SABR vs Conventional Radiotherapy for Improved Outcomes in NSCLC
A recent study compared the effectiveness of stereotactic ablative body radiotherapy (SABR) with conventional full fractionated radiotherapy (CRT) in prolonging time to local failure in patients with inoperable stage I non-small cell lung cancer (NSCLC), presented at the International Association for the Study of Lung Cancer 18th Annual World Conference (October 15-18, 2017; Yokohama, Japan).
Previous research has demonstrated the effectiveness of SABR as a treatment methods for patients with inoperable stage I NSCLC. However, comparative studies have yet to weigh the benefits of SABR to more conventional radiotherapy options in this population.
In a randomized phase III trial, researchers attempted to compare the effectiveness of SABR with CRT in prolonging time to local failure in patients with stage I disease. A total of 101 patients who refused surgery or had inoperable disease were given SABR (63%; 54 Gy in three fractions or 48 Gy in four fractions) or CRT (35%; 66 Gy in 33 fractions or 50 Gy in 20 fractions). Patients were followed for up to 2 years.
Enrollment eligibility was defined as demonstrating good ECOG performance scores (0 or 1) and having at least a 2 centimeter distance between the tumor and the lobar bronchus bifurcation.
Results of the study showed that patients win the SABR group benefited from superior freedom from local failure compared with patients in the CRT group (HR, 0.29; 95% CI, 0.13-0.66; P = .002). Additionally, overall survival rates were favored in the SABR group (HR, 0.51; 95% CI, 0.51-0.91; P = .02).
Researchers acknowledged that adverse events were more common in patients in the SABR group; grade 3 toxicities were noted in nine patients in the SABR group, compared with 2 patients in the CRT group. A grade 4 toxicity was observed in one patient in the SABR group, but none in the CRT group.
In their concluding remarks, researchers asserted that SABR is a more effective treatment approach than CRT for patients with inoperable stage I NSCLC.—Zachary Bessette