Adaptive Radiotherapy and Use of Simultaneous Integrated Boost in Treatment of Locally Advanced Oral Cavity, Oropharyngeal and Nasopharyngeal Cancers

AIM OF THE STUDY: To analyse the efficacy, toxicity and feasibility of adaptive radiotherapy while using simultaneous integrated boost in treated locally advanced head and neck cancers. The dose coverage of different sites whether the required level of tumour coverage will also be analyzed. MATERIALS AND METHODS: This is the prospective study and clinical data of 15 patients with carcinoma oral cavity, oropharynx and Nasopharynx were analyzed. The Patients were treated with IMRT technique along with Simultaneous Integrated Boost. Cone beam CT was done weekly once and re planning CT was done at TD: 40Gy after clinically verifying the response to the treatment. The set up errors, weight loss during the period of treatment, volume of tumor shrinkage were noted. RESULTS: Patient with large volume of disease either in the primary site or as nodal mass had significant decrease in volume at TD: 40 Gy. The tumor regression rate for individual patients were analyzed which showed that the planned inhomogeneity of dose distribution helps in better local control of the disease due to higher dose per fraction. CONCLUSION: Adaptive planning is highly individualized. Clinical and radiological examination during the course of treatment decides the necessity for adaptive planning. For patients who are treated with Simultaneous Integrated Boost technique the need for adaptive planning is warranted due to the radiobiological effect of high dose rate which translates to better tumor control