10 mosm/kg. yet total body sodium increases by about 1 mol. Understandably, in the face of such complex fluid and pressure adjustments, data on the changes of the RAS in normal pregnancy are often contradictory. However, there is general agreement that the angiotensinogen and inactive renin in plasma are greatly raised. Most groups have also found a considerable increase in active renin. These changes could lead to higher rates of angiotensin I (AI) formation (and hence high circulating angiotensin II levels), with adverse consequences for mother and foetus. The high proportion of inactive renin may reflect a reduction in the rate of activation of prorenin in order to avoid these consequences. This reduction may involve kallikreins which have been listed amongst the putative in vivo activators of prorenin. Excessive AI formation in pregnancy could also be avoided by the production of functionally different renins or angiotensinogens. Such changes will be difficult to detect with assays which require addition of extraneous renin or angiotensinogen.(ABSTRACT TRUNCATED AT 250 WORDS)
- Published
- 1986
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11. Serum renin activity during exposure to hypoxia
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E. S. Williams, R. E. Tuffley, Slater Jd, and D. Rubenstein
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Adult ,Male ,medicine.medical_specialty ,Endocrinology, Diabetes and Metabolism ,Emotions ,Posture ,Blood Pressure ,Endocrinology ,Heart Rate ,Internal medicine ,Phenethylamines ,Renin ,medicine ,Humans ,skin and connective tissue diseases ,Hypoxia ,business.industry ,Sodium ,Hypoxia (medical) ,Carbon Dioxide ,Circadian Rhythm ,Oxygen ,Pulmonary Alveoli ,Serum renin activity ,Potassium ,sense organs ,medicine.symptom ,business - Abstract
SUMMARY Changes of serum renin activity, heart rate, blood pressure, renal sodium, potassium and metadrenaline excretion and alveolar gas tensions were recorded during two 2–3 h exposures to 446 mmHg barometric pressure (simulated altitude of 4279 m or 14000 ft). Serum renin activity rose considerably during the first exposure and only slightly during the second. This effect was positively correlated with the changes of heart rate. There was little change in blood pressure or in the rate of renal excretion of sodium, potassium or the metadrenalines. It is suggested that the change of serum renin activity cannot be explained by a direct effect of hypoxaemia, emotion, posture or the diurnal rhythm of renin secretion but that it may be correlated with changes of cardiovascular function.
- Published
- 1970
12. The inhibiton of adrenergically provoked renin release by salbutamol in man.
- Author
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Wiggins, R, primary, Davies, R, additional, Basar, I, additional, and Slater, JD, additional
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- 1978
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13. The pervasive influence of conflicts of interest: a personal perspective.
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Benbadis SR, Faught RE, Sirven J, Slater JD, Sperling MR, and Hirsch LJ
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- 2010
14. The pervasive influence of conflicts of interest: A personal perspective.
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Torgovnick J, Sethi N, Arsura E, Martin JB, Benbadis SR, Faught RE, Sirven J, Slater JD, Sperling MR, and Hirsch LJ
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- 2010
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15. The Nguyen/Trofimov/Zietman article reviewed. Proton-beam vs intensity-modulated radiation therapy: too soon for a randomized trial.
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Slater JD and Schulte RW
- Published
- 2008
16. Horses are worthy of care: Horse sector participants' attitudes towards animal sentience, welfare, and well-being.
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Fiedler JM, Ayre ML, Rosanowski S, and Slater JD
- Abstract
Organisations for which sentient animals are central to the business model need to demonstrate the safeguarding of animal welfare and well-being. This requires providing positive experiences for animals which is critical to maintaining the social licence to operate. A cross-sectional survey captured the attitudes of experienced horse sector participants regarding sentience, welfare and well-being. Almost all respondents (99.9%; n = 676/677), believed horses were sentient. Analysis of open-ended responses identified two themes: (1) Sentience is a pathway to understanding the mental state, welfare and well-being of horses; and (2) A moral obligation for humans to consider sentience. Respondents' observations that horses reacted to stimuli and responded to their surroundings underpinned their belief that horses were sentient. Theme one related to respondents' understanding of sentience and how sentience informed their interpretations of horse behaviours and the making of inferences regarding the equine mental state. Theme two related to a moral obligation believed to exist towards horses because humans manage the horses' environment and need to consider the impact of their interactions with horses. These obligations were perceived as responsibilities to consider sentience when determining good welfare and well-being in horse activity settings, when interacting with horses and when training and competing with horses. The results suggested a sophisticated understanding of sentience existed among experienced horse sector participants, who recognised the sentient horse as worthy of care. We propose that leveraging experienced participants' existing knowledge of sentience could support the implementation of the Five Domains model when updating organisational policies., Competing Interests: None., (© The Author(s) 2025.)
- Published
- 2025
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17. The brain-heart connection: Value of concurrent ECG and EEG recordings in epilepsy management.
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Slater JD, Benbadis S, and Verrier RL
- Abstract
Concurrent electrocardiogram (ECG) and electroencephalogram (EEG) recording both ictally and interictally has significant value in the comprehensive management of epilepsy. This review highlights the diagnostic utility of simultaneous ECG and EEG monitoring in differentiating between epileptic and cardiac events, detecting cardiac abnormalities, and identifying autonomic dysfunction. The critical role of this combined approach to defining the mechanisms underlying cardiac morbidity and sudden cardiac death in patients with epilepsy and in guiding therapeutic interventions is underscored. The "Epileptic Heart Syndrome" is examined, illustrating how chronic epilepsy can adversely affect cardiac structure and function, leading to increased risk for interictal cardiac arrhythmias, morbidities, and mortality. The findings emphasize the need for standardized protocols for routine concurrent ECG and EEG recording in epilepsy monitoring units both ictally and interictally to ensure comprehensive patient care, improve diagnostic accuracy, and potentially reduce epilepsy-related morbidity and mortality. Future research directions are proposed to address existing gaps and to advance the technology and methodology for concurrent monitoring including wearable and computer-based monitoring systems., Competing Interests: The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: Jeremy Slater is CMO of Stratus, Inc., and reports financial support and administrative support provided by Stratus including employment, equity or stocks, and non-financial support. He owns stock in Zeto, Inc., a manufacturer of a dry electrode EEG headset. Selim Benbadis is National Medical Director of Stratus. Richard Verrier is a member of the Medical Advisory Board of Stratus and has received lecture honoraria from Stratus and from UCB., (© 2024 The Authors. Published by Elsevier Inc.)
- Published
- 2024
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18. Horse Sector Participants' Attitudes towards Anthropomorphism and Animal Welfare and Wellbeing.
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Fiedler JM, Ayre ML, Rosanowski S, and Slater JD
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Anthropomorphizing can misinform the making of inferences about animal mental experiences. This is a consideration when implementing the Five Domains Model for animal welfare assessment. An online survey run in 2021 captured horse sector participants' perspectives about anthropomorphism and wellbeing in relation to horses. Most respondents, 82.9% ( n = 431/520), believed that anthropomorphism could influence horse welfare and wellbeing. These respondents were then asked how, in their opinion, anthropomorphism might relate to horse welfare. A thematic analysis identified two themes: (1) 'Anthropomorphism can influence how people relate to horses' and (2) 'Anthropomorphism can have consequences for horse welfare and wellbeing'. The results suggested that experienced respondents were aware of the complexities surrounding anthropomorphic attitudes and that anthropomorphism can have beneficial and detrimental consequences on horse welfare and wellbeing. Benefits include a sense of relatedness to a horse, while detriments include the potential to misinterpret horse behaviors. The authors propose that anthropomorphism has a place in horse welfare and wellbeing when used critically and with caution. This study recommends that there is a need to actively manage anthropomorphism when organizations update policies and practices and implement the Five Domains Model. More research is required to understand the effects of anthropomorphism on horse-related practices.
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- 2024
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19. The unforeseen future: Impacts of the COVID-19 pandemic on home video-EEG telemetry.
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Brunnhuber F, Slater JD, Goyal S, Amin D, and Winston JS
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- Humans, Pandemics, Retrospective Studies, Video Recording methods, Electroencephalography methods, Telemetry methods, COVID-19, Epilepsy diagnosis, Epilepsy epidemiology
- Abstract
The coronavirus disease 2019 (COVID-19) pandemic had widespread impact on health care systems globally-particularly services arranged around elective admission and attendance such as epilepsy monitoring units and home video-EEG telemetry (HVET). Here, we review the ongoing impacts of the pandemic on HVET services among several different providers who used different initial models of HVET. We discuss the features of HVET that led to success in providing continued diagnostic services to patients with epilepsy and related disorders and through retrospective audit of our services demonstrate the high diagnostic yield of HVET. We reflect on this unforeseen future and its implications for other diagnostic techniques and approaches., (© 2022 The Authors. Epilepsia published by Wiley Periodicals LLC on behalf of International League Against Epilepsy.)
- Published
- 2023
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20. Proton beam radiotherapy versus transarterial chemoembolization for hepatocellular carcinoma: Results of a randomized clinical trial.
