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Multidisciplinary Assessment and Reporting of Fitness to Drive in Brain Tumor Patients: A Gray Matter
S290
International Journal of Radiation Oncology Biology Physics
(range: 10-24) in 1 session, with a median of 2 bMet treated each; tumor size was 1.4 cm (range: 0.2 to 5.8); HI was 1.90 (range: 1.067-2.042); CI was 1.62 (range: 1.11-5.7); and isodose line (IDL) was 53% (range: 5095). Lesions were divided into “radioresistant” (typically melanoma and renal cell, n Z 100, 20.2%) and “radiosensitive” (all others, n Z 396, 79.8%). Cox proportional hazards regression was used to analyze significance of the following with LF and radiation necrosis (RN): HI, CI, IDL, dose, tumor size, recursive partitioning analysis (RPA) class, tumor radioresistance, primary tumor, smoking history, metastasis location, and WBRT history. Results: Median follow-up time by lesion was 6.8 mos (range: 0-49.6). Median survival time for the series was 14.2 mos. As defined per RECIST criteria, 9.5% of the lesions failed, 33.9% were stable, 38.3% partially responded, 17.1% responded completely, and 1.2% could not be assessed. The 12-month local control (LC) rate was 87.3%. On univariate analysis (UVA), the following were significant for LF: dose <20 Gy (HR Z 2.94, 95% CI Z 1.65-5.25, p Z 0.0003); tumor size (HR Z 1.67, 95% CI Z 1.28-2.18, p Z 0.0001); and cerebellum/brainstem location vs. other (HR Z 1.89, 95% CI Z 1.02-3.51, p Z 0.0431). NSCLC (HR Z 0.33, 95% CI Z 0.15-0.77, p Z 0.0097) was associated with better LC. On multivariate analysis (MVA), the following were significant for LF: tumor size (HR Z 1.70, 95% CI Z 1.30-2.22, p Z 0.0001) and cerebellum/brainstem location vs. other (HR Z 1.96, 95% CI Z 1.06-3.64, p Z 0.0331). Notable variables that were not significant for LF include the following: CI, IDL in %, IDL categorized as <70% vs. 70%, and HI. A total of 12.3% developed RN. Both UVA and MVA for RN showed nonsmokers (MVA: HR Z 1.97, 95% CI Z 1.14-3.41, p Z 0.0154) and CI (MVA: HR Z 0.24, 95% CI Z 0.09-0.61, p Z 0.0031) as significant. HI was not significant for RN. Conclusions: Our study of patients with 1-3 bMet treated with GK demonstrated no difference in LF and RN with varying HI. This result suggests that physicians can utilize higher IDL at 70% IDL and above. Treatment times are reduced without concern of increased LF or RN. Interestingly, the CI had no bearing on local outcome. Our study also supported the results of previous studies in demonstrating excellent local control rates. Author Disclosure: K. Shiue: None. G.H. Barnett: None. J.H. Suh: G. Consultant; Abbott Oncology. M.A. Vogelbaum: None. C.A. Reddy: None. R.J. Weil: None. L. Angelov: None. G. Neyman: G. Consultant; Elekta, Inc. S.T. Chao: None.
Results: Surveys (n Z 467) were distributed with 198 (43%) responding. Most (76%) felt that reporting guidelines were unclear. Neurologists (43%) and Family Physicians (22%) were felt to be the most responsible to report. Compared to specialists, Family Physicians were less likely to be comfortable with reporting (p Z 0.02), consider reporting (p < 0.001), and discuss the implications of driving (p < 0.001). Perceived barriers in assessing driving fitness included lack of tools (57%) and the impact on the patient-physician relationship (34%). A total of 158 patients receiving brain radiation therapy were available for analysis after excluding 21 patients (n Z 17 prophylactic cranial irradiation, n Z 4 ineligible to drive). In total, 48 patients (30%) were reported as unfit to drive, and 64 (41%) were advised to stop driving. Of the 53 patients with seizures, 36 (68%) were advised to stop driving, but in only 30 (56%) was a report made. Age, primary disease, previous neurosurgery, and the presence of seizures were predictive of physician reporting on Fisher’s exact test (p < 0.05). Seizures (OR 12.4) and primary brain cancer (OR 15.5) were predictive of reporting on logistic regression modeling. Conclusions: The assessment of fitness to drive in patients with brain tumors remains a challenge. The implications of driving for these patients are not routinely discussed and/or documented in their medical record. A multidisciplinary approach with allied health providers and increased accountability would prove to be invaluable in this understudied public health issue. Author Disclosure: A.V. Louie: None. E. Chan: None. M. Hanna: None. D.A. Palma: None. G.S. Bauman: None. B. Fisher: None. G.B. Rodriguez: None. A. Sathya: None. D.P. D’Souza: None.
