Clinical outcome of hypofractionated breath-hold image-guided SABR of primary lung tumors and lung metastases

摘要

Background Stereotactic Ablative RadioTherapy (SABR) of lung tumors/metastases has been shown to be an effective treatment modality with low toxicity. Outcome and toxicity were retrospectively evaluated in a unique single-institution cohort treated with intensity-modulated image-guided breath-hold SABR (igSABR) without external immobilization. The dose–response relationship is analyzed based on Biologically Equivalent Dose (BED). Patients and methods 50 lesions in 43 patients with primary NSCLC (n?=?27) or lung-metastases of various primaries (n?=?16) were consecutively treated with igSABR with Active-Breathing-Coordinator (ABC?) and repeat-breath-hold cone-beam-CT. After an initial dose-finding/-escalation period, 5x12?Gy for peripheral lesions and single doses of 5?Gy to varying dose levels for central lesions were applied. Overall-survival (OS), progression-free-survival (PFS), progression pattern, local control (LC) and toxicity were analyzed. Results The median BED2 was 83?Gy. 12 lesions were treated with a BED2 of 80?Gy. Median follow-up was 15 months. Actuarial 1- and 2-year OS were 67% and 43%; respectively. Cause of death was non-disease-related in 27%. Actuarial 1- and 2-year PFS was 42% and 28%. Progression site was predominantly distant. Actuarial 1- and 2?year LC was 90% and 85%. LC showed a trend for a correlation to BED2 (p?=?0.1167). Pneumonitis requiring conservative treatment occurred in 23%. Conclusion Intensity-modulated breath-hold igSABR results in high LC-rates and low toxicity in this unfavorable patient cohort with inoperable lung tumors or metastases. A BED2 of