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Bush DA, Volk M, Smith JC, Reeves ME, Sanghvi S, Slater JD, and deVera M
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- Humans, Protons, Treatment Outcome, Retrospective Studies, Carcinoma, Hepatocellular pathology, Liver Neoplasms pathology, Chemoembolization, Therapeutic methods, Proton Therapy
- Abstract
Background: This study compares survival rates, recurrence patterns, toxicity, and treatment cost in patients with hepatocellular carcinoma (HCC) treated with either transarterial chemoembolization (TACE) or proton beam radiotherapy (PBT)., Methods: Subjects with untreated HCC meeting Milan or San Francisco transplant criteria were recruited. Subjects were randomized to receive PBT (n = 36) or TACE (n = 40). Proton therapy was administered in 15 fractions over 3 weeks to a total dose of 70.2 Gy. TACE was repeated until complete or maximal response. The primary outcome measure was overall survival (OS). Secondary end points were progression-free survival (PFS), local control (LC), toxicity, and cost., Results: Of the 76 randomized patients, 74 were assessed for outcome measures. The 2-year OS for PBT versus TACE was similar at 68%, 95% confidence interval (CI), 0.54-0.86, and 65%, 95% CI, 0.52-0.83 (p = .80), however, median PFS was improved for PBT versus TACE (not reached vs. 12 months, p = .002). LC was improved with PBT versus TACE (hazard ratio, 5.64; 95% CI, 1.78-17.9, p = .003). Days of posttreatment hospitalization were 24 for PBT and 166 for TACE (p < .001). Total mean cost per patient for treatment and posttreatment care revealed a 28% cost savings for PBT., Conclusions: PBT and TACE yielded similar OS for treatment of HCC, but PFS and LC were improved with PBT compared to TACE. Patients treated with PBT required fewer courses of treatment, fewer posttreatment hospitalization days, and reduced cost of treatment compared to TACE. These data support the use of PBT as a viable treatment alternative to TACE for patients with HCC within transplant criteria., (© 2023 The Authors. Cancer published by Wiley Periodicals LLC on behalf of American Cancer Society.)
- Published
- 2023
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21. A phase II trial of gemcitabine and erlotinib followed by ChemoProton therapy plus capecitabine and oxaliplatin for locally advanced pancreatic cancer.
- Author
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Sanghvi SM, Coffman AR, Hsueh CT, Kang J, Park A, Solomon NL, Garberoglio CA, Reeves ME, Slater JD, and Yang GY
- Abstract
Background: Epidermal growth factor receptor (EGFR) is overexpressed in pancreatic cancer. EGFR expression plays a potentially important role in modulation of tumor sensitivity to either chemotherapy or radiotherapy. Erlotinib is a receptor tyrosine kinase inhibitor with specificity for EGFR/HER1. A phase II trial was conducted to explore the efficacy of a regimen utilizing erlotinib and proton therapy., Methods: Patients with unresectable or borderline resectable non-metastatic adenocarcinoma of the pancreas were included. Patients received 8-week systemic treatment with gemcitabine 1,000 mg/m
2 and erlotinib 100 mg (GE). If there was no evidence of metastatic disease after GE, then patients preceded with proton therapy to 50.4 Gy in 28 fractions with concurrent capecitabine 825 mg/m2 (CPT). This was followed with oxaliplatin 130 mg/m2 and capecitabine 1,000 mg/m2 (CapOx) for 4 cycles. The primary study objective was 1-year overall survival (OS). The benchmark was 43% 1-year survival as demonstrated in RTOG/NRG 98-12. The Kaplan-Meier method was used to estimate the one-year OS and the median OS and progression-free survival (PFS)., Results: The study enrolled 9 patients ages 47-81 years old (median 62) between January 2013 and March 2016, when the trial was closed due to low patient accrual. The 1-year OS rate was 55.6% (95% CI: 31% to 99%). The median OS was 14.1 months (95% CI: 11.4-NE) and the median PFS was 10.8 months (95% CI: 7.44-NE). A majority of patients completed CPT and GE, but only 33.3% completed the four cycles of CapOx. A third of patients experienced grade 3 toxicities, which were all hepatic along with one patient who also had grade 3 diarrhea. There were no grade 4 or 5 toxicities. Four patients were enrolled with borderline resectable disease, three of which were eligible for pancreaticoduodenectomy after GE and CPT treatment. One of two patients who underwent resection had a negative margin., Conclusions: This regimen for locally advanced pancreatic cancer (LAPC) exceeded the pre-specified benchmark and was safe and well tolerated. Additional investigations utilizing more current systemic treatment regimens with proton therapy are warranted., Trial Registration: ClinicalTrials.gov identifier (NCTNCT01683422)., Competing Interests: Conflicts of Interest: All authors have completed the ICMJE uniform disclosure form (available at https://jgo.amegroups.com/article/view/10.21037/jgo-22-327/coif). GY serves as the Editor-in-Chief of Journal of Gastrointestinal Oncology. CG, CTH and JS serve as unpaid editorial board members of Journal of Gastrointestinal Oncology from January 2021 to December 2022. The other authors have no conflicts of interest to declare., (2022 Journal of Gastrointestinal Oncology. All rights reserved.)- Published
- 2022
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22. Monte Carlo evaluation of high-gradient magnetically focused planar proton minibeams in a passive nozzle.
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McAuley GA, Lim CJ, Teran AV, Slater JD, and Wroe AJ
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- Monte Carlo Method, Phantoms, Imaging, Protons, Radiotherapy Dosage, Water, Proton Therapy methods
- Abstract
Objective . To investigate the potential of using a single quadrupole magnet with a high magnetic field gradient to create planar minibeams suitable for clinical applications of proton minibeam radiation therapy. Approach . We performed Monte Carlo simulations involving single quadrupole Halbach cylinders in a passively scattered nozzle in clinical use for proton therapy. Pencil beams produced by the nozzle of 10-15 mm initial diameters and particle range of ∼10-20 cm in water were focused by magnets with field gradients of 225-350 T m
-1 and cylinder lengths of 80-110 mm to produce very narrow elongated (planar) beamlets. The corresponding dose distributions were scored in a water phantom. Composite minibeam dose distributions composed from three beamlets were created by laterally shifting copies of the single beamlet distribution to either side of a central beamlet. Modulated beamlets (with 18-30 mm nominal central SOBP) and corresponding composite dose distributions were created in a similar manner. Collimated minibeams were also compared with beams focused using one magnet/particle range combination. Main results . The focusing magnets produced planar beamlets with minimum lateral FWHM of ∼1.1-1.6 mm. Dose distributions composed from three unmodulated beamlets showed a high degree of proximal spatial fractionation and a homogeneous target dose. Maximal peak-to-valley dose ratios (PVDR) for the unmodulated beams ranged from 32 to 324, and composite modulated beam showed maximal PVDR ranging from 32 to 102 and SOBPs with good target dose coverage. Significance. Advantages of the high-gradient magnets include the ability to focus beams with phase space parameters that reflect beams in operation today, and post-waist particle divergence allowing larger beamlet separations and thus larger PVDR. Our results suggest that high gradient quadrupole magnets could be useful to focus beams of moderate emittance in clinical proton therapy., (© 2022 Institute of Physics and Engineering in Medicine.)- Published
- 2022
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23. Proton stereotactic body radiation therapy for liver metastases-results of 5-year experience for 81 hepatic lesions.
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Coffman AR, Sufficool DC, Kang JI, Hsueh CT, Swenson S, McGee PQ, Nagaraj G, Patyal B, Reeves ME, Slater JD, and Yang GY
- Abstract
Background: To report on our institutional experience using Proton stereotactic body radiation therapy (SBRT) for patients with liver metastases., Methods: All patients with liver metastases treated with Proton SBRT between September 2012 and December 2017 were retrospectively analyzed. Local control (LC) and overall survival (OS) were estimated using the Kaplan-Meier method calculated from the time of completion of Proton SBRT. LC was defined according to Response Evaluation Criteria in Solid Tumors (RECIST) guidelines (version 1.1). Toxicity was graded according to Common Terminology Criteria for Adverse Events (CTCAE) version 4.0., Results: Forty-six patients with 81 lesions were treated with Proton SBRT. The median age was 65.5 years old (range, 33-86 years) and the median follow up was 15 months (range, 1-54 months). The median size of the gross tumor volume (GTV) was 2.5 cm (range, 0.7-8.9 cm). Two or more lesions were treated in 56.5% of patients, with one patient receiving treatment to a total of five lesions. There were 37 lesions treated with a biologically effective dose (BED) ≤60, 9 lesions with a BED of 61-80, 22 lesions with a BED of 81-100, and 13 lesions with a BED >100. The 1-year and 2-year LC for all lesions was 92.5% (95% CI, 82.7% to 96.8%). The grade 1 and grade 2 toxicity rates were 37% and 6.5%, respectively. There were no grade 3 or higher toxicities and no cases of radiation-induced liver disease (RILD)., Conclusions: Proton SBRT for the treatment of liver metastases has promising LC rates with the ability to safely treat multiple liver metastases. Accrual continues for our phase II trial treating liver metastases with Proton SBRT to 60 GyE (Gray equivalent) in 3 fractions., Competing Interests: Conflicts of Interest: All authors have completed the ICMJE uniform disclosure form (available at: http://dx.doi.org/10.21037/jgo-20-424). The authors have no conflicts of interest to declare., (2021 Journal of Gastrointestinal Oncology. All rights reserved.)
