MRI-guided stereotactic body radiation therapy for very elderly patients with primary lung cancer: a retrospective analysis of safety and efficacy profiles.

Purpose: Non-small cell lung cancer is the most common malignancy of the lung, with over 40% of the cases in patients aged 75 years or older. Many of these patients are inoperable due to comorbidities, limiting treatment options. Stereotactic body radiotherapy (SBRT) offers a curative alternative, achieving local control (LC) rates similar to surgery with manageable toxicity. This retrospective analysis aimed to investigate the efficacy and safety of MRI-guided SBRT (MRIgSBRT) for elderly lung cancer patients.

Materials and methods: Data of patients aged ≥ 75 years, treated in our Institution between 2017 and 2023, were retrospectively collected. Survival curves for local recurrence-free survival (LRFS), progression-free survival and overall survival (OS) were estimated using the Kaplan-Meier method. Toxicity was assessed using the Common Terminology Criteria for Adverse Events (CTCAE version 5.0) scale.

Results: The study included 38 patients with a total of 45 lung lesions, median age of 82 years (range 75-87). The median total radiotherapy dose was 62,5 Gy (range 24-75 Gy) delivered in 5 fractions (range 3-8). The median follow-up was of 16.9 months (range 0,97-66,7). The 1-, 2- and 3-year OS rates were 98% 96% and 80%, respectively, while the 1-, 2- and 3-year LRFS was 97,5%. Six patients (15.78%) and one patient (2.63%) had late G1 radiation-induced pneumonia and G2 dyspnoea, respectively.

Conclusions: MRIgSBRT is a valid therapeutic option for patients aged ≥ 75 with comorbidities, frailty and risk factors limiting their performance status and eligibility for invasive treatments, offering good LC and favourable toxicity profile.