Clinical outcomes and tumor laterality analysis after stereotactic body radiotherapy for peripheral pulmonary lesions: a retrospective single-institution study

Abstract

Stereotactic body radiotherapy (SBRT/SABR) is a curative treatment for early-stage lung cancer in patients unsuitable for surgery. While tumor laterality is routinely considered in surgical decision-making, its relevance to outcomes after SBRT remains unclear. This study evaluated clinical outcomes after SBRT and explored the association between tumor laterality and treatment outcomes. This single-institution retrospective study included consecutive patients treated with SBRT for peripheral pulmonary lesions between 2011 and 2024. Prescribed ablative doses corresponded to a median BED₁₀ > 100 Gy. Local recurrence (LR), loco-regional recurrence (LRR), distant metastases (DM), and cancer-specific death (CSD) were analyzed using competing-risk models; progression-free survival (PFS) and overall survival (OS) using Kaplan–Meier method. A total of 115 patients (median age 75 years) were treated with SBRT. The most common regimens were 42–54 Gy in three or 50–55 Gy in five fractions (median BED₁₀=116 Gy). Toxicities were mild and transient. At a median follow-up of 39 months, 5-year OS and PFS were 55% and 39%, with a 5-year cumulative incidence of LR of 7.1%. Left-sided tumors showed worse outcomes, including shorter OS (HR = 2.96, p  < 0.001), PFS (HR = 3.30, p  < 0.001), higher LRR (HR = 3.60, p  = 0.015), and CSD (HR = 3.96, p  = 0.003). These associations remained after adjustment for selected covariates in exploratory multivariable analyses. SBRT achieved excellent local control and favorable safety outcomes in routine clinical practice. Left-sided lesions were associated with less favorable clinical outcomes than right-sided lesions, suggesting that tumor laterality may warrant further investigation in patients undergoing SBRT.