26 results on '"Petkar, I."'
Search Results
2. Normal Tissue Complication Probability (NTCP) Modelling of Severe Acute Mucositis using a Novel Oral Mucosal Surface Organ at Risk
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Dean, J.A., Welsh, L.C., Wong, K.H., Aleksic, A., Dunne, E., Islam, M.R., Patel, A., Patel, P., Petkar, I., Phillips, I., Sham, J., Schick, U., Newbold, K.L., Bhide, S.A., Harrington, K.J., Nutting, C.M., and Gulliford, S.L.
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- 2017
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3. PO-2213 The impact of the tumour microenvironment on head and neck SCC cell viability and radiosensitivity.
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Chander, A., primary, Pellon Rodriguez, A., additional, Butterworth, V., additional, Guerrero Urbano, T., additional, Kong, A., additional, Lei, M., additional, Petkar, I., additional, Ng, T., additional, Moyes, D., additional, and Reis Ferreira, M., additional
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- 2023
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4. The Impact of Interactive MRI-Based Radiologist Review on Radiotherapy Target Volume Delineation in Head and Neck Cancer
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Adjogatse, D., primary, Petkar, I., additional, Reis Ferreira, M., additional, Kong, A., additional, Lei, M., additional, Thomas, C., additional, Barrington, S.F., additional, Dudau, C., additional, Touska, P., additional, Guerrero Urbano, T., additional, and Connor, S.E.J., additional
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- 2023
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5. Adherence to Swallow Exercises during (Chemo)Radiotherapy for Head and Neck Cancer
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Dunton, J., primary, Lord, R., additional, Lee, K., additional, Doughty, C., additional, Bogotto, A., additional, O'Neill, N., additional, Kong, A., additional, Reis Ferreira, M., additional, Guerrero Urbano, T., additional, Petkar, I., additional, and Lei, M., additional
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- 2022
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6. Assessment of Optimal Time Points for Collection of Patient Reported Outcome Measures for Patients Undergoing Radical Radiotherapy for Head and Neck Cancer
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Pascal, L., primary, Guerrero Urbano, T., additional, Petkar, I., additional, Reis Ferreira, M., additional, Kong, A., additional, Van Hemelrijck, M., additional, and Lei, M., additional
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- 2022
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7. The Impact of Real-Time MRI Radiology-Based Peer Review on Head and Neck Radiotherapy Target Volume Delineation
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Adjogatse, D., primary, Petkar, I., additional, Ferreira, M. Reis, additional, Kong, A., additional, Lei, M., additional, Thomas, C., additional, Dudau, C., additional, Touska, P., additional, Barrington, S., additional, Urbano, T. Guerrero, additional, and Connor, S., additional
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- 2022
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8. The impact of carcinoembryonic antigen flare in patients with advanced colorectal cancer receiving first-line chemotherapy
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Strimpakos, A.S., Cunningham, D., Mikropoulos, C., Petkar, I., Barbachano, Y., and Chau, I.
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- 2010
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9. PH-0387 Mandible osteoradionecrosis: a dosimetric study
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Humbert-Vidan, L., primary, Patel, V., additional, Begum, R.H., additional, McGovern, M., additional, Eaton, D., additional, Kong, A., additional, Petkar, I., additional, Reis Ferreira, M., additional, Lei, M., additional, King, A.P., additional, and Guerrero Urbano, T., additional
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- 2021
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10. P-265 Neoadjuvant radiotherapy for locally advanced rectal cancer during the first wave of COVID19 pandemic: Guy’s cancer cohort experience
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Sachdeva, A., primary, Nagpal, S., additional, Grzeda, M., additional, Russell, B., additional, Petkar, I., additional, Qureshi, A., additional, Van Hemelrijck, M., additional, Ross, P., additional, Harris, V., additional, and Owczarczyk, K., additional
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- 2021
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11. EP-1181 Structure delineation using a deformable image registration-based contour propagation in HNC
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Ng-Cheng-Hin, B., primary, McQuaid, D., additional, Dunlop, A., additional, Court, S., additional, Petkar, I., additional, Nutting, C., additional, Harrington, K., additional, Bhide, S., additional, and Newbold, K., additional
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- 2019
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12. Evaluation of a multi-atlas CT synthesis approach for MRI-only radiotherapy treatment planning
