Aug. 03, 2023
Fluorescence-guided surgery is an evidence-based surgical option for a variety of cancers. This technique allows surgical teams enhanced visibility of malignant tissues during the surgical procedure, making resection more thorough and accurate.
Surgical oncologists have recently studied the technique as it applies to epithelial ovarian cancer. Results of the study were published in the August 2022 issue of the Journal of Clinical Oncology.
"It was really exciting to be part of fluorescence-guided surgery," says Kristina A. Butler, M.D., M.S., a gynecologic oncologist at Mayo Clinic Comprehensive Cancer Center in Phoenix, Arizona. "For ovarian cancer, we have wonderful evidence-based medicine that volume of tumor removal at the time of surgery is directly correlated with the patient's overall survival and progression-free survival."
Dr. Butler explains that enhanced detection of tumor tissue helps the surgical team resect more malignant tissue, which should in turn lend itself to far better outcomes in ovarian cancer.
Pafolacianine injection for real-time ovarian cancer detection
The phase 3 multicenter study evaluated 109 patients with folate receptor-positive ovarian cancer to confirm safe and effective use of pafolacianine with intraoperative near-infrared imaging (NIR). All patients had a high clinical suspicion or diagnosis of epithelial ovarian cancer.
Patients received one 60-minute infusion of pafolacianine one hour prior to surgery. During the surgical procedures, all suspicious macroscopic lesions were documented for all patients using white light and palpation. Patients were then randomly assigned to be evaluated under a second condition or to proceed directly to surgical resection.
In the second evaluation, the care team identified additional lesions that were not visible under white light but were seen using NIR fluorescence imaging prior to surgery. Reimaging of the surgical field was conducted before abdominal closure.
For both study groups, lesions were sent to a central laboratory where pathologists evaluated the tissues blinded to the other experts' assessments and to the fluorescence status from surgery.
Researchers confirmed that the use of NIR fluorescence imaging in surgery identified additional tumors not otherwise seen with usual white light.
"This technology can be used with newly diagnosed patients, patients who have already had chemotherapy and patients with recurrent ovarian cancer," says Dr. Butler. "It opens up opportunities that did not exist for patients before."
Future directions for fluorescence-guided surgical procedures
The agent used in this study was approved by the FDA for use in surgical procedures. Researchers are now evaluating other agents to help further enhance surgical outcomes and address side effects.
Dr. Butler explains that some agents used in fluorescence-guided surgeries provide activity in other tissues such as lymph nodes, making it difficult to discern between cancerous tissue and tissue activated by various agents. Some agents illuminate necrotic tissue. And some, due to their mode of administration, have a high rate of side effects including nausea and vomiting.
"We're looking at other options that still provide enhanced outcomes of more tumor detection and resection," says Dr. Butler.
Experts at Mayo Clinic have been at the forefront of discussions in this space as new agents are brought into clinical research.
Dr. Butler and her team hope to next evaluate aminolevulinic acid hydrochloride, an agent currently approved for fluorescence-guided surgery of high-grade gliomas that is metabolized intracellularly and accumulates in cancer cells. The team aims to learn how this orally administered drug may be applicable to ovarian cancer resection in its ability to target cancerous tissue.
Mayo Clinic is one of a select group of medical centers in the United States to be recognized as a Specialized Program of Research Excellence (SPORE) for ovarian cancer research funded by the National Cancer Institute. To earn a highly competitive SPORE grant, institutions must demonstrate a high degree of collaboration between first-rate scientists and clinicians and show excellence in translational research projects.
For more information
Tanyi JL, et al. A phase III study of pafolacianine injection (OTL38) for intraoperative imaging of folate receptor-positive ovarian cancer (study 006). Journal of Clinical Oncology. 2022;41;276.
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