735P - Radiographic Parameters in Predicting Outcome of Patients with Hepatocellular Carcinoma (HCC) Treated with YTTRIUM-90 Microsphere Radioembolization (SIRT)

Abstract

ABSTRACT Background The predictive role of radiographic parameters in HCC pts undergoing transarterial hepatic selective internal radiotherapy (SIRT) is not fully characterized. The objective of this retrospective study was to determine whether radiographic parameters at baseline and/or radiographic changes following SIRT predict outcome in HCC pts treated with Yttrium-90 glass microsphere radioembolization. Methods Baseline and post-SIRT CT images (median of 6 weeks) were analyzed. Various features such as tumor size; attenuation; margins; enhancement; and amount of tumor necrosis were examined. Selected radiographic parameters were evaluated & correlated with PFS & OS. Objective response was assessed by RECIST 1.1 and Morphology, Attenuation, Size, and Structure (MASS) criteria (favorable (FR) vs. non favorable). Differences were analyzed using Wilcoxon Signed Rank Test and Fisher's Exact Test. Kaplan-Meier methods were used to estimate survival curves. Cox regression was used in uni- and multi- variable survival analyses Results Twenty-four pts (79% M; median age 63 y) received a median radiation dose of 1.965 GBq. On post-SIRT CT, 65% of tumors had decreased longest diameter (median decrease 8%, p = 0.27); 64% had decreased attenuation (median decrease 18 HU, p = 0.067), and 45% demonstrated increased tumor necrosis (p Conclusions In pts with HCC, pre-treatment tumor margins and shunt fraction may be developed as biomarkers to identify pts who are unlikely to benefit from SIRT. In addition, response evaluation by MASS criteria may provide better and earlier determination of lack of benefit from SIRT and the need for further therapy. Disclosure All authors have declared no conflicts of interest.