A National Cancer Database Analysis of Radiofrequency Ablation versus Stereotactic Body Radiotherapy in Early-Stage Non–Small Cell Lung Cancer

Summary

Investigators from the University of California and Sinai Medical Center compared the overall survival (OS) and rate of 30-day readmission after radiofrequency (RF) ablation and stereotactic body radiotherapy (SBRT) in patients with early-stage non–small cell lung cancer (NSCLC). Study population was extracted from the National Cancer Database (NCBB), and patients with stage 1a and 1b NSCLC treated with primary RF ablation or SBRT from 2004 to 2014 were included. Patients treated at low-volume centers, defined as facilities below the 95th percentile in volume of cases performed, were excluded. The final cohort comprised 4,454 cases of SBRT and 335 cases of RF ablation. Estimated median survival and follow-up were 38.8 months and 42.0 months, respectively. Patients treated with RF ablation had significantly more comorbidities (P < .001) and higher risk for an unplanned readmission within 30 days (hazard ratio = 11.536; P < .001). No difference in OS for the unmatched groups was found on multivariate Cox regression analysis (P = .285). No difference was found in the matched groups with 1-, 3-, and 5-year OS of 85.5%, 54.3%, and 31.9% in the SBRT group vs 89.3%, 52.7%, and 27.1% in the RF ablation group (P = .835). The authors concluded that there was no significant difference in OS between patients with early-stage NSCLC treated with RF ablation and SBRT.



Figure: Log-rank analysis of the propensity score adjusted Kaplan-Meier survival curves comparing treatment types and stratified by propensity score. The number of patients at risk is listed below each time interval. P value for the log-rank test is included. RFA = RF ablation.

Commentary

The results of this study shows that RF ablation and SBRT have similar OS for stage 1 NSCLC, in accordance to recent systematic review and other prospective studies as mentioned by the authors. Nonetheless, the rate of unplanned 30-day readmission was significantly higher in patients submitted to RF ablation. This could be explained by the presence of significantly more comorbidities in the RF ablation group (P = 0.001), but it is also likely related to the more invasive nature of percutaneous ablation compared to SBRT. Major limitations of the study were the significant sample size discrepancy between two groups, limited accuracy of data from NCDB and lack of information regarding technical procedure specifications and rate of local tumor control. However, this study provides a good insight of “real world” practice and how thermal ablation has been incorporated in the management of inoperable stage 1 NSCLC. It also paves the way for newer thermal ablative technologies such as microwave, which has the potential to improve local control by direct energy propagation, associated with less complication rates given the lower device profile.

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Post Author:
Ricardo Yamada, MD
Assistant Professor
Department of Radiology
Division of Vascular and Interventional Radiology
Medical University of South Carolina