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EP-1276: First implementation of intensity-modulated dynamic tumor-tracking RT in pancreatic cancer using a gimbaled linac
S80 observed. Univariate analysis showed a significant impact on OS only for Performance Status (p<0,005) Conclusions: After radical curative surgery for locally advanced pancreatic cancer, the combination of weekly GEM and RT is well tolerated and is associated with a low incidence of local recurrence EP-1276 First implementation of intensity-modulated dynamic tumor-tracking RT in pancreatic cancer using a gimbaled linac A. Nakamura1, T. Mizowaki1, S. Itasaka1, M. Nakamura1, Y. Ishihara1, N. Mukumoto1, M. Akimoto1, Y. Matsuo1, M. Kokubo2, M. Hiraoka1 1 Kyoto University Graduate School of Medicine, Radiation Oncology and Image-applied Therapy, Kyoto, Japan 2 Kobe City Medical Center General Hospital, Radiation Oncology, Kobe, Japan Purpose/Objective: We have developed and started intensity-modulated dynamic tumor-tracking radiotherapy (IM-DTRT) under real-time monitoring using the gimbaled linac of Vero4DRT in June 2013. This study reports the first experience in the world with IM-DTRT for patients with locally-advanced pancreatic cancer (LAPC) and evaluates the initial outcomes, treatment accuracy, and versatility. Materials and Methods: From June 2013, three patients with histologically proven LAPC and written informed consent were enrolled in this study. One Visicoil fiducial marker was percutaneously implanted inside or close to the tumor. IM-DTRT was performed with the gimbaled X-ray head which can swing the intensity-modulated beam towards the predicted tumor position based on the abdominal IR marker and a correlation model of external-to-internal motion. During the beam delivery, the Visicoil was continually monitored with the kV and MV imagers mounted on the gantry of the Vero4DRT, and a recalibration of the correlation model was done if needed. A total of 45 to 48 Gy were delivered to PTV boost in 15 fractions concurrently with once-weekly full-dose (1,000 mg/m2) gemcitabine. The following factors were evaluated: the differences in the volume of PTV and the absolute volume receiving 39Gy or 42Gy (V39 or V42) for stomach and duodenum between IM-DTRT and a conventional technique; the amplitudes of tumor motion during the IM-DTRT; the positional errors between the predicted tumor and irradiated positions; the in-room time for the daily treatment; and the treatment completion rate and the radiotherapy-induced acute toxicities. Results: The mean reduction in PTV volume was 16%. The planned V39/V42 to stomach and duodenum were reduced approximately by 90%/94% and 63%/71%, respectively, when compared with a conventional 4-field technique, while tumor doses were comparable. The mean daily peak-to-peak tumor motion along with the cranio-caudal direction was 11.2 mm (range, 7.3-25.8 mm). The 95th percentiles of positional errors were within 1.9, 2.8, and 3.2 mm in left-right, anterior-posterior, and cranio-caudal directions, respectively. The mean in-room time was 24.5 minutes. All patients completed the planned radiotherapy and concurrent gemcitabine. There were mild hematological toxicities relating to the concurrent chemotherapy, but no acute toxicities directly attributable to the IM-DTRT. Conclusions: IM-DTRT was safely and successfully implemented with the high accuracy and reasonable treatment time for patients with LAPC. Future studies are warranted to evaluate the treatment efficacy and tolerability. EP-1277 Downstaging of rectal cancer by long term preoperative chemoradiotherapy A. Masarykova1, D. Scepanovic1, M. Lukacovicova1, A. Hurakova1, M. Pobijakova1, Z. Dolinska1 1 National Oncology Institute, Radiation Oncology, Bratislava, Slovakia Purpose/Objective: Background. - Preoperative chemoradiotherapy provides a significant benefit in the local control of rectal cancer. Postchemoradiotherapy downstaging from cStage II-III to ypStage 0-I indicates a favorable prognosis. Purpose - To show how long term preoperative chemoradiotherapy had effect on downstaging of rectal cancer in our patients. Materials and Methods: Between 2004 and 2010, 250 patients with resectable cT1-4cN0-positive lymph nodes (+) rectal carcinoma without sphincters' infiltration have been analyzed. All patients performed classically fractionated preoperative chemoradiation (1.8Gy x 25-28 fractions with 5-fluorouracil or capecitabine) with subsequent total mesorectal excision (TME) (118 patients) or preoperative chemoradiation with a same dose and drugs followed by non TME (132 patients), both
