Study of comparison of acute toxicities between sequential intensity-modulated radiation therapy and simultaneous integrated boost intensity-modulated radiation therapy in head-and-neck cancers

Purpose: The purpose of this study is to assess and compare the acute toxicities between sequential intensity-modulated radiation therapy and simultaneous integrated boost (SIB) intensity-modulated radiation therapy in head-and-neck cancers using Common Terminology Criteria for Adverse Events (CTCAE) version 4.03. Materials and Methods: Patients with histologically proven squamous cell carcinoma of head and neck at the department of radiotherapy (RT), from December 2018 to July 2020, were taken up for this study. Patients were divided into sequential intensity-modulated RT (IMRT) arm and SIB-IMRT arm. Patients treated with sequential IMRT were treated so as to receive a total dose of 70 Gy in 35 fractions, 2 Gy/fractions, 5 fractions per week – 70 Gy in 35 fractions to the primary tumor, 66 Gy in 33 fractions to high-risk clinical target volume (CTV1), 60 Gy in 30 fractions to high-risk CTV2 and 50 Gy in 25 fractions to elective nodes/low-risk CTV3. Patients treated with SIB-IMRT were treated so as to receive a total dose of 66 Gy in 30 fractions – 2.2 Gy/fraction to gross tumor volume/PTV 66, 60 Gy in 30 fractions – 2.0 Gy/fraction to high-risk nodes (PTV 60), 54 Gy in 30 fractions – 1.8 Gy/fraction to elective nodes (PTV 54), respectively. Patients received concurrent chemotherapy with weekly injections cisplatin (35mg/m2) or injection carboplatin (AUC 2). Toxicities were assessed using CTCAE v 4.03. Results: Higher grades of radiation-induced dermatitis and mucositis were observed in patients in SIB-IMRT. No patients experienced Grade 4 toxicity. The results confirm that irradiation according to our SIB-IMRT protocol is a treatment option with acceptable toxicity. Conclusion: SIB-IMRT is feasible, although associated with increased rates of skin and mucosal toxicity.