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Stereotactic Body Radiation for Pancreatic Cancer: Results of an International Survey of Practice Patterns
E132
International Journal of Radiation Oncology Biology Physics
serial endoscopy and/or imaging studies. Overall survival (OS) and local control (LC) rates were calculated by the Kaplan-Meier method. Toxicities were evaluated by the Common Terminology Criteria for Adverse Events version 4.0. Results: For all 78 patients, the 3-year LC and OS rates were 62% and 26%, respectively; they were 100% and 100%, respectively, in Group 1, and 76% and 40%, respectively, in Group 2. The 2-year LC and OS were 63% and 15%, respectively, in Group 3, and 62% and 16%, respectively, in Group 4. Overall response rate was 76% (complete response in 28 and partial response in 31). Grade 3 or higher acute toxicities, mainly hematological, were observed in 45% of the patients and 10% experienced grade 3-4 late toxicities. Conclusion: CRT with standard FP and 60-70 Gy of radiation appears to be tolerable for patients with esophageal cancer. Although outcome of this treatment in inoperable patients is not satisfactory, the 3-year LC of 100% for stage I patients and 76% for stage II-III operable patients appear promising. Further investigation is warranted to clarify the optimal radiation dose in CRT for esophageal cancer. Author Disclosure: T. Kondo: None. Y. Shibamoto: None. A. Hayashi: None. T. Takaoka: None. T. Murai: None. A. Miyakawa: None. C. Sugie: None. T. Yanagi: None. M. Matsuo: None.
after accounting for tumor burden and CTP score. Our results suggest that HCC patients with left-sided lesions may benefit from a modified therapeutic approach. Author Disclosure: K.A. Plichta: None. S.K. Bhatia: None. M.W. Karwal: None. A. Reed: None. J. Buatti: None.
2334 Outcomes of Hepatocellular Carcinoma Treated With SBRT: Does Lesion Location Matter? K.A. Plichta, S.K. Bhatia, M.W. Karwal, A. Reed, and J. Buatti; University of Iowa Hospitals and Clinics, Iowa City, IA Purpose/Objective(s): We evaluated the impact of location of hepatocellular carcinoma (HCC) on overall survival (OS) in patients who received liver stereotactic body radiation therapy (SBRT). Materials/Methods: We identified 67 patients with HCC who received SBRT at our institution between 2003 and 2014. Inclusion criteria were a radiographic or pathologic diagnosis of HCC and a minimum of one year follow-up (or death prior to one year). Of the 67 total patients, 60 received trans-arterial chemoembolization (TACE) prior to SBRT, 7 received transplants after TACE+ SBRT, and 7 received SBRT as single modality treatment. Child-Turcotte-Pugh (CTP) and model for end-stage liver disease (MELD) scores were recorded. Cross-sectional imaging (MRI and/or CT scans) were reviewed for lesion location and size. Lesion location was classified as left (segments II, III, IV), right (segments V, VI, VII, VIII) or both/caudate. As a measure of overall tumor burden, maximum lesion diameter (which was additive in the case of multiple lesions) was recorded. Kaplan-Meier analyses with log rank tests were performed to evaluate OS. A predictive model was then built using Cox proportional hazards regression. Results: Of the 67 total patients, 46 were CTP A, 19 were CTP B, 1 was CTP C, and 1 had unknown CTP status. Overall survival was increased among CTP A patients in comparison to CTP B/C (median survival 32 .1 months vs 23.6 months, pZ0.002). A significant cut-off value was not identified for MELD scores. For tumor burden, a cutoff value was identified at 2.05cm using ROC analysis. Tumor burden <2.05cm resulted in significantly higher OS (69.2 months vs 23.6 months, pZ0.001). In terms of lesion location, 15 patients had left-sided lesions, 42 patients had right-sided lesions and 10 patients had lesions in both/ caudate. OS among the three groups was significant (median survival left: 17.7 