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Guerreiro, F., Burgos, Ninon, Dunlop, A., Wong, K., Petkar, I., Nutting, C., Harrington, K., Bhide, S., Newbold, K., Dearnaley, D., deSouza, N. M., Morgan, V. A., McClelland, J., Nill, S., Cardoso, M. J., Ourselin, S., Oelfke, U., Knopf, A. C., Centre for Medical Image Computing (CMIC), University College of London [London] (UCL), and Deutsches Krebsforschungszentrum Heidelberg
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Male ,Original Paper ,Radiotherapy Planning, Computer-Assisted ,Biophysics ,Prostatic Neoplasms ,Radiotherapy Dosage ,Physics and Astronomy(all) ,Magnetic Resonance Imaging ,nervous system diseases ,MRI-only radiotherapy workflow ,Oropharyngeal Neoplasms ,Atlases as Topic ,Radiology Nuclear Medicine and imaging ,[INFO.INFO-IM]Computer Science [cs]/Medical Imaging ,Feasibility Studies ,Humans ,Radiotherapy, Intensity-Modulated ,Tomography, X-Ray Computed ,Algorithms ,Multi-atlas approach ,Synthetic CT ,Retrospective Studies - Abstract
Highlights • Establishing MRI-only RTP workflows requires synthetic CTs for dose calculation. • This study evaluates the feasibility of using a multi-atlas CT synthesis approach. • The proposed method was validated on head and neck and prostate cancer patients. • Results showed an accurate bone estimation for future patient positioning. • Results showed that synthetic CTs are suitable to perform clinical dose calculations., Background and purpose Computed tomography (CT) imaging is the current gold standard for radiotherapy treatment planning (RTP). The establishment of a magnetic resonance imaging (MRI) only RTP workflow requires the generation of a synthetic CT (sCT) for dose calculation. This study evaluates the feasibility of using a multi-atlas sCT synthesis approach (sCTa) for head and neck and prostate patients. Material and methods The multi-atlas method was based on pairs of non-rigidly aligned MR and CT images. The sCTa was obtained by registering the MRI atlases to the patient’s MRI and by fusing the mapped atlases according to morphological similarity to the patient. For comparison, a bulk density assignment approach (sCTbda) was also evaluated. The sCTbda was obtained by assigning density values to MRI tissue classes (air, bone and soft-tissue). After evaluating the synthesis accuracy of the sCTs (mean absolute error), sCT-based delineations were geometrically compared to the CT-based delineations. Clinical plans were re-calculated on both sCTs and a dose-volume histogram and a gamma analysis was performed using the CT dose as ground truth. Results Results showed that both sCTs were suitable to perform clinical dose calculations with mean dose differences less than 1% for both the planning target volume and the organs at risk. However, only the sCTa provided an accurate and automatic delineation of bone. Conclusions Combining MR delineations with our multi-atlas CT synthesis method could enable MRI-only treatment planning and thus improve the dosimetric and geometric accuracy of the treatment, and reduce the number of imaging procedures.
- Published
- 2017
13. Fusobacterium is toxic for head and neck squamous cell carcinoma and its presence may determine a better prognosis.
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Chander A, Iacovacci J, Pellon A, Kataria R, Grigoriadis A, Maher J, Sears C, Bachrach G, Urbano TG, Lei M, Petkar I, Kong A, Ng T, Orlandi E, Iacovelli NA, De Cecco L, Serafini MS, Moyes D, Rancati T, and Ferreira MR
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- Humans, Prognosis, Fusobacterium isolation & purification, Carcinoma, Squamous Cell, Fusobacterium Infections complications, Fusobacterium Infections microbiology, Male, Female, Head and Neck Neoplasms microbiology, Squamous Cell Carcinoma of Head and Neck microbiology
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- 2024
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14. Dysphagia-optimised intensity-modulated radiotherapy versus standard radiotherapy in patients with pharyngeal cancer - Authors' reply.
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Nutting C, Finneran L, Roe J, Petkar I, Rooney K, and Hall E
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- Humans, Radiotherapy Dosage, Radiotherapy, Intensity-Modulated adverse effects, Deglutition Disorders etiology, Pharyngeal Neoplasms radiotherapy, Carcinoma, Squamous Cell radiotherapy, Radiation Oncology, Head and Neck Neoplasms
- Abstract
Competing Interests: CN reports research funding paid to their institution from Cancer Research UK and stock options from Advanced Oncotherapy. LF and EH report research funding paid to their institution from Cancer Research UK. EH reports grants received by their institution as contribution to support central trial costs for non-commercial trials from Accuray, Varian Medical Systems, AstraZeneca, Janssen-Cilag, Bayer, Roche Products, and Merck Sharp & Dohme. All other authors declare no competing interests.
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- 2023
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15. Dysphagia-optimised intensity-modulated radiotherapy versus standard intensity-modulated radiotherapy in patients with head and neck cancer (DARS): a phase 3, multicentre, randomised, controlled trial.
