Analysis of Pathologic Complete Response 10 Weeks After Radiotherapy—A Radiobiological Sin

To the Editor In the Measuring the Integration of Stereotactic Ablative Radiotherapy Plus Surgery for Early Stage Non–Small Cell Lung Cancer (MISSILE-NSCLC) trial, Palma and colleagues¹ reported on a well-executed phase 2 trial of stereotactic ablative radiotherapy (SABR) followed by definitive resection in early-stage NSCLC. Surprisingly, this study showed that the pathological complete response (pCR) rate was only 60% at 10 weeks after SABR. This is substantially lower than the assumed pCR rate and challenges us to revisit some commonly held assumptions about SABR.