In-vivo characterization of cancer-related changes in white adipose tissue using quantitative ultrasound

Cancerous breast lesions can induce localized microstructural changes in adjacent white adipose tissue (WAT), altering adipocyte size and number density. Current methods for assessing changes in WAT are inherently invasive. We hypothesize that quantitative ultrasound (QUS) methods based on backscatter coefficient (BSC) are sensitive to cancer-related microstructural alterations in WAT. Female subjects (N = 112, mean age 54 ± 16) scheduled for ultrasound-guided core needle biopsy of lesions categorized as BIRADS ≥4b were recruited. Radiofrequency (RF) echo data of each lesion were acquired using a GE Logiq E10 scanner with an ML6-15 probe (9 MHz center frequency). Two QUS parameters, effective scatterer diameter (ESD) and effective acoustic concentration (EAC), were computed from RF echo data using a reference phantom method. Parameters were analyzed within the lesion, in WAT ≤4 mm from the lesion edge, and in WAT > 4 mm away. ESD was higher near malignant lesions (p = 0.02) compared to benign, with no differences in distant WAT. Moreover, malignant tumors showed higher ESD (p = 0.004) and lower EAC (p = 0.003) compared to benign lesions. A support vector machine operating only on lesion-adjacent WAT parameters achieved area under the ROC of 0.72 for differentiating benign and malignant tumors. These findings suggest QUS is sensitive to cancer-related microstructural properties of WAT and may provide an effective means for characterizing adipocytes non-invasively and in-vivo. [Work supported by NIH Grant R21EB035809 (CH).]