Utility of photoacoustic patterns in intra-operative margin assessment of breast cancer post neoadjuvant chemotherapy

Utility of photoacoustic patterns in intra-operative margin assessment of breast cancer post neoadjuvant chemotherapy

Photoacoustics

10.1016/j.pacs.2025.100701

https://doi.org/10.1016/j.pacs.2025.100701

Yonggeng Goh, Ghayathri Balasundaram, Hui Min Tan, Thomas Choudary Putti, Renzhe Bi, Mikael Hartman, Shaik Ahmad Buhari, Celene Wei Qi Ng, Su Ann Lui, Serene Si Ning Goh, Wei Qi Leong, Eric Fang, Swee Tian Quek, Malini Olivo

Breast cancer; Collagen; Intra-operative margin assessment; Neoadjuvant chemotherapy; Tissue chromophores; Ultrasound guided photoacoustics.

23 February 2025

Goh, Y., Balasundaram, G., Tan, H. M., Putti, T. C., Bi, R., Hartman, M., Buhari, S. A., Ng, C. W. Q., Lui, S. A., Goh, S. S. N., Leong, W. Q., Fang, E., Quek, S. T., & Olivo, M. (2025). Utility of photoacoustic patterns in intra-operative margin assessment of breast cancer post neoadjuvant chemotherapy. Photoacoustics, 43, 100701. https://doi.org/10.1016/j.pacs.2025.100701

Purpose To evaluate the feasibility and accuracy of ultrasound-guided photoacoustic tomography (US-PA) for intraoperative margin assessment in breast-conserving surgery (BCS) following neoadjuvant chemotherapy (NACT). Methods This study, approved by the local Institutional Review Board, included 21 women with histologically confirmed breast cancer referred for BCS post-NACT. Data from 4 participants were used for training while 17 participants were analyzed. US-PA imaging was performed using the MSOT inVision 512-ECHO system, capturing chromophores like lipids, collagen, and hemoglobin up to a 5 mm depth. Imaging results were compared to histopathological findings, and diagnostic accuracy was calculated. Results US-PA imaging demonstrated a high diagnostic accuracy of 89.0 %, with a sensitivity and negative predictive value (NPV) of 100 %, specificity of 86.9 %, and positive predictive value (PPV) of 59.4 %. Excellent inter-observer agreement (kappa = 1) was observed. No laser-induced tissue damage was noted. The average scan time per specimen was approximately 20 minutes. False positives (n = 11) were primarily due to post-therapy fibrotic changes and extremely close tumor extensions (<2 mm). Conclusion US-PA provided clear visualization of tissue components, accurately correlating with histopathology. The method's high NPV minimizes the risk of re-operations and locoregional recurrence. Although the PPV was lower, it did not impact clinical management as surgeons typically excise wider margins in such cases. The study highlighted US-PA’s potential as a promising tool for intraoperative margin assessment in BCS post-NACT, offering a rapid, accurate, and safe method. Further studies with larger sample sizes are needed to confirm these findings and enhance quantitative assessment methods.

Attribution 4.0 International (CC BY 4.0)

This research / project is supported by the Agency for Science, Technology and Research (A*STAR) - Intramural funding support, Central Research Fund (UIBR) 2021
Grant Reference no. :

This research / project is supported by the National Research Foundation, Singapore - Industry Alignment Fund - Pre-Positioning: Translational Biophotonics Innovation Platform
Grant Reference no. : H19H6a0025

This research / project is supported by the National Medical Research Council - Clinician Scientist individual research grant- new investigator grant (CS-IRG-NIG).
Grant Reference no. :

https://oar.a-star.edu.sg/communities-collections/articles/21499

2213-5979

Skin Research Lab