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Nutting C, Finneran L, Roe J, Sydenham MA, Beasley M, Bhide S, Boon C, Cook A, De Winton E, Emson M, Foran B, Frogley R, Petkar I, Pettit L, Rooney K, Roques T, Srinivasan D, Tyler J, and Hall E
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- Humans, Male, Female, Middle Aged, Quality of Life, Chemoradiotherapy adverse effects, Radiotherapy, Intensity-Modulated adverse effects, Deglutition Disorders etiology, Head and Neck Neoplasms radiotherapy
- Abstract
Background: Most newly diagnosed oropharyngeal and hypopharyngeal cancers are treated with chemoradiotherapy with curative intent but at the consequence of adverse effects on quality of life. We aimed to investigate if dysphagia-optimised intensity-modulated radiotherapy (DO-IMRT) reduced radiation dose to the dysphagia and aspiration related structures and improved swallowing function compared with standard IMRT., Methods: DARS was a parallel-group, phase 3, multicentre, randomised, controlled trial done in 22 radiotherapy centres in Ireland and the UK. Participants were aged 18 years and older, had T1-4, N0-3, M0 oropharyngeal or hypopharyngeal cancer, a WHO performance status of 0 or 1, and no pre-existing swallowing dysfunction. Participants were centrally randomly assigned (1:1) using a minimisation algorithm (balancing factors: centre, chemotherapy use, tumour type, American Joint Committee on Cancer tumour stage) to receive DO-IMRT or standard IMRT. Participants and speech language therapists were masked to treatment allocation. Radiotherapy was given in 30 fractions over 6 weeks. Dose was 65 Gy to primary and nodal tumour and 54 Gy to remaining pharyngeal subsite and nodal areas at risk of microscopic disease. For DO-IMRT, the volume of the superior and middle pharyngeal constrictor muscle or inferior pharyngeal constrictor muscle lying outside the high-dose target volume had a mandatory 50 Gy mean dose constraint. The primary endpoint was MD Anderson Dysphagia Inventory (MDADI) composite score 12 months after radiotherapy, analysed in the modified intention-to-treat population that included only patients who completed a 12-month assessment; safety was assessed in all randomly assigned patients who received at least one fraction of radiotherapy. The study is registered with the ISRCTN registry, ISRCTN25458988, and is complete., Findings: From June 24, 2016, to April 27, 2018, 118 patients were registered, 112 of whom were randomly assigned (56 to each treatment group). 22 (20%) participants were female and 90 (80%) were male; median age was 57 years (IQR 52-62). Median follow-up was 39·5 months (IQR 37·8-50·0). Patients in the DO-IMRT group had significantly higher MDADI composite scores at 12 months than patients in the standard IMRT group (mean score 77·7 [SD 16·1] vs 70·6 [17·3]; mean difference 7·2 [95% CI 0·4-13·9]; p=0·037). 25 serious adverse events (16 serious adverse events assessed as unrelated to study treatment [nine in the DO-IMRT group and seven in the standard IMRT group] and nine serious adverse reactions [two vs seven]) were reported in 23 patients. The most common grade 3-4 late adverse events were hearing impairment (nine [16%] of 55 in the DO-IMRT group vs seven [13%] of 55 in the standard IMRT group), dry mouth (three [5%] vs eight [15%]), and dysphagia (three [5%] vs eight [15%]). There were no treatment-related deaths., Interpretation: Our findings suggest that DO-IMRT improves patient-reported swallowing function compared with standard IMRT. DO-IMRT should be considered a new standard of care for patients receiving radiotherapy for pharyngeal cancers., Funding: Cancer Research UK., Competing Interests: Declaration of interests CN reports research funding paid to their institution from Cancer Research UK and stock options from Advanced Oncotherapy. LF, MAS, ME, and EH report research funding paid to their institution from Cancer Research UK. EH reports grants received by their institution as contribution to support central trial costs for non-commercial trials from Accuray, Varian Medical Systems, AstraZeneca, Janssen-Cilag, Bayer, Roche Products, and Merck Sharp and Dohm. CB reports leadership roles for OncoDNA and RCR Cyclotron Trust (unpaid). TR reports membership of the POPPY Trial independent data monitoring committee and being Vice President of Clinical Oncology at the Royal College of Radiologists. All other authors declare no competing interests., (Copyright © 2023 The Author(s). Published by Elsevier Ltd. This is an Open Access article under the CC BY 4.0 license. Published by Elsevier Ltd.. All rights reserved.)
