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Sarcoma

Sarcoma Poster Presentations 2

P63: Enhanced tumor delineation using fluorescence lifetime imaging of indocyanine green in human sarcomas

Friday, March 22, 2024
2:46pm – 2:52pm ET
Location: C110

    Author(s)

  • RP

    Rahul Pal, PhD

    Instructor
    Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Charlestown MA, United States

    • Oral Poster Presenter(s)

  • Thinzar M. Lwin, MD (she/her/hers)

    Assistant Professor
    Department of Surgical Oncology, City of Hope National Medical Center, Duarte, CA, California, United States

    • Submitter(s)

  • Thinzar M. Lwin, MD (she/her/hers)

    Assistant Professor
    Department of Surgical Oncology, City of Hope National Medical Center, Duarte, CA, California, United States

    • Author(s)

  • Thinzar M. Lwin, MD (she/her/hers)

    Assistant Professor
    Department of Surgical Oncology, City of Hope National Medical Center, Duarte, CA, California, United States

  • MK

    Murali Krishnamoorthy, PhD

    Post Doctorate Scholar
    Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Charlestown MA, United States

  • HC

    Hannah R. Collins, n/a

    Research Staff
    Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Charlestown MA, United States

  • Corey D. Chan, MD

    Post Doctorate Scholar
    Newcastle University Centre for Cancer, Translational and Clinical Research Institute, Newcastle University, Newcastle upon Tyne, UK, United States

  • KW

    Kurt R. Weiss, MD

    Associate Professor of Surgery
    Department of Orthopedic Surgery, University of Pittsburgh School of Medicine, Pittsburgh, PA, United States

  • KR

    Kenneth Rankin, MD

    Professor of Surgery
    Newcastle University Centre for Cancer, Translational and Clinical Research Institute, Newcastle University, Newcastle upon Tyne, UK, United States

  • SL

    Santiago Lozano-Calderon, MD, PhD

    Associate Professor of Surgery
    Department of Orthopedic Surgery, Massachusetts General Hospital, Harvard Medical School, Boston MA, United States

  • AK

    Anand TN Kumar, PhD

    Associate Professor in Radiology
    Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Charlestown MA, United States

Introduction: Complex surgeries are performed to resect sarcomas, but tissue discrimination at the time of resection is determined subjectively; by visual inspection, palpation, and clinical judgment. Unrecognized deposits of remaining tumors can lead to local recurrence and decreased survival. There is a vital need for an objective approach to enhance intraoperative tumor identification. Current approaches to intra-operative detection of fluorescence are based on the detection of fluorescence intensity and do not offer adequate contrast. We evaluate the detection of fluorescence lifetime (FLT) using indocyanine green (ICG) contrast to improve the sensitivity and accuracy of sarcoma identification.


Methods: We performed an IRB approved clinical study of 22 patients undergoing surgery for sarcomas who received ICG intravenously (0.5-1mg/kg) prior to surgery. Fresh and formalin fixed resection specimens from surgeries performed at MGH, University of Newcastle upon Tyne, and UPMC were imaged. Wide-field imaging was performed using white light, fluorescence intensity, and time-domain fluorescence lifetime (FLT) imaging. Slides underwent FLT microscopy (FLIM) and H&E staining. Histology images were annotated by pathologists blinded to fluorescence images. Tumor-normal tissue boundaries were identified. Distribution of fluorescence intensity and FLT were measured. Sensitivity, specificity, and ROC analyses were performed.


Results: Paired tumor and normal tissue data were available for 8/22 sarcoma patients. The average fluorescence intensity in the tumor was highly heterogeneous; in 3 patients, there was even a higher fluorescence in the normal tissue compared to the tumors (Figure 1B). Mean FLT in all tumors were significantly longer than the normal tissue FLT (Figure 1C). The sensitivity and specificity for ICG-FLT in detection of tumors was 94.2 ± 3.0% and 93.3 ± 2.2% (J = 86.1 ± 4.6%) respectively, with an accuracy of 97.1± 1.3% (Figure 1D). The sensitivity and specificity for standard fluorescence intensity imaging in detection of tumors was 62.7 ± 31.6% and 51.7 ± 12.1% (J = 32.4 ± 13.1%) respectively, with an accuracy of 54.4 ± 24.7%.


Conclusions: In patients who have received ICG prior to surgery, measurement of FLT demonstrated significantly longer lifetimes in sarcomas compared to the surrounding normal tissue. While fluorescence intensity was able to highlight the tumor, FLT imaging had a higher sensitivity, specificity, and accuracy in delineating sarcomas. The work demonstrates a highly promising potential application of FLT for next-generation fluorescence-guided surgery.

Learning Objectives:

  • Participants will be able to identify the limitations of current standard of care technology for intra-operative sarcoma identification
  • Participants will be able to learn about advances in technology for intra-operative sarcoma identification
  • Participants will be learn about the ability to use time domain as a variable promising for enhancement of intra-operative sarcoma identification