Effects of radiotherapy after hyperbaric oxygenation on malignant gliomas

Abstract

The purpose of this non-randomized trial was to evaluate the efficacy of radiotherapy combined with hyperbaric oxygen (HBO) in patients with malignant glioma. Between 1987 and 1997, 29 patients in whom computerized tomography (CT) or magnetic resonance imaging (MRI) scans showed post-operative residual tumours were locally irradiated with nitrosourea-based chemotherapy. Treatments were consecutively combined with HBO at two institutions since 1991 and 1993. Fifteen patients were irradiated daily after HBO, and the periods of time from decompression to irradiation were within 15 and 30 min in 11 and four patients respectively. Fourteen other patients were treated without HBO. Tumour responses were assessed by CT or MRI scans and survival times were compared between the treated groups. In the HBO group, 11 of 15 patients (73%) showed ≥ 50% tumour regression. All responders were irradiated within 15 min after decompression. In the non-HBO group, four of 14 patients (29%) showed tumour regression. The median survivals in patients with and without HBO were 24 and 12 months, respectively, and were significantly different ( P < 0.05). No serious side-effects were observed in the HBO patients. In conclusion, irradiation after HBO seems to be a useful form of treatment for malignant gliomas, but irradiation should be administered immediately after decompression. © 1999 Cancer Research Campaign

Phase II trial of radiotherapy after hyperbaric oxygenation with chemotherapy for high-grade gliomas

“…Moreover, the administration of radiotherapy after HBO enabled the application of conventional fractionation of radiotherapy and the combination of modern radiotherapy techniques including patient fixation and three-dimensional conformal therapy. Several reports have also indicated the antitumour activity of irradiation immediately after HBO in conventionally fractionated irradiation (Kohshi et al, 1999;Beppu et al, 2003). Kohshi et al (1999) applied radiotherapy after HBO to high-grade glioma patients with residual disease.…”

“…This hypothesis suggests that radiotherapy immediately after HBO may increase the sensitivity of hypoxic tumour cells to radiotherapy without increasing the injury to normal brain tissue. Recently, several studies have shown the feasibility of this treatment regimen with HBO applied prior to radiotherapy for high-grade gliomas (Kohshi et al, 1999;Beppu et al, 2003;Ogawa et al, 2003). However, there has been little information regarding the clinical efficacy and safety of this treatment strategy.…”

Preservation of tumour oxygen after hyperbaric oxygenation monitored by magnetic resonance imaging

“…Therefore, irradiation immediately after decompression is considered to be effective for malignant tumours without exerting the influence of radiation on normal tissue. Furthermore, multivariate analysis in our small series revealed that combination with HBO was a good predictive prognostic factor for survival (Kohshi et al, 1999).…”

Intravascular HbO2 saturations, perfusion and hypoxia in spontaneous and transplanted tumor models

“…9,10 Additional clinical studies seeking to manipulate tumor blood flow and oxygen delivery, either up or down, in order to improve either radioor chemotherapeutic response are also in progress. 11,12 Despite the encouraging pre-clinical results of these types of strategies, [13][14][15] the underlying physiological alterations remain poorly understood and a variety of different tumor models must continue to be utilized to obtain detailed quantitative measurements of tumor vascular structure and function. Key questions remain as to the differences in vascular structure and function among various transplantable tumor models, as well as between spontaneous and transplanted tumors.…”