ESTRO 33, 2014 performed 6 weeks after finish of the preoperative chemoradiotherapy. Of the 250 patients there were 1 patient with cT1, 9 patients (pts) with cT2, 60 pts with cT3, 12 pts with cT4, 11pts with cT2cN+, 138 pts with cT3cN+ and 19 patients with cT4cN+ stage of the disease. Results: After long term preoperative chemoradiotherapy and surgery, there were 33 pts with pT0, 18 pts with pT1, 85 pts with pT2, 37 pts with pT3, 2 pts with pT4 and 75 pts with pT(any)pN+. A patient with cT1 remained with no change of the stage. However, 33% of pts with initially cT2 stage of the disease, 57% with cT3 and 50% with cT4 achieved downstaging of the disease. A significant change occurred in patients with cT(any)cN+ initially stage of the disease. Ninety one percent of pts with cT2cN+, 83% with cT3cN+ and 100% with cT4cN+ reached downstaging of the disease. Among patients who reached downstaging 6 of them had and 150 had not local recurrence (p=0.0208). However, there was no statistically significant difference in survival between patients who reached downstaging and who did not (p=0.2710). Conclusions: The long term preoperative chemoradiotherapy had a big impact on downstaging in our patients. Downstaging had upward trend at higher initial stage of disease, especially cT3-4 and cT(any)cN+. From our results we assumed that the lower stage of the disease should have benefit from short course of radiotherapy where it is not necessary to achieve the downstaging. Our patients who reached downstaging by long term chemoradiotherapy had better local control without difference in survival. EP-1278 Radiation therapy for biliary tract tumors: Joint experience of three centers M.S. Karabey1, E. Yirmibesoglu Erkal1, A. Yolcu2, B.H. Bakkal3, O. Ay1, B. Sarper1, G. Aksu1, H.S. Erkal4 1 Kocaeli University Faculty of Medicine, Radiation Oncology, Kocaeli, Turkey 2 Selçuk University Faculty of Medicine, Radiation Oncology, Konya, Turkey 3 Bülent Ecevit University Faculty of Medicine, Radiaition Oncology, Zonguldak, Turkey 4 Sakarya University Faculty of Medicine, Radiaition Oncology, Sakarya, Turkey Purpose/Objective: In patients with biliary tract tumors, radiation therapy might be indicated as an adjuvant measure for those undergoing a curative resection or as a palliative measure for those deemed inoperable. This study presents the joint experience of three centers in the treatment of patients with biliary tract tumors with radiation therapy. Materials and Methods: Medical records of 27 patients, treated with radiation therapy from July 2007 through June 2013, were retrospectively reviewed. There were 14 males and 13 females. Their ages ranged from 46 to 86 years (median, 62 years). Tumor location was the extrahepatic biliary tract in 14 patients, the intrahepatic biliary tract in 4 patients and the perihilar region in 9 patients. A tissue diagnosis of adenocarcinoma was obtained in 19 patients through an invasive or surgical intervention prior to the management approach. A curative resection was performed for 16 patients, 11 of whom had microscopically involved surgical margins on histopathological analysis. All patients who had undergone a curative resection received postoperative radiation therapy with curative intent, whereas the remaining patients received radiation therapy with palliative intent. The target volume included the tumor bed and the regional lymph nodes in 20 patients and, additionally, the paraaortic lymph nodes in 7 patients. Radiation therapy doses ranged from 45 to 60 Gy (median, 50.4 Gy). Twenty patients with adequate performance status were treated with radiation therapy and chemotherapy, while the remaining 7 patients were treated with radiation therapy alone. Results: Follow-up ranged from 1 to 44 months (median, 17 months). Local control was not achieved in 10 out of 11 patients who received radiation therapy with palliative intent. Local recurrence was observed in 5 out of 16 patients who received radiation therapy with curative intent at 4 to 23 months (median, 7 months). Eight patients developed distant metastases at 5 to 16 months (median, 8 months). Fifteen patients died due to disease-related causes at 1 to 22 months (median, 9 months). At 2 years, overall survival probability was 33%, local failurefree survival probability was 33%, distant metastases-free survival probability was 57% and disease-free survival probability was 19%. A curative resection predicted improved local failure-free survival probability and improved disease-free survival on both univariate and multivariate analysis, whereas an extended radiation therapy target volume predicted improved local failure-free survival probability on univariate analysis.
