16 results on '"Grimm, Jimm"'
Search Results
2. Clinical evidence for dose tolerance of the central nervous system in hypofractionated radiotherapy.
- Author
-
Xue, Jinyu, Emami, Bahman, Grimm, Jimm, Kubicek, Gregory J., Asbell, Sucha O., Lanciano, Rachelle, Welsh, James S., Peng, Luke, Quon, Harry, Laub, Wolfram, Gui, Chengcheng, Spoleti, Nicholas, Das, Indra J., Goldman, Howard Warren, Redmond, Kristin J., Kleinberg, Lawrence R., and Brady, Luther W.
- Published
- 2018
- Full Text
- View/download PDF
3. Local recurrence patterns after postoperative stereotactic radiation surgery to resected brain metastases: A quantitative analysis to guide target delineation.
- Author
-
Gui, Chengcheng, Moore, Joseph, Grimm, Jimm, Kleinberg, Lawrence, McNutt, Todd, Shen, Colette, Chen, Linda, Bettegowda, Chetan, Lim, Michael, and Redmond, Kristin J.
- Abstract
Abstract Purpose In the treatment of resected metastatic brain disease, a recent phase 3 trial by the North Central Cancer Treatment Group (N107C/CEC.3) surprisingly found that the local control rate for whole-brain radiation therapy was better than that of stereotactic radiation surgery (SRS). To optimize target delineation, we performed a quantitative analysis of local failure patterns after postoperative SRS. Methods and materials Patients with brain metastases who were treated with surgery and SRS to the cavity were evaluated. Local failure was defined by pathologic confirmation or magnetic resonance imaging evidence of progression leading to further overlapping radiation therapy. T1 postgadolinium magnetic resonance imaging scans that were taken preoperatively and at recurrence were co-registered to the simulation computed tomography. Three volumes were compared: (1) Preoperative tumors, (2) resection cavities that were originally contoured as clinical target volumes for SRS, and (3) recurrent tumors. Overlap volume histograms quantified the proximity of the three volumes to the meninges. Results In the cohort of 173 patients, 18 patients experienced local failure in 19 resection cavities. The original SRS target volume overlapped with a median of 69.6% of the recurrent tumor. When the entire preoperative tumor was included, the overlap with the recurrent tumor increased to a median of 76.8%. Recurrent tumors were closer to the meninges than corresponding preoperative tumors (P =.03) but a median 8.2 mm expansion of the target volume from the meninges was needed to increase overlap with the recurrent tumor to 90%. Increases in overlap with the recurrent tumor were achieved most efficiently by uniformly expanding the contoured cavity and a median 2.8 mm expansion covered 90% of the recurrent tumor. Conclusions Our quantitative analysis of recurrence patterns suggests that a larger 3 mm uniform expansion of the SRS target volume substantially increases coverage of the volume that is later occupied by the recurrent tumor and may provide improved local control. The extent of the preoperative tumor in the target volume or expanding the target volume from the meninges provides little benefit. [ABSTRACT FROM AUTHOR]
- Published
- 2018
- Full Text
- View/download PDF
4. Volume effects in radiosurgical spinal cord dose tolerance: how small is too small?
- Author
-
Ma, Ting, Emami, Bahman, Grimm, Jimm, Xue, Jinyu, Asbell, Sucha, Kubicek, Gregory, Lanciano, Rachelle, Welsh, James, Peng, Luke, Gui, Chengcheng, Das, Indra, Goldman, Howard, Brady, Luther, Redmond, Kristin, and Kleinberg, Lawrence
- Abstract
Spinal cord dose constraints are a critical feature for stereotactic body radiation therapy (SBRT). Spinal cord maximum point dose (Dmax) by Monte Carlo (MC) calculations is used as a critical cord tolerance limit for SBRT, but information is lacking about its reproducibility. This study examines uncertainty of MC dose calculations for small volumes in spine SBRT. Seven consecutive spine radiosurgery cases were randomly selected to measure precision of the Dmax calculation in comparison to other volumes. Each plan was calculated five times using MC with a 2% uncertainty objective, and variabilities in dose-volume histogram (DVH) parameters across recalculations were evaluated with coefficient of variation (standard deviation divided by mean). The average ratio of D0.03 cc/Dmax was calculated across a larger series of 130 cases. The variability of Dmax was twice as high for D0.03 cc and five times as high for D1 cc across recalculations for the seven cases. For larger volumes, the variability was lower. The standard deviation of Dmax was 0.1959 Gy, compared to 0.0931 Gy, 0.0569 Gy, and 0.0364 Gy for D0.03 cc, D0.1 cc, and D1 cc, respectively. The average D0.03 cc/Dmax among 130 cases was 0.93. Dmax has greater variability compared to D0.03 cc, D0.1 cc, and D1 cc, potentially creating risks when used for guidance for spinal cord. D0.03 cc may be an attractive alternative with higher reliability while its limits could be obtained by scaling the reported Dmax limit by a factor of 0.93. This may help guide treatment planning and aid in discovering true dose constraints for spine SBRT.