- Published
- 2023
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16. Protocol letter: Intra-treatment Image Guided Adaptive Radiotherapy Dose-escalation Study (InGReS) - A Phase 1 multicentre feasibility study.
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Adjogatse D, Michaelidou A, Sanchez Nieto B, Kozarski R, Sassoon I, Evans M, Rackley T, Shah S, Eaton D, Pike L, Curry S, Gould SM, Thomas C, Kong A, Petkar I, Reis-Ferreira M, Connor S, Barrington SF, Lei M, and Guerrero Urbano T
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- Humans, Clinical Trials, Phase I as Topic, Feasibility Studies, Multicenter Studies as Topic, Radiotherapy Dosage, Radiotherapy Planning, Computer-Assisted methods, Radiotherapy, Image-Guided methods, Radiotherapy, Intensity-Modulated methods
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- 2023
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17. Clinical outcomes in relapsed oropharyngeal cancer after definitive (chemo) radiotherapy.
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De Felice F, Bird T, Michaelidou A, Jeannon JP, Simo R, Oakley R, Lyons A, Fry A, Cascarini L, Asit A, Thavaraj S, Reis Ferreira M, Petkar I, Kong A, Lei M, and Guerrero Urbano T
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- Humans, Squamous Cell Carcinoma of Head and Neck, Human Papillomavirus Viruses, Chronic Disease, Prognosis, Retrospective Studies, Papillomavirus Infections complications, Oropharyngeal Neoplasms drug therapy, Oropharyngeal Neoplasms radiotherapy, Mouth Neoplasms complications, Head and Neck Neoplasms complications
- Abstract
Objectives: To report clinical outcomes of relapsed oropharyngeal squamous cell carcinoma (OPSCC) after definitive intensity-modulated (chemo)radiotherapy [(C)RT]., Materials and Methods: Data for all relapsed patients treated for OPSCC with definitive (C)RT between 2010 and 2016 were collected. Primary end-point was post-failure survival (PFS)., Results: Overall, 273 OPSCC patients completed definitive (C)RT. Of these, 42 cases (n = 26 human papilloma virus (HPV)-negative; n = 16 HPV-positive) had relapsed (n = 23 persistent disease; n = 19 recurrent disease) and were included in the final analysis. Two-year PFS for the entire population was 30.6%; 20.5% for HPV-negative and 43.8% for HPV-positive patients. Salvage curative surgery was associated with a significantly higher 2 years PFS rate (56.2%) compared with palliative treatment (22.9%) and best supportive care (0%) (p < 0.001). A positive trend in 2 years PFS was recorded in the early complete response cases (49.5%) versus patients who did not achieve a complete response within 3 months of the end of (C)RT (23.0%) (p = 0.11)., Conclusion: A higher PFS rate is achieved when relapsed OPSCC cases are treated with salvage curative intent. HPV-positive disease and early complete response within 3 months from the end of (C)RT may be related to better PFS., (© 2021 Wiley Periodicals LLC.)
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- 2023
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18. The Impact of Interactive MRI-Based Radiologist Review on Radiotherapy Target Volume Delineation in Head and Neck Cancer.
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Adjogatse D, Petkar I, Reis Ferreira M, Kong A, Lei M, Thomas C, Barrington SF, Dudau C, Touska P, Guerrero Urbano T, and Connor SEJ
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- Female, Humans, Male, Middle Aged, Magnetic Resonance Imaging, Peer Review, Radiologists, Radiotherapy Planning, Computer-Assisted methods, Tumor Burden, Adult, Aged, Aged, 80 and over, Head and Neck Neoplasms diagnostic imaging, Head and Neck Neoplasms radiotherapy
- Abstract
Background and Purpose: Peer review of head and neck cancer radiation therapy target volumes by radiologists was introduced in our center to optimize target volume delineation. Our aim was to assess the impact of MR imaging-based radiologist peer review of head and neck radiation therapy gross tumor and nodal volumes, through qualitative and quantitative analysis., Materials and Methods: Cases undergoing radical radiation therapy with a coregistered MR imaging, between April 2019 and March 2020, were reviewed. The frequency and nature of volume changes were documented, with major changes classified as per the guidance of The Royal College of Radiologists. Volumetric alignment was assessed using the Dice similarity coefficient, Jaccard index, and Hausdorff distance., Results: Fifty cases were reviewed between April 2019 and March 2020. The median age was 59 years (range, 29-83 years), and 72% were men. Seventy-six percent of gross tumor volumes and 41.5% of gross nodal volumes were altered, with 54.8% of gross tumor volume and 66.6% of gross nodal volume alterations classified as "major." Undercontouring of soft-tissue involvement and unidentified lymph nodes were predominant reasons for change. Radiologist review significantly altered the size of both the gross tumor volume ( P = .034) and clinical target tumor volume ( P = .003), but not gross nodal volume or clinical target nodal volume. The median conformity and surface distance metrics were the following: gross tumor volume Dice similarity coefficient = 0.93 (range, 0.82-0.96), Jaccard index = 0.87 (range, 0.7-0.94), Hausdorff distance = 7.45 mm (range, 5.6-11.7 mm); and gross nodular tumor volume Dice similarity coefficient = 0.95 (0.91-0.97), Jaccard index = 0.91 (0.83-0.95), and Hausdorff distance = 20.7 mm (range, 12.6-41.6). Conformity improved on gross tumor volume-to-clinical target tumor volume expansion (Dice similarity coefficient = 0.93 versus 0.95, P = .003)., Conclusions: MR imaging-based radiologist review resulted in major changes to most radiotherapy target volumes and significant changes in volume size of both gross tumor volume and clinical target tumor volume, suggesting that this is a fundamental step in the radiotherapy workflow of patients with head and neck cancer., (© 2023 by American Journal of Neuroradiology.)
