Robustness of the neurological prognostic score in brain metastasis patients treated with Gamma Knife radiosurgery

OBJECTIVEThe neurological prognostic score (NPS) was recently proposed as a means for predicting neurological outcomes, such as the preservation of neurological function and the prevention of neurological death, in brain metastasis patients treated with Gamma Knife radiosurgery (GKRS). NPS consists of 2 groups: Group A patients were expected to have better neurological outcomes, and Group B patients were expected to have poorer outcomes. NPS robustness was tested in various situations.METHODSIn total, 3040 patients with brain metastases that were treated with GKRS were analyzed. The cumulative incidence of the loss of neurological function independence (i.e., neurological deterioration) was estimated using competing risk analysis, and NPS was compared between Groups A and B by employing Gray's model. NPS was tested to determine if it can be applied to 5 cancer categories—non–small cell lung cancer, small cell lung cancer, gastrointestinal tract cancer, breast cancer, and other cancers—as well as if it can...