Old but new methods in radiation oncology: hyperbaric oxygen therapy.

The presence of hypoxic tumor cells is widely regarded as one of the main reasons behind the failure to control malignant tumors with radiotherapy treatments. Since hyperbaric oxygenation (HBO) improves the oxygen supply to the hypoxic tumor cells, HBO therapy has previously been used in combination with simultaneous radiotherapy to treat malignant tumors. In some clinical trials, significant improvements in local control and survival have been seen in cancers of the head and neck and the uterine cervix. However, the delivery of simultaneous HBO therapy and radiotherapy is both complex and time-consuming, with some trials reporting increased side effects. As a result, the regimen of HBO therapy in combination with simultaneous radiotherapy has yet to be used as a standard treatment for malignant tumors. In recent years, however, radiotherapy immediately after HBO therapy has been emerging as an attractive approach for overcoming hypoxia in cancer treatment. Several studies have reported that radiotherapy immediately after HBO therapy was safe and seemed to be effective in patients with high-grade gliomas. Also, this approach may protect normal tissues from radiation injury. To accurately estimate whether the delivery of radiotherapy immediately after HBO therapy can be beneficial in patients with high-grade gliomas and other cancers, further prospective studies are warranted.

Phase II trial of radiotherapy after hyperbaric oxygenation with multiagent chemotherapy (procarbazine, nimustine, and vincristine) for high-grade gliomas: long-term results.

PURPOSE: To analyze the long-term results of a Phase II trial of radiotherapy given immediately after hyperbaric oxygenation (HBO) with multiagent chemotherapy in adults with high-grade gliomas. METHODS AND MATERIALS: Patients with histologically confirmed high-grade gliomas were administered radiotherapy in daily 2 Gy fractions for 5 consecutive days per week up to a total dose of 60 Gy. Each fraction was administered immediately after HBO, with the time interval from completion of decompression to start of irradiation being less than 15 minutes. Chemotherapy consisting of procarbazine, nimustine, and vincristine and was administered during and after radiotherapy. RESULTS: A total of 57 patients (39 patients with glioblastoma and 18 patients with Grade 3 gliomas) were enrolled from 2000 to 2006, and the median follow-up of 12 surviving patients was 62.0 months (range, 43.2-119.1 months). All 57 patients were able to complete a total radiotherapy dose of 60 Gy immediately after HBO with one course of concurrent chemotherapy. The median overall survival times in all 57 patients, 39 patients with glioblastoma and 18 patients with Grade 3 gliomas, were 20.2 months, 17.2 months, and 113.4 months, respectively. On multivariate analysis, histologic grade alone was a significant prognostic factor for overall survival (p < 0.001). During treatments, no patients had neutropenic fever or intracranial hemorrhage, and no serious nonhematologic or late toxicities were seen in any of the 57 patients. CONCLUSIONS: Radiotherapy delivered immediately after HBO with multiagent chemotherapy was safe, with virtually no late toxicities, and seemed to be effective in patients with high-grade gliomas.

Prospective trial of radiotherapy after hyperbaric oxygenation with chemotherapy for high-grade gliomas.

Twenty-one patients with high-grade gliomas were enrolled in a prospective trial of radiotherapy after hyperbaric oxygenation (HBO). Radiotherapy was administered in daily 2-Gy fractions up to a total dose of 60 Gy, and each fraction was delivered immediately after HBO. The current study indicated that radiotherapy immediately after HBO with chemotherapy was feasible for high-grade gliomas.