- Published
- 2019
- Full Text
- View/download PDF
5. Clinical evidence for dose tolerance of the central nervous system in hypofractionated radiotherapy
- Author
-
Xue, Jinyu, Emami, Bahman, Grimm, Jimm, Kubicek, Gregory, Asbell, Sucha, Lanciano, Rachelle, Welsh, James, Peng, Luke, Quon, Harry, Laub, Wolfram, Gui, Chengcheng, Spoleti, Nicholas, Das, Indra, Goldman, Howard, Redmond, Kristin, Kleinberg, Lawrence, and Brady, Luther
- Abstract
Stereotactic radiosurgery (SRS), stereotactic body radiotherapy (SBRT), and stereotactic ablative body radiotherapy (SABR) are commonly used in the treatment of central nervous system (CNS) disease. This study has refined the radiation toxicity estimates for some normal tissues of the CNS based on review and analysis of the clinical evidence for single fraction radiosurgery, hypofractionated SBRT, and conventionally fractionated radiation therapy. Published guidelines and protocols are reviewed. In the past, many normal tissue tolerances were compiled based on the experience of the investigators and publications in the literature. Some tolerances were determined by modeling or calculation using the existing biological formulas, in particular the linear quadratic (LQ) model. In the present study, the estimate of risk for each dose tolerance limit in some CNS tissues is provided exclusively with normal tissue complication probability (NTCP). The clinical outcomes are compared to understand the difference in biological effect between radiosurgery and radiotherapy. Normal tissue dose tolerances and the corresponding complication rates are provided for brainstem, optic nerves, cochlea, and spinal cord, including single fraction SRS, five-fraction SBRT, and conventional radiation therapy. Calculation of biologically effective dose (BED) or single fraction equivalent dose (SFED) alone using the LQ model conveys no consensus on the biological effect across different fractionations. Comparison of conventional radiation therapy to brain and spinal cord with single fraction equivalent dose leads to even conflicting clinical outcomes. Effective differences between single fraction SRS and conventional radiotherapy need to be better understood. The existing biological model might not be valid to predict the radiosurgical outcomes based on conventionally fractionated radiotherapy. However, application of the statistical dose response models of clinical SRS and SBRT outcomes data to selected current dose tolerance guidelines into simple tables can be a clinically useful resource.
- Published
- 2018
- Full Text
- View/download PDF
6. Estimated Risk Level of Unified Stereotactic Body Radiation Therapy Dose Tolerance Limits for Spinal Cord.
- Author
-
Grimm, Jimm, Sahgal, Arjun, Soltys, Scott G., Luxton, Gary, Patel, Ashish, Herbert, Scott, Xue, Jinyu, Ma, Lijun, Yorke, Ellen, Adler, John R., and Gibbs, Iris C.
- Abstract
A literature review of more than 200 stereotactic body radiation therapy spine articles from the past 20 years found only a single article that provided dose-volume data and outcomes for each spinal cord of a clinical dataset: the Gibbs 2007 article (Gibbs et al, 2007 1 ), which essentially contains the first 100 stereotactic body radiation therapy (SBRT) spine treatments from Stanford University Medical Center. The dataset is modeled and compared in detail to the rest of the literature review, which found 59 dose tolerance limits for the spinal cord in 1-5 fractions. We partitioned these limits into a unified format of high-risk and low-risk dose tolerance limits. To estimate the corresponding risk level of each limit we used the Gibbs 2007 clinical spinal cord dose-volume data for 102 spinal metastases in 74 patients treated by spinal radiosurgery. In all, 50 of the patients were previously irradiated to a median dose of 40 Gy in 2-3 Gy fractions and 3 patients developed treatment-related myelopathy. These dose-volume data were digitized into the dose-volume histogram (DVH) Evaluator software tool where parameters of the probit dose-response model were fitted using the maximum likelihood approach (Jackson et al, 1995 3 ). Based on this limited dataset, for de novo cases the unified low-risk dose tolerance limits yielded an estimated risk of spinal cord injury of ≤1% in 1-5 fractions, and the high-risk limits yielded an estimated risk of ≤3%. The QUANTEC D max limits of 13 Gy in a single fraction and 20 Gy in 3 fractions had less than 1% risk estimated from this dataset, so we consider these among the low-risk limits. In the previously irradiated cohort, the estimated risk levels for 10 and 14 Gy maximum cord dose limits in 5 fractions are 0.4% and 0.6%, respectively. Longer follow-up and more patients are required to improve the risk estimates and provide more complete validation. [ABSTRACT FROM AUTHOR]
- Published
- 2016
- Full Text
- View/download PDF
7. Introduction and Clinical Overview of the DVH Risk Map.
- Author
-
Asbell, Sucha O., Grimm, Jimm, Xue, Jinyu, Chew, Meng-Sang, and LaCouture, Tamara A.
