Researchers at the University of Texas Southwestern Harold C. Simmons Comprehensive Cancer Center in Dallas have determined that an emerging optical-based endoscopic technique called light reflectance spectroscopy can enable surgeons to rapidly and safely evaluate prostate tissue with 85 percent accuracy without excision to distinguish whether it is malignant or benign.
The scientists’ discovery, which measures light intensity reflected or back-scattered from tissues, could potentially lead to real-time tissue analysis as a standard part of prostate cancer surgery.
Benefits of using the light reflectance spectroscopy procedure include its facilitation of highly accurate surgical removal of cancerous tissue while sparing more healthy tissue, thereby minimizing likelihood of the cancer recurring and reducing necessity for additional treatment. However, researchers caution that more follow-up study is needed before this procedure can become a routine element of prostate cancer surgery.
“We used a novel light reflectance spectroscopy probe to evaluate surgical margins on radical prostatectomy tissue specimens and correlated the findings with pathological examination,” said UT Southwestern Professor of Urology and Radiology Dr. Jeffrey Cadeddu, lead author of a paper describing the study recently published in the Journal of Urology.
Titled “Light Reflectance Spectroscopy to Detect Positive Surgical Margins on Prostate Cancer Specimens,” the paper is co-authored by Cadeddu with UTSW assistant instructor of urology Dr. Aaron Lay; associate professor of pathology and urology Dr. Payal Kapur; Dr. Claus Roehrborn, chairman of urology and holder of the E.E. Fogelson and Greer Garson Fogelson Distinguished Chair in Urology and the S.T. Harris Family Chair in Medical Science; Monica S.C. Morgan; Xinlong Wang; Asim Ozayar; Maryam Sayah; Li Zeng; and Hanli Liu.
The study authors note that while intraoperative frozen section analysis is not generally performed to determine positive surgical margins during radical prostatectomies due to time constraints involved with traditional techniques and the technique’s unproven clinical usefulness, analysis to determine removal of all cancer surrounding the visible tumors edges is not routinely performed during surgery.
Consequently, undetected cancer cells can be left behind — termed “positive surgical margins.” But the investigators’ research demonstrated that a novel light reflectance spectroscopy probe can be used to evaluate positive surgical margins on ex vivo radical prostatectomy specimens, and its findings correlated with pathological examination.
Study participants were patients with intermediate- to high-risk disease who were undergoing radical prostatectomies — procedures in which the prostate gland and some of the surrounding tissue is surgically removed.
Immediately after the prostate gland was removed, light reflectance spectroscopy was performed on suspected malignant and benign prostate margins. Each sample was analyzed and correlated with pathological samples, which were analyzed post-surgery. Cross-validation of the predictive model showed the optical probe technique was able to predict positive surgical margins with 85 percent sensitivity, 86 percent specificity, and 86 percent accuracy.
The investigators conclude that light reflectance spectroscopy can identify positive surgical margins accurately in fresh ex vivo radical prostatectomy specimens, but caution that further study is required.
“This study highlights one of a growing number of technology platforms that aim to improve the outcomes of cancer surgery,” said Cadeddu, who holds the Ralph C. Smith, M.D., Distinguished Chair in Minimally Invasive Urologic Surgery. “Further study is required to determine whether such analysis may be used in real time to improve surgical decision-making and decrease the amount of tissue surgeons need to remove.”
According to the National Cancer Institute, prostate cancer is the second most common cancer in men after skin cancer and the second-leading cause of cancer-related deaths in U.S. men after lung cancer. The most recent NCI data available estimates that 220,800 men would be diagnosed with prostate cancer in 2015, with nearly 27,540 dying of the disease .
Researchers from UT Arlington also assisted with the study.