Survival and failure patterns of high-grade gliomas after three-dimensional conformal radiotherapy.

PURPOSE: The goal of three-dimensional (3-D) conformal radiation is to increase the dose delivered to tumor while minimizing dose to surrounding normal brain. Previously it has been shown that even escalated doses of 70 to 80 Gy have failure patterns that are predominantly local. This article describes the failure patterns and survival seen with high-grade gliomas given 90 Gy using a 3-D conformal intensity-modulated radiation technique. PATIENTS AND METHODS: From April 1996 to April 1999, 34 patients with supratentorial high-grade gliomas were treated to 90 Gy. For those that recurred, failure patterns were defined in terms of percentage of recurrent tumor located within the high-dose region. Recurrences with more than 95% of their volume within the high-dose region were considered central; those with 80% to 95%, 20% to 80%, and less than 20% were considered in-field, marginal, and distant, respectively. RESULTS: The median age was 55 years, and median follow-up was 11.7 months. At time of analysis, 23 (67.6%) of 34 patients had developed radiographic evidence of recurrence. The patterns of failure were 18 (78%) of 23 central, three (13%) of 23 in-field, two (9%) of 23 marginal, and zero (0%) of 23 distant. The median survival was 11.7 months, with 1-year survival of 47.1% and 2-year survival of 12.9%. No significant treatment toxicities were observed. CONCLUSION: Despite dose escalation to 90 Gy, the predominant failure pattern in high-grade gliomas remains local. This suggests that close margins used in highly conformal treatments do not increase the risk of marginal or distant recurrences. Our results indicate that intensification of local radiotherapy with dose escalation is feasible and deserves further evaluation for high-grade gliomas.

Phase 2 study of BCNU and temozolomide for recurrent glioblastoma multiforme: North American Brain Tumor Consortium study.

The purpose of this study was to evaluate the activity, measured in terms of progression-free survival (PFS) and response rates, of 1,3-bis(chloro-ethyl)-1-nitrosourea (BCNU) plus temozolomide in adult patients with recurrent glioblastoma multiforme. The phase 2 dose and schedule for this trial was BCNU 150 mg/m(2) i.v. followed in 2 h by temozolomide 550 mg/m(2) as a single oral dose. Treatment was repeated every 6 weeks for up to 8 cycles unless tumor progression was documented. The primary end point was PFS at 6 months (PFS-6). Response was a secondary end point, measured by MR imaging, neurological status, and steroid requirements prior to each 6-week cycle. The median age of eligible patients was 53, and 89.5% had no prior chemotherapy. All patients were evaluable for toxicity and time to progression. The PFS-6 was 21%. Overall survival was 68% at 6 months and 26% at 1 year. The MRI response for 36 patients was 2 partial responses, 2 minor responses, 19 cases of stable disease, and 13 immediate progressions. Median survival was 34 weeks, and median PFS was 11 weeks. Toxicity was primarily myelosuppression; no toxic deaths occurred. Historical phase 2 study data in this patient population show a PFS-6 of 15%. Recent data for use of temozolomide alone have shown a PFS-6 of 21%. We conclude that BCNU plus temozolomide when used in these doses and schedule has only modest activity, with significant toxicity, and appears to be no more effective than single-agent temozolomide.

Phase 1 trial of irinotecan (CPT-11) in patients with recurrent malignant glioma: a North American Brain Tumor Consortium study.