- Abstract
Radiation oncologists need reliable estimates of risk for various fractionation schemes for all critical anatomical structures throughout the body, in a clinically convenient format. Reliable estimation theory can become fairly complex, however, and estimates of risk continue to evolve as the literature matures. To navigate through this efficiently, a dose-volume histogram (DVH) Risk Map was created, which provides a comparison of radiation tolerance limits as a function of dose, fractionation, volume, and risk level. The graphical portion of the DVH Risk Map helps clinicians to easily visualize the trends, whereas the tabular portion provides quantitative precision for clinical implementation. The DVH Risk Map for rib tolerance from stereotactic ablative body radiotherapy (SABR) and stereotactic body radiation therapy (SBRT) is used as an example in this overview; the 5% and 50% risk levels for 1-5 fractions for 5 different volumes are given. Other articles throughout this issue of Seminars in Radiation Oncology present analysis of new clinical datasets including the DVH Risk Maps for other anatomical structures throughout the body. [ABSTRACT FROM AUTHOR]
- Published
- 2016
- Full Text
- View/download PDF
8. Esophageal Dose Tolerance in Patients Treated With Stereotactic Body Radiation Therapy.
- Author
-
Nuyttens, Joost J., Moiseenko, Vitali, McLaughlin, Mark, Jain, Sheena, Herbert, Scott, and Grimm, Jimm
- Abstract
Mediastinal critical structures such as trachea, bronchus, esophagus, and heart are among the dose-limiting factors for stereotactic body radiation therapy (SBRT) to central lung lesions. The purpose of this study was to characterize the risk of esophagitis for patients treated with SBRT and to develop a statistical dose-response model to assess the equivalent uniform dose, D 10% , D 5 cc , D 1 cc , and D max , to the esophagus and the risk of toxicity. Toxicity outcomes of a dose-escalation study of 56 patients who had taken CyberKnife treatment from 45-60 Gy in 3-7 fractions at the Erasmus MC-Daniel den Hoed Cancer Center were utilized to create the dose-response model for esophagus. A total of 5 grade 2 esophageal complications were reported (Common Terminology Criteria for Adverse Events version 3.0); 4 complications were early effects and 1 complication was a late effect. All analyses were performed in terms of 5-fraction equivalent dosing. According to our study, D 1 cc at a dose of 32.9 Gy and D max dose of 43.4 Gy corresponded to a complication probability of 50% for grade 2 toxicity. In this series of 58 CyberKnife mediastinal lung cases, no grade 3 or higher esophageal toxicity occurred. Our estimates of esophageal toxicity are compared with the data in the literature. Further research needs to be performed to establish more reliable dose limits as longer follow-up and toxicity outcomes are reported in patients treated with SBRT for central lung lesions. [ABSTRACT FROM AUTHOR]
- Published
- 2016
- Full Text
- View/download PDF
9. Multisession Radiosurgery for Hearing Preservation.
- Author
-
Rashid, Abdul, Karam, Sana D., Rashid, Beenish, Kim, Jeffrey H., Pang, Dalong, Jean, Walter, Grimm, Jimm, and Collins, Sean P.
- Abstract
Clinically relevant dose-tolerance limits with reliable estimates of risk in 1-5 fractions for cochlea are still unknown. Timmerman׳s limits from the October 2008 issue of Seminars in Radiation Oncology have served as the basis for clinical practice, augmented by updated constraints in TG-101 and QUANTEC, but the corresponding estimates of risk have not yet been well-reported. A total of 37 acoustic neuroma CyberKnife cases from Medstar Georgetown University Hospital treated in 3 or 5 fractions were combined with single-fraction Gamma Knife data from the 69 cases in Timmer 2009 to form an aggregate dataset of 106 cochlea cases treated in 1-5 fractions. Probit dose-response modeling was performed in the DVH Evaluator software to estimate normal tissue complication probability. QUANTEC recommends keeping single-fraction maximum dose to the cochlea less than 14 Gy to maintain less than 25% risk of serviceable hearing loss, and our 17.9% risk estimate for 14 Gy in 1 fraction is within their predicted range. In 5 fractions, our estimate of the Timmerman 27.5 Gy maximum cochlea dose limit was 17.4%. For cases in which lower risk is required, the Timmerman 12 Gy in 1 fraction and the TG-101 limit of 25 Gy in 5 fractions had an estimated risk level of 11.8% and 13.8%, respectively. High-risk and low-risk dose tolerance with risk estimates in 1-5 fractions are all presented. [ABSTRACT FROM AUTHOR]
