188 Re-N-DEDC Lipiodol for Treatment of Hepatocellular Carcinoma (HCC)-A Clinical and Prospective Study to Assess In-Vivo Distribution in Patients and Clinical Feasibility of Therapy.

Objective  The incidence of inoperable hepatocellular carcinoma (HCC) with/without malignant portal vein thrombosis (PVT) is increasing in India for the last decade; thus, Bhabha Atomic Research Centre (BARC), Mumbai, India, developed diethydithiocarbamate (DEDC), a new transarterial radionuclide therapy (TART) agent. ¹⁸⁸ Re-N-DEDC lipiodol is an emerging radiotherapeutic agent for inoperable HCC treatment due to its simple and onsite labeling procedure, cost-effectiveness, and least radiation-induced side effects. This study aimed to evaluate in-vivo biodistribution and clinical feasibility of ¹⁸⁸ Re-N-DEDC lipiodol TART in HCC and optimization of labeling procedure to assess post-labeling stability and radiochemical yield of labeled lipiodol with ¹⁸⁸ Re-N-DEDC complex. Materials and Methods  DEDC kits were obtained as gift from BARC, Mumbai. Therapy was given to 31 HCC patients. Post-therapy planar and single-photon emission computed tomography/computed tomography (SPECT/CT) imaging were performed to see tumor uptake and biodistribution. Clinical feasibility and toxicity were decided by Common Terminology Criteria for Adverse Events version 5.0 (CTCAE v 5.0). Statistical Analysis  Descriptive statistics was done for data using SPSS v22. Values was expressed as mean ± standard deviation or median with range. Results  Post-therapy planar and SPECT/CT imaging showed radiotracer localization in hepatic lesions. Few patients showed lungs uptake due to hepato-pulmonary shunt (lung shunt < 10%). Maximum clearance was observed through urinary tract with very less elimination through hepatobiliary route due to slow rate of leaching of tracer. No patient showed myelosuppression or any other long-term toxicity over median follow-up of 6 months. Mean overall % radiochemical yield of ¹⁸⁸ Re-N-DEDC lipiodol was 86.04 ± 2.35%. The complex ¹⁸⁸ Re-N-DEDC was found to be stable at 37°C under sterile condition over a period of 1 hour without any significant change on the % radiochemical purity (90.83 ± 3.24%, 89.78 ± 3.67%, 89.22 ± 3.77% at 0, 0.5, 1 hours, respectively). Conclusion  Human biodistribution showed very high retention of radiotracer in hepatic lesions with no long-term toxicity with this therapy. The kit preparation procedure is ideally suited for a busy hospital radio-pharmacy. By this procedure, ¹⁸⁸ Re-N-DEDC lipiodol can be prepared in high radiochemical yield within a short time (∼45 minutes). Thus, ¹⁸⁸ Re-N-DEDC lipiodol can be considered for TART in advanced and/or intermediate HCC.