Purpose: This study was designed to evaluate a combined modality treatment for malignant gliomas using radiation therapy with a radiosensitizer and an adjuvant chemotherapy regimen designed to modify resistance to BNCU.Methods and Materials: Patients were eligible if they were 15 years of age or older, and had newly diagnosed glioblastoma multiforme (GBM), or anaplastic glioma (AG). Treatment consisted of external beam radiotherapy given to a dose of 60 Gy using a single daily fraction Monday to Friday. Concurrent hydroxyurea at a dose of 300 mg/m2 every 6 h every other day was given during radiation. Following radiotherapy, patients were then treated with BCNU and 6-Thioguanine (6TG). The 6-TG was given by mouth every 6 h for 12 doses prior to BCNU. Patients were initially treated with 60 mg/m2/dose of 6TG, with escalation to a maximum dose of 100 mg/m2/dose. The primary study end points were time to tumor progression and survival.Results: A total of 245 eligible patients were enrolled from 1/18/88 to 12/26/91. The histologic subtypes included 135 GBM, and 110 with AG (103 with anaplastic astrocytoma, 7 with high-grade mixed oligoastrocytoma). For the GBM group, the median time to tumor progression (TTP) and median survival were 33 (95% CI 26, 39) and 56 (95% CI 49, 69) weeks, respectively. For the AG group the median TTP was 282 weeks (95% lower confidence bound = 155 weeks). Median survival for this group has not been reached (95% lower confidence bound = 284 weeks) with a median follow-up for surviving patients of 298 weeks. A proportional hazards model was used to look at potential prognostic factors for survival, including initial Karnofsky Performance Scale (KPS), age, and extent of surgery, as well as dose of 6TG. Higher KPS, and lower age, predicted for longer survival (p < 0.01, < 0.001) in GBM patients; lower age was significant (p = 0.05) for AG cases. A higher (greater than 95 mg/m2) or lower dose of 6TG was not statistically significant in this model.Conclusions: This therapy was no more effective in patients with GBM than other reported series. In patients with malignant gliomas other than GBM, prolonged progression-free and overall survival is noted, without a median survival reached at the time of this report. In this subset of AG patients, survival is comparable to recent studies using halogenated prymidines during radiation and Procarbazine, CCNU, and Vincristine (PCV) as adjuvant chemotherapy.

Although meningiomas are known to be induced by low doses of cranial irradiation, such as those given to treat tinea capitis, little experience has been reported on the induction of meningiomas by high-dose cranial irradiation. The authors describe a series of 10 patients with meningiomas and a previous history of high-dose radiation therapy, usually given for a primary brain tumor. Of the 10 patients, eight were female, three had multiple meningiomas, and the majority had other stigmata of previous radiation therapy. Eight meningiomas were examined pathologically and one-half were classified as either aggressive or atypical, or were noted to have a high bromodeoxyuridine labeling index. The average time from radiation therapy to diagnosis of a meningioma was 24 years (range 5 to 40 years), a shorter interval than that previously reported for meningiomas induced by lower doses of irradiation. Within this series, patient age at irradiation was significantly correlated with tumor latency; individuals who were younger at the time of radiation therapy had a shorter time to meningioma formation. The latency of meningioma formation is therefore influenced by both the radiation dose and the age of the patient at irradiation.

Two patients with esthesioneuroblastomas that disseminated in the central nervous system (CNS) and elsewhere are reported. The latest recurrences in the CNS were 19 years after the diagnosis in patient and 9 years after the diagnosis in the other. Because the treatment of patients with such late recurrences is complicated by previous surgical procedures and radiation therapy, we review therapeutic options for these patients. The literature has not previously stressed the occurrence of late metastases, including those to the CNS, after prolonged disease-free intervals.