- Published
- 2016
- Full Text
- View/download PDF
10. Dose-Response Model for Chest Wall Tolerance of Stereotactic Body Radiation Therapy.
- Author
-
Kimsey, Frank, McKay, Jesse, Gefter, Jeffrey, Milano, Michael T., Moiseenko, Vitali, Grimm, Jimm, and Berg, Ronald
- Abstract
Many recent studies have described rib fractures and chest wall pain following stereotactic body radiation therapy (SBRT). Although these toxicities generally are not life-threatening, the chest wall and ribs are considered dose-limiting tissues because of the potential effect on patients׳ quality of life. Few studies have reported dose-response models that can provide quantitative estimates of risk as a function of dose and volume. Notably, Memorial Sloan Kettering Cancer Center (Mutter et al 8 ) analyzed grade 2 or higher chest wall toxicity in a cohort of 126 patients treated with linear accelerator–based SBRT; the authors provided detailed dose-volume histogram (DVH) data to allow for pooled analyses. We pooled these 126 patients with an additional 44 patients treated with CyberKnife at the Erlanger Medical Center to create an updated dose-response model for chest wall tolerance. In the aggregate analysis, the 10% risk level for grade 2 or higher complications for D 70 cc was 16.2 Gy in 4 fractions, and the 50% risk level was D 70 cc = 65.1 Gy in 4 fractions. For D 2 cc , the 10% and 50% risk levels in 4 fractions were 43.0 Gy and 87.9 Gy, respectively. These dose-tolerance limits may help quantify chest wall toxicity risks. Further research continues to determine more accurate estimates of grade 3 risk levels. [ABSTRACT FROM AUTHOR]
- Published
- 2016
- Full Text
- View/download PDF
11. Biological implications of whole-brain radiotherapy versus stereotactic radiosurgery of multiple brain metastases.
- Author
-
JINYU XUE, KUBICEK, GREGORY J., GRIMM, JIMM, LACOUTURE, TAMARA, YAN CHEN, GOLDMAN, H. WARREN, and YORKE, ELLEN
- Published
- 2014
- Full Text
- View/download PDF
12. Low toxicity for lung tumors near the mediastinum treated with stereotactic body radiation therapy.
- Author
-
Srivastava, Roma, Asbell, Sucha O., LaCouture, Tamara, Kramer, Noel, Pahlajani, Niraj, Xue, Jinyu, Ahmad, Nazish, Chen, Yan, Croce, Raymond, and Grimm, Jimm
- Subjects
STEREOTACTIC radiotherapy ,MEDIASTINUM diseases ,LUNG cancer patients ,DRUG tolerance ,DOSE-effect relationship in pharmacology ,FOLLOW-up studies (Medicine) ,THERAPEUTICS - Abstract
Abstract: Purpose: To report the local control, survival, and low toxicity observed at the Cooper University Hospital CyberKnife Center post stereotactic body radiation therapy (SBRT) in the treatment of lung tumors near the mediastinum. Methods and Materials: Twenty-four medically inoperable lung cancer patients with tumors near the mediastinum were treated using the Accuray CyberKnife system (Accuray, Sunnyvale, CA) with Monte Carlo dose calculations and heterogeneity corrections from July 2008 to May 2010. The prescription dose ranged from 28.5 Gy to 60 Gy in 3-5 fractions. For conventional fractionation schemes, Emami et al
1 organized the dose tolerance limits into a unified format for clinical utility and partitioned them into 2 risk levels (5% and 50%) with preset volumes for most critical structures throughout the body. In contrast, statistical SBRT dose tolerance limits for mediastinal structures have not been established yet. We have sufficient experience at least to begin organizing a unified format with low-risk and high-risk partitions and preset volumes for 1-5 fractions exposing mediastinal structures. With the help of the (dose-volume histogram) DVH Evaluator, a software tool developed by our senior author, each treatment plan was assessed for safety and feasibility prior to treatment. The DVH Evaluator was also used to analyze the follow-up data and to create graphs of risk, called DVH Risk Maps, superimposing clinical data onto the unified SBRT dose tolerance limits. Results: It was not feasible to prescribe the doses of peripheral lung lesions for all tumors near the mediastinum because of known toxicity. The crude local tumor control rate achieved in our series was 92%. Median survival was 26.8 months for the primary lung cases and 9.6 months for the metastatic cases. No patients experienced grade 3 or higher toxicities. Conclusions: We affirm that SBRT is feasible in the treatment of centrally located lung cancers when the dose tolerance limits of critical structures are diligently respected. The low adverse event rates that we have experienced, combined with a good local tumor control rate, are encouraging. [Copyright &y& Elsevier]- Published
