Salvage SBRT for Previously Irradiated Lung Cancer

Purpose: Patients with locally recurrent lung cancer after definitive radiation therapy pose a challenge in management. Surgery is often not an option and chemotherapy offers poor long-term local control. Stereotactic body radiotherapy (SBRT) was investigated in an attempt to salvage locally recurrent lung cancer. Materials and Methods: From March, 2009 to January, 2010, 8 patients who had previous definitive radiation therapy for lung cancer at least six months prior to the diagnosis of locally recurrent disease underwent SBRT. Local recurrence was documented by CT, PET, and/or biopsy. Patients had to have Karnofsky Performance Score (KPS) > 70, no distant metastases by CT/PET and brain MRI, and lesions amenable to SBRT. SBRT dose deliveries were 12 Gy x 4, 10 Gy x 5, 8 Gy x 5, or 20 Gy x 3 at the treating physician’s discretion. No adjuvant chemotherapy was delivered. Results: Eight patients were included in this study. Patient characteristics were: 6 females and 2 males; ages 50 - 85 (median 71); KPS 70 - 100 (median 80); previous stage I (T1/2 N0) in 4 and stage II/III (T1/2 N1/N2) in 3, 1 pt had limited stage small cell; previous radiation doses 50 - 68 Gy in 1.8/2.5 Gy fractions; time interval from previous RT to SBRT 8 - 57 months (median 36 months); target lesion diameters 1.2 - 7.3 cm (median 4.5 cm). With a median FU of 18 months (11 - 20 months), 7 patients are alive. Crude local/regional control to date is 86% with distant metastases in 1/7 surviving patients. Acute pulmonary toxicities: cough grade 0 7/8, grade 1 1/8; pain grade 0 6/8, grade 1 2/8; dyspnea grade 2 8/8. 1 patient died 12 months after SBRT due to complications from a hip fracture. Her disease was locally controlled at the time of death. Discussion: In carefully selected patients who recur locally after previous conventional radiation therapy for lung cancer, SBRT can offer a well tolerated salvage therapy. Further follow up is needed to assess long-term local control, survival and toxicities.