As reported in JAMA Oncology by Swaminath et al, the Canadian phase III LUSTRE trial has shown no significant benefit in local tumor control with stereotactic body radiotherapy (SBRT) vs hypofractionated conventional radiotherapy (CRT) in patients with inoperable stage I non–small cell lung cancer (NSCLC).
Study Details
In the multicenter open-label trial, 233 patients with medically inoperable stage I disease (≤ 5 cm) were randomly assigned 2:1 between May 2014 and January 2020 to receive SBRT at 48 Gy in 4 fractions for peripheral NSCLC or 60 Gy in 8 fractions for central NSCLC (n = 154) or CRT at 60 Gy in 15 fractions (n = 79). Enrollment was closed early because of slow accrual. The primary outcome measure was local tumor control at 3 years. Local failures were centrally adjudicated.
Key Findings
Median follow-up was 36.1 months (interquartile range = 26.4–52.8 months). The local tumor control rate at 3 years was 87.6% (95% confidence interval [CI] = 81.9%–93.4%) in the SBRT group vs 81.2% (95% CI = 71.9%–90.5%) in the CRT group (hazard ratio [HR] = 0.61, 95% CI = 0.31–1.20, P = .15).
At 3 years, the event-free survival rate was 49.1% in the SBRT group vs 47.5% in the CRT group (HR = 1.02, 95% CI = 0.72–1.45, P = .87), and the overall survival rate was 63.5% vs 68.4% (HR = 1.18, 95% CI = 0.80–1.76, P = .40).
Minimal acute toxicity was reported. Late grade 3 or 4 toxicity was observed in 5 of 45 patients (11%) with central NSCLC and 2 of 109 patients (1.8%) with peripheral NSCLC in the SBRT group and in 1 of 19 patients (5%) with central NSCLC and 1 of 60 patients (2%) with peripheral NSCLC in the CRT group. One patient in the SBRT group with an ultracentral lesion died of an adverse event considered possibly related to treatment (hemoptysis).
The investigators concluded: “This [randomized controlled trial] compared lung SBRT with hypofractionated CRT that included central/ultracentral tumors. No difference was detected in [local tumor control] between groups. Severe toxic effects were limited, including patients with central tumors. The trial provides important prospective data evaluating SBRT; however, further research is necessary to determine if SBRT is more effective than CRT for peripheral and central NSCLC.”
Anand Swaminath, MD, of the Department of Oncology, McMaster University, and Division of Radiation Oncology, Juravinski Cancer Centre at Hamilton Health Sciences, Hamilton, Ontario, is the corresponding author of the JAMA Oncology article.
Disclosure: The study was supported by a Canadian Cancer Society Research Institute Impact grant. For full disclosures of all study authors, visit jamanetwork.com.