2189 Multidisciplinary Assessment and Reporting of Fitness to Drive in Brain Tumor Patients: A Gray Matter A.V. Louie, E. Chan, M. Hanna, D.A. Palma, G.S. Bauman, B. Fisher, G.B. Rodrigues, A. Sathya, and D.P. D’Souza; London Regional Cancer Program, London, ON, Canada Purpose/Objective(s): In some jurisdictions, there is a legal requirement for physicians to report medically unfit drivers. The objective of this study is to determine physician knowledge and attitudes on reporting legislation and driving assessment and to evaluate clinical decision-making with respect to fitness to drive in brain tumor patients. Materials/Methods: Physicians involved in brain tumor care were identified through the College of Physicians and Surgeons of Ontario and surveyed by mail. To maximize response rates, follow-up was conducted by phone and email two and four weeks later, respectively. Responses were analyzed for demographics, opinions, and factors influencing the decision to report a patient as unfit to drive. Fisher’s exact test was performed to determine significant differences in responses between specialists and family physicians. We also reviewed our institution’s clinical experience by identifying patients receiving brain radiation therapy between January and June 2009. Descriptive statistics and details of driving assessment were extracted retrospectively. Fisher’s exact test was performed and a logistic regression model was constructed to determine factors predictive of reporting.
2190 Use of a Noncoplanar Half-beam Block on the Lower Spinal Field to Decrease the Maximum Bowel and Cumulative Dose in Craniospinal Irradiation M. Kathpal and R. Davis; UMDNJ-RWJ, New Brunswick, NJ Purpose/Objective(s): To develop and compare a non-coplanar half beam block technique that can be used in both prone and supine treatment positions with conventional beam matching for craniospinal irradiation (CSI) in order to decrease the maximum cumulative dose and dose to the bowel, while maintaining the therapeutic dose to the spinal axis. Materials/Methods: Ten treatment plans from five patients who underwent CSI were analyzed. The bowel was contoured en bloc for each patient on his or her simulation cat scan. Two different geometric techniques for each patient were planned and analyzed. The first technique consisted of the conventional method for CSI utilizing two coplanar beams to cover the entire spinal axis. The other technique used a non-coplanar half beam block on the lower spinal beam to exactly match the upper spinal beam’s divergence. Four “featherings” between the two spinal beams for each technique were still necessary to minimize under and overdosing which occur at abutting beam fields. Maximum doses for the plan and the bowel were compared between the two techniques on the same patient. Results: The maximum bowel dose was decreased between 10 to 35 percent when the non-coplanar half beam block was used. The maximum doses for the conventional technique were 5 to 35 percent higher than the plans using a non-coplanar half beam block. The homogeneity of the dose to the spinal axis was not altered with the use of the non-coplanar half beam block. Conclusions: Use of a non-coplanar half beam block to match the two spinal fields in craniospinal irradiation significantly reduces the maximum dose to the bowel and of the entire plan possibly resulting in reduced gastrointestinal toxicity while maintaining therapeutic dose to the spinal axis. Author Disclosure: M. Kathpal: None. R. Davis: None.
