Utility of Color Doppler & Power Doppler Ultrasound in Detecting Prostate Cancer

Resident doctor, Dr. John Yu in the Department of Surgery specifically in the Urologic Surgery has an ongoing research entitled “Utility of Color Doppler and Power Doppler Ultrasound in Detecting Prostate Cancer in Comparison to Multiparametric MRI.” His study aims to compare Multiparametric ultrasound (Doppler, power doppler, grayscale UTZ, Harmonics view) with MPMRI in cancer detection rate in patients with clinical indication for prostate biopsy. The amount allotted for his research was Php 30,000.00.

Initial suspicion of prostate cancer is based on an abnormal digital rectal exam (DRE) or an elevated Prostate Specific antigen (PSA). Definitive diagnosis requires prostate biopsy usually performed under transrectal ultrasound guidance (TRUS). (2). Currently TRUS guided prostate biopsy is used to initially diagnose prostate cancer and MPMRI fusion biopsy of the prostate is best utilized as confirmatory biopsy if not performed initially or to better risk stratify patients who are considering active surveillance. (2).

The yield of TRUS guided prostate biopsy depends on the echogenicity of lesions on ultrasound. Most prostate cancers are hypoechogenic on UTZ but prostate cancer was only detected in 25.5% of these lesions (3). 39% of prostate cancer are isoechoic and 1% maybe hyperechoic (1). On the other hand, MPRI fusion biopsy of the prostate uses the PIRADS scoring system to stratify different lesions. PIRADS makes use of anatomical T2-weighted images, Diffusion weighted images (DWI) or Dynamic Contrast Enhanced images (DCE). When comparing it to MPMRI, a systematic TRUS guided prostate biopsy misses only 4% of clinically significant prostate cancer. MPMRI fusion biopsy detects fewer clinically insignificant prostate cancer compared to TRUS guided biopsy (4).

To improve cancer detection rate using UTZ, many have utilized the use of Multiparametric ultrasound. This includes the use of Doppler and power doppler ultrasound to detect higher vascularity of prostate cancer lesions compared to normal prostatic tissue (Doppler higher caliber vessels usually surrounding the prostate CA, Power doppler for smaller micro vascularity present within prostate cancer lesions), elastography to identify hardened suspicious nodules, harmonics view and contrast enhanced UTZ for better anatomical characterization.