High-dose-rate stereotactic brachytherapy for patients with newly diagnosed glioblastoma multiformes.

PURPOSE: To evaluate high-dose-rate (HDR) stereotactic brachytherapy (STBT) for glioblastoma multiforme (GBM).

MATERIALS AND

METHODS

Between August 1994 and December 1998, 28 patients with newly diagnosed GBM underwent surgery, external-beam radiotherapy (EBRT) and HDR STBT. STBT eligibility criteria included unifocal lesions, residual tumor < or = 6 cm in maximum diameter, supratentorial lesions, tumors not crossing the midline, tumors without subependymal spread and Karnofsky performance status (KPS) > 60. STBT was delivered over five consecutive days with two fractions per day for a total median dose of 30 Gy. Twenty-eight STBT eligible GBM patients treated with surgery and EBRT only over the same period were matched controls.

RESULTS

Median survival times for the STBT group and controls were 19.5 versus 12.5 months; one and two year survival rates were 89% versus 42% and 61% versus 28%, respectively (p = 0.12). Using multivariate analysis, age, KPS and HDR STBT were significant factors predicting survival. By RPA class, 2-year survival rates for STBT and controls were: III--78% versus 50%; IV--40% versus 0%; V--21% versus 15%, respectively. Corresponding median survival times in months were: 41.6 versus 21.2 (p = 0.39); 16.7 versus 12.1 (p = 0.36); 18.7 versus 10.6 (p = 0.02). No major complications were found in the STBT arm.

CONCLUSIONS

Because of small patient numbers, median survival time increases were only statistically significant in the RPA Class V patients, but a strong survival time trend emerged favoring patients undergoing HDR STBT. Further prospective study is warranted to fully assess the merits of this technique for GBM management.