Changes in PVBI
If at the end of therapy, PVBI showed little change, this value would be 100%; if it was markedly reduced, it would approach 0%. Changes in PBVI were then evaluated for their potential to monitor tumor vascular changes during chemotherapy and predict pathological response.
The study reported at SABCS involved 11 breast cancer patients undergoing neoadjuvant chemotherapy. The women were monitored with the NIR-US imager after every two treatment cycles until surgery. After surgery, based on the pathological assessment of the specimen, the patients were classified into three response groups: complete or near-complete responders, partial responders, and nonresponders.
The results showed that PBVI correlated with pathological response. At the end of treatment, nonresponders showed little change in PBVI from baseline (86.8%), whereas PBVI was significantly reduced from baseline in partial responders (46.3%) and in complete or near-complete responders (29.1%).
Complete responders had lower PBVI than partial responders (P < .02) and partial responders’ PBVIs were lower than those of nonresponders (P < .04).
“Even at the end of the second treatment cycle, the PBVI of the complete or near-complete responders was noticeably lower than that of the partial responders (P = .091) and nonresponders (P = .075),” added co-author Dr. Zhu.
The investigators concluded that NIR-US using PBVI to monitor vascular changes accurately predicted complete responders and nonresponders in this pilot study, and may offer the potential for early recognition of treatment efficacy and tailoring of the intervention to the response.
“Our future studies will include further technology development and increased cohort size,” Dr. Tannenbaum said.