Assessment of fiberoptic near-infrared Raman spectroscopy for diagnosis of bladder and prostate cancer

Objectives. To determine whether a fiberoptic Raman system, suitable for in vivo use, is able to differentiate between benign and malignant bladder and prostate pathologic findings in vitro. Raman spectroscopy is an optical technique that provides a measure of the molecular composition of tissue by analyzing the way that tissue scatters laser light. Laboratory studies have shown that the technique can be used to identify and characterize transitional cell carcinoma and prostate adenocarcinoma in vitro. Methods. A total of 220 Raman spectra were recorded from 29 snap-frozen bladder samples collected at cystoscopic procedures, and 197 Raman spectra were recorded from 38 snap-frozen prostate samples collected at transurethral resection of the prostate. The spectra were correlated with the histologic features and used to construct separate diagnostic algorithms for the bladder and prostate. These algorithms were tested as to their ability to determine the pathologic finding of a sample from its Raman spectrum. Results. The bladder algorithm was able to differentiate benign samples (normal and cystitis) from malignant samples (transitional cell carcinoma), with an overall accuracy of 84%. The prostate algorithm was able to differentiate benign samples (benign prostatic hyperplasia and prostatitis) from malignant samples (prostate cancer), with an overall accuracy of 86%. Conclusions. The results of this study have demonstrated that the clinical Raman system can provide an accurate and objective method to diagnose prostate and bladder cancer in vitro. Because the Raman probe is suitable for use during endoscopic, laparoscopic, or open procedures, this work paves the way for in vivo studies.