Radiotherapy Doses Evaluated in NSCLC

A randomized phase 2 study found that 30 Grays (Gy) in 1 fraction is equivalent to 60 Gy in 3 fractions in terms of toxicity, progression free survival (PFS) and overall survival (OS) for patients with non-small cell lung cancer (NSCLC), according to results presented at the International Association for the Study of Lung Cancer (IASLC) 17^th Annual World Conference on Lung Cancer in Austria.¹

The study was conducted to compare incidence of Radiation Therapy Oncology Group (RTOG) grade 3 or higher adverse events associated with 2 different Stereotactic Body Radiation Therapy (SBRT) regimens for patients with medically inoperable NSCLC.

Ninety-eight patients with NSCLC who had documented medical conditions that precluded lobectomy, and biopsy-proven peripheral T1/T2, N0 (clinically node negative by PET), and M0 tumors were included in the study. All patients received SBRT treatment. Patients were randomized to receive either 30 Gy in 1 fraction (Arm 1) or 60 Gy in 3 fractions (Arm 2) over at least 8 days. Secondary endpoints included local control, greater than 1 year toxicity, OS, and PFS.

Thirteen patients (27%) in Arm 1 and 16 patients (33%) in Arm 2 experienced RTOG grade 3 AEs. There were no grade 4 AEs. Thoracic grade 3 AEs were experienced by 8 patients (16%) in arm 1 and 6 patients (12%) in Arm 2. There were no differences in OS or PFS survival. OS at 2 years was 71% for Arm 1 and 61% for Arm 2. PFS at 1 year was 63% for Arm 1 and 51% for Arm 2.

The authors concluded that there is no significant difference between treating patients with 30 Gy in 1 fraction and 60 Gy in 3 fractions for toxicity, OS, or PFS.

Reference

1. Gomez Suescun JA, Videtic GM, Stephans K, et al. Phase II randomized study of 2 SBRT regimens for medically inoperable patients with node negative peripheral NSCLC. Paper presented at: International Association for the Study of Lung Cancer 17^th World Conference on Lung Cancer; December 2016; Vienna, Austria.