The best offense.
The Study: That’s right, we said non-small cell. The NVALT-11 trial randomized 175 patients with stage III NSCLC remaining progression-free after definitive chemoradiation to either PCI or observation. PCI regimens were 36 Gy / 18, 30 Gy / 12, or 30 Gy / 10. No re-staging brain MRI was performed either before or after PCI, but, remember, brain MRI is not indicated following definitive treatment unless symptomatic. The primary endpoint of rate of symptomatic brain mets at 2 years was significantly decreased with PCI from 27% → 7%, roughly translating to a number needed to treat of 5. But to put things in perspective, the median time to developing brain mets wasn’t even reached in either arm. And there was no impact on median overall (24 months) or progression free (12 months) survival. Neurocognitive toxicity, as expected, was worse with PCI. Most importantly, the big "what-ifs" in today's era of oncology make these results difficult to apply, namely in the context of effective immunotherapy and salvage radiosurgery. While there is no arguing that PCI works, applying it broadly doesn’t appear to meaningfully impact survival.
Bottom Line: PCI for stage III NSCLC slashes the development of symptomatic brain mets with no effect on survival. | De Ruysscher, J Clin Oncol 2018