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- 2023
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19. Quality assurance of dysphagia-optimised intensity modulated radiotherapy treatment planning for head and neck cancer.
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Tyler J, Bernstein D, Seithel M, Rooney K, Petkar I, Miles E, Clark CH, Hall E, and Nutting C
- Abstract
This study aimed to assess the impact of the margin applied to the clinical target volume, to create the planning target volume, on plan quality of a novel dysphagia-optimised intensity modulated radiotherapy technique developed within a head and neck cancer multicentre randomised controlled trial. Protocol compliant plans were used for a single benchmark planning case. Larger margins were associated with higher doses to adjacent organs at risk, particularly the inferior pharyngeal constrictor muscle, but coincided with some improved low dose target coverage. A 3 mm margin is recommended for this technique if local practices allow., Competing Interests: The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (© 2021 The Author(s).)
- Published
- 2021
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20. TNM 8 staging is a better prognosticator than TNM 7 for patients with locally advanced oral cavity squamous cell carcinoma treated with surgery and post-operative radiotherapy.
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Sambasivan K, Sassoon I, Thavaraj S, Kennedy R, Doss G, Michaelidou A, Odell E, Sandison A, Hall G, Morgan P, Collins LHC, Lyons A, Cascarini L, Fry A, Oakley R, Simo R, Jeannon JP, Petkar I, Reis Ferreira M, Kong A, Lei M, and Guerrero Urbano T
- Subjects
- Humans, Middle Aged, Neoplasm Recurrence, Local pathology, Neoplasm Staging, Prognosis, Retrospective Studies, Squamous Cell Carcinoma of Head and Neck, Head and Neck Neoplasms, Mouth Neoplasms pathology, Mouth Neoplasms radiotherapy, Mouth Neoplasms surgery
- Abstract
Purpose: To assess TNM 8 staging in discriminating overall survival (OS) amongst patients with locally advanced oral cavity squamous cell carcinoma (OCSCC) treated with surgery and post-operative radiotherapy (PORT), compared to TNM 7., Material and Methods: Data from OCSCC patients treated with surgery and PORT between January 2010 and December 2018 were reviewed. Demographics, tumour characteristics and treatment response data were collected, and patients staged according to both TNM 7 and TNM 8. OS and disease free survival (DFS) were estimated using the Kaplan Meier method. Univariate and multivariable analyses were conducted for factors affecting OS, DFS and early disease recurrence within 12 months., Results: Overall 172 patients were analyzed. Median follow up was 32 months for all patients and 48 months for surviving patients. TNM 8 staging demonstrated significant stratification of OS and DFS amongst the entire cohort, whereas TNM 7 staging did not. On multivariable analysis, TNM 8 stage, performance status (PS) and a positive surgical margin were prognostic for OS. Looking at disease recurrence within 12 months, TNM 8 stage IVB, presence of lymphovascular invasion (LVSI), younger age and lesser smoking history were predictive factors on multivariable analysis., Conclusion: TNM 8 is a good development of its predecessor in terms of predicting survival for patients with locally advanced OCSCC. We have also identified younger age (<60 years) and a smoking history of <10 pack years as risk factors for early disease recurrence, potentially representing a separate biological cohort within OCSCC patients., (Copyright © 2021 Elsevier B.V. All rights reserved.)
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- 2021
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21. Safety and Treatment Outcomes of Nivolumab for the Treatment of Recurrent or Metastatic Head and Neck Squamous Cell Carcinoma: Retrospective Multicenter Cohort Study.