- 2013
- Full Text
- View/download PDF
13. Dose-volume effects on brainstem dose tolerance in radiosurgery.
- Author
-
JINYU XUE, GOLDMAN, H. WARREN, GRIMM, JIMM, LACOUTURE, TAMARA, YAN CHEN, HUGHES, LESLEY, and YORKE, ELLEN
- Published
- 2012
- Full Text
- View/download PDF
14. Targeting Accuracy Considerations for Simultaneous Tumor Treating Fields Antimitotic Therapy During Robotic Hypofractionated Radiation Therapy
- Author
-
Biswas, Sharmi, Kapitanova, Irina, Divekar, Sabrina, Grimm, Jimm, Butterwick, Ian J., Garren, Daniel, Kleinberg, Lawrence R., Redmond, Kristin J., Lacroix, Michel, Mahadevan, Anand, and Forster, Kenneth M.
- Abstract
Purpose: Tumor treating fields (TTFields) is a novel antimitotic treatment that was first proven effective for glioblastoma multiforme, now with trials for several extracranial indications underway. Several studies focused on concurrent TTFields therapy with radiation in the same time period, but were not given simultaneously. This study evaluates the targeting accuracy of simultaneous radiation therapy while TTFields arrays are in place and powered on, ensuring that radiation does not interfere with TTFields and TTFields does not interfere with radiation. This is one of several options to enable TTFields to begin several weeks sooner, and opens potential for synergistic effects of combined therapy. Methods:TTFields arrays were attached to a warm saline water bath and salt was added until the TTFields generator reached the maximal 2000 mA peak-to-peak current. A ball cube phantom containing 2 orthogonal films surrounded by fiducials was placed in the water phantom, CT scanned, and a radiation treatment plan with 58 isocentric beams was created using a 3 cm circular collimator. Fiducial tracking was used to deliver radiation, the films were scanned, and end-to-end targeting error was measured with vendor-supplied software. In addition, radiation effects on electric fields generated by the TTFields system were assessed by examining logfiles generated from the field generator. Results:With TTFields arrays in place and powered on, the robotic radiosurgery system achieved a final targeting result of 0.47 mm, which was well within the submillimeter specification. No discernible effects on TTFields current output beyond 0.3% were observed in the logfiles when the radiation beam pulsed on and off. Conclusion:A robotic radiosurgery system was used to verify that radiation targeting was not adversely affected when the TTFields arrays were in place and the TTFields delivery device was powered on. In addition, this study verified that radiation delivered simultaneously with TTFields did not interfere with the generation of the electric fields.
- Published
- 2021
- Full Text
- View/download PDF
15. High Efficiency Narrowband Wireless Modems for ITS Applications
- Author
-
Grimm, Jimm, Fitz, Michael, Krogmeier, James, Chen, Tai-Ann, Magnusen, Tim, Gansman, Jerome, and Kuo, Wen-Yi
- Abstract
The Intelligent Transportation System (ITS) relies heavily on data communications systems to link field equipment such as traffic sensors, changeable message signs and incident response vehicles with traffic operations centers. This paper has two main purposes. The first is to present a review of data communications concepts essential in the design of wireless modems for the ITS 220 MHz spectral allocations. The second is to propose an architecture for such modems which offers a spectral efficiency much higher than that available in current products. The new modem architecture is implemented using the combination of a digital signal processor, discrete electronics, and high level software. All sophisticated signal processing is implemented in software to provide both high performance and flexibility. The system forms an ideal testbed for the design of future enhancements and modifications to fit specific ITS applications. A prototype has been constructed and subjected to full bench testing. Preliminary field testing has been performed and more is in progress.
- Published
- 1997
- Full Text
- View/download PDF
16. Dose Tolerance for Stereotactic Body Radiation Therapy.
- Author
-
Grimm, Jimm
- Published
- 2016
- Full Text
- View/download PDF
Catalog
Discovery Service for Jio Institute Digital Library
For full access to our library's resources, please sign in.