Stereotactic body radiotherapy in operable patients with stage I NSCLC: where is the evidence?

Abstract

This review summarizes the evidence of stereotactic body radiotherapy (SBRT) as an alternative to surgery (lobectomy and sublobar resection) for stage I NSCLC. Three randomized trials comparing SBRT and surgery were initiated but all three were stopped early due to poor accrual. As the next level of evidence, results from matched-pair analyses performed in single-institutional (n = 4), multi-institutional (n = 3) and population-based (n = 3) settings are available. There was close agreement between all studies that SBRT is at least equivalent to sublobar resection making it the preferred treatment for a high-risk population. SBRT was equivalent to lobectomy in the endpoints of loco-regional control and cancer-specific survival. Disease-free survival and overall survival were inferior after SBRT compared with lobectomy in one and two studies, respectively, and not significantly different in all other studies. Consequently, for patients without relevant comorbidities, who are accepting the risk of a surgical procedure, lobectomy remains the standard of care.

Keywords:

• early stage NSCLC
• lobectomy
• operability
• SBRT
• sublobar resection

Financial & competing interests disclosure

The author has no relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript. This includes employment, consultancies, honoraria, stock ownership or options, expert testimony, grants or patents received or pending, or royalties.

No writing assistance was utilized in the production of this manuscript.

Key issues

• SBRT is the guideline-recommended standard of care for patient with stage I NSCLC if they are medically inoperable because of underlying comorbidities.

• In operable patients refusing surgery, SBRT achieved local tumor control, disease-free survival and overall survival similar to the current standard of lobectomy.

• Three studies comparing SBRT and surgery in a randomized fashion were stopped early due to very poor accrual leaving us without level I evidence.

• Matched-pair analyses and studies using propensity-score matching provide high level of evidence in the absence of randomized controlled trials.

• In total >10 such studies have been performed and published and all studies consistently report that SBRT appears at least equivalent compared with sublobar resection – wedge resection and segmentectomy – in terms of local tumor control and survival.

• SBRT appears to be noninferior to lobectomy, especially in elderly patients and patients at increased risk for surgical complications.

• SBRT is associated with significantly decreased post-treatment morbidity and mortality compared with sublobar resection and lobectomy.