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Vasiliadou I, Breik O, Baker H, Leslie I, Sim VR, Hegarty G, Michaelidou A, Nathan K, Hartley A, Good J, Sanghera P, Fong C, Urbano TG, Lei M, Petkar I, Ferreira MR, Nutting C, Wong KH, Newbold K, Harrington K, Bhide S, and Kong A
- Abstract
Nivolumab is an anti-PD-1 monoclonal antibody currently used as immunotherapy for patients with recurrent/metastatic head and neck squamous cell carcinoma (HNSCC) with evidence of disease progression after platinum-based chemotherapy. This study evaluates real-world safety and treatment outcomes of non-trial nivolumab use. A retrospective multicenter cohort study of patients with recurrent/metastatic HNSCC treated with nivolumab between January 2017 and March 2020 was performed. Overall, 123 patients were included. The median age was 64 years, the majority of patients were male (80.5%) and had a smoking history (69.9%). Primary outcomes included overall response rate (ORR) of 19.3%, median progression-free survival (PFS) of 3.9 months, 1-year PFS rate of 16.8%, a median overall survival (OS) of 6.5 months and 1-year OS rate of 28.6%. These results are comparable to the CHECKMATE-141 study. Of 27 patients who had PD-L1 status tested, positive PD-L1 status did not significantly affect PFS ( p = 0.86) or OS ( p = 0.84). Nivolumab was well tolerated with only 15.1% experiencing immune-related toxicities (IRT) and only 6.7% of patients stopping due to toxicity. The occurrence of IRT appeared to significantly affect PFS ( p = 0.01) but not OS ( p = 0.07). Nivolumab in recurrent/metastatic HNSCC is well tolerated and may be more efficacious in patients who develop IRT.
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- 2021
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22. Inter-Observer Variation in Delineating the Pharyngeal Constrictor Muscle as Organ at Risk in Radiotherapy for Head and Neck Cancer.
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Petkar I, McQuaid D, Dunlop A, Tyler J, Hall E, and Nutting C
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Background and Purpose: To evaluate the inter-observer variation (IOV) in pharyngeal constrictor muscle (PCM) contouring, and resultant impact on dosimetry and estimated toxicity, as part of the pre-trial radiotherapy trial quality assurance (RTQA) within DARS, a multicenter phase III randomized controlled trial investigating the functional benefits of dysphagia-optimized intensity-modulated radiotherapy (Do-IMRT) in pharyngeal cancers., Methods and Materials: Outlining accuracy of 15 clinicians' superior and middle PCM (SMPCM) and inferior PCM (IPCM) were retrospectively assessed against gold standards (GS) using volume, location, and conformity indices (CIs) on a pre-trial benchmark case of oropharyngeal cancer. The influence of delineation variability on dose delivered to the constrictor muscles with Do-IMRT and resultant normal tissue complication probability (NTCP) for physician-scored radiation-associated dysphagia at 6 months was evaluated., Results: For GS, SMPCM, and IPCM volumes were 13.51 and 1.67 cm
3 ; corresponding clinician mean volumes were 12.18 cm3 (SD 3.0) and 2.40 cm3 (SD 0.9) respectively. High IOV in SMPCM and IPCM delineation was observed by the low DICE similarity coefficient value, along with high geographical miss index and discordance index values. Delineation variability did not significantly affect the mean dose delivered to the constrictors, relative to the GS plan. Mean clinician NTCP was 24.6% (SD 0.6), compared to the GS-NTCP of 24.7%., Conclusions: Results from this benchmark case demonstrate that inaccurate PCM delineation existed, even with protocol guidelines. This did not impact on delivered dose to this structure with Do-IMRT, or on estimated swallowing toxicity, in this single benchmark case., Competing Interests: CN is the chief investigator of DARS trial. The remaining authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2021 Petkar, McQuaid, Dunlop, Tyler, Hall and Nutting.)- Published
- 2021
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23. Practice patterns for the radical treatment of nasopharyngeal cancer by head and neck oncologists in the United Kingdom.
