C. Xie,1 X. Jin,2 and H. Su2; 1the First Affiliated Hospital of Wenzhou. Medical University, Wenzhou, China, 2the 1st Affiliated Hospital of. Wenzhou Medical ...
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Volume 96 Number 2S Supplement 2016 to estimate overall survival rate (OS), and the local control rate (LC). Treatment-related toxicity was scored according to the Common Terminology Criteria for Adverse Events v.4.0. Results: Between February 2013 and September 2015, 31 lesions in 30 patients were successfully treated. Median patient age was 75 years (range, 48e88). Twenty-three tumors were hepatocellular carcinomas (HCC) and eight were metastatic liver tumors. The median tumor diameter was 30 mm (range, 8e55). The delivered dose schedules were as follows: 40 Gy/5 fractions (fr) (n Z 4); 48 Gy/4 fr (n Z 15); 56 Gy/4 fr (n Z 3); 56 Gy/8 fr (n Z 5); and 60 Gy/8 fr (n Z 4). The median follow-up period was 14.4 months (range, 4.5e29.7). One-year OS and LC were 95.5% and 96.7%, respectively. Recurrences were observed in 14 patients (45%). Two patients (6%) had local recurrence and 14 (45%) developed distant metastases, including 11 who had new hepatic lesions outside of the irradiation field. No treatment-related toxicity of grade 4 or higher was observed. Grade 3 liver enzyme elevation was observed in one patient, and grade 2 biliary enzyme elevation was observed in two patients. Conclusion: Employing DTT-SBRT using a gimbal mounted Linac to treat liver tumors resulted in excellent OS and LC. This method has the potential to serve as an alternative treatment to the motion-encompassing SBRT for liver tumors. Author Disclosure: Y. Iizuka: None. Y. Matsuo: None. K. Takayama: None. N. Ueki: None. T. Mitsuyoshi: None. K. Ueki: None. H. Tanabe: None. M. Nakamura: None. T. Mizowaki: adviser; Mitsubishi Heavy Industries. M. Kokubo: Research Grant; Mitsubishi Heavy Industries. Consultant; Mitsubishi Heavy Industries. M. Hiraoka: None.
2363 Stereotactic Body Radiation Therapy (SBRT) Provides Excellent Local Control in the Treatment of Hilar and Intrahepatic Cholangiocarcinoma W.C. Jackson, L. Bazzi, E. Sapir, T.S. Lawrence, and M. Feng; University of Michigan, Ann Arbor, MI Purpose/Objective(s): We sought to assess freedom from local progression (FFLP) and treatment related toxicity in a cohort of patients treated with SBRT for unresectable hilar/intrahepatic cholangiocarcinoma or who had a positive surgical margin after resection. Materials/Methods: After IRB approval, we performed a retrospective review of all patients with hilar or intrahepatic cholangiocarcinoma treated with SBRT from 2006-2015 at our institution. SBRT was typically delivered over 3 to 5 fractions (median 5, interquartile range [IQR] 3-5). Fiducials were not commonly used (n Z 4). The radiation dose was prescribed the isodose surface that gave 99.5% coverage of the planning target volume. Local progression (LP) was assessed with follow-up CT or MRI imaging. Toxicity was graded using the common terminology criteria for adverse events. Predictors of freedom from local progression (FFLP) and overall survival (OS) were assessed using Kaplan Meier methods and the log-rank test. Multivariate analyses were performed using Cox-proportional hazard models. Results: Thirty-two patients were treated to a total of 40 lesions. Median follow-up post SBRT was 8.7 months (IQR 4.6-18.0 months). Three patients received SBRT for a positive surgical margin and in total 8 lesions had received prior local therapy. Five patients had additional extrahepatic disease at the time of SBRT. Median age was 64 years. Eight patients had underlying cirrhosis of the liver. Median baseline Child-Pugh score was 5 (IQR 5-6). Twenty-six cholangiocarcinomas (65%) were intrahepatic with the remaining 14 (35%) located in the hilum. Median tumor size was 2.75 cm (IQR 1.85-3.90). Median SBRT dose and biologically equivalent dose (BED) were 50 Gy (range 24-61 Gy) and 100 Gy (range 59.5-180 Gy), respectively. Five patients experienced a LP. Actuarial FFLP at 12 months post-SBRT was 86.5%. There were 17 deaths. Median OS was 16.9 months (IQR 5.9-25.2). On univariate and multivariate analysis, tumor location, use of fiducials, BED, and maximum tumor size did not predict for FFLP (all P 0.1). Increasing maximum tumor size was associated with
decreased OS on both univariate (HR: 2.9, 95% CI 1.1-7.4, P Z 0.04) and multivariate analyses (HR: 3.6, 95% CI: 1.1-11.5, P Z 0.03) when controlling for tumor location, use of fiducials, BED, and the presence of extrahepatic disease. Only one patient experienced a grade 3+ toxicity which was a biliary stricture requiring stenting approximately 3 months post-SBRT. Only 2 patients had an increase of greater than 2 points in their Child-Pugh 3 months post-SBRT. Eight patients have been successfully bridged to a liver transplant. Conclusion: SBRT is a well-tolerated and effective means of treatment for unresectable hilar/intrahepatic cholangiocarcinoma with 1-year rates of local control approaching 90%. Author Disclosure: W.C. Jackson: None. L. Bazzi: None. E. Sapir: None. T.S. Lawrence: Research Grant; NIH. Owner; Degradon Holding, LLC. President; Radiation Oncology Institute. M. Feng: Honoraria; Medivation/ Astellas, Genome Dx, Nanostring. Consultant; Genome Dx, Nanostring, Myriad, Varian. Patent/License Fees/Copyright; PFS Genomics for Radiotype DX. Chair; NRG GU Translational Research Program. Co-chair; IHE-RO. Member; NCCN Pancreas Guidelines.
2364 The Potential Involvement of Circular RNA in the Development of Radiation Resistance of Esophageal Cancer C. Xie,1 X. Jin,2 and H. Su2; 1the First Affiliated Hospital of Wenzhou Medical University, Wenzhou, China, 2the 1st Affiliated Hospital of Wenzhou Medical University, Wenzhou, China Purpose/Objective(s): Acquired radioresistance during radiation therapy is considered as the most important reason for local tumor recurrence or failure. Circular RNAs (circRNAs) have recently been identified as microRNA sponges and involved in various biological processes. The purpose of this study is to investigate the role of circRNAs in radioresistance of esophageal cancer. Materials/Methods: Human parental cell line KYSE-150 and self-established radioresistant esophageal cancer cell line KYSE-150R were cultured, and RNAs were extracted for microarray analyses. Quantitative Real-time PCR was used to confirm the circRNA expression profiles obtained from the microarray data. The circRNA/microRNA interaction was predicted and the differentially expressed circRNAs within all the comparisons were annotated. Results: A total of 3752 human circRNAs expressions from KYSE150R and KYSE-150 cell samples were quantitated, in which 74 circRNAs expressions with significant differential expressions (fold change2.0 and P
