Concurrent Weekly Cisplatin and Simultaneous Integrated Boost-IMRT in Locally Advanced Head and Neck Squamous Cell Carcinoma-An Institutional Experience.

 Concurrent chemoradiation with weekly cisplatin in locally advanced head and neck squamous cell carcinoma (LA-HNSCC) is widely practiced in India. Radiation with simultaneous integrated boost intensity-modulated radiotherapy (SIB-IMRT) has the advantage of executing IMRT in single phase with better dose distribution.  150 patients with LA-HNSCC treated between April 2015 and December 2019 were retrospectively evaluated. All patients received 70Gy in 33 to 35 fractions with SIB-IMRT and concurrent weekly cisplatin at a dose of 40 mg/m . Treatment compliance and toxicities were assessed. Overall survival (OS) was evaluated using Kaplan-Meier estimates; univariate and multivariate analysis of prognostic factors were also evaluated.  Median age was 58.5 years. Forty-five percent had primary oropharyngeal cancer. Sixty-two percent had T3 disease, 41% had N2 disease, and 51% had stage IV disease. All patients received 70Gy dose of RT. Median chemotherapy cycles were six, 84.7% received 200 mg/m . Acute grade 2 xerostomia was seen in 79%, grade 3 neutropenia, mucositis and pharyngitis were seen in 11, 15, and 21%, respectively. Complete response was seen in 66.6%. At median follow-up of 21.4 months (3-71) OS was 60% and median OS was 33.2 months. Estimated 2 and 3 year OS was 56 and 48%. On univariate analysis, absence of node, N0-N1, stage III, cisplatin use, dose per fraction 2.12Gy ,and complete response showed good OS ( <0.05). On multivariate analysis dose per fraction 2.12Gy and complete response showed good OS ( <0.05).  Definitive chemoradiation with weekly cisplatin and SIB-IMRT in LA-HNSCC is well tolerated with good clinical outcomes.