Role of Stereotactic Body Radiotherapy Prior to Orthotopic Liver Transplantation: Retrospective Evaluation of Pathologic Response and Outcomes

Publication date: Available online 4 January 2017
Source:International Journal of Radiation Oncology*Biology*Physics
Author(s): E.M. Mannina, H.R. Cardenes, F.D. Lasley, B. Goodman, J. Zook, S. Althouse, J.A. Cox, R. Saxena, J. Tector, M. Maluccio
IntroductionStereotactic body radiotherapy (SBRT) applied to early stage, localized hepatocellular carcinoma in our institutional Phase I-II trial showed acceptable toxicities and exceptional local control. The results of SBRT in patients who underwent definitive orthotopic liver transplantation (OLT) was analyzed herein.Materials & MethodsThe subjects of this retrospective report are 38 patients diagnosed with hepatocellular carcinoma who underwent SBRT per institutional Phase I-II eligibility criteria, prior to definitive OLT. Pre-OLT radiographs were compared with pathologic gold standard. Analysis of treatment failures and deaths was undertaken.ResultsWith median follow-up of 4.8 years from OLT, 9/38 patients (24%) recurred while 10/38 patients (26%) died. Kaplan-Meier estimates of 3-year overall survival (OS) and disease-free survival (DFS) are 77 and 74%, respectively. Sum longest dimension of tumors was significantly associated with DFS (HR 1.93, p=0.026). Pathologic response rate (complete + partial response) was 68%. Radiographic scoring criteria performed poorly; mRECIST produced highest concordance (kappa=0.224). Explants revealed viable tumor in 74% of evaluable patients. Treatment failures had statistically larger sum longest dimension of tumors (4.0 cm vs 2.8 cm, p=0.014) and non-statistically significant higher rates of lymphovascular space invasion (44% vs. 17%), cT2 disease (44% vs 21%), ≥ pT2 disease (67% vs 34%), multifocal tumors at time of SBRT (44% vs 21%) and less robust mean AFP response (-25 IU/mL vs -162 IU/mL).ConclusionsSBRT prior to OLT is a well-tolerated treatment providing 68% pathologic response though 74% of explants ultimately contained viable tumor. Radiographic response criteria poorly approximate pathology. Our data suggest further stratification of patients based on initial disease burden and treatment response.



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