months, right: 39.4 months, and both: 16.2 months, pZ0.001), and a significant difference in OS between patients with left versus right-sided lesions was found (p <0.0005). On multivariate analysis, CTP, tumor burden and lesion location remained significant (p-values 0.039 for CTP, 0.049 for tumor burden, and 0.011 for left versus right). Hazard ratios were 1.960 for CTP score (CI 1.035 to 3.709), 0.410 for left versus right lesion location (CI 0.205 to 0.818), and 2.282 for tumor burden (CI 1.004 to 5.186). Conclusion: HCC lesions located in the right side of the liver were associated with better overall survival in patients who received SBRT inclusive of patients who had subsequent transplant. This association persisted, even
2335 Stereotactic Body Radiation for Pancreatic Cancer: Results of an International Survey of Practice Patterns A. Parekh,1 L.M. Rosati,2 D.T. Chang,3 K.A. Goodman,4 A.C. Koong,5 and J.M. Herman6; 1Department of Radiation Oncology, Johns Hopkins Hospital, Baltimore, MD, 2Johns Hopkins University School of Medicine, Baltimore, MD, 3Stanford Cancer Institute, Stanford, CA, 4Memorial Sloan Kettering Cancer Center, New York, NY, 5Stanford University, Stanford, CA, 6Johns Hopkins Hospital, Baltimore, MD Purpose/Objective(s): Stereotactic body radiation therapy (SBRT) is an emerging treatment option for locally advanced and unresectable pancreatic cancer (PCA), with early studies showing promising results. SBRT significantly decreases the duration of treatment allowing for more rapid initiation of systemic chemotherapy or surgical management. However, no standardized guidelines for treatment exist and patterns of SBRT use for PCA are unclear. Here we report the results of an international survey of practice patterns of SBRT for PCA among radiation oncologists. Materials/Methods: Thirty-four academic radiation oncologists from the United States, Europe and Canada known to use SBRT in the setting of PCA were invited to complete a 26-item Web-based survey on practice patterns. Questions focused on decision-making processes, treatment management, and radiation therapy practice environment. Data were analyzed anonymously. Results: Twenty-eight of the 34 (82.3%) invited radiation oncologists completed the survey. Of the responders, 85.7% treat with 6-8 Gy x 5 fractions and 14.3% with 10-15 Gy x 3 fractions. 85.2% of physicians also prefer SBRT over intensity-modulated (IMRT) or 3D conformal (3D CRT) radiation therapy. The majority (92.9%) of responders use four-dimensional computed tomography (4D-CT) for simulation, with 48% using gating to account for breathing motion. Two-thirds of radiation oncologists use fiducials for tumor localization. Improvement in pain after SBRT is observed among 81.5% of responders. Approximately 55.5% report difficulty obtaining insurance clearance for pancreas SBRT in the absence of a clinical trial. The majority (96.3%) report using Linac-based radiation for treatment. The most significant variations in practice were related to gross tumor volume (GTV) to planning target volume (PTV) expansions and management of respiratory motion. Conclusion: SBRT is increasingly used for PCA and has emerged as a viable treatment option for this disease. The data presented here indicate that the majority of radiation oncologists treat with 6-8 Gy x 5 fractions and use fiducials with 4D-CT simulation for localization and planning. Although the majority of treating physicians prefer SBRT to standard radiation, pancreas SBRT may be underutilized due to difficulty obtaining insurance approval off protocol. Our investigation documents current pancreas SBRT practice patterns and highlights the need for prospective clinical trials as a means to develop consensus guidelines for this emerging treatment. Author Disclosure: A. Parekh: None. L.M. Rosati: None. D.T. Chang: None. K.A. Goodman: None. A.C. Koong: None. J.M. Herman: Research Grant; Nucletron.