- Published
- 2021
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24. Consensus Statement on Proton Therapy for Prostate Cancer.
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Bryant CM, Henderson RH, Nichols RC, Mendenhall WM, Hoppe BS, Vargas CE, Daniels TB, Choo CR, Parikh RR, Giap H, Slater JD, Vapiwala N, Barrett W, Nanda A, Mishra MV, Choi S, Liao JJ, and Mendenhall NP
- Abstract
Proton therapy is a promising but controversial treatment in the management of prostate cancer. Despite its dosimetric advantages when compared with photon radiation therapy, its increased cost to patients and insurers has raised questions regarding its value. Multiple prospective and retrospective studies have been published documenting the efficacy and safety of proton therapy for patients with localized prostate cancer and for patients requiring adjuvant or salvage pelvic radiation after surgery. The Particle Therapy Co-Operative Group (PTCOG) Genitourinary Subcommittee intends to address current proton therapy indications, advantages, disadvantages, and cost effectiveness. We will also discuss the current landscape of clinical trials. This consensus report can be used to guide clinical practice and research directions., Competing Interests: Conflicts of Interest: Nancy P. Mendenhall, MD, and William M. Mendenhall, MD, are Editor-in-Chief and Operating Editor, respectively, of the International Journal of Particle Therapy (IJPT). Bradford S. Hoppe, MD, MPH, and Neha Vapiwala, MD, are IJPT Associate Editors. The authors have no additional conflicts of interest to disclose., (©Copyright 2021 The Author(s).)
- Published
- 2021
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25. Seizure symptoms and ambulatory EEG findings: incidence of epileptiform discharges.
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Chen H, Koubeissi M, Aziz S, Slater JD, Al Bunni H, Khan MT, Ali NY, Khan FA, Alnobani A, Hussain FM, Syed AU, Fares A, Iqbal T, and Syed TU
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- Adult, Aged, Epilepsy epidemiology, Female, Humans, Incidence, Male, Middle Aged, Neurophysiological Monitoring statistics & numerical data, Practice Guidelines as Topic, Retrospective Studies, Seizures epidemiology, Self Report statistics & numerical data, Video Recording, Electroencephalography statistics & numerical data, Epilepsy diagnosis, Epilepsy physiopathology, Monitoring, Ambulatory statistics & numerical data, Seizures diagnosis, Seizures physiopathology
- Abstract
Aims: Ambulatory video-EEG monitoring has been utilized as a cost-effective alternative to inpatient video-EEG monitoring for non-surgical diagnostic evaluation of symptoms suggestive of epileptic seizures. We aimed to assess incidence of epileptiform discharges in ambulatory video-EEG recordings according to seizure symptom history obtained during clinical evaluation., Methods: This was a retrospective cohort study. We queried seizure symptoms from 9,221 consecutive ambulatory video-EEG studies in 35 states over one calendar year. We assessed incidence of epileptiform discharges for each symptom, including symptoms that conformed to a category heading, even if not included in the ILAE 2017 symptom list. We report incidences, odds ratios, and corresponding p values using Fisher's exact test and univariate logistic regression. We applied multivariable logistic regression to generate odds ratios for the six symptom categories that are controlled for the presence of other symptoms., Results: History that included motor symptoms (OR=1.53) or automatisms (OR=1.42) was associated with increased occurrence of epileptiform discharges, whereas history of sensory symptoms (OR=0.76) predicted lack of epileptiform discharges. Patient-reported symptoms that were associated with increased occurrence of epileptiform discharges included lip-smacking, moaning, verbal automatism, aggression, eye-blinking, déjà vu, muscle pain, urinary incontinence, choking and jerking. On the other hand, auditory hallucination memory deficits, lightheadedness, syncope, giddiness, fibromyalgia and chronic pain predicted absence of epileptiform discharges. The majority of epileptiform discharges consisted only of interictal sharp waves or spikes., Conclusions: Our study shows that the use of ILAE 2017 symptom categories may help guide ambulatory video-EEG studies.
- Published
- 2020
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26. Multiple sensory illusions are evoked during the course of proton therapy.
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Narici L, Titova E, Obenaus A, Wroe A, Loredo L, Schulte R, Slater JD, and Nelson GA
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- Adolescent, Adult, Cohort Studies, Female, Humans, Illusions psychology, Male, Middle Aged, Retrospective Studies, Young Adult, Brain physiology, Illusions physiology, Proton Therapy adverse effects
- Abstract
Visual illusions from astronauts in space have been reported to be associated with the passage of high energy charged particles through visual structures (retina, optic nerve, brain). Similar effects have also been reported by patients under proton and heavy ion therapies. This prompted us to investigate whether protons at the Loma Linda University Proton Therapy and Research Center (PTRC) may also affect other sensory systems beside evoking similar perceptions on the visual system. A retrospective review of proton radiotherapy patient records at PTRC identified 29 sensory reports from 19 patients who spontaneously reported visual, olfactory, auditory and gustatory illusions during treatment. Our results suggest that protons can evoke neuronal responses sufficient to elicit conscious sensory illusion experiences, in four senses (auditory, taste, smell, and visual) analogous to those from normal sensory inputs. The regions of the brain receiving the highest doses corresponded with the anatomical structures associated with each type of illusion. Our findings suggest that more detailed queries about sensory illusions during proton therapy are warranted, possibly integrated with quantitative effect descriptions (such as electroencephalography) and can provide additional physiological basis for understanding the effects of protons on central nervous system tissues, needed for radiation risk assessment in advance of deep space human exploration., Competing Interests: Declaration of Competing Interest The authors do not have any identified or perceived conflicts of interest associated with this study., (Copyright © 2020 The Committee on Space Research (COSPAR). Published by Elsevier Ltd. All rights reserved.)
- Published
- 2020
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27. The real-world economic impact of home-based video electroencephalography: the payer perspective.
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Slater JD, Eaddy M, Butts CM, Meltser I, and Murty S
- Subjects
- Adolescent, Adult, Aged, Aged, 80 and over, Child, Child, Preschool, Epileptic Syndromes, Female, Humans, Male, Middle Aged, Retrospective Studies, United States, Young Adult, Electroencephalography economics, Electroencephalography methods, Health Expenditures, Outpatients
- Abstract
Aims: Electroencephalography (EEG) is an established method to evaluate and manage epilepsy; video EEG (VEEG) has significantly improved its diagnostic value. This study compared healthcare costs and diagnostic-related outcomes associated with outpatient vs inpatient VEEG among patients with epilepsy in the US. Materials and methods: This study used Truven MarketScan Commercial and Medicare Supplemental claims databases. Patients with a VEEG between July 1, 2013 and December 31, 2016 were identified. Index event was the first VEEG claim, which was used to determine inpatient and outpatient cohorts. Continuous health plan enrollment 6 months pre- and 12 months post-index VEEG was required. Primary outcomes were costs during the index event and 12 months post index. A generalized linear model with gamma distribution and a log link was used to estimate adjusted index and post-index costs. Results: Controlling for baseline differences, epilepsy-related cost of index VEEG was significantly lower for the outpatient ($4,098) vs the inpatient cohort ($13,821; p < 0.0001). The cost differences observed at index were maintained in the post-index period. The 12-month post-index epilepsy-related costs were lower in the outpatient cohort ($6,114 vs $12,733, p < 0.0001). Time from physician referral to index VEEG was significantly shorter in the outpatient cohort (30.6 vs 42.5 days). Patients in the inpatient cohort were also more likely to undergo an additional subsequent follow-up inpatient VEEG ( p < 0.0001). Limitations: Administrative claims data have limitations, including lack of data on clinical presentation, disease severity, and comprehensive health plan information. Generalizability may be limited to a US insured population of patients who met study criteria. Conclusions: Index VEEG was less costly in an outpatient vs inpatient cohort, and costs were lower during the follow-up period of 12 months, suggesting that outpatient VEEG can be provided to appropriate patients as a less costly option. There were fewer follow-up tests in the outpatient cohort with similar pre- and post-index diagnoses.
- Published
- 2019
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28. A Continuous Clustering Algorithm for Detection of Local Sleep in Humans.
