CT-guided implantation of (125)I seeds (permanent brachytherapy) for metastatic tumors of the hepatic portal system: Effectiveness and safety in 13 patients.

Purpose: To retrospectively evaluate the efficacy and safety of CT-guided implantation of (125)I seeds (permanent brachytherapy) for metastatic tumors of the hepatic portal system (HPS).

Methods And Materials: Between January 2012 and January 2015, 13 patients with metastases measuring >3.0 cm in short-axis diameter, which remained in the HPS after conventional chemotherapy and/or transcatheter arterial chemoembolization, and for which an effective therapeutic dose from external beam radiotherapy could not be delivered, received CT-guided (125)I brachytherapy. Clinical data were studied retrospectively. In terms of metrological requirements, the minimum dose to 90% of the target volume (D90) was 90-160 Gy for (125)I seeds with activity of 2.96 × 10(7)Bq. CT-based evaluation after 2, 4, and 8 weeks, as well as 6 months after implantation enabled review of local control of tumors.

Results: All symptoms were improved after (125)I brachytherapy. The mean value for D90 for implantation of (125)I seeds was 136 Gy. Complete response (CR) + partial response (PR) was documented in 61.5%, 69.2%, and 84.6% of patients at 2 weeks, 4 weeks, and 6 months after implantation, respectively. Four of 13 patients had complete response, 7 cases had PR, 1 patient had stable disease, and 1 case had progressive disease. All metastatic foci were controlled by implantation. No serious complications were observed.

Conclusion: CT-guided (125)I brachytherapy is a safe and effective treatment for metastatic tumors of the HPS and can achieve good local control in the short term as long as the radiation dose is sufficient. CT-guided (125)I brachytherapy carries few complications, is simple, safe, and a good complement to cancer treatment.