International journal of radiation oncology, biology, physics 2015-04-01
Predictors of toxicity associated with stereotactic body radiation therapy to the central hepatobiliary tract.
ABSTRACT
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 volume receiving above BED10 of 72 Gy (VBED1072) ≥ 21 cm(3) (relative risk [RR]: 11.6, P<.0001), VBED1066 ≥ 24 cm(3) (RR: 10.5, P<.0001), and mean BED10 (DmeanBED10) cHBT ≥14 Gy (RR: 9.2, P<.0001), with VBED1072 and VBED1066 corresponding to V40 and V37.7 for 5 fractions and V33.8 and V32.0 for 3 fractions, respectively. VBED1072 ≥ 21 cm(3), VBED1066 ≥ 24 cm(3), and DmeanBED10 cHBT ≥14 Gy were consistently predictive of grade 3+ toxicity on multivariate analysis.
CONCLUSIONS
VBED1072, VBED1066, and DmeanBED10 to cHBT are associated with HB toxicity. We suggest VBED1072 < 21 cm(3) (5-fraction: V40 < 21 cm(3); 3-fraction: V33.8 < 21 cm(3)), VBED1066 < 24 cm(3) (5-fraction: V37.7 < 24 cm(3); 3-fraction: V32 < 24 cm(3)) as potential dose constraints for the cHBT when clinically indicated.
Related Questions
The Stanford report (Osmundson, IJROBP 2015) on central hepatobiliary tract toxicity recommended dose constraints to the cHBT that would limit dose to...
New comment by Radiation Oncologist at Ascension Saint Agnes Cancer Institute ( February 14, 2023)
I don't see any updates to this post. Any increased enthusiasm for central liver/cholangiocarcinoma SBRT???
If so, what constraints would you use for central biliary and other normal structures and what dose/fractionation would you use?
New answer by Radiation Oncologist at Mayo Clinic, Rochester (August 4, 2017)
I do offer repeat radiation for hepatobiliary cancer after definitive external beam or SBRT. The dose and fractionation really depends on the size of the recurrence, the statu...
Is there a role for re-irradiation? What cumulative dose constraints do you use for re-irradiation to the central hepatobiliary tract?
New answer by Radiation Oncologist at Mayo Clinic School of Medicine (April 22, 2021)
This is a challenging scenario for which there is no quick/easy solution. My initial assessment would involve obtaining a further understanding of the patient’s performa...