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Chelaru MI and Slater JD
- Subjects
- Adult, Cerebral Cortex, Electrocorticography, Humans, Video Recording, Algorithms, Drug Resistant Epilepsy physiopathology, Models, Statistical, Sleep physiology, Wakefulness
- Abstract
Objective: Research in animal models has shown that many EEG sleep features reflect local conditions, which is a consequence of relative inactivity of neuronal clusters. In humans, the authors previously reported that focal sleep patterns appear on the cortex during the wake state and suggested that this underlies the condition described as drowsiness. The focal changes at individual electrodes appeared as a combination of increased instantaneous amplitude in the delta band and decreased instantaneous frequency in the theta-alpha band during non-REM sleep, with the opposite occurring during the wake state, permitting their categorization as "active" and "inactive." A limitation of the previous work was the use of a binary k-means clustering algorithm, which created the possibility that the findings were biased toward a predominantly inactive state while the study subject was still awake. The present study tested the hypothesis that analyzing the same data by using a continuous rather than binary classifier would overcome this limitation., Methods: An analysis was performed on records from six patients with refractory epilepsy who were undergoing video-electrocorticographic monitoring with implanted subdural grid electrodes. A fuzzy c-means clustering algorithm was utilized after feature extraction from the recordings to create state classifications for each moment in each recording. A subsequent analysis was performed to determine the relative contributions of instantaneous amplitude versus instantaneous frequency to the classification., Results: Localized state changes consistent with the hypothesis were observed. The contributions from instantaneous frequency and amplitude appeared roughly equal., Conclusions: This study reveals evidence of local sleep during the wake state in humans.
- Published
- 2019
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29. Hypofractionated Proton Therapy in Early Prostate Cancer: Results of a Phase I/II Trial at Loma Linda University.
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Slater JM, Slater JD, Kang JI, Namihas IC, Jabola BR, Brown K, Grove R, Watt C, and Bush DA
- Abstract
Purpose: To determine whether a hypofractionated proton therapy regimen will control early-stage disease and maintain low rates of side effects similar to results obtained using standard-fraction proton therapy at our institution., Materials and Methods: A cohort of 146 patients with low-risk prostate cancer according to National Comprehensive Cancer Network guidelines (Gleason score <7, prostate-specific antigen [PSA] <10, tumor stage of T1-T2a) received 60 Gy (cobalt Gy equivalent) of proton therapy (20 fractions of 3.0 Gy per fraction) in 4 weeks, a dose biologically equivalent to standard fractionation (44-45 fractions of 1.8 Gy to a total of 79.2 to 81 Gy in 0 weeks). Patients were evaluated at least weekly during treatment, at which time documentation of treatment tolerance and acute reactions was obtained. Follow-up visits were conducted every 3 months for the first 1 years, every 6 months for the next 3 years, then annually. Follow-up visits consisted of history and physical examination, PSA measurements, and evaluation of toxicity., Results: The median follow-up time was 42 months (range, 3-96 months). Acute grade 2 urinary toxicity occurred in 16% (20/120) of the patients; acute grade 2 or higher gastrointestinal toxicity was seen in 1.7% (2/120). At 9 months, 1 patient had late grade 3 urinary toxicity, which resolved by 12 months; no grade 3 gastrointestinal toxicities occurred. The 3-year biochemical survival rate was 99.3% (144/145). The median time to PSA nadir was 30 months., Conclusion: Hypofractionated proton therapy of 60 Gy in 20 fractions was safe and effective for patients with low-risk prostate cancer., Competing Interests: Conflicts of Interest Statement: The authors have no relevant conflicts of interest to disclose., (©Copyright 2019 The Author(s).)
- Published
- 2019
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30. Analysis of Morbidity and Outcomes Associated With Use of Subdural Grids vs Stereoelectroencephalography in Patients With Intractable Epilepsy.
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Tandon N, Tong BA, Friedman ER, Johnson JA, Von Allmen G, Thomas MS, Hope OA, Kalamangalam GP, Slater JD, and Thompson SA
- Subjects
- Adolescent, Adult, Blood Loss, Surgical, Blood Transfusion statistics & numerical data, Drug Resistant Epilepsy physiopathology, Drug Resistant Epilepsy surgery, Electrodes, Implanted, Electroencephalography, Female, Hematoma epidemiology, Humans, Length of Stay, Male, Neurosurgical Procedures, Operative Time, Robotic Surgical Procedures methods, Stereotaxic Techniques, Subdural Space, Surgical Wound Infection epidemiology, Treatment Outcome, Young Adult, Drug Resistant Epilepsy diagnosis, Electrocorticography methods, Postoperative Complications epidemiology
- Abstract
Importance: A major change has occurred in the evaluation of epilepsy with the availability of robotic stereoelectroencephalography (SEEG) for seizure localization. However, the comparative morbidity and outcomes of this minimally invasive procedure relative to traditional subdural electrode (SDE) implantation are unknown., Objective: To perform a comparative analysis of the relative efficacy, procedural morbidity, and epilepsy outcomes consequent to SEEG and SDE in similar patient populations and performed by a single surgeon at 1 center., Design, Setting and Participants: Overall, 239 patients with medically intractable epilepsy underwent 260 consecutive intracranial electroencephalographic procedures to localize their epilepsy. Procedures were performed from November 1, 2004, through June 30, 2017, and data were analyzed in June 2017 and August 2018., Interventions: Implantation of SDE using standard techniques vs SEEG using a stereotactic robot, followed by resection or laser ablation of the seizure focus., Main Outcomes and Measures: Length of surgical procedure, surgical complications, opiate use, and seizure outcomes using the Engel Epilepsy Surgery Outcome Scale., Results: Of the 260 cases included in the study (54.6% female; mean [SD] age at evaluation, 30.3 [13.1] years), the SEEG (n = 121) and SDE (n = 139) groups were similar in age (mean [SD], 30.1 [12.2] vs 30.6 [13.8] years), sex (47.1% vs 43.9% male), numbers of failed anticonvulsants (mean [SD], 5.7 [2.5] vs 5.6 [2.5]), and duration of epilepsy (mean [SD], 16.4 [12.0] vs17.2 [12.1] years). A much greater proportion of SDE vs SEEG cases were lesional (99 [71.2%] vs 53 [43.8%]; P < .001). Seven symptomatic hemorrhagic sequelae (1 with permanent neurological deficit) and 3 infections occurred in the SDE cohort with no clinically relevant complications in the SEEG cohort, a marked difference in complication rates (P = .003). A greater proportion of SDE cases resulted in resection or ablation compared with SEEG cases (127 [91.4%] vs 90 [74.4%]; P < .001). Favorable epilepsy outcomes (Engel class I [free of disabling seizures] or II [rare disabling seizures]) were observed in 57 of 75 SEEG cases (76.0%) and 59 of 108 SDE cases (54.6%; P = .003) amongst patients undergoing resection or ablation, at 1 year. An analysis of only nonlesional cases revealed good outcomes in 27 of 39 cases (69.2%) vs 9 of 26 cases (34.6%) at 12 months in SEEG and SDE cohorts, respectively (P = .006). When considering all patients undergoing evaluation, not just those undergoing definitive procedures, favorable outcomes (Engel class I or II) for SEEG compared with SDE were similar (57 of 121 [47.1%] vs 59 of 139 [42.4%] at 1 year; P = .45)., Conclusions and Relevance: This direct comparison of large matched cohorts undergoing SEEG and SDE implantation reveals distinctly better procedural morbidity favoring SEEG. These modalities intrinsically evaluate somewhat different populations, with SEEG being more versatile and applicable to a range of scenarios, including nonlesional and bilateral cases, than SDE. The significantly favorable adverse effect profile of SEEG should factor into decision making when patients with pharmacoresistant epilepsy are considered for intracranial evaluations.
- Published
- 2019
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31. Experimental validation of magnetically focused proton beams for radiosurgery.
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McAuley GA, Teran AV, McGee PQ, Nguyen TT, Slater JM, Slater JD, and Wroe AJ
- Subjects
- Monte Carlo Method, Water, Magnetic Phenomena, Protons, Radiosurgery methods
- Abstract
We performed experiments using a triplet of quadrupole permanent magnets to focus protons and compared their dose distributions with unfocused collimated beams using energies and field sizes typically employed in proton radiosurgery. Experiments were performed in a clinical treatment room wherein small-diameter proton beams were focused by a magnet triplet placed immediately upstream of a water tank. The magnets consisted of segments of Sm
2 Co17 rare-earth permanent magnetic material adhered into Halbach cylinders with nominal field gradients of 100, 150, 200, and 250 T m-1 . Unmodulated beams with initial diameters of 3 mm-20 mm were delivered using a single scattering system with nominal energies of 127 and 157 MeV (respective ranges of ~10 cm and 15 cm in water), commonly used for proton radiosurgery at our institution. For comparison, small-diameter unfocused collimated beams were similarly delivered. Transverse and depth dose distributions were measured using radiochromic film and a diode detector, respectively, and compared between the focused and unfocused beams (UNF). The focused beams produced low-eccentricity beam spots (defined by the 80% dose contour) at Bragg depth, with full width at 80% maximum dose values ranging from 3.8 to 7.6 mm. When initial focused beam diameters were larger than matching unfocused diameters (19 of 29 cases), the focused beams peak-to-entrance dose ratios were 13% to 73% larger than UNF. In addition, in 17 of these cases the efficiency of dose delivery to the target was 1.3× to 3.3× larger. Both peak-to-entrance dose ratios and efficiency tended to increase with initial beam diameter, while efficiency also tended to increase with magnet gradient. These experimental results are consistent with our previous Monte Carlo (MC) studies and suggest that a triplet of quadrupole Halbach cylinders could be clinically useful for irradiating small-field radiosurgical targets with fewer beams, lower entrance dose, and shorter treatment times.- Published
- 2019
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32. Outcome of ambulatory video-EEG monitoring in a ˜10,000 patient nationwide cohort.
