Stereotactic radiosurgery for patients with brain metastases

Abstract

www.thelancet.com/oncology Vol 15 June 2014 e247 between patients with two to four metastases and those with fi ve to ten metastases (3·07 mL vs 3·54 mL). Additionally, the minimum volume of 0·02 mL at the bottom of the range for both groups raises questions about whether the 1 T MRI used by the investigators is suffi ciently sensitive to measure tumours of this size. Fourth, stereotactic radiosurgery was not shown to be better than whole-brain radiotherapy in patients with fi ve to ten metastases. Wholebrain radiotherapy is the standard treatment for non-oligometastatic patients. A Cochrane review showed that stereotactic radiosurgery plus whole-brain radiotherapy does not increase survival in patients with two to four brain metastases compared with whole-brain radiotherapy alone, but this combination did increase the frequency of local control, particularly in patients with only one brain metastasis. Use of whole-brain radiotherapy has been questioned because it is associated with late eff ect on neurocognitive function, but brain tumour progression seems to adversely aff ect neurocognitive function more than whole-brain radiotherapy does. Neurological function needs more detailed assessment than the MiniMental State Examination used by Yamomoto and colleagues, and in view of the scarce data for wholebrain radiotherapy in their study, the conclusions about neurological function should be interpreted with caution. In conclusion, despite the relevance of Yamamoto and colleagues’ study, its messages need to be interpreted carefully. Oversimplifi cation of oncological treatment should be avoided. The feasibility of stereotactic radiosurgery in patients with up to ten brain metastases seems to be undiscussed in the context of modern radiation technology such as radiosurgery with CyberKnife or Linacbased. Therefore the use of stereotactic radiosurgery in non-oligometastatic patients—who died mainly from primary disease in Yamomoto and colleagues’ study—does not seem to be benefi cial.