Diffuse optical tomography breast imaging measurements are modifiable with pre-surgical targeted and endocrine therapies among women with early stage breast cancer.

Diffuse optical tomography breast imaging system (DOTBIS) non-invasively measures tissue concentration of hemoglobin, which is a potential biomarker of short-term response to neoadjuvant chemotherapy. We evaluated whether DOTBIS-derived measurements are modifiable with targeted therapies, including AKT inhibition and endocrine therapy. We conducted a proof of principle study in seven postmenopausal women with stage I-III breast cancer who were enrolled in pre-surgical studies of the AKT inhibitor MK-2206 (n = 4) or the aromatase inhibitors exemestane (n = 2) and letrozole (n = 1). We performed DOTBIS at baseline (before initiation of therapy) and post-therapy in the affected breast (tumor volume) and contralateral, unaffected breast, and measured tissue concentrations (in μM) of total hemoglobin (ctTHb), oxyhemoglobin (ctO2Hb), and deoxyhemoglobin (ctHHb), as well as water fraction (%). We found consistent decreases in DOTBIS-measured hemoglobin concentrations in tumor volume, with median percent changes for ctTHb, ctHHb, ctO2Hb, and water fraction for the entire cohort of − 27.1% (interquartile range [IQR] 37.5%), − 49.8% (IQR 29.3%), − 33.5% (IQR 47.4%), and − 3.6% (IQR 10.6%), respectively. In the contralateral breast, median percent changes for ctTHb, ctHHb, ctO2Hb, and water fraction were + 1.8% (IQR 26.7%), − 8.6% (IQR 29.3%), + 6.2% (IQR 29.5%), and + 1.9% (IQR 30.7%), respectively. We demonstrated that DOTBIS-derived measurements are modifiable with pre-surgical AKT inhibition and endocrine therapy, supporting further investigation of DOTBIS as a potential imaging assessment of response to neoadjuvant targeted therapies in early stage breast cancer.