Efficacy and toxicity of Iodine-125 seed implantation for lymph node recurrence secondary to esophageal cancer after radiotherapy: a multicenter retrospective study

BACKGROUND/OBJECTIVE: This multicenter study aimed to explore the efficacy and toxicity of radioactive Iodine-125 seed implantation for lymph node recurrence in patients with esophageal cancer after external radiotherapy. METHODS: Clinical data of eligible patients from 5 centers in China were retrospectively reviewed. A total of 126 patients between January 2016 and March 2019 were included. The median interval between previous radiotherapy and radioactive Iodine-125 seed implantation was calculated. The target volume was 2.1–128.1 cm(3) (median, 22.2 cm(3)) and the median postoperative D90 is 120.6 Gy (range, 101.7–192). Short-term efficacy of tumor response, the long-term efficacy of local progression-free survival (LRFS) and overall survival (OS), and treatment-related toxicity were reported. RESULTS: For tumor response, 37 (29.4%), 51 (40.5%), 14 (11.1%), and 24 (19.0%) patients achieved complete response, partial response, stable disease and progressive disease, respectively. The 1-, 2- and 3-year LPFS and OS rates were 48.8%, 23.0% and 15.9%, and 80.2%, 38.8%, and 24.5%, respectively. Multivariate analysis identified Karnofsky performance status (P = 0.041) and tumor response (P = 0.049) as independent prognostic factors for LPFS; initial tumor stage (P = 0.034), lesion volume (P = 0.017), and tumor response (P = 0.004) as independent prognostic factors for OS. In total, 77 (61.1%) patients suffered from skin reactions and the incidence of grade 3–5 skin toxicity was 5.6% (7/126). CONCLUSION: Radioactive Iodine-125 seed implantation seems efficient with acceptable toxicity for the treatment of lymph node recurrence secondary to esophageal cancer. A head-to-head study is needed to further evaluate the survival benefit.