- Email: [email protected]
Vector Analysis of Bladder Cancer Patient Setup Utilizing a Magnetic Resonance Image Guided Radiation Therapy (MR-IGRT) System
Poster Viewing E261
Volume 96 Number 2S Supplement 2016 Materials/Methods: The outcomes of patients with progressive, symptomatic mCRPC with bone metastases treated with Ra-223 between Oct. 2009 and Dec. 2015 were analyzed. The association between baseline characteristics and outcomes were analyzed using descriptive statistics while overall survival (OS) was estimated using the Kaplan-Meier method. Toxicities were assessed using NCI CTCAE v4.0. Results: A total of 36 patients were analyzed. Median follow-up was 6.8 months (range, 1.5-34.7). Median age was 75 years (range, 49-88). Prior to commencing Ra-223, 14 patients (39%) were treated with abiraterone acetate (abi), 17 patients (47%) with enzalutamide (enza), and 14 patients (39%) with docetaxel; 16 patients (44%) received more than one agent and 7 (19%) received none. The median number of Ra-223 injections received was 5 (range, 1-6). Nineteen patients (53%) discontinued therapy prematurely. Median OS for the total cohort was 10.0 months (95% CI, 4.5-15.0). There was a non-significant trend towards shorter OS in those patients that had received prior abi or enza vs. those that had received neither of these agents (median 6.8 vs. 14.0 months; HR 2.67; 95% CI, 0.87-8.20; log-rank P Z 0.087). Forty-four percent of patients who received prior abi/enza completed all 6 planned injections vs. 55% of those that did not. There were differences seen in the baseline characteristics of these two groups: mean PSA 272 vs. 114 mcg/L, and proportion with 20 metastases 64% vs. 44%, respectively. Cumulative incidence of grade 3 hematologic toxicity during or after treatment was as follows: anemia 19%, neutropenia 0%, and thrombocytopenia 11%. Conclusion: This cohort of patients receiving Ra-223 spans the era prior to the advent of abi and enza and thus included patients with and without prior exposure to these agents. Patients receiving these agents prior to commencing Ra-223 were less likely to complete the 6 planned injections, and had a non-significant trend toward shorter survival, raising the hypothesis that earlier integration of Ra-223 in the mCRPC disease course may be preferred. This apparent association may reflect greater disease burden in more heavily pre-treated patients, rather than diminished efficacy of Ra-223. Finally, the toxicity profile of Ra-223 observed in this realworld setting was relatively favorable and comparable to that seen in the phase III trial that led to regulatory approval. Author Disclosure: A. Bang: None. S. Malone: Independent Contractor; The Ottawa Hospital. E.Y. Leung: Independent Contractor; The Ottawa Hospital. C. Canil: Independent Contractor; The Ottawa Hospital. L. Eapen: Independent Contractor; The Ottawa Hospital. S.C. Morgan: Independent Contractor; The Ottawa Hospital.
2634 Stereotactic Body Radiation Therapy to the Prostate: Patterns of Care in the National Cancer Data Base J.P. Weiner,1,2 D. Schwartz,1,2 M. Shao,1,2 V. Osborn,1,2 and D. Schreiber1,2; 1SUNY Downstate Medical Center, Brooklyn, NY, 2 Veterans Affairs NY Harbor Healthcare System, Brooklyn, NY Purpose/Objective(s): To analyze the utilization and patterns of care of stereotactic body radiation therapy (SBRT) in the treatment of prostate cancer. Materials/Methods: Men who were diagnosed with localized prostate cancer between 2004 and 2012 and treated with radiation therapy were included. Men were categorized as receiving external beam radiation, prostate brachytherapy, or SBRT to the prostate or pelvis. Descriptive statistics were used to analyze stereotactic radiation therapy usage and compared via Chi Square or Fisher’s Exact Test. Results: There were 299,186 patients identified, of which 5,078 (1.7%) were identified as receiving SBRT. Of those, 2,108 had low risk disease (41.5%), 2,251 had intermediate risk disease (44.3%) and 719 had high risk disease (14.2%). The relative utilization of SBRT increased from 0.1% in 2004 to 4.0% in 2012 (P<0.001). The relative utilization over time increased more rapidly in academic programs from 0.1% in 2004 to 7.1% of all patients receiving radiation in 2012 (P<0.001). In non-academic programs, there was a slower increase in utilization from 0.1% in 2004 to 2.6% in 2012. The most commonly utilized fractionation scheme included
5 fractions in 4,635 patients (91.3%), with 725 cGy x 5 the most common fractionation scheme (49.6%) followed by 700 cGy x 5 (21.3%). Doses of 750 cGy per day were more commonly utilized in non-academic centers (32.3%) compared to academic centers (26.1%). Conclusion: SBRT is slowly increasing acceptance, but more so in academic facilities. 700-725 cGy x 5 fractions appears to be the most commonly utilized fractionation scheme. As further long-term data regarding the safety and efficacy emerges, the relative utilization of SBRT is expected to continue to increase. Author Disclosure: J.P. Weiner: None. D. Schwartz: None. M. Shao: None. V. Osborn: None. D. Schreiber: None.
