Ultrasound-Guided Photoacoustic Imaging for the Detection of Metastases in Inguinal Lymph Nodes

PRIMARY OBJECTIVE:

I. To estimate the mean difference in oxygen saturation (%sO2) between healthy and malignant inguinal lymph nodes using ultrasound-guided photoacoustic imaging (PAI) in cancer patients.

SECONDARY OBJECTIVE:

I. To examine the role of ultrasound-guided PAI in detecting metastases in the inguinal lymph nodes and ultrasound features of lymph nodes such as the size, shape of the lymph nodes.

OUTLINE:

Patients undergo standard of care ultrasound of the lymph nodes, then undergo ultrasound-guided PAI over 3-5 minutes. Patients then undergo standard of care ultrasound-guided fine needle aspiration (FNA) or biopsy a suspicious lymph node.

After completion of study, patients are followed up for 3 months.

Inclusion criteria

• Pathologically proven primary malignancy
• Suspicious inguinal lymph nodes for metastasis on a conventional imaging modality
• Scheduled to undergo ultrasound-guided fine needle aspiration cytology or biopsy

Exclusion criteria

• Melanoma patients, since the melanocytes may have a "masking effect"
• The deeper inguinal lymph nodes (3-5 cm deep) and smaller (< 1 cm in short axis) in dimensions will be excluded from the study