In the treatment of patients with interstitial lung disease (ILD) and early-stage non–small cell lung cancer (NSCLC), stereotactic ablative radiotherapy (SABR) has met the prespecified acceptability thresholds for both toxicity and efficacy, according to the single-arm, phase II ASPIRE-ILD study.
ASPIRE-ILD included 39 adult patients (median age 78 years, 59 percent male, 92 percent had a history of smoking) with fibrotic ILD and a diagnosis of T1-2N0 NSCLC. These patients received SABR at a dose of 50 Gy in 5 fractions, administered every other day.
The success of SABR was measured against the following criteria: the primary endpoint of median overall survival (OS) had to be longer than 1 year, with the rates of grade 3-4 toxic effects being <35 percent and of grade 5 toxic effects being <15 percent. Progression-free survival (PFS), local control (LC), quality-of-life outcomes, and changes in pulmonary function were also assessed as secondary outcomes.
At baseline, most patients (70 percent) reported dyspnoea. The median forced expiratory volume in first second of expiration was 80 percent predicted, the median forced vital capacity was 84 percent predicted, and the median diffusion capacity of the lung for carbon monoxide was 49 percent predicted. The median follow-up was 19 months.
The median OS was 25 months (95 percent confidence interval [CI], 14 months to not reached), with a 1-year OS rate of 79 percent (95 percent CI, 62–89; p<0.001). Median PFS was 19 months (95 percent CI, 13–28 months), while the 2-year LC rate was 92 percent (95 percent CI, 69–98).
For adverse events, 31 percent had grade 1-2 toxicities, 10 percent had grade 3 toxicities, none had grade 4 toxicities, and 7.7 percent had grade 5 toxicities (all due to respiratory deterioration).
The findings support the use of SABR for curative-intent treatment for patients with early-stage NSCLC and fibrotic ILD following a careful discussion of risks and benefits.