OBJECTIVE: To evaluate the detection of near-infrared fluorescence from prostate tumors stained with a prostate-specific membrane antigen (PSMA)-targeted tracer developed in our institution with a novel robotic imaging system.
METHODS: Prostate cancer cell lines PC3-pip (PSMA positive) and PC3-flu (PSMA negative) were implanted subcutaneously into 6 immunodeficient mice. When tumors reached 5 mm, a PSMA-targeted fluorescent conjugate was injected intravenously. The first 3 mice underwent near-infrared imaging immediately and hourly up to 4 hours after injection to determine the time necessary to obtain peak fluorescence and were killed. The last 3 mice were imaged once preoperatively and were euthanized 120 minutes later. Excision of the tumors was performed by using a novel robotic imaging system to detect near-infrared fluorescence in real time. Specimens were submitted for pathology.
RESULTS: In the first 3 mice, we found 120 minutes as the time needed to observe peak fluorescence from the PSMA-positive tumors. We identified discrete near-infrared fluorescence from 2 of 3 PSMA-positive tumors with the robotic imaging system. Surgical margins were negative for all excised specimens except for one PSMA-negative tumor.
CONCLUSIONS: Real-time near-infrared fluorescence imaging of prostate cancer is feasible with a novel robotic imaging system. Further research is needed to optimize the signal intensity detectable from prostate cancer with our tracer. Toxicologic studies are needed before its clinical use.
Written by:
Laydner H, Huang SS, Heston WD, Autorino R, Wang X, Harsch KM, Magi-Galluzzi C, Isac W, Khanna R, Hu B, Escobar P, Chalikonda S, Rao PK, Haber GP, Kaouk JH, Stein RJ. Are you the author?
Section of Laparoscopic and Robotic Surgery, Glickman Urological and Kidney Institute, Cleveland Clinic, Cleveland, OH 44195, USA.
Reference: Urology. 2013 Feb;81(2):451-6.
doi: 10.1016/j.urology.2012.02.075
PubMed Abstract
PMID: 23374828
UroToday.com Investigative Urology Section