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Syed TU, LaFrance WC Jr, Loddenkemper T, Benbadis S, Slater JD, El-Atrache R, AlBunni H, Khan MT, Aziz S, Ali NY, Khan FA, Alnobani A, Hussain FM, Syed AU, and Koubeissi MZ
- Subjects
- Adolescent, Adult, Aged, Ambulatory Care methods, Child, Cohort Studies, Female, Humans, Male, Middle Aged, Monitoring, Physiologic, Outcome Assessment, Health Care, Statistics, Nonparametric, United States epidemiology, Video Recording, Young Adult, Electroencephalography methods, Epilepsy diagnosis, Epilepsy epidemiology
- Abstract
Purpose: We evaluate outcome of in-home diagnostic ambulatory video-EEG monitoring (AVEM) performed on a nationwide cohort of patients over one calendar year, and we compare our findings with outcomes of inpatient adult and pediatric VEM performed during the same year at two academic epilepsy centers., Methods: This is a retrospective cohort study. We obtained AVEM outcome data from an independent ambulatory-EEG testing facility. Inpatient VEM data from a 4-bed adult epilepsy center and an 8-bed pediatric epilepsy center were also included. Primary outcome measure was composite percentage of VEM records with epileptiform activity on EEG tracings or at least one video-recorded pushbutton event. We assessed patient-reported symptoms documented in AVEM event diaries., Results: Of 9221 AVEM recordings performed across 28 states, 62.5% attained primary outcome. At least one patient-activated pushbutton event was captured on video in 54% of AVEM recordings (53.6% in adults, 56.1% in children). Epileptiform activity was reported in 1657 (18.0%) AVEM recordings (1473 [88.9%] only interictal, 9 [0.5%] only ictal, 175 [10.6%] both interictal and ictal). Most common patient-reported symptomatology during AVEM pushbutton events was behavioral/autonomic/emotional in adults and children. Compared to AVEM, inpatient VEM captured more confirmed representative events in adult and pediatric samples., Conclusions: AVEM is useful for non-urgent diagnostic evaluation of events., (Copyright © 2019 British Epilepsy Association. Published by Elsevier Ltd. All rights reserved.)
- Published
- 2019
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33. A phase I trial of Proton stereotactic body radiation therapy for liver metastases.
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Kang JI, Sufficool DC, Hsueh CT, Wroe AJ, Patyal B, Reeves ME, Slater JD, and Yang GY
- Abstract
Background: A phase I trial to determine the maximum tolerated dose (MTD) of Proton stereotactic body radiation therapy (SBRT) for liver metastases in anticipation of a subsequent phase II study., Methods: An institutional IRB approved phase I clinical trial was conducted. Eligible patients had 1-3 liver metastases measuring less than 5 cm, and no metastases location within 2 cm of the GI tract. Dose escalation was conducted with three dose cohorts. The low, intermediate, and high dose cohorts were planned to receive 36, 48, and 60 respectively to the internal target volume (ITV) in 3 fractions. At least 700 mL of normal liver had to receive <15. Dose-limiting toxicity (DLT) included acute grade 3 liver, intestinal or spinal cord toxicity or any grade 4 toxicity. The MTD is defined as the dose level below that which results in DLT in 2 or more of the 6 patients in the highest dose level cohort., Results: Nine patients were enrolled (6 male, 3 female): median age 64 years (range, 33-77 years); median gross tumor volume (GTV) 11.1 mL (range, 2.14-89.3 mL); most common primary site, colorectal (5 patients). Four patients had multiple tumors. No patient experienced a DLT and dose was escalated to 60 in 3 fractions without reaching MTD. The only toxicity within 90 days of completion of treatment was one patient with a grade 1 skin hyperpigmentation without tenderness or desquamation. Two patients in the low dose cohort had local recurrence and repeat SBRT was done to previously treated lesions without any toxicities., Conclusions: Biologically ablative Proton SBRT doses are well tolerated in patients with limited liver metastases with no patients experiencing any grade 2+ acute toxicity. Results from this trial provide the grounds for an ongoing phase II Proton SBRT study of 60 over 3 fractions for liver metastases., Competing Interests: Conflicts of Interest: The authors have no conflicts of interest to declare.
- Published
- 2019
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34. Improved long-term patient-reported health and well-being outcomes of early-stage breast cancer treated with partial breast proton therapy.
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Teichman SL, Do S, Lum S, Teichman TS, Preston W, Cochran SE, Garberoglio CA, Grove R, Davis CA, Slater JD, and Bush DA
- Subjects
- Aged, Aged, 80 and over, Breast Neoplasms pathology, Breast Neoplasms surgery, Female, Humans, Mastectomy, Segmental, Middle Aged, Neoplasm Staging, Patient Reported Outcome Measures, Patient Satisfaction, Quality of Life, Treatment Outcome, Breast Neoplasms radiotherapy, Proton Therapy
- Abstract
Background: Because early-stage breast cancer can be treated successfully by a variety of breast-conservation approaches, long-term quality of life (QoL) is an important consideration in assessing treatment outcomes for these patients. This study compares patient-reported QoL outcomes among women with stage 0-2 disease treated via lumpectomy followed by whole breast irradiation (WBI) or partial breast proton irradiation (PBPT)., Methods: In this cross-sectional study, 129 participants evaluated QoL several years post-treatment by responding to subjective instruments, including established scalar questionnaires and self-report measures. Responses were averaged between the two groups., Results: At 6.5 years (median) postdiagnosis, participants' demographic, and clinical characteristics were similar. Patient-reported outcomes were reported as mean scale scores for the two groups, all displaying significant differences favoring PBPT, including: cosmetic breast cancer treatment outcome scale (BCTOS) (PBPT mean 1.45, WBI mean 1.88, P < 0.001); breast pain (PBPT mean 1.30, WBI mean 1.67, P < 0.05); breast texture (BPT mean 1.44, WBI mean 1.91, P < 0.001); clothing fit (PBPT mean 1.06, WBI 1.46, P < 0.001); fatigue (PBPT mean 2.24, WBI mean 3.77, P < 0.002); impact of daily life fatigue on personal relations (OBPT mean 0.83, WBI mean 2.15, P < 0.001); and self-consciousness (appearance dissatisfaction) (PBPT mean 1.38, WBI mean 1.77, P < 0.004)., Conclusion: Patients' responses suggest that PBPT is associated with improved overall QoL compared to standard whole breast treatment. These self-perceptions are reported by patients who are 5-10 years post-treatment, and that PBPT may enhance QoL in a multitude of interrelated ways., (© 2018 The Authors. Cancer Medicine published by John Wiley & Sons Ltd.)
- Published
- 2018
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35. Monte Carlo evaluation of magnetically focused proton beams for radiosurgery.
- Author
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McAuley GA, Heczko SL, Nguyen TT, Slater JM, Slater JD, and Wroe AJ
- Subjects
- Humans, Magnetics, Monte Carlo Method, Phantoms, Imaging, Protons, Radiosurgery methods, Radiotherapy Planning, Computer-Assisted methods
- Abstract
The purpose of this project is to investigate the advantages in dose distribution and delivery of proton beams focused by a triplet of quadrupole magnets in the context of potential radiosurgery treatments. Monte Carlo simulations were performed using various configurations of three quadrupole magnets located immediately upstream of a water phantom. Magnet parameters were selected to match what can be commercially manufactured as assemblies of rare-earth permanent magnetic materials. Focused unmodulated proton beams with a range of ~10 cm in water were target matched with passive collimated beams (the current beam delivery method for proton radiosurgery) and properties of transverse dose, depth dose and volumetric dose distributions were compared. Magnetically focused beams delivered beam spots of low eccentricity to Bragg peak depth with full widths at the 90% reference dose contour from ~2.5 to 5 mm. When focused initial beam diameters were larger than matching unfocused beams (10 of 11 cases) the focused beams showed 16%-83% larger peak-to-entrance dose ratios and 1.3 to 3.4-fold increases in dose delivery efficiency. Peak-to-entrance and efficiency benefits tended to increase with larger magnet gradients and larger initial diameter focused beams. Finally, it was observed that focusing tended to shift dose in the water phantom volume from the 80%-20% dose range to below 20% of reference dose, compared to unfocused beams. We conclude that focusing proton beams immediately upstream from tissue entry using permanent magnet assemblies can produce beams with larger peak-to-entrance dose ratios and increased dose delivery efficiencies. Such beams could potentially be used in the clinic to irradiate small-field radiosurgical targets with fewer beams, lower entrance dose and shorter treatment times.
- Published
- 2018
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36. Fractionated Proton Beam Therapy for Acoustic Neuromas: Tumor Control and Hearing Preservation.
