Treatment outcomes and prognostic factors of metastasis-directed radiotherapy for oligometastatic endometrial cancer

Purpose: To evaluate outcomes and prognostic factors associated with metastasis-directed radiotherapy (MDRT) for oligometastatic endometrial cancer. Methods and materials:We retrospectively analyzed 101 patients (203 lesions) with 5 metastatic lesions treated with MDRT between 2015 and 2025.Oligometastatic states were classified according to the ESTRO-EORTC framework.Endpoints were overall survival (OS), progression-free survival (PFS), and local failure-free survival (LFFS).Prognostic factors were assessed using multivariable Cox regression, and toxicities were graded using CTCAE v5.0.Results: At a median follow-up of 36.4 months, 3-year OS, PFS, and 2-year LFFS rates were 76.3%, 24.5%, and 64.7%, respectively.Multivariable analyses revealed that favorable oligometastatic disease classification, endometrioid histology, favorable radiotherapy (RT) response, and maximum dose 40 Gy (equivalent dose in 2 Gy fractions, / = 10) were independently associated with improved OS.All factors except for histology were significant for PFS.In a propensity-matched analysis, repeated MDRT for recurrent oligometastases showed a trend toward improved OS compared with a single course.One grade 3 event occurred with no grade 4 toxicity.Conclusions: MDRT yielded favorable outcomes in oligometastatic endometrial cancer.Oligometastatic classification, histology, and RT response were major prognostic factors.MDRT may be a viable option within a multidisciplinary framework for de novo and recurrent oligometastases, but validation in prospective multicenter studies is warranted.