BACKGROUND: Even after surgery and radiotherapy, malignant gliomas still have a 
poor prognosis. The authors report on their experience with IORT in 71 patients.
PATIENTS AND METHODS: From May 1992 to February 2004, 71 patients with malignant 
gliomas were treated with IORT. 26 patients suffered from grade III gliomas, 45 
patients from glioblastomas (GBM). IORT was carried out using a standard 
electron tube and 9- to 18-MeV electrons. 52/71 patients who were primarily 
treated received 20 Gy IORT + 60 Gy postoperative radiotherapy, 19/71 patients 
with recurrences only received IORT (20-25 Gy).
RESULTS: The complication rates were 1.4% for wound infections and 5.6% for 
hemorrhage. Median disease-specific survival amounted to 14.9 months (gliomas 
III) and 14.2 months (GBM). The 2-year survival rates amounted to 26.9% (gliomas 
III) and 6.8% (GBM; p = 0.0296). Total versus subtotal resection had no 
significant influence on survival (p = 0.0741), nor had age, sex, tumor site, 
performance status, size, primary versus recurrence, and radiation dose. A 
comparison to a conventionally treated patient group did not show a significant 
survival improvement. 3 months after treatment, initial symptoms had improved in 
59% (hemiparesis), 50% (aphasia), 50% (hemianopsia), and 60% (convulsions).
CONCLUSION: IORT has been shown to be feasible; perioperative complication rates 
were not increased. Survival was generally not improved compared to a historical 
control group. Recurrences achieved the same survival as primary tumors, and GBM 
also had a slightly increased survival, thus being possible indications for 
IORT.