Long-term outcomes after reirradiation in nasopharyngeal carcinoma with intensity-modulated radiotherapy: A meta-analysis.

BACKGROUND: The purpose of this clinical review was to summate the published data for the long-term outcomes of reirradiation with intensity-modulated radiotherapy (IMRT) for locally recurrent nasopharyngeal carcinoma (NPC). METHODS: We searched biomedical literature databases for eligible studies published from January 2005 to September 2016. Outcomes of interests were 5-year local failure-free survival, distant failure-free survival, overall survival (OS), and toxicities. Meta-analysis was performed using a random effects model. RESULTS: We found 4 comparative and 8 noncomparative studies (n = 1768). Reirradiation was associated with pooled event rates of 72% (95% confidence interval [CI] 66%-78%; I2 = 84%), 85% (95% CI 82%-88%; I2 = 69%), and 41% (95% CI 36%-47%; I2 = 80%) for 5-year local failure-free survival, distant failure-free survival, and OS, respectively, with significant heterogeneity among the study results. The pooled event rate for grade 5 toxicities was 33% (95% CI 30%-35%; I2 = 0%) with minimal heterogeneity. CONCLUSION: Reirradiation with IMRT for locally recurrent NPC could confer long-term disease control and survival but is associated with significant mortality.