During the past two decades, prostate cancer (PCa) has become the most commonly diagnosed cancer and
ranks as the second leading cause of cancer deaths for American men. Prostate biopsy is the standard
procedure for evaluating the presence and aggressiveness of PCa. Guided by transrectal ultrasound (TRUS)
and preprocedure magnetic resonance imaging (MRI), small pieces of tissues are removed from the prostate.
The architectural heterogeneities are assigned a Gleason score as a quantitative description of the
aggressiveness. However, TRUS has low sensitivity to PCa. MRI has limited availability, and a spatial
mismatch can occur when co-registering the preprocedure MRI with the real-time TRUS. Therefore, standard
TRUS-guided biopsy, either with or without additional MRI, suffers from missing or under-sampling clinically
significant tumors, leading to under-grading of PCa. At-risk patients with rising blood-based biomarkers
undergo repeated and saturated biopsies, causing extra diagnostic costs and time as well as anxiety and pain.
We propose to solve this long-standing technical gap in PCa diagnosis by introducing a needle photoacoustic
(PA) probe for online guidance of TRUS biopsy. As validated in our preliminary studies on both animal models
and human tissues, quantitative multispectral PA signal analysis possesses the unique capability of objectively
characterizing the architectural heterogeneities in prostate tissues and grading PCa in vivo. Our needle PA
probe has an all-optical design that allows a small probe dimension to avoid causing additional invasiveness to
the current biopsy procedure. Taking advantage of the optical penetration, the needle PA probe can assess the
histopathological information in a tissue volume much larger than that of a standard biopsy core without tissue
removal. Hence, PA pre-biopsy measurements, performed together with the TRUS needle biopsy, can provide
highly valuable diagnostic information covering the whole prostate. Core extractions can then be focused within
the suspicious cancerous region(s). The central hypothesis of this research is that a fine needle probe-based
PA prostate pre-biopsy can guide prostate biopsy, improve the core yield, and decrease false negative rates.
The objective of this study is to validate the correlation between the PA measurements and the PCa grading
through an observational human subjects study. The specific aims include investigating the performance of the
needle PA probe in accessing PCa using 1) biopsy tissue cores; 2) ex vivo human prostate samples procured
through prostatectomy, and 3) human subjects. We will leverage the research team's extensive expertise in the
clinical practice of PCa diagnosis and pathology as well as PA technology. The proposed pre-biopsy procedure
is designed within the framework of current clinical practice and is, therefore, highly translational. The
knowledge gained in this study will prepare us to conduct a future clinical trial of the proposed diagnostic
procedure in detecting PCa. Once successfully tested, the PA pre-biopsy will benefit PCa patients by
facilitating accurately targeted needle biopsies for the early detection of clinically significant PCa.