Hypofractionated Radiotherapy Using Simultaneous Integrated Boost Technique with Concurrent and Adjuvant Temozolomide for Glioblastoma

Aim: This study was conducted to assess the safety and efficacy of postoperative hypofractionated radiotherapy (HRT) using simultaneous integrated boost (SIB) technique for glioblastoma (GBM) compared to conventional radiotherapy (CRT).

Study Design: This was a prospective study with historical control arm.

Place and Duration of the Study: Department of Clinical Oncology and Nuclear Medicine, Mansoura University Hospital, Mansoura, Egypt, between May 2017 and June 2019.

Methods: The intervention (HRT) group included 30 patients who received 3D conformal HRT with SIB using field in field (FIF) technique to deliver a differential radiation dose to different targets. Planning target volume 60 (PTV60) includes the gross target volume (GTV) plus a 5-mm margin, and PTV45 includes the GTV plus a 15-mm margin. PTV60 will receive 60 Gy in 20 fractions, and PTV45 will receive 45 Gy in the same 20 fractions (one fraction daily and 5 days per week).The CRT group included 30 patients who received 3D conformal CRT with total dose 60 Gy in 2-Gy fractions delivered over 6 weeks. Both groups was planned to receive concurrent and adjuvant temozolamide.

Results: The median PFS was 10 months in both groups. The median OS was 13 months in HRT group versus 12 months in CRT group which is statistically non significant. The toxicities were mild and acceptable. Performance status and adjuvant temozolamide were significant predictors that affect the overall survival.

Conclusions: HRT with SIB using 3D conformal RTH with (FIF) technique in patients with GBM is a feasible and safe treatment and its results is comparable to the conventional radiotherapy.