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Barnes CJ, Bush DA, Grove RI, Loredo LN, and Slater JD
- Abstract
Purpose: This prospective cohort evaluated patients with acoustic neuroma treated with proton irradiation at Loma Linda University Medical Center. A dose of 50.4 Gy in 28 fractions was given to improve hearing preservation while maintaining tumor control., Patients and Methods: Ninety-five patients were treated from March 1991 to March 2008. Fractionated proton radiotherapy at daily doses of 1.8 Gy was employed. Patients were treated to 1 of 3 total doses: 59.4 Gy, used initially for patients without serviceable hearing; 54 Gy, used for patients with serviceable hearing through October 2000; and 50.4 Gy used since 2001 for patients with serviceable hearing. Survival and local control were calculated using the Kaplan-Meier method. Logistic regression analysis was preformed comparing dose, tumor size, and tumor location with hearing preservation., Results: Ninety-four patients were assessable; the median follow-up was 64 months. Five-year local control rates for the 59.4 Gy, 54 Gy, and 50.4 Gy groups were 95%, 97%, and 92%, respectively ( P = .80); the overall 10-year actuarial control rate was 90%. Cranial nerve injuries occurred in <5% in all groups. Four-year actuarial rates of hearing preservation were maintained in 44% of patients treated with 54 Gy and 64% treated with 50.4 Gy ( P = .284). On multivariate analysis, initial tumor diameter (≤1.5 cm) was found to be a prognostic factor for maintaining serviceable hearing in both groups ( P = .011)., Conclusions: Fractionated proton therapy of 50.4 Gy offers excellent local control and minimal cranial nerve toxicities. Improved rates of hearing preservation that are comparable with radiosurgery were seen with 50.4 Gy compared with higher doses, although this did not reach significance. Maintaining hearing was found to be associated with smaller initial tumor size., Competing Interests: Conflict of Interest Statement: Actual or potential conflicts of interest do not exist for any of the listed authors., (© Copyright 2018 International Journal of Particle Therapy.)
- Published
- 2018
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37. A simple clinical score for prediction of nonepileptic seizures.
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Rao SR, Slater JD, and Kalamangalam GP
- Subjects
- Counseling, Electroencephalography, Humans, Retrospective Studies, Seizures psychology, Symptom Assessment, Seizures diagnosis
- Abstract
Psychogenic nonepileptic seizures (PNES), often mistaken for epilepsy in community practice, require inpatient video-EEG (VEEG) monitoring for diagnostic confirmation. We developed a simple score designed for use in an outpatient setting to predict the subsequent VEEG diagnosis of PNES. We retrospectively compared fifty-five consecutive patients with VEEG-proven PNES (N
1 =55) with a group of randomly selected patients with VEEG-proven epilepsy (N2 =55). Patients were divided into two groups: I) a 'truly retrospective' group of 27 patients with PNES and 27 patients with epilepsy whose data served to develop the score, and II) a 'pseudoprospective' group of 28 patients each with PNES and epilepsy to whom the score was applied. Six features in the history of the Group I cohort appeared more prominent in patients with PNES than patients with epilepsy and were assigned escalating numerical values as follows: number of declared drug allergies (0, 0.5, 1), number of declared comorbidities (0, 0.5, 1), number of previous invasive medical interventions of any type (0, 0.5, 1), and a history of significant psychological or physical trauma (0 or 1). In addition, a score was assigned to verbal description of the seizures themselves as being consistent (=0), atypical (=1), or indeterminate (=0.5) for epilepsy. The values were added to yield an omnibus score ranging from 0 to 6. Scoring of Group II subjects in a blinded fashion revealed that in general patients with PNES had higher scores, and the majority obtained a score >2; most patients with epilepsy scored <1.5. Group difference in the mean between the PNES and epilepsy cohort was highly significant (p<0.0001, Wilcoxon rank-sum test). Our score is a simple clinical instrument based on the patient history that may find use in the triage of patients awaiting hospitalization for VEEG and in pre-VEEG counseling., (Copyright © 2017 Elsevier Inc. All rights reserved.)- Published
- 2017
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38. Individualized 4-dimensional computed tomography proton treatment for pancreatic tumors.
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Knecht ML, Wang N, Vassantachart A, Mifflin R, Slater JD, and Yang GY
- Abstract
Background: The goal of this study is to determine whether a phase or reconstruction of a 10-phase 4 dimensional computed tomography (4D CT) scan can be used as the primary planning scan for proton treatment of the pancreas, thus eliminating the need for second a slow CT or free breathing CT., Methods: Ten patients with pancreatic adenocarcinoma were simulated with 4D CT and a proton treatment plan generated based upon one of three primary planning scans, the T0 phase, T50 phase or average reconstruction. These plans were then exported to each of the remaining phases of the 4D CT and the dose to 95% of the target (D95) calculated. Plans were deemed adequate if the D95 remained at 99% of the prescribed dose or greater., Results: For the ten patients in this study anterior abdominal motion was found to range from 2-27 mm (mean 7.50±6.79 mm). For 9 of 10 patients the anterior abdominal motion was ≤8 mm and all three primary planning scans provided adequate target coverage, resulting in minimum D95 coverage per plan of T0_plan 99.7%, T50_plan 99.3% and AVE_plan 99%. However no plan provided adequate target coverage on the single patient with the largest anterior abdominal motion, 27 mm, and cranio-caudal motion, 20 mm, with minimum D95 values of T0_plan 96.3%, T50_plan 68%, and AVE_plan 68%., Conclusions: The primary plans tested based up on the T0, T50 and average reconstructions provided adequate D95 coverage throughout the respiratory cycle as long as the anterior abdominal motion was ≤8 mm and can be considered for use as the primary proton planning scan., Competing Interests: Conflicts of Interest: The authors have no conflicts of interest to declare.
- Published
- 2017
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39. Focal Changes to Human Electrocorticography With Drowsiness: A Novel Measure of Local Sleep.
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Slater JD, Chelaru MI, Hansen BJ, Beaman C, Kalamangalam G, Tandon N, and Dragoi V
- Subjects
- Adult, Brain physiopathology, Brain Waves, Drug Resistant Epilepsy physiopathology, Female, Humans, Linear Models, Male, Middle Aged, Neurophysiological Monitoring, Preoperative Period, Signal Processing, Computer-Assisted, Video Recording, Wakefulness physiology, Young Adult, Brain physiology, Electrocorticography, Sleep Stages physiology
- Abstract
Drowsiness may be defined as the progressive loss of cortical processing efficiency that occurs with time passing while awake. This loss of cortical processing efficiency is reflected in focal changes to the electroencephalogram, including islands of increased delta power concurrent with drop-offs in neuronal activity (i.e., focal cortical inactivity). The authors hypothesized that these focal changes are evidenced at individual electrodes by combination of increased instantaneous amplitude in delta band and decreased instantaneous frequency in theta-alpha band, permitting their categorization as "active" and "inactive." An analysis of records from six patients with refractory epilepsy undergoing video-electrocorticographic monitoring was conducted. Feature extraction and state classification on multiple recordings revealed focal changes consistent with the hypothesis, as well as progressively increased numbers of inactive electrodes with time awake. The implications of these findings on the study of sleep, and particularly local sleep, are discussed.
- Published
- 2017
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40. Effects of vertebral-body-sparing proton craniospinal irradiation on the spine of young pediatric patients with medulloblastoma.
- Author
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MacEwan I, Chou B, Moretz J, Loredo L, Bush D, and Slater JD
- Abstract
Purpose: To investigate the long-term effects of vertebral-body-sparing proton craniospinal irradiation (CSI) on the spine of young patients with medulloblastoma., Methods and Materials: Six children between the ages of 3 and 5 years with medulloblastoma were treated with vertebral-body-sparing proton CSI after maximal safe resection. Radiation therapy was delivered in the supine position with posterior beams targeting the craniospinal axis, and the proton beam was stopped anterior to the thecal sac. Patients were treated with a dose of either 23.4 Gy or 36 Gy to the craniospinal axis followed by a boost to the posterior fossa and any metastatic lesions. Chemotherapy varied by protocol. Radiographic effects on the spine were evaluated with serial imaging, either with magnetic resonance imaging scans or plain film using Cobb angle calculations, the presence of thoracic lordosis, lumbar vertebral body-to-disc height ratios, and anterior-posterior height ratios. Clinical outcomes were evaluated by patient/family interview and medical chart review., Results: Overall survival and disease free survival were 83% (5/6) at follow-up. Median clinical and radiographic follow-up were 13.6 years and 12.3 years, respectively. Two patients were clinically diagnosed with scoliosis and treated conservatively. At the time of follow-up, no patients had experienced chronic back pain or required spine surgery. No patients were identified to have thoracic lordosis. Diminished growth of the posterior portions of vertebral bodies was identified in all patients, with an average posterior to anterior ratio of 0.88, which was accompanied by compensatory hypertrophy of the posterior intervertebral discs., Conclusion: Vertebral-body-sparing CSI with proton beam did not appear to cause increased severe spinal abnormalities in patients treated at our institution. This approach could be considered in future clinical trials in an effort to reduce toxicity and the risk of secondary malignancy and to improve adult height.
- Published
- 2017
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41. A unified statistical model for the human electrocorticogram.