2191 Frameless, Real-time, Surface Imaging Guided Radiosurgery (SIG-RS): Clinical Outcomes for Brain Metastases H. Pan, L.I. Cervin˜o, T. Pawlicki, S.B. Jiang, J. Alksne, M. Russell, K.T. Murphy, A.J. Mundt, C. Chen, and J.D. Lawson; UCSD, La Jolla, CA
International Journal of Radiation Oncology Biology Physics
(range: 10-24) in 1 session, with a median of 2 bMet treated each; tumor size was 1.4 cm (range: 0.2 to 5.8); HI was 1.90 (range: 1.067-2.042); CI was 1.62 (range: 1.11-5.7); and isodose line (IDL) was 53% (range: 5095). Lesions were divided into “radioresistant” (typically melanoma and renal cell, n Z 100, 20.2%) and “radiosensitive” (all others, n Z 396, 79.8%). Cox proportional hazards regression was used to analyze significance of the following with LF and radiation necrosis (RN): HI, CI, IDL, dose, tumor size, recursive partitioning analysis (RPA) class, tumor radioresistance, primary tumor, smoking history, metastasis location, and WBRT history. Results: Median follow-up time by lesion was 6.8 mos (range: 0-49.6). Median survival time for the series was 14.2 mos. As defined per RECIST criteria, 9.5% of the lesions failed, 33.9% were stable, 38.3% partially responded, 17.1% responded completely, and 1.2% could not be assessed. The 12-month local control (LC) rate was 87.3%. On univariate analysis (UVA), the following were significant for LF: dose <20 Gy (HR Z 2.94, 95% CI Z 1.65-5.25, p Z 0.0003); tumor size (HR Z 1.67, 95% CI Z 1.28-2.18, p Z 0.0001); and cerebellum/brainstem location vs. other (HR Z 1.89, 95% CI Z 1.02-3.51, p Z 0.0431). NSCLC (HR Z 0.33, 95% CI Z 0.15-0.77, p Z 0.0097) was associated with better LC. On multivariate analysis (MVA), the following were significant for LF: tumor size (HR Z 1.70, 95% CI Z 1.30-2.22, p Z 0.0001) and cerebellum/brainstem location vs. other (HR Z 1.96, 95% CI Z 1.06-3.64, p Z 0.0331). Notable variables that were not significant for LF include the following: CI, IDL in %, IDL categorized as <70% vs. 70%, and HI. A total of 12.3% developed RN. Both UVA and MVA for RN showed nonsmokers (MVA: HR Z 1.97, 95% CI Z 1.14-3.41, p Z 0.0154) and CI (MVA: HR Z 0.24, 95% CI Z 0.09-0.61, p Z 0.0031) as significant. HI was not significant for RN. Conclusions: Our study of patients with 1-3 bMet treated with GK demonstrated no difference in LF and RN with varying HI. This result suggests that physicians can utilize higher IDL at 70% IDL and above. Treatment times are reduced without concern of increased LF or RN. Interestingly, the CI had no bearing on local outcome. Our study also supported the results of previous studies in demonstrating excellent local control rates. Author Disclosure: K. Shiue: None. G.H. Barnett: None. J.H. Suh: G. Consultant; Abbott Oncology. M.A. Vogelbaum: None. C.A. Reddy: None. R.J. Weil: None. L. Angelov: None. G. Neyman: G. Consultant; Elekta, Inc. S.T. Chao: None.
Results: Surveys (n Z 467) were distributed with 198 (43%) responding. Most (76%) felt that reporting guidelines were unclear. Neurologists (43%) and Family Physicians (22%) were felt to be the most responsible to report. Compared to specialists, Family Physicians were less likely to be comfortable with reporting (p Z 0.02), consider reporting (p < 0.001), and discuss the implications of driving (p < 0.001). Perceived barriers in assessing driving fitness included lack of tools (57%) and the impact on the patient-physician relationship (34%). A total of 158 patients receiving brain radiation therapy were available for analysis after excluding 21 patients (n Z 17 prophylactic cranial irradiation, n Z 4 ineligible to drive). In total, 48 patients (30%) were reported as unfit to drive, and 64 (41%) were advised to stop driving. Of the 53 patients with seizures, 36 (68%) were advised to stop driving, but in only 30 (56%) was a report made. Age, primary disease, previous neurosurgery, and the presence of seizures were predictive of physician reporting on Fisher’s exact test (p < 0.05). Seizures (OR 12.4) and primary brain cancer (OR 15.5) were predictive of reporting on logistic regression modeling. Conclusions: The assessment of fitness to drive in patients with brain tumors remains a challenge. The implications of driving for these patients are not routinely discussed and/or documented in their medical record. A multidisciplinary approach with allied health providers and increased accountability would prove to be invaluable in this understudied public health issue. Author Disclosure: A.V. Louie: None. E. Chan: None. M. Hanna: None. D.A. Palma: None. G.S. Bauman: None. B. Fisher: None. G.B. Rodriguez: None. A. Sathya: None. D.P. D’Souza: None.