2336 Predictors of Survival in Yttrium-90 Radioembolization of Hepatic Malignancies With Resin Microspheres N.B. Newman,1 P.A. Ohman-Strickland,2 D. Carpizo,3 B. Benson,1 R.H. Gensure,1 C.A. Schonewolf,1 R.A. Moss,4 L. Melstrom,3 J.L. Nosher,5 and S.K. Jabbour6; 1Rutgers Cancer Institute of New Jersey Department of Radiation Oncology, New Brunswick, NJ, 2Rutgers School
International Journal of Radiation Oncology Biology Physics
serial endoscopy and/or imaging studies. Overall survival (OS) and local control (LC) rates were calculated by the Kaplan-Meier method. Toxicities were evaluated by the Common Terminology Criteria for Adverse Events version 4.0. Results: For all 78 patients, the 3-year LC and OS rates were 62% and 26%, respectively; they were 100% and 100%, respectively, in Group 1, and 76% and 40%, respectively, in Group 2. The 2-year LC and OS were 63% and 15%, respectively, in Group 3, and 62% and 16%, respectively, in Group 4. Overall response rate was 76% (complete response in 28 and partial response in 31). Grade 3 or higher acute toxicities, mainly hematological, were observed in 45% of the patients and 10% experienced grade 3-4 late toxicities. Conclusion: CRT with standard FP and 60-70 Gy of radiation appears to be tolerable for patients with esophageal cancer. Although outcome of this treatment in inoperable patients is not satisfactory, the 3-year LC of 100% for stage I patients and 76% for stage II-III operable patients appear promising. Further investigation is warranted to clarify the optimal radiation dose in CRT for esophageal cancer. Author Disclosure: T. Kondo: None. Y. Shibamoto: None. A. Hayashi: None. T. Takaoka: None. T. Murai: None. A. Miyakawa: None. C. Sugie: None. T. Yanagi: None. M. Matsuo: None.
after accounting for tumor burden and CTP score. Our results suggest that HCC patients with left-sided lesions may benefit from a modified therapeutic approach. Author Disclosure: K.A. Plichta: None. S.K. Bhatia: None. M.W. Karwal: None. A. Reed: None. J. Buatti: None.
2334 Outcomes of Hepatocellular Carcinoma Treated With SBRT: Does Lesion Location Matter? K.A. Plichta, S.K. Bhatia, M.W. Karwal, A. Reed, and J. Buatti; University of Iowa Hospitals and Clinics, Iowa City, IA Purpose/Objective(s): We evaluated the impact of location of hepatocellular carcinoma (HCC) on overall survival (OS) in patients who received liver stereotactic body radiation therapy (SBRT). Materials/Methods: We identified 67 patients with HCC who received SBRT at our institution between 2003 and 2014. Inclusion criteria were a radiographic or pathologic diagnosis of HCC and a minimum of one year follow-up (or death prior to one year). Of the 67 total patients, 60 received trans-arterial chemoembolization (TACE) prior to SBRT, 7 received transplants after TACE+ SBRT, and 7 received SBRT as single modality treatment. Child-Turcotte-Pugh (CTP) and model for end-stage liver disease (MELD) scores were recorded. Cross-sectional imaging (MRI and/or CT scans) were reviewed for lesion location and size. Lesion location was classified as left (segments II, III, IV), right (segments V, VI, VII, VIII) or both/caudate. As a measure of overall tumor burden, maximum lesion diameter (which was additive in the case of multiple lesions) was recorded. Kaplan-Meier analyses with log rank tests were performed to evaluate OS. A predictive model was then built using Cox proportional hazards regression. Results: Of the 67 total patients, 46 were CTP A, 19 were CTP B, 1 was CTP C, and 1 had unknown CTP status. Overall survival was increased among CTP A patients in comparison to CTP B/C (median survival 32 .1 months vs 23.6 months, pZ0.002). A significant cut-off value was not identified for MELD scores. For tumor burden, a cutoff value was identified at 2.05cm using ROC analysis. Tumor burden <2.05cm resulted in significantly higher OS (69.2 months vs 23.6 months, pZ0.001). In terms of lesion location, 15 patients had left-sided lesions, 42 patients had right-sided lesions and 10 patients had lesions in both/ caudate. OS among the three groups was significant (median survival left: 17.7 months, right: 39.4 months, and both: 16.2 months, pZ0.001), and a significant difference