Clinical and imaging tools in the early diagnosis of prostate cancer, a review

Abstract

Measurement of serum Prostate Specific Antigen (PSA) level is useful to detect early prostate cancer. PSA-screening may reduce the mortality rate from prostate cancer, but this is associated with a high rate of overdiagnosis and overtreatment. To improve the detection of clinically significant cancers, several auxiliary clinical and imaging tools can be used. The absolute PSA value can be complemented with parameters such as PSA velocity, PSA density and free/total PSA. Transrectal Ultrasound (TRUS) has only moderate accuracy in the detection of prostate carcinoma, but is very useful in the estimation of prostate volume and thus calculation of PSA-density. The role of Magnetic Resonance Imaging (MRI) in diagnosis and staging of prostate carcinoma is rapidly increasing. Morphologic T2-weighted MR images (T2-WI), preferably with an endorectal coil, depict the prostatic anatomy with high resolution and can detect tumoral areas within the peripheral zone of the prostate. Addition of MR spectroscopic imaging (MRSI), dynamic contrast enhanced MRI (DCE-MRI) and/or diffusion weighted imaging (DWI) further increase the diagnostic performance of MRI. The gold standard for diagnosis of prostate carcinoma is histological assessment obtained by transrectal ultrasound-guided systematic core needle biopsy. In the future, imaging-based targeted biopsies may improve the biopsy yield and decrease the number of biopsy cores. Computed Tomography (CT) and positron emission tomography (PET) have no value in early prostate cancer detection and the indications are limited to lymph node staging and detection of distant metastases.