Patterns of relapse in patients with high grade glioma receiving combined treatments including stereotactic re-irradiation for a first relapse.

PURPOSE: Bevacizumab and stereotactic treatment are efficient combined or alone in relapse glioma. However, patterns of relapse after this kind of salvage treatment have never been studied. The purpose of this unicentric retrospective analysis was to assess and understand the patterns of relapse of high grade glioma treated with stereotactic radiation, with or without bevacizumab. PATIENTS AND METHODS: Twenty patients with high grade glioma relapse received a stereotactic radiation; among them two patients received temozolomide and eight patients received bevacizumab; among the latter, four received also irinotecan. We matched the stereotactic radiation treatment planning scan with the images of the first treatment and of the second relapse in order to determine the patterns of failure and associate dosimetric profile. RESULTS: For the total population, median follow-up from the first diagnosis and relapse were 46.1 and 17.6 months, respectively. Among the 13 patients who relapsed, ten did not receive chemotherapy and three received it (P<0.05), two received temozolomide and one bevacizumab. Patients who received bevacizumab had no "out-of-field" recurrences. Among the 32 irradiated relapses, 15 were "in-field" recurrences; among them two were treated with bevacizumab and 13 were not (P<0.05). For the 32 lesions, a favourable prognostic factor of control was the association of a high-dose of irradiation and the use of bevacizumab. CONCLUSION: For patients with relapsed high grade glioma, local control was higher with combined bevacizumab and high-dose stereotactic radiation.

[Stereotactic radiotherapy of intracranial benign tumors]. / Radiothérapie en conditions stéréotaxiques des tumeurs bénignes intracrâniennes.

Stereotactic radiotherapy can be delivered in one fraction or in multiple fractions schedule. It is used in benign tumours such as meningiomas, mainly localized in the base of the skull, for acoustic schwannoma and pituitary tumours. Whatever the tumour, results with the Gamma Knife(®) are the most numerous, but those obtained by linear accelerators, adapted or dedicated, are comparable. The peripheral dose is preferred to the dose delivered to the isocentre. One fraction stereotactic irradiation should be proposed in small lesions and fractionated treatment for tumours larger. Whatever the tumour, the results are satisfactory with a control rate of 90%. However, this value reflects a disparity assessment, radiological stability for meningiomas, radiological stability and preservation of useful hearing in schwannoma and radiological stability and a decrease in hormonal secretions for pituitary adenomas. Overall complication rates are low. In total, the treatment of benign lesions with stereotactic irradiation gives satisfactory results with few complications.