Stereotactic Body Radiotherapy for Lung Oligo-metastases: Systematic Review and International Stereotactic Radiosurgery Society Practice Guidelines

Purpose: A systematic review of treatment characteristics, outcomes, and treatment-related toxicities of stereo-tactic body radiation therapy (SBRT) for pulmonary oligometastases served as the basis for development of this International Stereotactic Radiosurgery Society (ISRS) practice guideline. Methods: In accordance with PRISMA guidelines, a systematic review was performed of retrospective series with & GE;50 patients/lung metastases, prospective trials with & GE;25 patients/lung metastases, analyses of specific high -risk situations, and all randomized trials published between 2012 and July 2022 in the MEDLINE or Embase database using the key words "lung oligometastases", "lung metastases", "pulmonary metastases", "pulmonary oligometastases", "stereotactic body radiation therapy (SBRT)" and "stereotactic ablative body radiotherapy (SBRT)". Weighted random effects models were used to calculate pooled outcomes estimates. Results: Of the 1884 articles screened, 35 analyses (27 retrospective-, 5 prospective, and 3 randomized trials) reporting on treatment of >3600 patients and >4650 metastases were included. The median local control was 90 % (Range: 57-100 %) at 1 year and 79 % (R: 70-96 %) at 5 years. Acute toxicity & GE;3 was reported for 0.5 % and late toxicity & GE;3 for 1.8 % of patients. A total of 21 practice recommendations covering the areas of staging & patient selection (n = 10), SBRT treatment (n = 10), and follow-up (n = 1) were developed, with agreements rates of 100 %, except for recommendation 13 (83 %). Conclusion: SBRT represents an effective definitive local treatment modality combining high local control rates with low risk of radiation-induced toxicities.