- Author
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Kalamangalam GP, Chelaru MI, and Slater JD
- Subjects
- Adult, Cerebral Cortex physiology, Electrodes, Implanted, Epilepsy diagnosis, Female, Humans, Male, Brain Mapping methods, Cerebral Cortex physiopathology, Electroencephalography methods, Epilepsy physiopathology, Models, Statistical, Sleep Stages physiology
- Abstract
Objective: Extracellular field potentials (ECFs) generated in the cerebral cortex span a vast range of spatiotemporal scales. The process(es) leading to this large dynamic range remain debatable. Here we propose a novel statistical description of the amplitude spectrum of the human electrocorticogram (ECoG)., Methods: Spectral analysis was performed on long-term recordings from epilepsy patients undergoing pre-surgical evaluation with intracranial electrodes. Amplitude spectra were fit with a multi-component Gaussian model on semi-logarithmic axes., Results: The Gaussian formulation provided excellent fits to the data. It also suggested how the changes accompanying the sleep-wake cycle and certain epileptiform transitions could be understood by variation in the parameters of the model., Conclusions: The proposed continuum model synthesizes several previous observations regarding the statistical structure of the resting human ECoG. It offers a conceptual platform for understanding the EEG changes accompanying the sleep-wake cycle and pathologically hypersynchronous behaviour., Significance: Statistical characterisation of the spectral distribution of field potentials yield insight into the cortico-cortical interactions that underlie the summated cortical ECFs comprising the ECoG. Such insight is relevant for a synoptic understanding of major state changes in the brain that are diagnosed in clinical practice by visual inspection of the ECoG., (Copyright © 2016 International Federation of Clinical Neurophysiology. Published by Elsevier Ireland Ltd. All rights reserved.)
- Published
- 2016
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42. Reactivation of visual-evoked activity in human cortical networks.
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Chelaru MI, Hansen BJ, Tandon N, Conner CR, Szukalski S, Slater JD, Kalamangalam GP, and Dragoi V
- Subjects
- Adult, Electrocardiography, Female, Humans, Magnetic Resonance Imaging, Male, Middle Aged, Models, Neurological, Photic Stimulation, Psychophysics, Spectrum Analysis, Visual Cortex diagnostic imaging, Wakefulness, Young Adult, Brain Mapping, Epilepsy pathology, Evoked Potentials, Visual physiology, Nerve Net physiopathology, Visual Cortex physiopathology, Visual Perception physiology
- Abstract
In the absence of sensory input, neuronal networks are far from being silent. Whether spontaneous changes in ongoing activity reflect previous sensory experience or stochastic fluctuations in brain activity is not well understood. Here we demonstrate reactivation of stimulus-evoked activity that is distributed across large areas in the human brain. We performed simultaneous electrocorticography recordings from occipital, parietal, temporal, and frontal areas in awake humans in the presence and absence of sensory stimulation. We found that, in the absence of visual input, repeated exposure to brief natural movies induces robust stimulus-specific reactivation at individual recording sites. The reactivation sites were characterized by greater global connectivity compared with those sites that did not exhibit reactivation. Our results indicate a surprising degree of short-term plasticity across multiple networks in the human brain as a result of repeated exposure to unattended information., (Copyright © 2016 the American Physiological Society.)
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- 2016
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43. Randomized Clinical Trial Comparing Proton Beam Radiation Therapy with Transarterial Chemoembolization for Hepatocellular Carcinoma: Results of an Interim Analysis.
- Author
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Bush DA, Smith JC, Slater JD, Volk ML, Reeves ME, Cheng J, Grove R, and de Vera ME
- Subjects
- Antineoplastic Agents administration & dosage, Carcinoma, Hepatocellular mortality, Chemoembolization, Therapeutic mortality, Disease-Free Survival, Dose Fractionation, Radiation, Ethiodized Oil administration & dosage, Female, Humans, Liver Neoplasms mortality, Male, Middle Aged, Prospective Studies, Proton Therapy mortality, Carcinoma, Hepatocellular therapy, Chemoembolization, Therapeutic methods, Liver Neoplasms therapy, Proton Therapy methods
- Abstract
Purpose: To describe results of a planned interim analysis of a prospective, randomized clinical trial developed to compare treatment outcomes among patients with newly diagnosed hepatocellular carcinoma (HCC)., Methods and Materials: Eligible subjects had either clinical or pathologic diagnosis of HCC and met either Milan or San Francisco transplant criteria. Patients were randomly assigned to transarterial chemoembolization (TACE) or to proton beam radiation therapy. Patients randomized to TACE received at least 1 TACE with additional TACE for persistent disease. Proton beam radiation therapy was delivered to all areas of gross disease to a total dose of 70.2 Gy in 15 daily fractions over 3 weeks. The primary endpoint was progression-free survival, with secondary endpoints of overall survival, local tumor control, and treatment-related toxicities as represented by posttreatment days of hospitalization., Results: At the time of this analysis 69 subjects were available for analysis. Of these, 36 were randomized to TACE and 33 to proton. Total days of hospitalization within 30 days of TACE/proton was 166 and 24 days, respectively (P<.001). Ten TACE and 12 proton patients underwent liver transplantation after treatment. Viable tumor identified in the explanted livers after TACE/proton averaged 2.4 and 0.9 cm, respectively. Pathologic complete response after TACE/proton was 10%/25% (P=.38). The 2-year overall survival for all patients was 59%, with no difference between treatment groups. Median survival time was 30 months (95% confidence interval 20.7-39.3 months). There was a trend toward improved 2-year local tumor control (88% vs 45%, P=.06) and progression-free survival (48% vs 31%, P=.06) favoring the proton beam treatment group., Conclusions: This interim analysis indicates similar overall survival rates for proton beam radiation therapy and TACE. There is a trend toward improved local tumor control and progression-free survival with proton beam. There are significantly fewer hospitalization days after proton treatment, which may indicate reduced toxicity with proton beam therapy., (Copyright © 2016 Elsevier Inc. All rights reserved.)
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- 2016
- Full Text
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44. Evaluation of the dosimetric properties of a diode detector for small field proton radiosurgery.
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McAuley GA, Teran AV, Slater JD, Slater JM, and Wroe AJ
- Subjects
- Computer Simulation, Humans, Linear Energy Transfer, Linear Models, Monte Carlo Method, Proton Therapy instrumentation, Radiosurgery instrumentation, Radiotherapy Dosage, Radiotherapy Planning, Computer-Assisted methods, Radiotherapy Planning, Computer-Assisted statistics & numerical data, Water, X-Ray Film, Proton Therapy methods, Radiometry instrumentation, Radiosurgery methods
- Abstract
The small fields and sharp gradients typically encountered in proton radiosurgery require high spatial resolution dosimetric measurements, especially below 1-2 cm diameters. Radiochromic film provides high resolution, but requires postprocessing and special handling. Promising alternatives are diode detectors with small sensitive volumes (SV) that are capable of high resolution and real-time dose acquisition. In this study we evaluated the PTW PR60020 proton dosimetry diode using radiation fields and beam energies relevant to radiosurgery applications. Energies of 127 and 157 MeV (9.7 to 15 cm range) and initial diameters of 8, 10, 12, and 20mm were delivered using single-stage scattering and four modulations (0, 15, 30, and 60mm) to a water tank in our treatment room. Depth dose and beam profile data were compared with PTW Markus N23343 ionization chamber, EBT2 Gafchromic film, and Monte Carlo simulations. Transverse dose profiles were measured using the diode in "edge-on" orientation or EBT2 film. Diode response was linear with respect to dose, uniform with dose rate, and showed an orientation-dependent (i.e., beam parallel to, or perpendicular to, detector axis) response of less than 1%. Diodevs. Markus depth-dose profiles, as well as Markus relative dose ratio vs. simulated dose-weighted average lineal energy plots, suggest that any LET-dependent diode response is negligible from particle entrance up to the very distal portion of the SOBP for the energies tested. Finally, while not possible with the ionization chamber due to partial volume effects, accurate diode depth-dose measurements of 8, 10, and 12 mm diameter beams were obtained compared to Monte Carlo simulations. Because of the small SV that allows measurements without partial volume effects and the capability of submillimeter resolution (in edge-on orientation) that is crucial for small fields and high-dose gradients (e.g., penumbra, distal edge), as well as negligible LET dependence over nearly the full the SOBP, the PTW proton diode proved to be a useful high-resolution, real-time metrology device for small proton field radiation measurements such as would be encountered in radiosurgery applications.
- Published
- 2015
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45. Antimicrobial resistance, equine practitioners and human health: A true One Health issue or political interference?
- Author
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Slater JD
- Subjects
- Animals, Awareness, Bacterial Infections drug therapy, Bacterial Infections microbiology, Decision Making, Drug Resistance, Bacterial, Drug Utilization, Europe, Horses, Humans, Public Health, Zoonoses, Anti-Bacterial Agents pharmacology, Bacterial Infections veterinary, Horse Diseases microbiology, Politics, Veterinarians
- Published
- 2015
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46. Periodic Lateralized Epileptiform Discharges and Afterdischarges: Common Dynamic Mechanisms.
