Presented at ASTRO last year as a plenary, the MDA randomized trial of SRS alone vs SRS + WBRT is published in Lancet Oncology. This is an interesting trial, as it had a neurocognitive primary endpoint, which is one of the larger concerns with WBRT. This trial certainly adds to the data on the neurocognitive effects of WBRT, however, one can't help but focus on the survival difference between the arms. I would venture that the data presented in the paper, especially the lack of any differences in neurologic deaths and the lack of any difference in the larger RTOG and Japanese trials, that this is not a treatment effect. Then the question remains, what did cause this, and could it have influenced the primary endpoint? Another point that I will add to this is the trial was stopped due to a 4 month evaluation of memory, as opposed to a later time point. I would suggest that this may be too early of a measurement time for the long term effects of WBRT.
Nonetheless, this trial does support the use of SRS alone in this population and the prospective nature of the neurocognitive evaluation is to be applauded.
[Articles] Neurocognition in patients with brain metastases treated with radiosurgery or radiosurgery plus whole-brain irradiation: a randomised controlled trial: "It is unclear whether the benefit of adding whole-brain radiation therapy (WBRT) to stereotactic radiosurgery (SRS) for the control of brain-tumours outweighs the potential neurocognitive risks. We proposed that the learning and memory functions of patients who undergo SRS plus WBRT are worse than those of patients who undergo SRS alone. We did a randomised controlled trial to test our prediction."