Salvage Radiotherapy for Solitary Metachronous Bone Metastasis in Patients with Breast Cancer

Abstract

Aim: We assessed the efficacy and toxicity of salvage radiotherapy for solitary metachronous bone metastasis (SMBM) in patients with breast cancer.

Patients and methods: We retrospectively analyzed 17 patients with SMBM who were treated with salvage radiotherapy. First failure was detected as SMBM in all patients. Salvage radiotherapy using three-dimensional treatment planning was performed at a median total dose of 50 Gy. Median daily dose was 2.0 Gy.

Results: Median follow-up was 40 months. Local recurrence of SMBM was noted in only two patients. The 3-year overall survival, progression-free survival, and local control rates were 93%, 51%, and 85%, respectively. Median overall and progression-free survival were 74 and 30 months, respectively. Toxicities were mild, and bone fractures were not observed.

Conclusion: Salvage radiotherapy for SMBM was able to achieve higher local control rates without severe toxicity, as well as to provide longer progression-free survival; therefore, this may be an effective modality.

Keywords: Breast cancer; bone metastasis; oligometastases; radiotherapy.