Angular restriction fluorescence optical projection tomography to localize micrometastases in lymph nodes

Area of Science:

• Biomedical Imaging
• Cancer Diagnostics
• Optical Physics

Background:

• Lymph node biopsy is crucial for breast cancer staging.
• Current pathological methods are slow and sample minimal tissue.
• Limitations exist in accurately assessing the entire lymph node volume.

Purpose of the Study:

• To develop a rapid, low-cost 3D imaging protocol for whole lymph nodes.
• To enhance spatial resolution in lymph node optical projection tomography (OPT).
• To evaluate the efficacy of OPT in detecting small metastases.

Main Methods:

• Developed a fluorescence optical projection tomography (OPT) protocol.
• Utilized angular restriction of photon detection to improve resolution.
• Employed filtered-backprojection reconstruction for image analysis.
• Tested the protocol using porcine lymph node metastases models.

Main Results:

• Demonstrated rapid 3D imaging of whole lymph nodes.
• Achieved improved spatial resolution by exploiting low tissue scattering.
• Successfully detected and localized 200-μm metastases in 1-cm lymph nodes.
• Confirmed the sufficiency of simple filtered-backprojection reconstruction.

Conclusions:

• Low-cost OPT offers a fast and effective method for whole lymph node imaging.
• This technique holds potential for improving breast cancer staging accuracy.
• OPT can reliably detect clinically significant micrometastases.