Category: Imaging & Image Guided Therapy: New Therapies

MP4-9 - Optical Biopsy using Confocal Microscopy for Differentiation of Renal Cell Carcinoma versus Benign Tissue

Fri, Sep 21
10:00 AM - 12:00 PM

Introduction & Objective : Novel optical imaging modalities are under development towards the goal of an “optical biopsy” to efficiently provide pathologic analysis at point of care.  Confocal microscopy works on the principle of point excitation in the specimen (diffraction limited spot) & point detection of the resulting fluorescent signal.  As a result, serial optical sectioning of intact specimens can be achieved which allows for in situ imaging of cellular-level structures. The goal of this study is to assess ability of confocal microscopy to accurately differentiate between renal cell carcinoma and normal kidney.

Methods : From June 2016 to February 2018, 113 patients underwent Robotic Laparoscopic Partial nephrectomy or Radical nephrectomy for Renal cell carcinoma at the University of Arizona College of Medicine.  After IRB approval, 17 biopsies of normal and tumor tissue were harvested, stained with acridine orange, and imaged with a Nikon E600 C1 Confocal Microscope. Samples were submitted for concomitant H&E staining.  Subsequently both histologic and optical images were reviewed by pathologists.

Results : 118 confocal images were obtained, confirmed renal cell carcinoma  (n=66) as well as normal renal tissue (n=52).  Six confocal images were used as a training set  for  reviewers(n=8).  The reviewers were then asked to rate images on a 6-point benign to cancer scale. Results were analyzed using web based ROC calculator. Presence or absence of renal tubules and glomeruli were determined to be the optimal method to distinguish normal from cancerous tissue. The average accuracy, sensitivity, specificity, and area under the empirical ROC curve was 91%, 98%, 81%, and 0.94 respectively.


Conclusions :

This preliminary study suggests confocal microscopy can distinguish cancer from normal tissue with high sensitivity and specificity. Reviewers were able to be trained efficiently in assessing the confocal images. Further studies will be needed to validate the reproducibility and statistical significance of this technique and to demonstrate clinical applicability.

Benjamin R. Lee

Professor and Chief, Urology
University of Arizona College of Medicine
Tucson, Arizona

Dr. Benjamin Lee, Professor & Chief of Urology at the University of Arizona College of Medicine has focused his career on advancing new treatments for renal cell carcinoma as well as calculus disease, while developing new technologies & techniques for Urologic Oncology & Endourology. He is author or co-author of more than 200 manuscripts, book chapters, videos and abstracts. Dr. Lee graduated from Cornell University magna cum laude. He then attended the Johns Hopkins School of Medicine, and continued his training at the James Buchanan Brady Urological Institute at the Johns Hopkins Hospital. He was Assistant Professor at the North Shore Long Island Jewish Medical Center, and then promoted to Associate Professor. He was promoted to Professor with tenure at the Department of Urology at the Tulane University School of Medicine in 2008, and assumed the position of Professor and Chief of Urology at the University of Arizona College of Medicine in 2016. He has published on methods identifying methods of decreasing recurrence of cancer; explanations why the immune system may be activated differently following laparoscopy compared to open surgery, and has developed nanotechnology applications in urologic disease as well as studies into preserving kidney function during laparoscopic & robotic kidney surgery. Dr. Lee’s research has been recognized by awards from the American Urological Association, The Endourological Society and Urology Journal. He was awarded the prestigious Arthur Smith Award in 2008 for his contributions to the discipline of robotics, laparoscopy, and minimally invasive surgery. He was Organizing Secretary of the 31st World Congress of Endourology which was held in New Orleans, LA in 2013.

Michael C. Phung

Urology Resident
Division of Urology, University of Arizona College of Medicine
Tucson, Arizona

Andrew Rouse

Tucson, Arizona

Erika Bracamonte

Associate Professor, Director of Surgical Pathology
Department of Pathology, University of Arizona College of Medicine
Tucson, Arizona

Arthur Gmitro

Tucson, Arizona