ESTRO 33, 2014 performed 6 weeks after finish of the preoperative chemoradiotherapy. Of the 250 patients there were 1 patient with cT1, 9 patients (pts) with cT2, 60 pts with cT3, 12 pts with cT4, 11pts with cT2cN+, 138 pts with cT3cN+ and 19 patients with cT4cN+ stage of the disease. Results: After long term preoperative chemoradiotherapy and surgery, there were 33 pts with pT0, 18 pts with pT1, 85 pts with pT2, 37 pts with pT3, 2 pts with pT4 and 75 pts with pT(any)pN+. A patient with cT1 remained with no change of the stage. However, 33% of pts with initially cT2 stage of the disease, 57% with cT3 and 50% with cT4 achieved downstaging of the disease. A significant change occurred in patients with cT(any)cN+ initially stage of the disease. Ninety one percent of pts with cT2cN+, 83% with cT3cN+ and 100% with cT4cN+ reached downstaging of the disease. Among patients who reached downstaging 6 of them had and 150 had not local recurrence (p=0.0208). However, there was no statistically significant difference in survival between patients who reached downstaging and who did not (p=0.2710). Conclusions: The long term preoperative chemoradiotherapy had a big impact on downstaging in our patients. Downstaging had upward trend at higher initial stage of disease, especially cT3-4 and cT(any)cN+. From our results we assumed that the lower stage of the disease should have benefit from short course of radiotherapy where it is not necessary to achieve the downstaging. Our patients who reached downstaging by long term chemoradiotherapy had better local control without difference in survival. EP-1278 Radiation therapy for biliary tract tumors: Joint experience of three centers M.S. Karabey1, E. Yirmibesoglu Erkal1, A. Yolcu2, B.H. Bakkal3, O. Ay1, B. Sarper1, G. Aksu1, H.S. Erkal4 1 Kocaeli University Faculty of Medicine, Radiation Oncology, Kocaeli, Turkey 2 Selçuk University Faculty of Medicine, Radiation Oncology, Konya, Turkey 3 Bülent Ecevit University Faculty of Medicine, Radiaition Oncology, Zonguldak, Turkey 4 Sakarya University Faculty of Medicine, Radiaition Oncology, Sakarya, Turkey Purpose/Objective: In patients with biliary tract tumors, radiation therapy might be indicated as an adjuvant measure for those undergoing a curative resection or as a palliative measure for those deemed inoperable. This study presents the joint experience of three centers in the treatment of patients with biliary tract tumors with radiation therapy. Materials and Methods: Medical records of 27 patients, treated with radiation therapy from July 2007 through June 2013, were retrospectively reviewed. There were 14 males and 13 females. Their ages ranged from 46 to 86 years (median, 62 years). Tumor location was the extrahepatic biliary tract in 14 patients, the intrahepatic biliary tract in 4 patients and the perihilar region in 9 patients. A tissue diagnosis of adenocarcinoma was obtained in 19 patients through an invasive or surgical intervention prior to the management approach. A curative resection was performed for 16 patients, 11 of whom had microscopically involved surgical margins on histopathological analysis. All patients who had undergone a curative resection received postoperative radiation therapy with curative intent, whereas the remaining patients received radiation therapy with palliative intent. The target volume included the tumor bed and the regional lymph nodes in 20 patients and, additionally, the paraaortic lymph nodes in 7 patients. Radiation therapy doses ranged from 45 to 60 Gy (median, 50.4 Gy). Twenty patients with adequate performance status were treated with radiation therapy and chemotherapy, while the remaining 7 patients were treated with radiation therapy alone. Results: Follow-up ranged from 1 to 44 months (median, 17 months). Local control was not achieved in 10 out of 11 patients who received radiation therapy with palliative intent. Local recurrence was observed in 5 out of 16 patients who received radiation therapy with curative intent at 4 to 23 months (median, 7 months). Eight patients developed distant metastases at 5 to 16 months (median, 8 months). Fifteen patients died due to disease-related causes at 1 to 22 months (median, 9 months). At 2 years, overall survival probability was 33%, local failurefree survival probability was 33%, distant metastases-free survival probability was 57% and disease-free survival probability was 19%. A curative resection predicted improved local failure-free survival probability and improved disease-free survival on both univariate and multivariate analysis, whereas an extended radiation therapy target volume predicted improved local failure-free survival probability on univariate analysis.