Simultaneous integrated boost (SIB), a field-in-field escalation technique, has been introduced to deliver higher radiation dose to the certain part of target with the same fractionation scheme. The aim of this study was to investigate the value of chemoradiation (CCRT) using SIB in glioblastoma and the correlation with surgical extent.

The SIB technique provides the higher radiobiological effect with the same fractionation scheme, i.e. 69 Gy over 6 weeks, which might increase the loco-regional control. Besides, the co-registration with magnetic resonance imaging (MRI) strengthens the precision of target delineation as well as higher possibility to spare adjacent normal brain tissue.

In this protocol, the newly diagnosed, primary glioblastoma patients received SIB 69 Gy/30 fractions to preoperative tumor bed and surgical cavity, while 60 Gy/30 fractions were covering preoperatively edematous area. To determine the status of surgical extent, postoperative CT scan and MRI was acquired within 72 hours and at 4th week after surgery. During the period of chemoradiation, acute neurotoxicity and hematological toxicity was assessed as well.

Inclusion Criteria:

• age 18 years or above
• newly diagnosed, tissue-proven glioblastoma
• pre-radiotherapy Karnofsky performance score (KPS) ≧60.

Exclusion Criteria:

• any previous history of chemotherapy or radiotherapy
• receiver of any investigating agents
• recurrent GBM
• any second malignancies.