Radium-223 as an Additional Therapeutic Strategy in Highly Selected Patients With Metastatic Breast Cancer: A Case Report

Abstract

Radium-223 is commonly used in metastatic prostate cancer, targeting specifically bone metastases. The use of radium-223 remains, however, poorly evaluated in metastatic breast cancer. We report a case of radium-223 treatment in a 59-year-old patient with bone-only metastatic disease that progressed on multiple lines of systemic treatments. Radium-223 was very well tolerated and resulted in a regression of activity of bone metastases and in a 6-month progression-free survival. However, progression occurred in the liver, reflecting the fact that radium-223 should be combined with other systemic agents. This suggests that this therapeutic option is feasible and could be proposed in highly selected patients with bone metastatic disease outside of the prostate cancer field. Positron Emission Tomography appears also as a valuable tool for the evaluation of radium-223 efficacy.

Keywords: bone metastases; breast cancer; chemotherapy; positron emitted tomography; radium-223.

Figure 1

FDG PET-Scan before and after radium-223 treatment. The images circled in red depict a decrease of FDG uptake in axial skeletal metastases, reflecting a response to treatment. The images circled in green illustrate medullary regeneration in humerus and femur after treatment by showing homogeneization of FDG uptake. The images circled in yellow illustrate a decrease of FDG uptake in the right humeral head. For example, the Maximum Standardized Uptake Value (SUVmax) decreased of 59.2% in the at the 10th dorsal vertebra (12.38 in pre- to 5.05 in post- radium-223) and of 63.6% in the sacrum (14.91 in pre- to 5.43 in post-radium-223). The SUVmax of the Aorta bloodpool was 2.76 in pre- and 2.25 in post-radium-223 (-18%). The SUVmax in normal liver (reference) was 2.14 in pre- and 2.20 in post-radium-223 (+2.8%).

Figure 2

⁹⁹mTc-HDP bone scan before and after radium-223 treatment. The images circled in red depict a decrease of ⁹⁹Tc uptake reflecting decreased metastatic activity. The images circled in green show an increase in bone uptake in the right humeral head reflecting bone reconstruction (given a decrease of FDG uptake on PET-CT). The images circled in blue illustrate a global decrease in ⁹⁹Tc uptake of the axial skeleton.

Figure 3

Lumbar spine CT-scan before and after Radium-223 treatment. The CT-scan performed after Radium-223 shows bone formation in lumbar vertebras.

Figure 4

Timeline.