An experience with simultaneous integrated boost-volumetric-modulated arc therapy in the definitive treatment of head and neck cancer: An Indian data.

Background: There are very few prospective studies comparing simultaneous integrated boost versus sequential boost in the setting of definitive treatment modality of head and neck squamous cell cancer (HNSCC), especially in the Indian scenario.
Materials and Methods: We prospectively randomized 50 patients with biopsy-proven squamous cell carcinoma of the oropharynx, hypopharynx, and larynx malignancies, stage T1-3, enlarged node measuring ≤3 cm that are planned for definitive radiotherapy with chemotherapy into either hypo-fractionated simultaneous integrated (Hypo-SIB VMAT) boost arm or conventional (Conv-VMAT) boost arm.
Results: Most of the patients were men and aged less than 50 years. Patients with nodal involvement were 76% in Hypo-SIB VMAT and 80% in Conv-VMAT arm. The overall stage group distribution of II, III, and IVA were 16%, 44%, 40%, and 12%, 56%, and 32%, respectively, in both arms. All patients completed the intended treatment in both arms. Overall survival at the end of 2 years was 84% in Hypo-SIB VMAT arm and 80% in the Conv-VMAT arm (P = 0.25); disease-free survival (DFS) was 88% and 72%, respectively (P = 0.12); and locoregional recurrence-free survival (LRFS) was 92% and 84%, respectively (P = 0.38). All the acute and chronic toxicities in both the arms were comparable with no significant difference in any of the toxicities. The average overall treatment time (OTT) in Hypo-SIB VMAT arm is 39.4 days and in Conv-VMAT arm is 50.2 days (P = 0.00001) which is statistically significant.
Conclusions: Accelerated Hypo-SIB VMAT has similar response and toxicities as compared to Conv-VMAT in the setting of definitive concurrent chemoradiation of HNSCC patients with the advantage of less OTT, faster treatment delivery, and patient compliance.