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Dose-volumetric Analysis of Radiation-induced Gastroduodenal Toxicity in Unresectable Hepatocellular Carcinoma Patients Treated with Three-dimensional Conformal Radiotherapy
Proceedings of the 50th Annual ASTRO Meeting Materials/Methods: All patients aged . or = 70 year with rectal cancer who underwent preoperative RT combined with oral UFUR plus LV at the Taipei Veterans General Hospital between 5/2000 and 8/2005 were retrospectively reviewed. Patients who were proved rectal adenocarcinoma (clinical staged T2-4N0-2M0) received pelvic RT of 45 Gy in 20 fractions over 28 days and concurrent chemotherapy consisting of oral tegafur-uracil (UFUR) (200 mg/m2/day) plus leucovorin (LV) (45 mg/ day) on Day 1-28. The UFUR (250 mg/m2/day) and LV were continued on day 36-63. Surgery was performed on day 70. Response, recurrence, and toxicity data were recorded. Survival was determined by using the Kaplan-Meier method. Results: Of 134 patients with rectal cancer who underwent preoperative RT combined with oral UFUR plus LV, 56 (41.8%) patients aged . or = 70 years and comprised our study population (43 male, 13 female; median age 75 years). Of these elderly patients, 54 (96.4%) patients completed the concurrent chemoradiotherapy (5 with reduced dose). Acute toxicities were as follows: for Grade 1-2, GI = 87.5%, GU = 42.9%, skin = 42.9%, and hematologic = 33.9%; for Grade 3-4, GI = 3.6% and GU = 1.8%. Fortysix patients received curative or palliative surgery. Among the 39 patients receiving curative resection, downstaging occurred in 29 (66.7%), pathological complete response in 11 (28.2%), and sphincter preservation in 19 (48.7%) with lower-seated tumors. The 3year overall survival was 66.3% and 3-year disease-free survival was 56.1%. Conclusions: Oral UFUR with LV administered with preoperative RT are effective in tumor downstaging, pathological complete response, and sphincter preservation with tolerable toxicity in elderly patients with rectal cancer. Author Disclosure: Y. Lin, None; L. Wang, None; S. Yang, None; J. Lin, None; T. Lin, None; W. Chen, None; H. Wang, None; J. Jiang, None; Y. Chao, None; S. Yen, None.
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Volumetric Image Guidance: Does Routine Usage Prompt Adaptive Re-planning
J. A. Tanyi, W. D. D’Souza, M. Fuss Oregon Health and Science University, Portland, OR Purpose/Objective(s): To investigate how the use of volumetric image-guidance using an on-board cone-beam CT system impacts on the frequency of adaptive re-planning. Materials/Methods: Since July 2008, 146 patients have undergone a course of external beam radiation therapy using volumetric CBCT image-guidance. Targets were located in the brain, head and neck, chest, abdomen, and pelvis (non prostate). The majority of patients (57.5%) were treated with a hypo-fractionated treatment regimen. The frequency of image-guidance ranged from daily to once weekly (87.7% daily image-guidance, remainder weekly or twice weekly). We assessed with which frequency adaptive replanning was conducted and the assessed medical need for re-planning. Scheduled boost planning was not considered in this analysis, even when an adjustment would have been justified by review of CBCT. Results: In the population studied, radiation plans of 34 patients (23.3%) were adapted at least once (up to 6 times) during their course of EBRT as a result of image-guidance CBCT review. Most common causes for adaptive planning were: tumor change (mostly shrinkage; 10 patients; 4 patients more than 1 plan change), change in abdominal girth (systematic change in hollow organ filling; n = 7, 2 patients more than 1 change), weight loss (n = 5), and systematic setup deviation from simulation (n = 5). Adaptive plan change was required mostly for conventionally fractionated courses, only 5 patient plans undergoing hypo-fractionated treatment were adjusted. We will document significant consequences of changed anatomy on prescribed dosimetry. In over 91% of adapted plans, the dosimetry did deviate from the prescribed plan dose by more than 5% for at least 10% of the target volume, or organs-at-risk in close proximity to the target volume. Exemplary cases of tumor change, organ filling change, as well as weight loss will be presented along with unusual adaptive scenarios (massive intestinal contrast accumulation following radiology exam, unexpected tumor location change). Conclusions: Routine use of volumetric image-guidance has, in our practice, increased the demand for adaptive re-planning. The CBCT image-guidance provides sufficient imaging information to reliably predict the need for dose adjustment, as in almost all cases studied, the initial and adapted dosimetry differed from each other to a degree that was considered clinically significant. Author Disclosure: J.A. Tanyi, None; W.D. D’Souza, None; M. Fuss, None.
