Purpose: To report the results of interstitial brachytherapy (IBT) without salvage surgery for isolated cervical lymph node relapses.
Patient and methods: From 1970 to 1989, 84 patients were treated; 76 patients had relapsed in sites of previous external beam radiation. In 72 patients, IBT was sole salvage treatment (mean, 56.5 Gy). In 12 patients IBT (mean, 38 Gy) was combined with further external beam radiotherapy (mean, 41 Gy).
Results: Local control in the neck was 49% at 1 year, 31% at 2 years, and 0% at 5 years. Overall survival was 33% at 1 year, 13% at 2 years, and 1% at 5 years. Significant toxicity occurred in 35% (7% fatal). Multivariate analysis shows survival after salvage was better for patients who had achieved initial control for > or =18 months before relapse (0% vs. 13% at 3 years, p < 0.0002). Lymph node control was better for patients who received total salvage dose > or =60 Gy (0% vs. 56% at 3 years, p = 0.0004).
Conclusion: Given its poor efficiency and its toxicity, IBT must be considered only when surgery is contraindicated and if lymph node relapse occurs after a minimal interval of 18 months.