On second thought.

Top Line: NRG CC001 showed that hippocampal avoidance and memantine reduced the risk of cognitive failure compared to standard whole brain radiation for patients with brain mets.

The Study: So, is the same true for prophylactic treatment in patients with SCLC? In this randomized phase 3 trial from the Netherlands, 168 patients with limited (70%) or extensive (30%) stage SCLC eligible for prophylactic cranial irradiation (PCI) were randomized to standard 25 Gy in 10 fractions whole brain radiation or the same with hippocampal avoidance (HA). Planning goals included hippocampus average dose of 8.5 Gy or less (bilateral), hippocampus D1% 10 Gy or less, absolute Dmax 28.75 Gy, and V115% < 1% of the PTV. The trial sought to determine if HA-PCI reduced the risk of neurocognitive failure 4 and 8 months after treatment. This was measured with the Hopkins Verbal Learning Test-Revised (HVLT-R) with failure defined as a drop in recall score of 5 points or more from baseline. At 4 months, there was no significant difference in neurocognitive failure with ~30% experiencing failure at 4 months in both arms. And there was still no difference at 8 months. In addition, and as expected, there was no difference in overall survival or the cumulative incidence of brain mets (15-20%) at 2 years. In 2019, abstract results of the PREMER trial found that HA-PCI did reduce the decline in delayed recall, and NRG CC003 is an ongoing randomized trial comparing standard PCI and HA-PCI.

TBL: This randomized trial did not demonstrate a reduction in neurocognitive failure with hippocampal avoidance for patients with SCLC receiving PCI. | Belderbos, J Thorac Oncol 2021