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Dose-volumetric Analysis of Radiation-induced Gastroduodenal Toxicity in Unresectable Hepatocellular Carcinoma Patients Treated with Three-dimensional Conformal Radiotherapy
H. Kim1, L. Do Hoon1, P. Seung Woon2, B. Yoo2, K. Koh2, J. Lee2, M. Choi2, W. Park1, S. Huh1, Y. Ahn1 1 Department of Radiation Oncology, Seoul, Republic of Korea, 2Department of Medicine, Seoul, Republic of Korea Purpose/Objective(s): To identify the dosimetric parameters that correlate with the risk of radiation-induced gastroduodenal toxicity (RIGDT) after three-dimensional conformal radiotherapy (3D-CRT) for patients with unresectable hepatocellular carcinoma (HCC). Materials/Methods: We retrospectively analyzed dose-volume histograms (DVHs) and clinical records of 81 HCC patients treated with 3D-CRT with a daily dose of 3 Gy. The median radiation dose was 36 Gy and the grade of RIGDT was defined by modifying the gastritis toxicity from the Common Toxicity Criteria. The evaluated dosimetric parameters were the mean, maximum, and minimum doses given to the gastroduodenum (GD) and the percentage of GD volume receiving more than 5, 10, 15, 20, 25, 30, and 35 Gy. To obtain a predictive value for Grade 3 RIGDT, receiver operating characteristic curves (ROC) were used. Results: Grade 2 and 3 RIGDT developed in 30 patients (37.0%) and 9 patients (11.1%), respectively. All of the parameters except the maximum and minimum doses significantly affected the development of Grade 3 toxicity. By ROC analysis, V30 and V35 were the best predictors for Grade 3 toxicity, and the optimal cut-off values were 12% and 5%, respectively. Conclusions: There was a dose-volume relationship in the development of RIGDT and administration of less radiation to a smaller GD volume may be the best way to prevent RIGDT. Author Disclosure: H. Kim, None; L. Do Hoon, None; P. Seung Woon, None; B. Yoo, None; K. Koh, None; J. Lee, None; M. Choi, None; W. Park, None; S. Huh, None; Y. Ahn, None.
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Volumetric Image Guidance: Does Routine Usage Prompt Adaptive Re-planning
J. A. Tanyi, W. D. D’Souza, M. Fuss Oregon Health and Science University, Portland, OR Purpose/Objective(s): To investigate how the use of volumetric image-guidance using an on-board cone-beam CT system impacts on the frequency of adaptive re-planning. Materials/Methods: Since July 2008, 146 patients have undergone a course of external beam radiation therapy using volumetric CBCT image-guidance. Targets were located in the brain, head and neck, chest, abdomen, and pelvis (non prostate). The majority of patients (57.5%) were treated with a hypo-fractionated treatment regimen. The frequency of image-guidance ranged from daily to once weekly (87.7% daily image-guidance, remainder weekly or twice weekly). We assessed with which frequency adaptive replanning was conducted and the assessed medical need for re-planning. Scheduled boost planning was not considered in this analysis, even when an adjustment would have been justified by review of CBCT. Results: In the population studied, radiation plans of 34 patients (23.3%) were adapted at least once (up to 6 times) during their course of EBRT as a result of image-guidance CBCT review. Most common causes for adaptive planning were: tumor change (mostly shrinkage; 10 patients; 4 patients more than 1 plan change), change in abdominal girth (systematic change in hollow organ filling; n = 7, 2 patients more than 1 change), weight loss (n = 5), and systematic setup deviation from simulation (n = 5). Adaptive plan change was required mostly for conventionally fractionated courses, only 5 patient plans undergoing hypo-fractionated treatment were adjusted. We will document significant consequences of changed anatomy on prescribed dosimetry. In over 91% of adapted plans, the dosimetry did deviate from the prescribed plan dose by more than 5% for at least 10% of the target volume, or organs-at-risk in close proximity to the target volume. Exemplary cases of tumor change, organ filling change, as well as weight loss will be presented along with unusual adaptive scenarios (massive intestinal contrast accumulation following radiology exam, unexpected tumor location change). Conclusions: Routine use of volumetric image-guidance has, in our practice, increased the demand for adaptive re-planning. The CBCT image-guidance provides sufficient imaging information to reliably predict the need for dose adjustment, as in almost all cases studied, the initial and adapted dosimetry differed from each other to a degree that was considered clinically significant. Author Disclosure: J.A. Tanyi, None; W.D. D’Souza, None; M. Fuss, None.
2251
Dose-volumetric Analysis of Radiation-induced Gastroduodenal Toxicity in Unresectable Hepatocellular Carcinoma Patients Treated with Three-dimensional Conformal Radiotherapy
H. Kim1, L. Do Hoon1, P. Seung Woon2, B. Yoo2, K. Koh2, J. Lee2, M. Choi2, W. Park1, S. Huh1, Y. Ahn1 1 Department of Radiation Oncology, Seoul, Republic of Korea, 2Department of Medicine, Seoul, Republic of Korea Purpose/Objective(s): To identify the dosimetric parameters that correlate with the risk of radiation-induced gastroduodenal toxicity (RIGDT) after three-dimensional conformal radiotherapy (3D-CRT) for patients with unresectable hepatocellular carcinoma (HCC). Materials/Methods: We retrospectively analyzed dose-volume histograms (DVHs) and clinical records of 81 HCC patients treated with 3D-CRT with a daily dose of 3 Gy. The median radiation dose was 36 Gy and the grade of RIGDT was defined by modifying the gastritis toxicity from the Common Toxicity Criteria. The evaluated dosimetric parameters were the mean, maximum, and minimum doses given to the gastroduodenum (GD) and the percentage of GD volume receiving more than 5, 10, 15, 20, 25, 30, and 35 Gy. To obtain a predictive value for Grade 3 RIGDT, receiver operating characteristic curves (ROC) were used. Results: Grade 2 and 3 RIGDT developed in 30 patients (37.0%) and 9 patients (11.1%), respectively. All of the parameters except the maximum and minimum doses significantly affected the development of Grade 3 toxicity. By ROC analysis, V30 and V35 were the best predictors for Grade 3 toxicity, and the optimal cut-off values were 12% and 5%, respectively. Conclusions: There was a dose-volume relationship in the development of RIGDT and administration of less radiation to a smaller GD volume may be the best way to prevent RIGDT. Author Disclosure: H. Kim, None; L. Do Hoon, None; P. Seung Woon, None; B. Yoo, None; K. Koh, None; J. Lee, None; M. Choi, None; W. Park, None; S. Huh, None; Y. Ahn, None.
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