Comparison of Hyperfractionated to Conventionally Fractionated Salvage IMRT for Locoregionally Advanced Recurrent Nasopharyngeal Carcinoma

Abstract

PURPOSE/OBJECTIVE(S): Salvage intensity modulated radiation therapy (IMRT) for locoregionally advanced recurrent nasopharyngeal carcinoma (NPC) is always challenging due to the inherently high dose received by the nearby organs at risk (OARs) in the first course of radiation therapy. We prospectively studied the efficacy and safety of hyperfractionated (HF) IMRT and compared to a historical cohort treated with conventionally fractionated (CF) IMRT. MATERIALS/METHODS: Ten consecutive patients with locoregionally advanced (T3-T4, N0-N1, M0) NPC prospectively recruited and treated with induction chemotherapy gemcitabine/platinum for 3 cycles followed by 9-field (HF-IMRT) (64.8 Gy/54 fr/5.5 weeks, twice daily, interfractional interval 37 hours) concurrent with weekly platinum for 6 cycles. Objective response rate (ORR), local failure-free survival (LFFS), regional failure-free survival (RFFS), overall survival (OS) and treatment-related complications were compared to a historical cohort of another 10 patients in the same setting treated with 3 cycles of induction chemotherapy followed by CF-IMRT (60 Gy/30 fr/6 weeks). RESULTS: Median age was 59.5 years (HF-IMRT) and 44.0 years (CF-IMRT, P=.764). After a median follow up of 27.9 months (range 5.2 to 69.0 months), ORR were 40.0% (HF-IMRT) and 30.0% (CF-IMRT, P=.871) respectively. Median LFFS showed a trend in favor of HF-IMRT (33.6 months [95% CI 12.2–55.1 months] vs 14.8 months [95% CI 14.1–15.4 months], P=.179). RFFS (40.8 months vs not reached, P=.857) and OS (31.9 months vs 34.3 months, P=.681) were not different between the 2 groups. Commonest chronic treatment-related complications were brain necrosis (10.0% in HF-IMRT vs 20.0% in CF-IMRT; P=.531), aspiration pneumonia (40.0% in HF-IMRT vs 20.0% in CF-IMRT; P=.329) and hemorrhage (0% in HF-IMRT vs 30.0% in CF-IMRT; P=.060). CONCLUSION: HF-IMRT offered marginally better LFFS and relatively less treatment-related hemorrhage compared to CF-IMRT in locoregionally advanced recurrent NPC.