Stereotactic body radiation therapy-based treatment model for stage I medically inoperable small cell lung cancer

To report on medically inoperable stage I small cell lung cancer (SCLC) patients for whom stereotactic body radiation therapy (SBRT) was employed to manage the primary tumor.

Review of our institutional review board approved SBRT registry revealed 6 cases of stage I SCLC out of 430 patients over a 6-year interval (2004-2010). All patients had biopsy proven disease and deemed medically inoperable by a thoracic surgeon. Our institutional approach was to treat with a combination of SBRT, platinum-etoposide chemotherapy (CHT) and prophylactic cranial irradiation (PCI). SBRT was delivered using a Novalis/BrainLAB platform and ExacTrac (BrainLab, Westchester, IL) for image guidance.

Patient characteristics included a median Karnofsky performance scale of 80, a median age of 68 years, 4 females, and 1 patient still smoking at presentation. Impaired pulmonary function caused inoperability in 50% of cases. Tumor characteristics included median tumor size of 2.6 cm and median positron emission tomography-standard uptake valuemax of 9. The SBRT was 60 Gy/3 fractions (3 patients), 50 Gy/5 fractions (2 patients), 30 Gy/1 fraction (1 patient). Median follow-up was 11.9 months. There was no grade 3 or higher, and 1 grade 2, toxicity. Three patients were alive at analysis and 3 patients had died of non-cancer causes. At 1 year, local control was 100%, there was no regional nodal failure, and 1 patient had distant failure (liver). Overall and disease-free survivals at 1 year were 63% and 75%, respectively.

Employing SBRT for stage I medically inoperable SCLC is rational, with excellent local control and encouraging disease-specific survival. The absence of regional nodal failure supports positron emission tomography for mediastinal staging. Platinum-based CHT may be feasible in vulnerable populations.