Purpose: To evaluate radiation therapy regimens for improvement in local control in patients with limited-stage small cell lung cancer.
Materials and methods: Radical radiation therapy results in 117 patients with limited-stage small cell lung cancer were retrospectively reviewed. The protocols in 90 patients were 40 Gy in 20 fractions (n = 28), 50 Gy in 25 fractions (n = 32), and 45 Gy in 30 fractions (accelerated hyperfractionation, n = 30). The other 27 patients received thoracic irradiation (dose range, 20-60 Gy; median dose, 54 Gy). All patients underwent systemic chemotherapy.
Results: The 5-year Kaplan-Meier survival rates in the patients with N0, N1, N2, and N3 disease were 26%, 34%, 18%, and 0%, respectively; the rates of in-field relapse were 25%, 36%, 26%, and 25%, respectively; and the rates of marginal relapse were 0%, 9%, 15%, and 29%, respectively. In 56% of patients with marginal relapse, the relapse site was at the upper margin. The 4-year in-field control rates for the patients who underwent 40, 50, and 45 Gy were 51%, 70%, and 56%, respectively.
Conclusion: Patients with N3 limited-stage small cell lung cancer should undergo a separate protocol, and the upper margin should be extended in patients with N2 or N3 disease.