Prospective memory impairment following whole brain radiotherapy in patients with metastatic brain cancer

Objective: To investigate the prospective memory (PM) impairment following whole brain radiotherapy (WBRT) in cancer patients with brain metastases. Method: Eighty-one patients with metastatic brain cancer, agreeing to undergo WBRT, were enrolled and subjected to a battery of cognitive neuropsychological tests, including the mini-mental state examination (MMSE), verbal fluency test (VFT), digit span test (DST), and event-based and time-based prospective memory (EBPM and TBPM) tasks, before and after radiotherapy. Results: The patients with metastatic brain cancer after WBRT exhibited a significant decrease in the MMSE, DST, VFT, and EBPM scores (t = 6.258, 10.192, 5.361, -5.892, P < 0.01), but nonsignificant decrease in the TBPM scores (t = -1.172, P > 0.05). Conclusion: There is significant EBPM impairment in cancer patients with brain metastases after WBRT, whereas that in the TBPM remained relatively unaffected. The result suggests that EBPM impairment may be as an early cognitive impairment marker in patients with BM who undergo WBRT.