Clinical Evaluation of a Prototype Tri-modal Imaging Instrument for Guiding Breast Cancer Surgery

Breast conservation surgery (BCS) is performed on patients with breast cancer with the intent to resect and completely remove the tumour while conserving as much of the surrounding normal tissue as possible. Currently, there is no way for surgeons to determine the adequacy of surgical resection in real-time during surgery; the assessment of surgical margins requires histological examination that is not available in real-time and is impractical in most clinical cases. This results in a re-excision rate of 23% among Canadian women in order to achieve optimal surgical margins. In addition, the presence or absence of cancer in tumor draining lymph nodes is recognized as a key element for breast cancer staging; however, lymph node dissection can be associated with overtreatment and morbidity (nerve damage and post surgical lymphedema) and histological analysis of nodes can be time consuming and thus delay subsequent procedures. In an effort to address these issues, we have designed and constructed, in collaboration with Sogang University, Seoul, S. Korea, a novel imaging system that performs three complementary imaging modalities (tri-modal): ultrasound (US), photoacoustic (PA) and fluorescence (FL).

This first-in-human pilot study will recruit 10 breast cancer patients undergoing breast conserving surgery at Princess Margaret Hospital (Toronto, Canada). The study is designed to test our tri-modal (US, PA, FL) imaging technology in breast cancer patients. The overall goal is to obtain initial information on the technical feasibility of the tri-modal system in a peri-operative setting and to confirm the anticipated safety of the procedures. Additionally, it will provide initial data on the ability of this system to detect/localize primary breast cancer lesions and cancer-involved lymph nodes prior to surgery.