Efficacy and Safety of Iodine-125 Brachytherapy in the Treatment of Recurrent or Metastatic Head and Neck Squamous Cell Carcinoma

Background: Recurrent or metastatic (R/M) head and neck squamous cell carcinoma (HNSCC) is a difficult challenge for physicians, especially when patients have been treated with external beam radiotherapy. The purpose of this study was to assess the clinical efficacy and safety of computed tomography (CT)-guided iodine-125 brachytherapy as a palliative treatment for R/M HNSCC. Methods: From May 2011 to July 2018, we enrolled 87 patients with R/M HNSCC who had previously received external beam radiotherapy. Among these patients, 43 successfully underwent CT-guided iodine-125 brachytherapy and chemotherapy (group A); 44 patients who only received chemotherapy (group B) were matched with patients in group A. Patients' pain score, Eastern Cooperative Oncology Group (ECOG) score, tumor compression symptoms, and side effects of iodine-125 implantation were recorded. Clinical follow-up was performed to assess progression-free survival (PFS) and overall survival (OS). Results: Both groups of patients completed the treatment and were followed up for 9-66 months, with a median follow-up time of 44 months. The OS was 51 months (95% CI: 42.93-59.06 months) versus 28 months (95% CI: 23.79-32.21 months) (p < 0.05), the PFS was 10 months (95% CI: 6.15-13.84 months) versus 6 months (95% CI: 4.40-7.59 months) (p < 0.05) in groups A and B, respectively. The RR in group A was 25/43 (58.14%) versus 15/44 (34.10%) in group B (p < 0.05). Compared with group B, patients in group A had lower pain scores, better physical performance, and better improvement of compression symptoms. No serious treatment-related complications were observed in either group of patients. Conclusion: Compared with chemotherapy alone, iodine-125 seed implantation combined with chemotherapy was a more effective and safer strategy for R/M HNSCC.