[Hypofractionated stereotactic radiotherapy for brain metastasis: Benefit of additional whole brain radiotherapy?]

PURPOSE: To study overall survival, risk of neurological death, local recurrence and development of new brain metastasis in patients treated for brain oligometastases with hypofractionated stereotactic radiotherapy with CyberKnife® , according to the association or not with an additional whole brain irradiation.

PATIENTS AND METHODS: Institutional retrospective study of 102 patients treated for one to three brain metastasis: 76 with exclusive hypofractionated stereotactic radiotherapy and 26 with hypofractionated stereotactic radiotherapy and whole brain irradiation. Objectives were assessed and compared between these two groups according to the Kaplan-Meier method and Cox model.

RESULTS: Median follow-up was 18.8 months. There were no difference between exclusive hypofractionated stereotactic radiotherapy and hypofractionated stereotactic radiotherapy with whole brain irradiation for overall survival (respective median 21.5 and 20.1 months), risk of neurological death (respectively 9.2% and 15.4% at one year). At one year: the risk of cerebral progressive disease was greater in the group receiving exclusive hypofractionated stereotactic radiotherapy (respectively 43.4% vs. 26.2%, P=0.043), the risk of local recurrence was 25% versus 17.6% (P=0.28) and the development of new brain metastasis was 23.7% versus 11.5% (P=0.27). After salvage treatments, crude local control was similar in the two groups, respectively 78.6% and 73.5%. Whole brain irradiation has been avoided for 72.4% of patients in the group receving exclusive hypofractionated stereotactic radiotherapy.

CONCLUSION: Whole brain irradiation improves local control of brain metastatic disease in addition to hypofractionated stereotactic radiotherapy. Sparing whole brain irradiation for salvage treatments only does not affect overall survival or risk of neurological death in selected patients with favourable prognosis.