Predicting response to breast cancer neoadjuvant chemotherapy using diffuse optical spectroscopy.

Area of Science:

• Biomedical Optics
• Medical Imaging
• Cancer Diagnostics

Background:

• Diffuse optical spectroscopy (DOS) and imaging are advanced techniques for quantifying tissue biochemical composition.
• These methods measure concentrations of deoxy-hemoglobin (ctHHb), oxy-hemoglobin (ctO2Hb), water (ctH2O), and lipids.
• Previous studies utilized DOS for breast tumor characterization and monitoring neoadjuvant chemotherapy response.

Purpose of the Study:

• To investigate if DOS measurements before and during neoadjuvant chemotherapy can predict pathological response.
• To assess the utility of DOS in monitoring early treatment effects in breast cancer patients undergoing adriamycin/cytoxan therapy.

Main Methods:

• DOS measurements were taken from 11 patients before and 1 week into a 3-month neoadjuvant chemotherapy regimen.
• Baseline and early treatment measurements of ctHHb, ctO2Hb, ctH2O, and lipids were compared between responders and non-responders.
• Statistical analysis, including discrimination analysis, was used to evaluate predictive capabilities.

Main Results:

• Baseline DOS revealed higher tumor ctHHb, ctO2Hb, ctH2O, and scattering slope, with lower lipids compared to normal tissue.
• Responders showed significant drops in ctHHb (27%), ctO2Hb (33%), and ctH2O (11%) within 1 week, unlike non-responders.
• Early ctHHb levels predicted response with 83% sensitivity and 100% specificity; combined ctHHb and ctH2O changes achieved 100% sensitivity and specificity.
• Pretreatment tumor-to-normal ctO2Hb ratio was higher in responders (2.82) than non-responders (1.82).

Conclusions:

• DOS is sensitive to tumor metabolism and biochemical changes during chemotherapy.
• Early DOS measurements can effectively predict and monitor individual patient response to neoadjuvant chemotherapy.
• This technique holds potential for personalized treatment strategies in breast cancer.