Adult Brain Tumors Treatment (PDQ®): Treatment - Health Professional Information [NCI] - Treatment Option Overview
Repeat radiation therapy (re-irradiation)
Because there are no randomized trials, the role of repeat radiation after disease progression or the development of radiation-induced cancers is also ill defined. The literature is limited to small retrospective case series, which makes interpretation difficult. The decision to use repeat radiation must be made carefully because of the risk of neurocognitive deficits and radiation-induced necrosis. One advantage of radiosurgery is the ability to deliver therapeutic doses to recurrences that may require the re-irradiation of previously irradiated brain tissue beyond tolerable dose limits.
For many years, the nitrosourea carmustine (BCNU) was the standard chemotherapy added to surgery and radiation for malignant gliomas. This was based upon a randomized trial (RTOG-8302) of 467 patients conducted by the Brain Tumor Study Group that compared four regimens after initial resection:
- Semustine (methyl-CCNU).
- Radiation therapy.
- Radiation therapy plus carmustine.
- Radiation therapy plus semustine.
The radiation therapy plus carmustine arm had the best survival rate.[Level of evidence: 1iiA] A modest impact on survival using nitrosourea-containing chemotherapy regimens for malignant gliomas was confirmed in a patient-level meta-analysis of 12 randomized trials (combined HR death = 0.85; 95% CI, 0.78–0.91).
However, the oral agent, temozolomide, has since replaced the nitrosoureas as the standard systemic chemotherapy for malignant gliomas based upon a large multicenter trial (NCT00006353) of glioblastoma patients conducted by the EORTC-National Cancer Institute of Canada that showed a survival advantage.[21,22][Level of evidence: 1iiA] In that study, 573 patients with glioblastoma were randomly assigned to receive standard radiation to the tumor volume with a 2- to 3-cm margin (60 Gy, 2 Gy per fraction, over 6 weeks) alone or with temozolomide (75 mg/m2 orally per day during radiation therapy for up to 49 days, followed by a 4-week break, and then up to six cycles of five daily doses every 28 days at a dose of 150 mg/m2 increasing to 200 mg/m2 after the first cycle). Patients in the combined therapy group were given prophylactic therapy for pneumocystis carinii during the period of concomitant radiation therapy and temozolomide. OS was statistically significantly better in the combined radiation therapy/temozolomide group (HR for death = 0.6; 95% CI, 0.5–0.7; survival at 3 years was 16.0% vs. 4.4%).