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. (C) 2016 Published by Elsevier Masson SAS on behalf of Societe francaise de radiotherapie oncologique (SFRO).