The role of interventional radiotherapy (brachytherapy) in nasopharynx tumors: A systematic review.

Purpose: Nasopharyngeal cancers (NPC) are very aggressive, and the recurrence rate after radical therapy is high. This study aimed to evaluate the efficacy of brachytherapy (BT) also called interventional radiotherapy (IRT) in primary NPC in comparison with external beam radiotherapy (EBRT) alone. Material and methods: A systematic search was performed in Scopus, Cochrane, and PubMed databases. Clinical query based on PICO framework was as follows: In patients with NPC (P), is EBRT plus IRT (I) superior to EBRT alone (C) in terms of local control (LC) and toxicity (O)? Full articles evaluating the efficacy of IRT as a boost after EBRT in patients with NPC were considered. Results: Eight papers, including 1,320 patients fulfilled the inclusion criteria. The median 5-year LC for IRT group and no-IRT group was 98% (range, 95.8-100%) and 86% (range, 80.2-91%), respectively; the median 5-year overall survival (OS) for IRT group and no-IRT group was 93.3% (range, 89.2-97.5%) and 82.9% (range, 74.8-91.1%), respectively; the median 5-year DFS for IRT group and no-IRT group was 94.2% (range, 92.5-96%) and 83.9% (range, 73.3-94.6%), respectively; the median 5-year cancer-specific survival (CSS) for IRT group and no-IRT group was 96% (range, 94.5-97.5%) and 88.2% (range, 83.4-93.1%), respectively. G1-2 and G3-4 toxicities were similar in some articles, or significantly lower in patients treated with IRT in other papers. Conclusions: Data suggest that IRT may improve results of external beam radiotherapy in primary NPCs, especially when using new technologies.