Robotic Stereotactic Ablative Radiotherapy for Patients with Early-Stage Lung Cancer: Results of an Interim Analysis.

BACKGROUND/

OBJECTIVES

Surgery is the primary treatment for early-stage lung cancer. Patients with medically inoperable lung carcinomas and patients who refuse to undergo surgery are treated with definite radiotherapy. Stereotactic ablative radiotherapy (SABR) is a compelling non-invasive therapeutic modality for this group of patients that confers promising results.

METHODS

We report an interim analysis of an ongoing trial. Eighty-one patients with medically inoperable early-stage (T1,2N0) lung cancer underwent SABR in our institution. SABR was delivered via the CyberKnife M6 robotic radiosurgery system. The endpoints of the analysis were treatment efficacy and tolerance.

RESULTS

There were no acute or late toxicities from the skin or the connective tissue of the thorax. A grade 2/3 lung injury of non-clinical significance was noted in 6% of patients, which was directly related to a higher biologically effective dose (BEDα/β = 3) and larger irradiation lung volumes in both univariate and multivariate analyses. A local control (LC) was achieved in 100% of the patients at the first follow-up, and the projected 24-month local progression-free survival (LPFS) rate was 95%. The projected 24-month disease-specific overall survival (OS) was 94%.

CONCLUSIONS

High LC and OS rates can be achieved with SABR for early-stage lung cancer, with minimal toxicity. This study continues to recruit patients.