A phase II trial of accelerated radiotherapy using weekly stereotactic conformal boost for supratentorial glioblastoma multiforme: RTOG 0023.
OBJECTIVE
This phase II trial was performed to assess the feasibility, toxicity, and efficacy of dose-intense accelerated radiation therapy using weekly fractionated stereotactic radiotherapy (FSRT) boost for patients with glioblastoma multiforme (GBM).


METHODS
Patients with histologically confirmed GBM with postoperative enhancing tumor plus tumor cavity diameter <60 mm were enrolled. A 50-Gy dose of standard radiation therapy (RT) was given in daily 2-Gy fractions. In addition, patients received four FSRT treatments, once weekly, during Weeks 3 to 6. FSRT dosing of either 5 Gy or 7 Gy per fraction was given for a cumulative dose of 70 or 78 Gy in 29 (25 standard RT + 4 FSRT) treatments over 6 weeks. After the RT course, carmustine (BCNU) at 80 mg/m(2) was given for 3 days, every 8 weeks, for 6 cycles.


RESULTS
A total of 76 patients were analyzed. Toxicity included: 3 Grade 4 chemotherapy, 3 acute Grade 4 radiotherapy, and 1 Grade 3 late. The median survival time was 12.5 months. No survival difference is seen when compared with the RTOG historical database. Patients with gross total resection (41%) had a median survival time of 16.6 months vs. 12.0 months for historic controls with gross total resection (p = 0.14).


CONCLUSIONS
This first, multi-institutional FSRT boost trial for GBM was feasible and well tolerated. There is no significant survival benefit using this dose-intense RT regimen. Subset analysis revealed a trend toward improved outcome for GTR patients suggesting that patients with minimal disease burden may benefit from this form of accelerated RT.
Cardinale
Robert
R
Medical College of Virginia/Virginia Commonwealth University, Richmond, VA, USA. bobcardinale@aol.com
Won
Minhee
M
Choucair
Ali
A
Gillin
Michael
M
Chakravarti
Arnab
A
Schultz
Christopher
C
Souhami
Luis
L
Chen
Allan
A
Pham
Huong
H
Mehta
Minesh
M
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D019583:Dose Fractionation, Radiation; D005240:Feasibility Studies; D005260:Female; D005909:Glioblastoma / Q000401:mortality / Q000601:surgery*; D006801:Humans; D008297:Male; D008875:Middle Aged; D016634:Radiosurgery / Q000379:methods* / Q000401:mortality; D020266:Radiotherapy, Conformal / Q000379:methods; D015173:Supratentorial Neoplasms / Q000401:mortality / Q000601:surgery*; D016019:Survival Analysis; D013997:Time Factors