Necrosis for the mostest.

Top Line: Radionecrosis is classically seen as an undesired risk to mitigate during radiosurgery planning.

The Study: We’re here to reframe. Here is an international retrospective study of 697 patients with 4536 brain mets across 11 institutions in 4 countries treated with both immune checkpoint inhibition (ICI) and single fraction stereotactic radiosurgery (SRS) 18=20 Gy x 1 for non-small cell lung cancer, melanoma or renal cell carcinoma brain mets. Of these, 10% had subsequent radiographic radionecrosis. Interestingly, on multivariable analysis, presence of radiographic radionecrosis (HR 0.66) along with performance status (HR 0.98) were the only recorded features associated with improved overall survival. We’ll pause to note that’s quite the hazard ratio. Median survival after radiographic necrosis was 29 months versus 23 months without. There were the usual dosimetric suspects, such as the volume of brain receiving at least 12 Gy and prior history of whole brain, associated with developing radiographic necrosis—making the additional association with survival all the more intriguing.

TBL: A large international series of patients points to an interesting association between radiographic necrosis following brain SRS for brain mets and improved overall survival. | Lehrer, JNS 2022