Acquisition of equal or better planning results with interstitial brachytherapy when compared with intensity-modulated radiotherapy in tongue cancers

Abstract Purpose Intensity-modulated radiotherapy (IMRT) technique in external beam radiotherapy and interstitial implant brachytherapy (ISBT) play important role in the treatment of head and neck cancers. Both are proved to be highly conformal techniques of radiotherapy. In this study, we investigated whether ISBT can give treatment planning results similar to those of IMRT. Methods and Materials Fifteen patients with tongue cancer treated with interstitial high-dose-rate brachytherapy were replanned. They were evaluated with the IMRT planning system. Contouring of target volume, including all critical structures was done on the IMRT treatment planning system to closely match implant brachytherapy planning system. Treatment plans were generated after specifying the goals in the prescription. Conformity index and dose to critical organ were calculated and compared between IMRT and ISBT. Planning time was also recorded for both the techniques in all the cases. Results Very good dose conformity was observed in ISBT, which was almost the same as that in IMRT. Dose to the critical structure was lower in ISBT in all the cases. Planner time was also less in ISBT for more number of cases. Conclusions Results show that ISBT treatment modality produces equal or superior planning results when compared with IMRT with our optimization techniques. These results encourage us to continue ISBT practice.