2189 Multidisciplinary Assessment and Reporting of Fitness to Drive in Brain Tumor Patients: A Gray Matter A.V. Louie, E. Chan, M. Hanna, D.A. Palma, G.S. Bauman, B. Fisher, G.B. Rodrigues, A. Sathya, and D.P. D’Souza; London Regional Cancer Program, London, ON, Canada Purpose/Objective(s): In some jurisdictions, there is a legal requirement for physicians to report medically unfit drivers. The objective of this study is to determine physician knowledge and attitudes on reporting legislation and driving assessment and to evaluate clinical decision-making with respect to fitness to drive in brain tumor patients. Materials/Methods: Physicians involved in brain tumor care were identified through the College of Physicians and Surgeons of Ontario and surveyed by mail. To maximize response rates, follow-up was conducted by phone and email two and four weeks later, respectively. Responses were analyzed for demographics, opinions, and factors influencing the decision to report a patient as unfit to drive. Fisher’s exact test was performed to determine significant differences in responses between specialists and family physicians. We also reviewed our institution’s clinical experience by identifying patients receiving brain radiation therapy between January and June 2009. Descriptive statistics and details of driving assessment were extracted retrospectively. Fisher’s exact test was performed and a logistic regression model was constructed to determine factors predictive of reporting.
2190 Use of a Noncoplanar Half-beam Block on the Lower Spinal Field to Decrease the Maximum Bowel and Cumulative Dose in Craniospinal Irradiation M. Kathpal and R. Davis; UMDNJ-RWJ, New Brunswick, NJ Purpose/Objective(s): To develop and compare a non-coplanar half beam block technique that can be used in both prone and supine treatment positions with conventional beam matching for craniospinal irradiation (CSI) in order to decrease the maximum cumulative dose and dose to the bowel, while maintaining the therapeutic dose to the spinal axis. Materials/Methods: Ten treatment plans from five patients who underwent CSI were analyzed. The bowel was contoured en bloc for each patient on his or her simulation cat scan. Two different geometric techniques for each patient were planned and analyzed. The first technique consisted of the conventional method for CSI utilizing two coplanar beams to cover the entire spinal axis. The other technique used a non-coplanar half beam block on the lower spinal beam to exactly match the upper spinal beam’s divergence. Four “featherings” between the two spinal beams for each technique were still necessary to minimize under and overdosing which occur at abutting beam fields. Maximum doses for the plan and the bowel were compared between the two techniques on the same patient. Results: The maximum bowel dose was decreased between 10 to 35 percent when the non-coplanar half beam block was used. The maximum doses for the conventional technique were 5 to 35 percent higher than the plans using a non-coplanar half beam block. The homogeneity of the dose to the spinal axis was not altered with the use of the non-coplanar half beam block. Conclusions: Use of a non-coplanar half beam block to match the two spinal fields in craniospinal irradiation significantly reduces the maximum dose to the bowel and of the entire plan possibly resulting in reduced gastrointestinal toxicity while maintaining therapeutic dose to the spinal axis. Author Disclosure: M. Kathpal: None. R. Davis: None.
2191 Frameless, Real-time, Surface Imaging Guided Radiosurgery (SIG-RS): Clinical Outcomes for Brain Metastases H. Pan, L.I. Cervin˜o, T. Pawlicki, S.B. Jiang, J. Alksne, M. Russell, K.T. Murphy, A.J. Mundt, C. Chen, and J.D. Lawson; UCSD, La Jolla, CA