in OS between patients with left versus right-sided lesions was found (p <0.0005). On multivariate analysis, CTP, tumor burden and lesion location remained significant (p-values 0.039 for CTP, 0.049 for tumor burden, and 0.011 for left versus right). Hazard ratios were 1.960 for CTP score (CI 1.035 to 3.709), 0.410 for left versus right lesion location (CI 0.205 to 0.818), and 2.282 for tumor burden (CI 1.004 to 5.186). Conclusion: HCC lesions located in the right side of the liver were associated with better overall survival in patients who received SBRT inclusive of patients who had subsequent transplant. This association persisted, even
2335 Stereotactic Body Radiation for Pancreatic Cancer: Results of an International Survey of Practice Patterns A. Parekh,1 L.M. Rosati,2 D.T. Chang,3 K.A. Goodman,4 A.C. Koong,5 and J.M. Herman6; 1Department of Radiation Oncology, Johns Hopkins Hospital, Baltimore, MD, 2Johns Hopkins University School of Medicine, Baltimore, MD, 3Stanford Cancer Institute, Stanford, CA, 4Memorial Sloan Kettering Cancer Center, New York, NY, 5Stanford University, Stanford, CA, 6Johns Hopkins Hospital, Baltimore, MD Purpose/Objective(s): Stereotactic body radiation therapy (SBRT) is an emerging treatment option for locally advanced and unresectable pancreatic cancer (PCA), with early studies showing promising results. SBRT significantly decreases the duration of treatment allowing for more rapid initiation of systemic chemotherapy or surgical management. However, no standardized guidelines for treatment exist and patterns of SBRT use for PCA are unclear. Here we report the results of an international survey of practice patterns of SBRT for PCA among radiation oncologists. Materials/Methods: Thirty-four academic radiation oncologists from the United States, Europe and Canada known to use SBRT in the setting of PCA were invited to complete a 26-item Web-based survey on practice patterns. Questions focused on decision-making processes, treatment management, and radiation therapy practice environment. Data were analyzed anonymously. Results: Twenty-eight of the 34 (82.3%) invited radiation oncologists completed the survey. Of the responders, 85.7% treat with 6-8 Gy x 5 fractions and 14.3% with 10-15 Gy x 3 fractions. 85.2% of physicians also prefer SBRT over intensity-modulated (IMRT) or 3D conformal (3D CRT) radiation therapy. The majority (92.9%) of responders use four-dimensional computed tomography (4D-CT) for simulation, with 48% using gating to account for breathing motion. Two-thirds of radiation oncologists use fiducials for tumor localization. Improvement in pain after SBRT is observed among 81.5% of responders. Approximately 55.5% report difficulty obtaining insurance clearance for pancreas SBRT in the absence of a clinical trial. The majority (96.3%) report using Linac-based radiation for treatment. The most significant variations in practice were related to gross tumor volume (GTV) to planning target volume (PTV) expansions and management of respiratory motion. Conclusion: SBRT is increasingly used for PCA and has emerged as a viable treatment option for this disease. The data presented here indicate that the majority of radiation oncologists treat with 6-8 Gy x 5 fractions and use fiducials with 4D-CT simulation for localization and planning. Although the majority of treating physicians prefer SBRT to standard radiation, pancreas SBRT may be underutilized due to difficulty obtaining insurance approval off protocol. Our investigation documents current pancreas SBRT practice patterns and highlights the need for prospective clinical trials as a means to develop consensus guidelines for this emerging treatment. Author Disclosure: A. Parekh: None. L.M. Rosati: None. D.T. Chang: None. K.A. Goodman: None. A.C. Koong: None. J.M. Herman: Research Grant; Nucletron.
2336 Predictors of Survival in Yttrium-90 Radioembolization of Hepatic Malignancies With Resin Microspheres N.B. Newman,1 P.A. Ohman-Strickland,2 D. Carpizo,3 B. Benson,1 R.H. Gensure,1 C.A. Schonewolf,1 R.A. Moss,4 L. Melstrom,3 J.L. Nosher,5 and S.K. Jabbour6; 1Rutgers Cancer Institute of New Jersey Department of Radiation Oncology, New Brunswick, NJ, 2Rutgers School