Imaging-guided adaptive radiation therapy in limited-stage small cell lung cancer: Current evidence and clinical perspectives.

Small cell lung cancer (SCLC) remains among the most aggressive thoracic malignancies and continues to present major therapeutic challenges despite advances in multimodality treatment. Limited-stage SCLC (LS-SCLC), representing approximately one-third of cases, is conventionally managed with concurrent chemoradiotherapy delivered with curative intent. Radiation therapy (RT) is central to treatment; however, rapid treatment related anatomical and volumetric changes may alter target geometry and reduce the accuracy of plans generated from baseline imaging. Adaptive RT (ART) has emerged as an imaging-guided strategy that enables treatment modification according to evolving anatomy during RT delivery. This narrative review examines the rationale and current evidence supporting imaging-guided ART in LS-SCLC, with emphasis on imaging-informed decision-making and contemporary implementation considerations. LS-SCLC represents a biologically compelling setting for adaptive treatment because of its rapid treatment responsiveness; however, important uncertainties remain regarding patient selection, imaging schedules, adaptive triggers, and workflow standardization. Prospective studies incorporating standardized adaptive workflows and clinically meaningful endpoints are required to determine whether observed dosimetric advantages translate into measurable clinical benefit.