White matter changes on magnetic resonance imaging following whole-brain radiotherapy for brain metastases

The purpose of this study was to evaluate white matter (WM) abnormalities induced by WBRT.

Twenty-four patients (11 men and 13 women; age range 38-74 years, median 60 years) who survived for more than 1 year after completion of WBRT (radiation dose range 30-40 Gy, median 35 Gy) at our institution between January 2000 and June 2003 were followed up with magnetic resonance (MR) scans for 11-51 months (median 19 months). We evaluated WM changes attributable to WBRT as grade 0-6 and assessed possible contributing factors by statistical analysis.

WM changes were found in 20 patients: Eight were assessed as grade 2, three as grade 3, and nine as grade 5. In total, 12 patients developed grade 3 or higher WM changes. Age (<60 vs > or =60 years), sex, radiation dose (< or =35 vs >35 Gy), chemotherapy (with CDDP vs without CDDP), biologically effective dose (< or =120 vs >120 Gy1), and head width (<16.3 vs > or =16.3 cm) were found not to be relevant to the incidence or severity of the WM changes.

Long-term survivors who have under-gone WBRT may have a higher incidence of WM abnormalities.