Treatment outcomes of re-irradiation using stereotactic ablative radiotherapy to lung: a propensity score matching analysis

• Published in: Radiation oncology (London, England) England), 2021-11, Vol.16 (1), p.222-222, Article 222
• Main Authors: Lee, Tae Hoon, Kim, Dong-Yun, Wu, Hong-Gyun, Lee, Joo Ho, Kim, Hak Jae
• Format: Article
• Language: English
• Subjects: Ablation; Adult; Aged; Aged, 80 and over; Cancer therapies; Carcinoma, Non-Small-Cell Lung - mortality; Carcinoma, Non-Small-Cell Lung - radiotherapy; Carcinoma, Non-Small-Cell Lung - surgery; Care and treatment; Clinical outcomes; Dose Fractionation, Radiation; Dosimetry; Esophagus; Female; Histology; Humans; Irradiation; Lung cancer; Lung Neoplasms - mortality; Lung Neoplasms - radiotherapy; Lung Neoplasms - surgery; Magnetic resonance imaging; Male; Matching; Medical imaging; Medical prognosis; Medical records; Metastases; Metastasis; Middle Aged; Patient outcomes; Patients; Prognosis; Propensity Score; Radiation therapy; Radiosurgery; Radiosurgery - mortality; Re-irradiation; Re-Irradiation - mortality; Retrospective Studies; Simulation; Stereotactic radiation therapy; Survival; Survival Rate; Tomography; Toxicity; Tumors
• ISSN: 1748-717X; 1748-717X
• DOI: 10.1186/s13014-021-01948-6

The purpose of this study was to compare the treatment efficacy and safety of re-irradiation (re-RT) using stereotactic ablative radiotherapy (SABR) and initial SABR for primary, recurrent lung cancer or metastatic lung tumor. A retrospective review of the medical records of 336 patients who underwent lung SABR was performed. Re-RT was defined as the overlap of the 70% isodose line of second-course SABR with that of the initial radiotherapy, and 20 patients were classified as the re-RT group. The median dose of re-RT using SABR was 54 Gy (range 48-60 Gy), and the median fraction number was 4 (range 4-6). One-to-three case-matched analysis with propensity score matching was used, and 60 patients were included in the initial SABR group of the matched cohort. The 1- and 2-year local control rates for the re-RT group were 73.9% and 63.3% and those for the initial SABR group in the matched cohort were 92.9% and 87.7%, respectively (P = 0.013). There was no difference in distant metastasis-free, progression-free, and overall survival rates. The crude grade ≥ 2 toxicity rates were 40.0% for the re-RT group and 25.0% for the initial SABR group (P = 0.318). Re-RT group had higher acute grade ≥ 2 toxicity rates (25.0% vs 5.0%, P = 0.031). One incident of grade 3 toxicity (pulmonary) was reported in the re-RT group; there was no grade 4‒5 toxicity. The local control rate of the in-field re-RT SABR was lower than that of the initial SABR without compromising the survival rates. The toxicity of re-RT using SABR was acceptable.