- Author
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Kalamangalam GP and Slater JD
- Subjects
- Adolescent, Adult, Aged, Aged, 80 and over, Electroencephalography, Epilepsy etiology, Female, Humans, Male, Mass Spectrometry, Middle Aged, Nervous System Diseases complications, Nonlinear Dynamics, Retrospective Studies, Young Adult, Brain Waves physiology, Epilepsy diagnosis, Functional Laterality physiology, Periodicity
- Abstract
Purpose: No neurophysiological hypothesis currently exists addressing how and why periodic lateralized epileptiform discharges (PLEDs) arise in certain types of brain disease. Based on spectral analysis of clinical scalp EEG traces, the authors formulated a general mechanism for the emergence of PLEDs., Methods: The authors retrospectively analyzed spectra of PLED time series and control EEG segments from the opposite hemisphere in 25 hospitalized neurological patients. The observations led to the development of a phenomenological model for PLED emergence., Results: Similar to that observed in our previous work with afterdischarges, an analytic relationship is found between the spectrum of the baseline EEG and the PLED EEG, characterized by "condensation" of the main baseline spectral cluster, with variable inclusion of higher harmonics of the condensate., Conclusions: Periodic lateralized epileptiform discharges may arise by synchronization of preexisting local field potentials, through a variable combination of enhancement of excitatory neurotransmission and inactivation of inhibitory neurotransmission provoked by the PLED-associated disease process. Higher harmonics in the PLED spectrum may arise by recurrent feedback, possibly from entrained single units. A mechanism is suggested for PLED emergence in certain diseased brain states and the association of PLEDs with EEG seizures. The framework is a spatially extended version of that, which the authors proposed, underlies afterdischarge and analogous to the cooperative behavior seen in a variety of natural multi-oscillator systems.
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- 2015
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47. Evaluation of normal tissue exposure in patients receiving radiotherapy for pancreatic cancer based on RTOG 0848.
- Author
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Ling TC, Slater JM, Mifflin R, Nookala P, Grove R, Ly AM, Patyal B, Slater JD, and Yang GY
- Abstract
Background: Pancreatic cancer is a highly aggressive malignancy. Chemoradiotherapy (CRT) is utilized in many cases to improve locoregional control; however, toxicities associated with radiation can be significant given the location of the pancreas. RTOG 0848 seeks to evaluate chemoradiation using either intensity-modulated radiation therapy (IMRT) or 3D conformal photon radiotherapy (3DCRT) modalities as an adjuvant treatment. The purpose of this study is to quantify the dosimetric changes seen when using IMRT or 3D CRT photon modalities, as well as proton radiotherapy, in patients receiving CRT for cancer of the pancreas treated per RTOG 0848 guidelines., Materials: Ten patients with pancreatic head adenocarcinoma treated between 2010 and 2013 were evaluated in this study. All patients were simulated with contrast-enhanced CT imaging. Separate treatment plans using IMRT and 3DCRT as well as proton radiotherapy were created for each patient. All planning volumes were created per RTOG 0848 protocol. Dose-volume histograms (DVH) were calculated and analyzed in order to compare plans between the three modalities. The organs at risk (OAR) evaluated in this study are the kidneys, liver, small bowel, and spinal cord., Results: There was no difference between the IMRT and 3DCRT plans in dose delivered to the kidneys, liver, or bowel. The proton radiotherapy plans were found to deliver lower mean total kidney doses, mean liver doses, and liver D1/3 compared to the IMRT plans. The proton plans also gave less mean liver dose, liver D1/3, bowel V15, and bowel V50 in comparison to the 3DCRT., Conclusions: For patients receiving radiotherapy per ongoing RTOG 0848 for pancreatic cancer, there was no significant difference in normal tissue sparing between IMRT and 3DCRT treatment planning. Therefore, the choice between the two modalities should not be a confounding factor in this study. The proton plans also demonstrated improved OAR sparing compared to both IMRT and 3DCRT treatment plans.
- Published
- 2015
- Full Text
- View/download PDF
48. Clinical immobilization techniques for proton therapy.
- Author
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Wroe AJ, Bush DA, Schulte RW, and Slater JD
- Subjects
- Humans, Proton Therapy instrumentation, Radiosurgery instrumentation, Radiosurgery methods, Neoplasms radiotherapy, Neoplasms surgery, Proton Therapy methods
- Abstract
Proton therapy through the use of the Bragg peak affords clinicians a tool with which highly conformal dose can be delivered to the target while minimizing integral dose to surrounding healthy tissue. To gain maximum benefit from proton therapy adequate patient immobilization must be maintained to ensure accurate dose delivery. While immobilization in external beam radiation therapy is designed to minimize inter- and intra-fraction target motion, in proton therapy there are other additional aspects which must be considered, chief of which is accurately determining and maintaining the targets water-equivalent depth along the beam axis. Over the past 23 years of treating with protons, the team at the James M. Slater Proton Treatment and Research Center at Loma Linda University Medical Center have developed and implemented extensive immobilization systems to address the specific needs of protons. In this publication we review the immobilization systems that are used at Loma Linda in the treatment of head and neck, prostate, upper GI, lung and breast disease, along with a description of the intracranial radiosurgery immobilization system used in the treatment of brain metastasis and arteriovenous malformations (AVM's)., (© The Author(s) 2014.)
- Published
- 2015
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49. Analysis of Intensity-Modulated Radiation Therapy (IMRT), Proton and 3D Conformal Radiotherapy (3D-CRT) for Reducing Perioperative Cardiopulmonary Complications in Esophageal Cancer Patients.
- Author
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Ling TC, Slater JM, Nookala P, Mifflin R, Grove R, Ly AM, Patyal B, Slater JD, and Yang GY
- Abstract
Background. While neoadjuvant concurrent chemoradiotherapy has improved outcomes for esophageal cancer patients, surgical complication rates remain high. The most frequent perioperative complications after trimodality therapy were cardiopulmonary in nature. The radiation modality utilized can be a strong mitigating factor of perioperative complications given the location of the esophagus and its proximity to the heart and lungs. The purpose of this study is to make a dosimetric comparison of Intensity-Modulated Radiation Therapy (IMRT), proton and 3D conformal radiotherapy (3D-CRT) with regard to reducing perioperative cardiopulmonary complications in esophageal cancer patients. Materials. Ten patients with esophageal cancer treated between 2010 and 2013 were evaluated in this study. All patients were simulated with contrast-enhanced CT imaging. Separate treatment plans using proton radiotherapy, IMRT, and 3D-CRT modalities were created for each patient. Dose-volume histograms were calculated and analyzed to compare plans between the three modalities. The organs at risk (OAR) being evaluated in this study are the heart, lungs, and spinal cord. To determine statistical significance, ANOVA and two-tailed paired t-tests were performed for all data parameters. Results. The proton plans showed decreased dose to various volumes of the heart and lungs in comparison to both the IMRT and 3D-CRT plans. There was no difference between the IMRT and 3D-CRT plans in dose delivered to the lung or heart. This finding was seen consistently across the parameters analyzed in this study. Conclusions. In patients receiving radiation therapy for esophageal cancer, proton plans are technically feasible while achieving adequate coverage with lower doses delivered to the lungs and cardiac structures. This may result in decreased cardiopulmonary toxicity and less morbidity to esophageal cancer patients.
- Published
- 2014
- Full Text
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50. An interictal EEG spectral metric for temporal lobe epilepsy lateralization.
- Author
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Kalamangalam GP, Cara L, Tandon N, and Slater JD
- Subjects
- Adult, Aged, Brain Mapping, Epilepsy, Temporal Lobe diagnosis, Female, Humans, Male, Middle Aged, Rest, Sensitivity and Specificity, Signal Processing, Computer-Assisted, Sleep, Young Adult, Brain physiopathology, Electroencephalography methods, Epilepsy, Temporal Lobe physiopathology, Functional Laterality
- Abstract
Objective: Visually-obvious abnormalities in the resting baseline EEG--slowing, spiking and high-frequency oscillations (HFOs)--are cardinal, though incompletely understood, features of the seizure onset zone in focal epilepsy. We hypothesized that evidence of cortical network dysfunction in temporal lobe epilepsy (TLE) would persist in the absence of visually-classifiable abnormalities in the baseline EEG recorded within the conventional passband, and that metrics of such dysfunction could serve as a lateralizing diagnostic in TLE., Methods: Epochs of resting EEG without significant abnormalities in light sleep over several days were compared between a group of 10 patients with proven TLE and 10 subjects without epilepsy. A novel laterality metric computed from the line length of normalized power spectra from the temporal channels was compared between the two groups., Results: Significant group differences in spectral line length laterality metric were found between the TLE and control group. At the individual level, seven of 10 TLE patients had highly significant laterality metrics, all concordant with the known laterality of their disease., Significance: Detailed spectral analysis offers novel insight into TLE network behavior, independent of the orthodox abnormalities of EEG slowing, spikes or HFOs. The results may be deployed in a practical diagnostic manner, offer insight into the EEG manifestations of disordered cellular network architecture in TLE, and maybe understood through simple analogy with the theory of linear time-invariant physical systems., (Copyright © 2014 Elsevier B.V. All rights reserved.)
- Published
- 2014
- Full Text
- View/download PDF
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