A Dual-Modality Photoacoustic and Ultrasound Imaging System for Noninvasive Sentinel Lymph Node Detection: Preliminary Clinical Results

摘要

Sentinel lymph node biopsy (SLNB) has emerged as an accurate, less invasive alternative toudaxillary lymph node dissection, and it has rapidly become the standard of care for patients withudclinically node-negative breast cancer. The sentinel lymph node (SLN) hypothesis states that theudpathological status of the axilla can be accurately predicted by determining the status of the firstud(i.e., sentinel) lymph nodes that drain from the primary tumor. Physicians use radio-labeledudsulfur colloid and/or methylene blue dye to identify the SLN, which is most likely to containudmetastatic cancer cells. However, the surgical procedure causes morbidity and associatedudexpenses. To overcome these limitations, we developed a dual-modality photoacoustic andudultrasound imaging system to noninvasively detect SLNs based on the accumulation ofudmethylene blue dye. Ultimately, we aim to guide percutaneous needle biopsies and provide audminimally invasive method for axillary staging of breast cancer. The system consists of a tunableuddye laser pumped by a Nd:YAG laser, a commercial ultrasound imaging system (Philips iU22),udand a multichannel data acquisition system which displays co-registered photoacoustic andudultrasound images in real-time. Our clinical results demonstrate that real-time photoacousticudimaging can provide sensitive and specific detection of methylene blue dye in vivo. Whileudpreliminary studies have shown that in vivo detection of SLNs by using co-registeredudphotoacoustic and ultrasound imaging is feasible, further investigation is needed to demonstrateudrobust SLN detection.