Dosimetric comparison of three dimensional conformal radiotherapy and intensity modulated radiotherapy in high grade gliomas

Abstract

Treatment of high-grade gliomas continues to be frustrating for the clinician as the medial survival stands at a dismal 14.5 months for glioblastoma multiforme (GBM) with the current standard of care. Given the high dose and generous margins required to be irradiated, three dimensional conformal radiotherapy (3DCRT) has become standard practice. Radiation dose escalation beyond 60 Gy, by means of stereotactic or intensity modulated radiotherapy (IMRT) boost, has not yielded clinically significant benefits in terms of local control or survival. At the same time, the potential of IMRT to spare normal tissues such as the brain stem and the optic apparatus makes it an attractive tool for modern radiation oncologists in seeking to improve post-radiotherapy quality of life. At our centre, we have been treating a large number of cases of high grade glioma with 3DCRT and IMRT for the last several years. The present study has been an effort to understand any potential benefits that IMRT, even without dose escalation, can offer.