2635 Vector Analysis of Bladder Cancer Patient Setup Utilizing a Magnetic Resonance Image Guided Radiation Therapy (MR-IGRT) System B.W. Fischer-Valuck, O.L. Green, S. Mutic, H.A. Gay, and J.M. Michalski; Washington University School of Medicine, St. Louis, MO Purpose/Objective(s): Inter and intra-fraction anatomy changes in patients undergoing radiation therapy (RT) for bladder cancer (BC) are common but have thus far been studied with implanted fiducial markers, limited quality 2-D orthogonal films and computed tomography (CT). The adverse impact of daily set-up variation could be more significant than appreciated. Our goal was to employ the soft tissue imaging capabilities of an integrated magnetic resonance image-guided RT (MR-IGRT) system to analyze daily positioning. Materials/Methods: Fourteen patients with BC were treated on a MRIGRT system. Patient setup was performed via volumetric MR imaging with a resolution of 0.15 x 0.15 cm. Alignment was performed according to skin marks then shifts assessed by comparing the treatment volume from the planning CT to the daily MR image. Two hundred forty pretreatment MR images were analyzed and 3 shifts were recorded for each image. A vector shift was calculated by combining the square root of the combined sum of the shifts squared. Number of times that the vector of combined shifts would have exceeded the planning tumor volume (PTV) was recorded. Results: The daily volumetric MR imaging allowed for accurate alignment and daily monitoring of bladder volume and normal tissue anatomy. Recorded shifts of the treated volume were 0.90.5 cm in the right/left direction, 0.70.3 cm in the anterior/posterior direction, and 0.70.4 cm in the cranio-caudal direction. In 66 (28%) of cases the vector shift was initially greater than the PTV margin. For 2 patients, pre-treatment MR imaging revealed the tumor reduced in size and dose to the bowel would have exceeded constraints, and treatment adaptation was performed to reduce normal tissue toxicity. Using CTCAE criteria, no grade 3 or higher toxicities have been reported. Conclusion: Accurate and reproducible treatment delivery is required to avoid marginal misses to the target volume as well as excess dose to normal tissue. MR-IGRT allows for excellent soft tissue visualization which enables for the avoidance of potential setups errors by allowing daily alignment changes to ensure the target is included in the PTV. It also allows the ability to make treatment changes based on anatomy variations. Author Disclosure: B.W. Fischer-Valuck: None. O.L. Green: Honoraria; ViewRay. S. Mutic: Research Grant; ViewRay. Honoraria; ViewRay. Consultant; ViewRay. Advisory Board; ViewRay. Travel Expenses; ViewRay. Stock; ViewRay. Royalty; ViewRay. H.A. Gay: None. J.M. Michalski: None.
