Safety and Clinical Efficacy of Selective High Dose Radioembolization for Treatment of Breast Cancer Liver Metastases.

Breast cancer is the second most common cancer globally and the leading cause of cancer-related death among females worldwide. Treatment options for patients with liver metastases from breast cancer are very limited and prognosis remains poor. Radioembolization has emerged as a promising treatment for patients however there is a lack of ideal dosimetry techniques specific for breast cancer. The benefit of targeted high dose selective internal radiation therapy has been established for treatment in hepatocellular cancer and other malignancies however there is limited information on use in breast cancer. This study examines the safety and clinical efficacy of high dose radiation segmentectomy for treatment of patients with breast cancer liver metastases.

Materials and Methods:

This is an IRB approved retrospective review. From March 2021 – July 2023, a total of 15 patients underwent targeted high dose segmentectomy for breast cancer liver metastases. Demographic information, cancer status, receptor status, and number of lines of prior chemotherapy were recorded. Size Treatment consisted of 1-2 sessions of selective administration of yttrium-90 glass microspheres with a target dose of 200Gy using MIRD model dosimetry. Safety parameters evaluated were pre and post procedure liver chemistry, MELD and ALBI scores. Adverse events were monitored. Clinical efficacy was evaluated using RECIST and PERCIST criteria.

Results: Procedure was technically successful in 100% of patients. 0 serious adverse events were encountered. 3 of 15 patients encountered a transient increase in total bilirubin. Objective response was seen in 12 of 15 patients. 8 of 15 patients had a complete response of the target lesion. 6 of 15 patients had progression of disease in non-targeted area of the liver at 12 months.  The 1 year overall survival was 12 of 15 (80%). Lesions less than 6cm were significantly more likely to have an objective response p< 0.01 or complete response p< 0.001.

Conclusion:

Selective targeted high dose radioembolization for treatment of breast cancer liver metastases is safe and effective at target tumor dose of 200 Gy. Patients with limited disease and tumor burden less than 6 cm are likely to benefit the most.