The feasibility of prostate cancer detection by triple spectroscopy.

OBJECTIVES

To determine the feasibility of ex situ prostate cancer detection by triple spectroscopy. A positive surgical margin following radical prostatectomy is an adverse factor for recurrence-free survival. Detection of residual cancer cells in vivo would be the most useful, allowing the resection of such tissue during the procedure. Aside from the use of frozen sections, the ability to detect positive surgical margins is limited. Laser-induced autofluorescence, white-light remission, and high-frequency impedance spectroscopy are methods that allow discrimination of tissues of different dignities based on their specific signature. We tested whether the combination of these techniques can differentiate malignant and benign prostate tissue ex vivo.

MATERIALS AND METHODS

In preparation for future in vivo measurements, an ex vivo study was performed to detect characteristics of prostate tissue. Ninety-five tissue samples from 32 patients undergoing radical prostatectomy for clinically localized prostate cancer were taken immediately after removal of the prostate and stored in liquid nitrogen. Tissue samples were thawed for laser-induced autofluorescence, white-light remission, and high-frequency impedance spectroscopy. Based on these results, a computerized algorithm was developed for tissue differentiation.

RESULTS

The statistical analysis of laser-induced autofluorescence and white-light remission data demonstrated a differentiation of benign and malignant prostate tissue with a sensitivity of 87.5% and a specificity of 87.3%. By adding the acquired high-frequency impedance data to the statistical analysis, sensitivity and specificity were increased to 93.8% and 92.4%.

CONCLUSION

A highly accurate differentiation of prostate tissue was achieved in an ex vivo model. In vivo studies need to be performed to evaluate whether this technique can be successful in an intraoperative setting to detect positive surgical margins.