Phase II study of stereotactic body radiotherapy to primary tumor and metastatic locations in oligometastatic nonsmall-cell lung cancer patients.

BACKGROUND

Stereotactic body radiotherapy (SBRT) has emerged as a treatment modality in patients presenting with oligometastatic nonsmall-cell lung cancer (NSCLC). SBRT is used as a local consolidative treatment to metastatic disease sites. The majority of patients included in SBRT trials for oligometastatic NSCLC have controlled primary tumors and brain metastases.

PATIENTS AND METHODS

Oligometastatic NSCLC patients with ≤5 metastatic lesions were included in a prospective phase II trial to evaluate efficacy and toxicity of SBRT to all disease sites, primary tumor and metastatic locations. SBRT to a dose of 50 Gy in 10 fractions was delivered. Positron emission tomography-computed tomography (PET-CT) was carried out at baseline and 3 months after SBRT to evaluate the metabolic response rate according to PET Response Criteria in Solid Tumors (PERCIST). The progression-free survival (PFS) and overall survival (OS) were calculated using Kaplan-Meier method from start of chemotherapy or radiotherapy. Side-effects were scored using the National Cancer Institute Common Terminology Criteria for Adverse Events (NCI CTCAE) version 3.0.

RESULTS

Twenty-six patients received SBRT after induction chemotherapy (n = 17) or as a primary treatment (n = 9). Median follow-up was 16.4 months. Overall metabolic response rate was 60% with seven patients (30%) achieving a complete metabolic remission and 7 (30%) a partial metabolic response. Any acute grade 2 toxicity was observed in four patients (15%) and grade 3 pulmonary toxicity in two patients (8%). Median PFS and OS were 11.2 and 23 months. The 1-year PFS and 1-year OS rate were 45% and 67%, respectively.

CONCLUSION

SBRT to all disease sites, primary tumor and metastatic locations, in oligometastatic NSCLC patients produced an acceptable median PFS of 11.2 months.