Comparison of clinical response of ¹⁸⁸Re-N- DEDC lipiodol and ⁹⁰Y-SIRsphere for treatment of Inoperable hepatocellular carcinoma

FDA approved ⁹⁰Y-microspheres TheraSpheres and SIRspheres TARE have been recommended treatment of intermediate stage (BCLC B) HCC who are not good candidates for TACE due to multiple bulky tumors and advanced stage (BCLC C) with solitary lesion and segmental or lobar PVT. ¹⁸⁸Re-N-DEDC lipiodol is an emerging TART agent due to its comparable β-energy (Eβmax 2.1 MeV) and penetration range (11mm) of ¹⁸⁸Re to ⁹⁰Y. Indigenously developed TART agent DEDC (Diethyl-dithiocarbamato) by BARC, Mumbai, labelled with ¹⁸⁸Re in lipiodol phase has advantage of simple and on-site labelling procedure, cost-effectiveness and least radiation induced side effects. Present study aimed to compare the clinical response of ¹⁸⁸Re-N-DEDC lipiodol and ⁹⁰Y-SIRsphere for treatment of intermediate and/or advanced HCC. Radiologically and biochemically confirmed HCC patients with/ without PVT having ECOG performance status ≤2 and Child Pugh score A /B were recruited. Baseline serum alpha-fetoprotein (AFP) was obtained for biochemical correlation and follow-up. Total 14 patients, 7 in each groups, had comparable lesion size were recruited for this study. Pre-therapy dosimetry was performed by patient-specific partition model for ⁹⁰Y-SIRsphere, while empirical activity recommended by IAEA were injected trans-arterially for ¹⁸⁸Re-N-DEDC lipiodol. Response was assessed at 2 months post- therapy by mRECIST criteria and S. AFP level. Further, follow- up was performed at every 3 months to know disease status. Fourteen (14) patients (13 male; 1 female); 7 patients in each ¹⁸⁸Re-N-DEDC lipiodol and ⁹⁰Y-SIRsphere groups, with mean age 56.2 ± 12.45 years have been recruited for this study. Overall mean injected activity was 3.26±1.7GBq for ⁹⁰Y-SIRsphere group, and 3.29±1.16GBq for ¹⁸⁸Re-N-DEDC lipiodol group. The median follow-up period was of 6 months. Radiologically, in ⁹⁰Y-SIRsphere group, 2 patients had complete or nearly complete response, 4 patients had partial response and 1 had disease progression; while in ¹⁸⁸Re-N-DEDC group, 2 patients had complete response, 3 had partial response; 1 had stable disease and 1 had disease progression. Biochemically, 3 patients (1 in ⁹⁰Y-SIRsphere group and 2 in N-DEDC group) had non-AFP producing tumor. Thus, of 6 patients in ⁹⁰Y-SIRsphere group, 2 had complete response and 4 showed partial response, while in N-DEDC group, of 5 patients, 1 had complete response, 3 had partial response and 1 showed disease progression. TARE with ⁹⁰Y-SIRsphere and ¹⁸⁸Re-N-DEDC lipiodol shows almost similar response in intermediate/advanced HCC patients. Thus, indigenously developed DEDC kits labelled with ¹⁸⁸Re-lipiodol can be used as a viable economic TARE agent for HCC treatment. (author)