Use of stereotactic body radiation therapy for medically inoperable multiple primary lung cancer

Introduction: To review outcomes of medically inoperable patients treated with stereotactic body radiation therapy (SBRT) for multiple primary lung cancer (MPLC). Methods: We retrospectively reviewed the charts of 10 patients (21 lesions) treated with SBRT for synchronous (seven), metachronous (one) or synchronous/metachronous lung cancers. All patients were male, medically inoperable and had a median age of 66 years. Eight patients had bilateral disease and two had unilateral disease. All patients had a histological diagnosis in at least one of the two lesions and four patients (44.4%) had both lesions biopsied. There were 18 T1 lesions and three T2 lesions. SBRT was in three fractions of 20 Gy or five fractions of 11-12 Gy to each lesion. Results: Mean and median follow up were 18.8 and 15.5 months, respectively. At analysis, six patients (60.0%) are alive, and five of these living patients (83.3%) have no evidence of disease recurrence or progression. Four patients (44.4%) developed distant metastatic disease. Twenty lesions (95.2%) achieved in-field local control. No patients experienced acute pulmonary complications and only two patients (22.2%) experienced late grade I lung toxicity as per the Radiation Therapy Oncology Group toxicity criteria. Conclusion: SBRT for MPLC in medically inoperable patients is a safe, feasible and effective treatment approach.