Stereotactic body radiotherapy to the left lung in right lateral decubitus: A challenging case report

This case report describes a lung stereotactic body radiotherapy (SBRT) treatment complicated by the patient's inability to tolerate standard supine positioning, requiring simulation and delivery in the right lateral decubitus position. Five major workflow challenges were encountered involving patient positioning, 4DCT acquisition, treatment planning involving gantry‑clearance limitations, patient‑specific QA, and CBCT‑based image guidance. Customized solutions, including non-standard respiratory-surrogate placement for 4DCT, off‑center isocentering, customized limited‑arc CBCT, and measurement‑based patient-specific QA, enabled safe and effective treatment. This case highlights the need for adaptable SBRT workflows for patients unable to tolerate conventional positioning.