Intraoperative frozen section analysis is not routinely performed to determine positive surgical margins (PSM) at radical prostatectomy (RP) due to time requirement and unproven clinical utility. Light reflectance spectroscopy (LRS) measures light intensity reflected or backscattered from tissues and can be used to differentiate malignant from benign tissue.
We used a novel LRS probe to evaluate PSM on ex-vivo RP specimens and correlate its findings with pathologic examination.
Patients with intermediate- to high-risk disease undergoing RP were enrolled. LRS was performed on suspected malignant and benign prostate capsule immediately following organ extraction. Each LRS at 530-830nm was analyzed and correlated with pathologic results. A regression model and forward sequential selection algorithm were developed for optimal feature selection. Eighty percent of LRS data were selected to train a logistic regression model, which was evaluated by the remaining 20% data. This was repeated 5 times to calculate averaged sensitivity, specificity, and accuracy.
LRS analysis was performed on 17 ex-vivo prostate specimens, where a total of 11 histologic PSM and 22 negative margins were measured. Two selected features from 700nm to 830nm were identified as unique to malignant tissue. Cross-validation in performance of the predictive model showed that the optical probe predicted PSM with 85% sensitivity 86% specificity, an accuracy of 86% and AUC of 0. 95.
LRS can identify PSM accurately in fresh ex-vivo RP specimens. Further study is required to determine if such analysis may be used in real-time to improve surgical decision-making and reduce PSM rates.
The Journal of urology. 2015 Sep 24 [Epub ahead of print]
Monica S C Morgan, Aaron H Lay, Xinlong Wang, Payal Kapur, Asim Ozayar, Maryam Sayah, Li Zeng, Hanli Liu, Claus G Roehrborn, Jeffrey A Cadeddu
Department of Urology, University of Texas Southwestern Medical Center, Dallas, Texas. , Department of Urology, University of Texas Southwestern Medical Center, Dallas, Texas. , Department of Bioengineering, University of Texas at Arlington, Arlington, Texas. , Department of Pathology, University of Texas Southwestern Medical Center, Dallas, TX. , Department of Urology, University of Texas Southwestern Medical Center, Dallas, Texas. , Department of Urology, University of Texas Southwestern Medical Center, Dallas, Texas. , Department of Industrial and Manufacturing Systems Engineering at Arlington, Arlington, Texas. , Department of Bioengineering, University of Texas at Arlington, Arlington, Texas. , Department of Urology, University of Texas Southwestern Medical Center, Dallas, Texas. , Department of Urology, University of Texas Southwestern Medical Center, Dallas, Texas.