2636 The Effect of Lovastatin on Preservation of Erectile Function After Radiation Therapy (RT) for Prostate Cancer: Secondary Analysis of a Prospective Study M.S. Anscher,1 M.G. Chang,2 D. Moghanaki,3 M. Rosu,4 R.B. Mikkelsen,4 D. Holdford,5 V. Skinner,6 B.M. Grob,1 A. Sanyal,1
Volume 96 Number 2S Supplement 2016 Materials/Methods: The outcomes of patients with progressive, symptomatic mCRPC with bone metastases treated with Ra-223 between Oct. 2009 and Dec. 2015 were analyzed. The association between baseline characteristics and outcomes were analyzed using descriptive statistics while overall survival (OS) was estimated using the Kaplan-Meier method. Toxicities were assessed using NCI CTCAE v4.0. Results: A total of 36 patients were analyzed. Median follow-up was 6.8 months (range, 1.5-34.7). Median age was 75 years (range, 49-88). Prior to commencing Ra-223, 14 patients (39%) were treated with abiraterone acetate (abi), 17 patients (47%) with enzalutamide (enza), and 14 patients (39%) with docetaxel; 16 patients (44%) received more than one agent and 7 (19%) received none. The median number of Ra-223 injections received was 5 (range, 1-6). Nineteen patients (53%) discontinued therapy prematurely. Median OS for the total cohort was 10.0 months (95% CI, 4.5-15.0). There was a non-significant trend towards shorter OS in those patients that had received prior abi or enza vs. those that had received neither of these agents (median 6.8 vs. 14.0 months; HR 2.67; 95% CI, 0.87-8.20; log-rank P Z 0.087). Forty-four percent of patients who received prior abi/enza completed all 6 planned injections vs. 55% of those that did not. There were differences seen in the baseline characteristics of these two groups: mean PSA 272 vs. 114 mcg/L, and proportion with 20 metastases 64% vs. 44%, respectively. Cumulative incidence of grade 3 hematologic toxicity during or after treatment was as follows: anemia 19%, neutropenia 0%, and thrombocytopenia 11%. Conclusion: This cohort of patients receiving Ra-223 spans the era prior to the advent of abi and enza and thus included patients with and without prior exposure to these agents. Patients receiving these agents prior to commencing Ra-223 were less likely to complete the 6 planned injections, and had a non-significant trend toward shorter survival, raising the hypothesis that earlier integration of Ra-223 in the mCRPC disease course may be preferred. This apparent association may reflect greater disease burden in more heavily pre-treated patients, rather than diminished efficacy of Ra-223. Finally, the toxicity profile of Ra-223 observed in this realworld setting was relatively favorable and comparable to that seen in the phase III trial that led to regulatory approval. Author Disclosure: A. Bang: None. S. Malone: Independent Contractor; The Ottawa Hospital. E.Y. Leung: Independent Contractor; The Ottawa Hospital. C. Canil: Independent Contractor; The Ottawa Hospital. L. Eapen: Independent Contractor; The Ottawa Hospital. S.C. Morgan: Independent Contractor; The Ottawa Hospital.
2634 Stereotactic Body Radiation Therapy to the Prostate: Patterns of Care in the National Cancer Data Base J.P. Weiner,1,2 D. Schwartz,1,2 M. Shao,1,2 V. Osborn,1,2 and D. Schreiber1,2; 1SUNY Downstate Medical Center, Brooklyn, NY, 2 Veterans Affairs NY Harbor Healthcare System, Brooklyn, NY Purpose/Objective(s): To analyze the utilization and patterns of care of stereotactic body radiation therapy (SBRT) in the treatment of prostate cancer. Materials/Methods: Men who were diagnosed with localized prostate cancer between 2004 and 2012 and treated with radiation therapy were included. Men were categorized as receiving external beam radiation, prostate brachytherapy, or SBRT to the prostate or pelvis. Descriptive statistics were used to analyze stereotactic radiation therapy usage and compared via Chi Square or Fisher’s Exact Test. Results: There were 299,186 patients identified, of which 5,078 (1.7%) were identified as receiving SBRT. Of those, 2,108 had low risk disease (41.5%), 2,251 had intermediate risk disease (44.3%) and 719 had high risk disease (14.2%). The relative utilization of SBRT increased from 0.1% in 2004 to 4.0% in 2012 (P<0.001). The relative utilization over time increased more rapidly in academic programs from 0.1% in 2004 to 7.1% of all patients receiving radiation in 2012 (P<0.001). In non-academic programs, there was a slower increase in utilization from 0.1% in 2004 to 2.6% in 2012. The most commonly utilized fractionation scheme included
5 fractions in 4,635 patients (91.3%), with 725 cGy x 5 the most common fractionation scheme (49.6%) followed by 700 cGy x 5 (21.3%). Doses of 750 cGy per day were more commonly utilized in non-academic centers (32.3%) compared to academic centers (26.1%). Conclusion: SBRT is slowly increasing acceptance, but more so in academic facilities. 700-725 cGy x 5 fractions appears to be the most commonly utilized fractionation scheme. As further long-term data regarding the safety and efficacy emerges, the relative utilization of SBRT is expected to continue to increase. Author Disclosure: J.P. Weiner: None. D. Schwartz: None. M. Shao: None. V. Osborn: None. D. Schreiber: None.
