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Title: Predictors of Toxicity Associated With Stereotactic Body Radiation Therapy to the Central Hepatobiliary Tract

Purpose: To identify dosimetric predictors of hepatobiliary (HB) toxicity associated with stereotactic body radiation therapy (SBRT) for liver tumors. Methods and Materials: We retrospectively reviewed 96 patients treated with SBRT for primary (53%) or metastatic (47%) liver tumors between March 2006 and November 2013. The central HB tract (cHBT) was defined by a 15-mm expansion of the portal vein from the splenic confluence to the first bifurcation of left and right portal veins. Patients were censored for toxicity upon local progression or additional liver-directed therapy. HB toxicities were graded according to Common Terminology Criteria for Adverse Events version 4.0. To compare different SBRT fractionations, doses were converted to biologically effective doses (BED) by using the standard linear quadratic model α/β = 10 (BED10). Results: Median follow-up was 12.7 months after SBRT. Median BED10 was 85.5 Gy (range: 37.5-151.2). The median number of fractions was 5 (range: 1-5), with 51 patients (53.1%) receiving 5 fractions and 29 patients (30.2%) receiving 3 fractions. In total, there were 23 (24.0%) grade 2+ and 18 (18.8%) grade 3+ HB toxicities. Nondosimetric factors predictive of grade 3+ HB toxicity included cholangiocarcinoma (CCA) histology (P<.0001), primary liver tumor (P=.0087), and biliary stent (P<.0001). Dosimetric parameters most predictive of grade 3+ HB toxicity were volumemore » receiving above BED10 of 72 Gy (V{sub BED10}72) ≥ 21 cm{sup 3} (relative risk [RR]: 11.6, P<.0001), V{sub BED10}66 ≥ 24 cm{sup 3} (RR: 10.5, P<.0001), and mean BED10 (Dmean{sub BED10}) cHBT ≥14 Gy (RR: 9.2, P<.0001), with V{sub BED10}72 and V{sub BED10}66 corresponding to V40 and V37.7 for 5 fractions and V33.8 and V32.0 for 3 fractions, respectively. V{sub BED10}72 ≥ 21 cm{sup 3}, V{sub BED10}66 ≥ 24 cm{sup 3}, and Dmean{sub BED10} cHBT ≥14 Gy were consistently predictive of grade 3+ toxicity on multivariate analysis. Conclusions: V{sub BED10}72, V{sub BED10}66, and Dmean{sub BED10} to cHBT are associated with HB toxicity. We suggest V{sub BED10}72 < 21 cm{sup 3} (5-fraction: V40 < 21 cm{sup 3}; 3-fraction: V33.8 < 21 cm{sup 3}), V{sub BED10}66 < 24 cm{sup 3} (5-fraction: V37.7 < 24 cm{sup 3}; 3-fraction: V32 < 24 cm{sup 3}) as potential dose constraints for the cHBT when clinically indicated.« less
Authors:
; ;  [1] ;  [2] ;  [1] ;  [1]
  1. Department of Radiation Oncology, Stanford University, Stanford, California (United States)
  2. Department of Radiation Oncology, The Ohio State University, Columbus, Ohio (United States)
Publication Date:
OSTI Identifier:
22458672
Resource Type:
Journal Article
Resource Relation:
Journal Name: International Journal of Radiation Oncology, Biology and Physics; Journal Volume: 91; Journal Issue: 5; Other Information: Copyright (c) 2015 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved.; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
62 RADIOLOGY AND NUCLEAR MEDICINE; COMPARATIVE EVALUATIONS; GY RANGE 10-100; HAZARDS; HISTOLOGY; LIMITING VALUES; LIVER; METASTASES; MULTIVARIATE ANALYSIS; NEOPLASMS; PATIENTS; RADIATION DOSES; RADIOTHERAPY; REVIEWS; TOXICITY; VEINS