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Petkar I, Bhide S, Newbold K, Harrington K, and Nutting C
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- Head pathology, Humans, Nasopharyngeal Neoplasms pathology, Neck pathology, Neoplasm Staging, United Kingdom, Nasopharyngeal Neoplasms drug therapy, Nasopharyngeal Neoplasms radiotherapy, Oncologists, Practice Patterns, Physicians'
- Abstract
Objective: Advances in radiation delivery, imaging techniques, and chemotherapy have significantly improved treatment options for non-metastatic nasopharyngeal cancers (NPC). However, their impact on the practice in the United Kingdom (UK), where this tumour is rare, is unknown. This study examined the current attitudes of UK head and neck oncologists to the treatment of NPC., Methods: UK head and neck oncologists representing 19/23 cancer networks were sent an invitation email with a personalised link to a web-based survey designed to identify the influence of tumour and nodal staging on current NPC management practices., Results: 26/42 (61%) of clinicians responded. Induction chemotherapy followed by concomitant chemoradiation was the treatment of choice for Stage III (69%) and IVa/b (96%), with cisplatin and 5-fluorouracil combination being the most commonly used induction chemotherapy regimen (88%). 16 centres (61%) used a geometric approach, adding variable margins of 0-10 mm to the gross tumour volume to define their therapeutic dose clinical target volume. 54% of respondents used 3 radiotherapy (RT) prescription doses to treat NPC. Retropharyngeal nodal region irradiation policy was inconsistent, with nearly one-quarter treating the entire group to a radical dose., Conclusion: Significant heterogeneity currently exists in the RT practice of NPC in the UK. A consensus regarding the optimal curative, function-sparing treatment paradigm for NPC is necessary to ensure cancer survivors have satisfactory long-term health-related quality of life. Advances in knowledge: This is the first study to highlight the significant variation in RT practice of NPC in the UK.
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- 2018
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24. Evaluation of a multi-atlas CT synthesis approach for MRI-only radiotherapy treatment planning.
- Author
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Guerreiro F, Burgos N, Dunlop A, Wong K, Petkar I, Nutting C, Harrington K, Bhide S, Newbold K, Dearnaley D, deSouza NM, Morgan VA, McClelland J, Nill S, Cardoso MJ, Ourselin S, Oelfke U, and Knopf AC
- Subjects
- Algorithms, Feasibility Studies, Humans, Male, Oropharyngeal Neoplasms diagnostic imaging, Oropharyngeal Neoplasms radiotherapy, Prostatic Neoplasms diagnostic imaging, Prostatic Neoplasms radiotherapy, Radiotherapy Dosage, Radiotherapy, Intensity-Modulated methods, Retrospective Studies, Atlases as Topic, Magnetic Resonance Imaging methods, Radiotherapy Planning, Computer-Assisted methods, Tomography, X-Ray Computed methods
- Abstract
Background and Purpose: Computed tomography (CT) imaging is the current gold standard for radiotherapy treatment planning (RTP). The establishment of a magnetic resonance imaging (MRI) only RTP workflow requires the generation of a synthetic CT (sCT) for dose calculation. This study evaluates the feasibility of using a multi-atlas sCT synthesis approach (sCT
a ) for head and neck and prostate patients., Material and Methods: The multi-atlas method was based on pairs of non-rigidly aligned MR and CT images. The sCTa was obtained by registering the MRI atlases to the patient's MRI and by fusing the mapped atlases according to morphological similarity to the patient. For comparison, a bulk density assignment approach (sCTbda ) was also evaluated. The sCTbda was obtained by assigning density values to MRI tissue classes (air, bone and soft-tissue). After evaluating the synthesis accuracy of the sCTs (mean absolute error), sCT-based delineations were geometrically compared to the CT-based delineations. Clinical plans were re-calculated on both sCTs and a dose-volume histogram and a gamma analysis was performed using the CT dose as ground truth., Results: Results showed that both sCTs were suitable to perform clinical dose calculations with mean dose differences less than 1% for both the planning target volume and the organs at risk. However, only the sCTa provided an accurate and automatic delineation of bone., Conclusions: Combining MR delineations with our multi-atlas CT synthesis method could enable MRI-only treatment planning and thus improve the dosimetric and geometric accuracy of the treatment, and reduce the number of imaging procedures., (Copyright © 2017 Associazione Italiana di Fisica Medica. All rights reserved.)- Published
- 2017
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25. DARS: a phase III randomised multicentre study of dysphagia- optimised intensity- modulated radiotherapy (Do-IMRT) versus standard intensity- modulated radiotherapy (S-IMRT) in head and neck cancer.
