Bone Quality Assessment During Breast Cancer Treatment via Wrist Tomosynthesis in the Mammography Setting - ABSTRACT/PROJECT SUMMARY Breast cancer (BC) is the most common cancer in the world. A great majority of these cancers are the type called hormone receptor positive, which are treated with medicine that interferes with estrogen (called aromatase inhibitors, or AI). As a result, substantial bone loss occurs putting these patients at risk of fracture during or after therapy. Given that over 90% of breast cancer patients survive 5 years or longer after therapy, such extreme weakening of bones represents a big problem for a large group of people. This weakening of bones is due to a complex pattern of bone loss, involving microscopic structure in different parts of the bone. These patterns of bone loss are also different between people who are young and not yet in menopause compared to those who are postmenopausal. The standard tool for examining bone health (“DXA scan”) is not sufficient to capture such minute details of bone. The devices that are able to image these details are not available everywhere, and they are not in routine use. Additional to this, making appointments for secondary concerns can be overwhelming and create extra anxiety for cancer patients. For these reasons, breast cancer patients who are at risk of suffering a fracture down the road may not be identified and may not be helped. The main idea for this project is to monitor breast cancer patients’ bone quality using the same equipment used for their mammography and at the same time they receive mammographic follow up. This is technically novel, because assessing bone quality with the device called tomosynthesis, which is typically used for imaging and measuring breast density, is a unique use of these devices. Therefore, the main goal of this project is to evaluate how bone quality metrics measurable from digital tomosynthesis images of the wrist (DWT) change over time in postmenopausal (Aim 1) and premenopausal (Aim 2) BC patients receiving AI therapy, and how well these metrics predict computationally derived bone strength and patient fracture status (Aim 3) compared to standard DXA measures, by performing a set of longitudinal and cross-sectional studies. The proposed project is expected to provide a complete picture about the utility of the DWT approach in BC patients treated with AIs. DWT is expected to provide bone density measures similar to DXA. In this case, DWT could take place of DXA in the mammography setting. Because the patients can receive it during their routine mammographic follow-up, this would eliminate the unnecessary anxiety from scheduling additional DXA tests and ensure that bone exams are not neglected. It is further expected that DWT derived microstructure and biomechanical measures, which are accurate measures of bone mechanical integrity, will be sensitive indicators of bone response to therapy. In this case, DWT would not only offer a system convenient for the patient and efficient for the health care system, but it would also offer a more accurate assessment of bone quality and fracture risk. The results of this study will inform next steps about how to proceed with translating DWT to clinical practice.
