Photoacoustic Lymph Node Imaging


In this spectroscopic photoacoustic imaging study, the investigators will acquire images (only) to:

1. determine if spectroscopic photoacoustic imaging can acquire high fidelity images in a clinical setting,

2. discover if blood oxygen saturation changes are observable in breast cancer patients during early stages of metastatic invasion, and

3. compare the sensitivity and specificity of photoacoustic imaging with ultrasound imaging for the detection of lymph node metastases.

The results from imaging will not be used in any decision making process. This study is solely used to test the photoacoustic imaging device and evaluate it against the current standard of care. The device is completely noninvasive and uses only safe levels of energy as determined by the American National Standards Institute (ANSI) and the FDA. The device does not pose a serious to the health, safety, or welfare of the patient.

Full Title of Study: “A Preliminary Study of Photoacoustic Imaging to Detect Micrometastases in the Lymph Nodes of Breast Cancer Patients”

Study Type

  • Study Type: Interventional
  • Study Design
    • Allocation: N/A
    • Intervention Model: Single Group Assignment
    • Primary Purpose: Basic Science
    • Masking: None (Open Label)
  • Study Primary Completion Date: May 1, 2021

Detailed Description

The study is centered on determining whether photoacoustic imaging of blood oxygen saturation can detect lymph node metastases.

Patients who are returning for an ultrasound exam after detection of a suspicious node via magnetic resonance imaging will be enrolled in the study.

Enrolled patients will receive a clinical ultrasound exam, as is the current standard of care. Suspicious nodes will be identified and imaged with combined ultrasound and spectroscopic photoacoustic imaging. Measurements will be acquired with three to five replicates with slightly modified transducer positioning to measure system and intranodal variance of the measurements. One to five contralateral axillary lymph nodes will be imaged to serve as a control and to determine patient-to-patient variability in lymph node saturated oxygen. The distance from the skin to the lymph node will also be measured with ultrasound imaging for each node.

If the ultrasound imaging identifies a suspicious node, patients will undergo ultrasound guided biopsy to confirm the true metastatic state of the nodes. Suspicious nodes will be clipped to facilitate identification at the time of axillary node dissection. During the sentinel node procedure, investigators will use intraoperative photoacoustic imaging to measure the blood oxygenation in the sentinel lymph node immediately prior to its removal. Histology will be performed on all biopsy samples and excised nodes to determine the true metastatic state of the node(s).


  • Diagnostic Test: Spectroscopic photoacoustic imaging
    • Spectroscopic photoacoustic imaging uses a laser that is pulsed for a nanosecond, applying laser light to the patient’s skin. Hemoglobin and melanin absorb the laser’s energy and convert it to heat, which rapidly expands local tissue and produces a broadband ultrasound wave and is detected with a clinical ultrasound transducer. Because the signal is proportional to the optical absorption in tissue, high resolution images of the lymph nodes can be acquired from the detected ultrasound waves, and can be used to measure saturated oxygen in the nodes.

Arms, Groups and Cohorts

  • Experimental: Spectroscopic photoacoustic imaging
    • Any suspicious lymph nodes identified through ultrasound will be imaged with spectroscopic photoacoustic imaging, which is a diagnostic test to measure saturated oxygen in the nodes.

Clinical Trial Outcome Measures

Primary Measures

  • Spectroscopic photoacoustic image acquisition feasibility
    • Time Frame: Through study completion, an average of 12 weeks
    • Determine the feasibility of using spectroscopic photoacoustic imaging to determine the metastatic state of lymph nodes prior to surgery/biopsy by measuring changes in blood oxygen saturation.

Secondary Measures

  • Spectroscopic photoacoustic image depth
    • Time Frame: Day 1, up to 12 weeks after imaging
    • Determine the maximum imaging depth that can be reliably achieved with spectroscopic photoacoustic imaging.
  • Spectroscopic photoacoustic imaging device comparison
    • Time Frame: Day 1, up to 12 weeks after imaging
    • Determine the variance of saturated oxygen measurements acquired with spectroscopic photoacoustic imaging.

Participating in This Clinical Trial

Inclusion Criteria

1. Subjects are female age 18 or older with a detected breast lesion.

2. Subjects have suspected lymph node involvement as determined by MRI.

3. Subjects are scheduled for an ultrasound exam of the suspected node(s).

4. Subjects are capable of giving informed consent.

Exclusion Criteria

1. Subjects who have had prior surgery in or near the axillary lymph nodes.

2. Subjects currently undergoing chemotherapy, radiation therapy, hormone therapy, or targeted therapy for the breast cancer.

3. Subjects who will be receiving neoadjuvant therapy prior to the sentinel lymph node biopsy.

4. Subjects who are homeless persons or have active drug/alcohol dependence or abuse history.

5. Subjects who are pregnant or breast-feeding.

Gender Eligibility: Female

Minimum Age: 18 Years

Maximum Age: N/A

Are Healthy Volunteers Accepted: No

Investigator Details

  • Lead Sponsor
    • Geoff Luke
  • Collaborator
    • Dartmouth College
  • Provider of Information About this Clinical Study
    • Sponsor-Investigator: Geoff Luke, Co-Investigator and Regulatory Sponsor – Dartmouth-Hitchcock Medical Center
  • Overall Official(s)
    • Roberta M. diFlorio-Alexander, MD, Principal Investigator, Dartmouth-Hitchcock Medical Center

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