- Author
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Petkar I, Rooney K, Roe JW, Patterson JM, Bernstein D, Tyler JM, Emson MA, Morden JP, Mertens K, Miles E, Beasley M, Roques T, Bhide SA, Newbold KL, Harrington KJ, Hall E, and Nutting CM
- Subjects
- Chemoradiotherapy, Clinical Trials, Phase III as Topic, Deglutition Disorders etiology, Humans, Multicenter Studies as Topic, Quality of Life, Radiation Injuries etiology, Radiotherapy, Intensity-Modulated adverse effects, Randomized Controlled Trials as Topic, Squamous Cell Carcinoma of Head and Neck, Carcinoma, Squamous Cell radiotherapy, Deglutition Disorders prevention & control, Head and Neck Neoplasms radiotherapy, Radiation Injuries prevention & control
- Abstract
Background: Persistent dysphagia following primary chemoradiation (CRT) for head and neck cancers can have a devastating impact on patients' quality of life. Single arm studies have shown that the dosimetric sparing of critical swallowing structures such as the pharyngeal constrictor muscle and supraglottic larynx can translate to better functional outcomes. However, there are no current randomised studies to confirm the benefits of such swallow sparing strategies. The aim of Dysphagia/Aspiration at risk structures (DARS) trial is to determine whether reducing the dose to the pharyngeal constrictors with dysphagia-optimised intensity- modulated radiotherapy (Do-IMRT) will lead to an improvement in long- term swallowing function without having any detrimental impact on disease-specific survival outcomes., Methods/design: The DARS trial (CRUK/14/014) is a phase III multicentre randomised controlled trial (RCT) for patients undergoing primary (chemo) radiotherapy for T1-4, N0-3, M0 pharyngeal cancers. Patients will be randomised (1:1 ratio) to either standard IMRT (S-IMRT) or Do-IMRT. Radiotherapy doses will be the same in both groups; however in patients allocated to Do-IMRT, irradiation of the pharyngeal musculature will be reduced by delivering IMRT identifying the pharyngeal muscles as organs at risk. The primary endpoint of the trial is the difference in the mean MD Anderson Dysphagia Inventory (MDADI) composite score, a patient-reported outcome, measured at 12 months post radiotherapy. Secondary endpoints include prospective and longitudinal evaluation of swallow outcomes incorporating a range of subjective and objective assessments, quality of life measures, loco-regional control and overall survival. Patients and speech and language therapists (SLTs) will both be blinded to treatment allocation arm to minimise outcome-reporting bias., Discussion: DARS is the first RCT investigating the effect of swallow sparing strategies on improving long-term swallowing outcomes in pharyngeal cancers. An integral part of the study is the multidimensional approach to swallowing assessment, providing robust data for the standardisation of future swallow outcome measures. A translational sub- study, which may lead to the development of future predictive and prognostic biomarkers, is also planned., Trial Registration: This study is registered with the International Standard Randomised Controlled Trial register, ISRCTN25458988 (04/01/2016).
- Published
- 2016
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26. Assessment of fully-automated atlas-based segmentation of novel oral mucosal surface organ-at-risk.
- Author
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Dean JA, Welsh LC, McQuaid D, Wong KH, Aleksic A, Dunne E, Islam MR, Patel A, Patel P, Petkar I, Phillips I, Sham J, Newbold KL, Bhide SA, Harrington KJ, Gulliford SL, and Nutting CM
- Subjects
- Atlases as Topic, Dose-Response Relationship, Radiation, Humans, Radiometry methods, Radiotherapy Dosage, Head and Neck Neoplasms radiotherapy, Mouth Mucosa radiation effects, Organs at Risk
- Abstract
Background and Purpose: Current oral mucositis normal tissue complication probability models, based on the dose distribution to the oral cavity volume, have suboptimal predictive power. Improving the delineation of the oral mucosa is likely to improve these models, but is resource intensive. We developed and evaluated fully-automated atlas-based segmentation (ABS) of a novel delineation technique for the oral mucosal surfaces., Material and Methods: An atlas of mucosal surface contours (MSC) consisting of 46 patients was developed. It was applied to an independent test cohort of 10 patients for whom manual segmentation of MSC structures, by three different clinicians, and conventional outlining of oral cavity contours (OCC), by an additional clinician, were also performed. Geometric comparisons were made using the dice similarity coefficient (DSC), validation index (VI) and Hausdorff distance (HD). Dosimetric comparisons were carried out using dose-volume histograms., Results: The median difference, in the DSC and HD, between automated-manual comparisons and manual-manual comparisons were small and non-significant (-0.024; p=0.33 and -0.5; p=0.88, respectively). The median VI was 0.086. The maximum normalised volume difference between automated and manual MSC structures across all of the dose levels, averaged over the test cohort, was 8%. This difference reached approximately 28% when comparing automated MSC and OCC structures., Conclusions: Fully-automated ABS of MSC is suitable for use in radiotherapy dose-response modelling., (Copyright © 2016 The Authors. Published by Elsevier Ireland Ltd.. All rights reserved.)
- Published
- 2016
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