A randomized prospective study comparing acute toxicity, compliance and objective response rate between simultaneous integrated boost and sequential intensity-modulated radiotherapy for locally advanced head and neck cancer.

Purpose: Intensity-modulated radiotherapy (IMRT) provides higher dose to target volumes and limits the dose to normal tissues. IMRT may be applied using either simultaneous integrated boost (SIB-IMRT) or sequential boost (SEQ-IMRT) technique. The objectives of this study were to compare acute toxicity and objective response rates between SIB-IMRT and SEQ-IMRT in patients with locally advanced head and neck cancer.

Materials and methods: Total 110 patients with locally advanced carcinoma of oropharynx, hypopharynx, and larynx were randomized equally into the two arms (SIB-IMRT vs. SEQ-IMRT). Patients in SIB-IMRT arm received dose of 66 Gy in 30 fractions, 5 days a week, over 6 weeks. SEQ-IMRT arm's patients received 70 Gy in 35 fractions over 7 weeks. Weekly concurrent cisplatin chemotherapy was given in both arms. Patients were assessed for acute toxicities during the treatment and for objective response at 3 months after the radiotherapy.

Results: Grade 3 dysphagia was significantly more with SIB-IMRT compared to SEQ-IMRT (72% vs. 41.2%; p = 0.006) but other toxicities including mucositis, dermatitis, xerostomia, weight-loss, incidence of nasogastric tube intubation and hospitalization for supportive management were similar in both the arms. Patients in SIB-IMRT arm showed better treatment-compliance and had significantly less treatment-interruption compared to SEQ-IMRT arm (p = 0.028). Objective response rates were similar in both the arms (p = 0.783).

Conclusion: Concurrent chemoradiation with SIB-IMRT for locally advanced head and neck cancer is well-tolerated and results in better treatment-compliance, similar objective response rates, comparable incidence of mucositis and higher incidence of grade 3 dysphagia compared to SEQ-IMRT.