Efficacy and Prognosis of CT-Guided Implantation of 125I Seeds As Salvage Treatment for Recurrent Nasopharyngeal Carcinoma after External Beam Radiotherapy--a Long-Term Experience at a Single Institution

Abstract

Sixteen patients were accrued to the phase I dose escalating (range 51w63GyE in 17w21 fractions) protocol. No patient experienced grade 4 toxicities, thus the MTD was set at 63 GyE/21 fractions, the highest of the protocol dose scheme. Thirty-nine LR-NPC patients (AJCC stage I/II/III/IVA-B disease in 4/8/10/17 patients) were accrued to the phase II study. All patients completed planned 63GyE/21 daily fractions without break. With a median follow-up of 8.4 (range 2.0w21.9) months, 1 patient died from massive hemorrhage subsequent to mucosal necrosis. The 1-year overall, local progression-free, regional recurrence-free, and distant metastasis free survival rates were 95.0%, 87.1%, 96.4%, and 100%, respectively. No patient experienced acute toxicity of grade 3. Grade 3 or above late toxicities observed included mucosal necrosis (5.1%), xerostomia (2.6%), hearing loss (5.1%), and temporal lobe necrosis (2.6%). Conclusion: This was the first prospective clinical trial to evaluate the efficacy and safety of CIRT for LR-NPC. Our results suggested that CIRT provided promising OS at 1 year with infrequent severe toxicities.