Iodine-125 seed implantation for residual hepatocellular carcinoma or cholangiocellular carcinoma in challenging locations after transcatheter arterial chemoembolization: Initial experience and findings.

Purpose To evaluate the clinical efficacy and safety of computed tomography (CT)-guided iodine-125 (125I) seed implantation (ISI) for hepatocellular carcinoma (HCC) or cholangiocellular carcinoma (CCC) lesions in challenging locations after transcatheter arterial chemoembolization (TACE). Material and methods A retrospective single-center review of 24 patients with HCC or CCC tumors in challenging locations (hepatic dome or close to the heart/diaphragm/hepatic hilum) was conducted. Patients who underwent CT-guided 125I implantation from May 2014 to January 2019 were recruited. Patients' demographics and details including technical success, treatment response, patient survival, and complication rate were also evaluated. Results Treated tumors were located in the hepatic dome (n = 10; 41.7%), subcapsularly (n = 6; 25%), close to the heart (n = 3; 12.5%), and in the liver hilum (n = 5; 20.8%). The mean maximum diameter of tumors in challenging locations was 40.08 ±11.34 mm (range, 25-68 mm). TACE (2 ±1, 1-4 times) was applied before ISI. There were 27 ISI treatments administered (3 patients also received supplemental ISI). The total number of implanted seeds was 1,160, with mean 48 ±16 seed per patient (range, 30-90 seeds). The mean D90 value for ISI was 125 Gy. Technical success rate was 100%, while a complete response + partial response (CR + PR) was documented in 70.83%, 79.17%, 83.33%, and 79.17% of patients at 3, 6, 12, and 24 months post-ISI, respectively. There were no major complications, although 2 cases experienced 125I seed transfer to the diaphragm, and 1 case experienced transfer to the heart cavity. Conclusions CT-guided ISI for HCC or CCC lesions in challenging locations after TACE is both highly effective and safe.