Stereotactic ablative radiotherapy (SABR) in non-surgical non small cell lung cancer: Effects on respiratory function

AIM:To study lung function and treatment-related radiological and clinical toxicity in a cohort of patients with non-small cell lung cancer (NSCLC) who underwent Stereotactic Ablative Radiotherapy (SABR). METHODS:31 patients with NSCLC stage IA-IB unfit/refusing surgery were treated with single Volumetric Modulated Arc Therapy with fractionation schedule depending on tumor location. Follow-up was performed at 45, 135, 225, 315 days (T45, T135.. by means of body plethysmography, diffusion capacity for CO (D L CO) and blood gas analysis. RESULTS: preliminary analysis was performed on 31/31 patients at T45, 25/31 at T135, 22/31 at T225 and 13/31 at T315. Total lung capacity (TLC) decreased significantly,without changes in forced expiratory volume in 1s /vital capacity ratio, from 6.02±1.30 liters to 5.54±1.33 at T225 (p L CO (but not ratio between D L CO and dilution alveolar volume D L CO/VA) decreases significantly since T45. Arterial oxygen tension (PaO2) was slightly reduced only until T135 (75.2±8.4 vs 71.9±8.5 mmHg, p L CO reduction (p CONCLUSIONS:Preliminary data suggest good tolerability for SABR with slight persistent lung volume and D L CO reduction but only transient PaO2 reduction over time.