2635 Vector Analysis of Bladder Cancer Patient Setup Utilizing a Magnetic Resonance Image Guided Radiation Therapy (MR-IGRT) System B.W. Fischer-Valuck, O.L. Green, S. Mutic, H.A. Gay, and J.M. Michalski; Washington University School of Medicine, St. Louis, MO Purpose/Objective(s): Inter and intra-fraction anatomy changes in patients undergoing radiation therapy (RT) for bladder cancer (BC) are common but have thus far been studied with implanted fiducial markers, limited quality 2-D orthogonal films and computed tomography (CT). The adverse impact of daily set-up variation could be more significant than appreciated. Our goal was to employ the soft tissue imaging capabilities of an integrated magnetic resonance image-guided RT (MR-IGRT) system to analyze daily positioning. Materials/Methods: Fourteen patients with BC were treated on a MRIGRT system. Patient setup was performed via volumetric MR imaging with a resolution of 0.15 x 0.15 cm. Alignment was performed according to skin marks then shifts assessed by comparing the treatment volume from the planning CT to the daily MR image. Two hundred forty pretreatment MR images were analyzed and 3 shifts were recorded for each image. A vector shift was calculated by combining the square root of the combined sum of the shifts squared. Number of times that the vector of combined shifts would have exceeded the planning tumor volume (PTV) was recorded. Results: The daily volumetric MR imaging allowed for accurate alignment and daily monitoring of bladder volume and normal tissue anatomy. Recorded shifts of the treated volume were 0.90.5 cm in the right/left direction, 0.70.3 cm in the anterior/posterior direction, and 0.70.4 cm in the cranio-caudal direction. In 66 (28%) of cases the vector shift was initially greater than the PTV margin. For 2 patients, pre-treatment MR imaging revealed the tumor reduced in size and dose to the bowel would have exceeded constraints, and treatment adaptation was performed to reduce normal tissue toxicity. Using CTCAE criteria, no grade 3 or higher toxicities have been reported. Conclusion: Accurate and reproducible treatment delivery is required to avoid marginal misses to the target volume as well as excess dose to normal tissue. MR-IGRT allows for excellent soft tissue visualization which enables for the avoidance of potential setups errors by allowing daily alignment changes to ensure the target is included in the PTV. It also allows the ability to make treatment changes based on anatomy variations. Author Disclosure: B.W. Fischer-Valuck: None. O.L. Green: Honoraria; ViewRay. S. Mutic: Research Grant; ViewRay. Honoraria; ViewRay. Consultant; ViewRay. Advisory Board; ViewRay. Travel Expenses; ViewRay. Stock; ViewRay. Royalty; ViewRay. H.A. Gay: None. J.M. Michalski: None.
2636 The Effect of Lovastatin on Preservation of Erectile Function After Radiation Therapy (RT) for Prostate Cancer: Secondary Analysis of a Prospective Study M.S. Anscher,1 M.G. Chang,2 D. Moghanaki,3 M. Rosu,4 R.B. Mikkelsen,4 D. Holdford,5 V. Skinner,6 B.M. Grob,1 A. Sanyal,1