Target dissonance.

With stereotactic ablative radiation (SABR) being hyped with more and more impressive goals—think curing early-stage non-small cell lung cancer (NSCLC) sans surgery and prolonging survival in the setting of mets—this editorial poses the need to reexamine our laissez-faire attitude toward SABR clinical target volumes (CTV). For example, we’ve seen evidence that ensuring a less-steep dose fall-off during SABR for NSCLC where at least a 3 cm additional margin receives at least 20 Gy results in significantly better overall disease control. In practice, however, this undefined region of microscopic spread receives highly variable coverage depending on a wide array of technologies, motion management, and planning parameters. What’s more, bone/spine metastases are unique in the metastatic setting with contouring guidelines encouraging CTV margins. In summary, with the stakes higher than ever with SABR across many indications, “more intentional targeting (versus incidental exposure) of the CTV would ensure dosimetric coverage, but perhaps without appreciable increases in normal tissue complication risk if lower dose coverage is accepted.” | Katz, Clin Oncol 2022