This study was conducted to determine the maximum tolerated dose and dose-limiting toxicity of irinotecan (CPT-11) administered every 3 weeks to adults with progressive malignant glioma who were treated with enzyme inducing antiepileptic drug (EIAED) therapy, and to compare the pharmacokinetics with those in patients not on EIAED therapy treated at the recommended phase 2 dose for other cancers. The CPT-11 dose was 350 mg/m(2) i.v. every 3 weeks and remained fixed in patients not on EIAED therapy, but the dose was escalated by 50-mg/m(2) increments in patients on EIAED therapy. CPT-11 and its metabolites SN-38, SN-38 glucuronide (SN-38G), and APC (7-ethyl-10[4-N-(5 aminopentanoic acid)-1-piperidine]-carbonyloxycamptothecin) were characterized in both groups. Patients on EIAEDs received 350 to 800 mg/m(2) of CPT-11. Dose-limiting toxicity was due to grade 3 diarrhea despite maximal doses of loperamide. The systemic levels of CPT-11, APC, SN-38G, and SN-38 were all lower in the EIAED group. There was a moderate-to-fair relationship between CPT-11 dose and the area under the curve (AUC) for CPT-11 and APC over the 2, but no relationship dosage range of 350 to 800 mg/m between CPT-11 dose and the AUC for SN-38 or SN-38G. At the 750-mg/m(2) dose, the AUC for CPT-11 (21.6 microg x h/ml) matched the AUC (21.6 microg x h/ml) in the non-EIAED group treated with 350 mg/m(2) of CPT-11. We conclude that the recommended phase 2 dose of CPT-11 for patients on EIAEDs is 750 mg/m(2) when given every 3 weeks. A phase 2 study of patients with recurrent malignant glioma is ongoing to assess the efficacy of CPT-11 when the dose is stratified according to the use of EIAEDs.

Phase III randomized study of radiotherapy plus procarbazine, lomustine, and vincristine with or without BUdR for treatment of anaplastic astrocytoma: final report of RTOG 9404.

PURPOSE: This study was an open-label, randomized Phase III trial in newly diagnosed patients with anaplastic glioma other than glioblastoma multiforme comparing external beam radiotherapy (EBRT) plus adjuvant procarbazine, cyclohexylchloroethylnitrosurea (lomustine), and vincristine (PCV) chemotherapy with or without bromodeoxyuridine (BUdR) given as a 96-h infusion each week of RT. METHODS AND MATERIALS: Only patients 18 years or older with newly diagnosed anaplastic glioma were eligible. A central pathology review was accomplished for most patients, but was not mandated before registration. The study had initially opened as a Northern California Oncology Group trial in 1991, becoming an Intergroup Radiation Therapy Oncology Group (RTOG), Southwestern Oncology Group and the North Central Cancer Treatment Group study in July 1994. A total accrual of 293 patients was planned for the sample size, using survival as the primary end point. The experimental arm (RT/BUdR + PCV) was to be compared with the control arm (RT + PCV) using a one-sided alpha = 0.05, with a power of 85% for detecting an increase in median survival from 160 to 240 weeks, assuming a 3-year follow-up after enrollment completion. RESULTS: Between July 1994 and August 1996, 134 patients were randomized to EBRT + PCV (non-BUdR patients) and 134 to EBRT/BUdR + PCV (BUdR patients). The study was closed before the full-anticipated accrual on the basis of an interim analysis that predicted no survival benefit for the BUdR arm. Of the 268 patients, 41 and 37, respectively, were ineligible or canceled primarily on the basis of the central pathology review findings. Thus, 93 patients and 97 patients were eligible/analyzable in the non-BUdR and BUdR arms, respectively. Patient characteristics were well balanced in both arms, with most <50 years old and in the RTOG recursive partitioning analysis (RPA) Class I category. The minimal potential follow-up was 4.6 years. The median survival for non-BUdR patients was 4.1 years compared with 4.6 years for the BUdR patients (p = 0.61). The 4-year overall survival rate was 51% in both arms. For RPA Class I patients (the best prognostic class), the median survival had not been reached for non-BUdR patients (4-year survival rate 61%) and was 5.6 years for BUdR patients (4-year survival rate 64%; p = 0.91). Each arm was also compared with the RTOG historical database for RPA Class I patients with no statistically significant difference found in overall survival (BUdR vs. historical, p = 0.31 and non-BUdR vs. historical, p = 0.48). Grade 4 toxicity occurred in 15 and 17 patients in the non-BUdR and BUdR arms, respectively, with one treatment-related death in the BUdR group. CONCLUSION: No survival advantage was noted by adding BUdR to EBRT and PCV in this patient population