Stereotactic Body Radiation Therapy for Pulmonary Metastasis from Colorectal Adenocarcinoma: Biologically Effective Dose 150 Gy is Preferred for Tumour Control

摘要

? 2023Aims: To compare the local control rate of pulmonary metastatic lesions in colorectal adenocarcinoma treated with stereotactic body radiation therapy (SBRT) using a biologically effective dose with an α/β ratio of 10 (BED10) of 150 Gy. Materials and methods: We analysed 231 pulmonary metastatic lesions from colorectal adenocarcinoma treated with SBRT in 135 patients. The patients were referred for the control of oligometastatic or oligoprogressive disease in the lungs. A dose of 40–60 Gy in three to eight fractions was delivered. The local control per tumour (LCpT) by BED10 was evaluated. The local control per patient (LCpP), pulmonary progression-free survival (PPFS), any progression-free survival (APFS) and overall survival were also reported as clinical outcomes. Results: A significant difference was observed in the LCpT between the BED10 groups (P < 0.001). The 1-, 2- and 3-year LCpT were 38.9%, 25.9% and 25.9% in BED10 < 100 group; 84.1%, 62.6% and 60.4% in 100 ≤ BED10 < 150 Gy group; and 97.3%, 94.9% and 85.2% in BED10 ≥ 150 Gy group, respectively. BED10 ≥ 150 Gy remained significant in the multivariate analysis of LCpT. The 3-year LCpP, PPFS, APFS and overall survival rates were 62.7%, 26.5%, 24.8% and 67.7%, respectively. Oligoprogression (versus oligometastasis), multiple pulmonary nodules and extrapulmonary metastasis were associated with a poor prognosis. Conclusion: A BED10 ≥ 150 Gy may be required to achieve sufficient local control. The indications for SBRT and the extent of metastatic disease should be assessed for proper estimation of the clinical outcomes.