Prostate imaging features that indicate benign or malignant pathology on biopsy

Abstract

Accurate diagnosis of clinically significant prostate cancer is essential in identifying patients who should be offered treatment with curative intent. Modifications to the Gleason grading system in recent years show that accurate grading and reporting at needle biopsy can improve identification of clinically significant prostate cancers. Extracapsular extension of prostate cancer has been demonstrated to be an adverse prognostic factor with greater risk of metastatic spread than organ-confined disease. Tumor volume may be an independent prognostic factor and should be considered in conjunction with other factors. Multi-parametric magnetic resonance imaging (MP-MRI) has become an increasingly important tool in the diagnosis and characterization of prostate cancer. MP-MRI allows T2-weighted (T2W) anatomical imaging to be combined with functional and physiological assessment. Diffusion-weighted imaging (DWI) has shown greater sensitivity, specificity and negative predictive value compared to prostate specific antigen (PSA) testing and T2W imaging alone and has a more positive correlation with Gleason score and tumour volume. Dynamic gadolinium contrast-enhanced (DCE) imaging can exhibit difficulties in distinguishing prostatitis from malignancy in the peripheral zone, and between benign prostatic hyperplasia (BPH) and malignancies in the transition zone (TZ). Computer aided diagnosis utilizes software to aid radiologists in detecting and diagnosing abnormalities from diagnostic imaging. New techniques of quantitative MRI, such as VERDICT MRI use tissue-specific factors to delineate different cellular and microstructural phenotypes, characterizing tissue properties with greater detail. Proton MR spectroscopic imaging (MRSI) is a more technically challenging imaging modality than DCE and DWI MRI. Over the last decade, choline and prostate-specific membrane antigen (PSMA) positron emission tomography (PET) have developed as better tools for staging than conventional imaging. While hyperpolarized MRI shows promise in improving the imaging and differentiation of benign and malignant lesions there is further work required. Accurate reading and interpretation of diagnostic investigations is key to accurate identification of abnormal areas requiring biopsy, sparing those in whom benign or indolent disease can be managed by non-invasive means. Embracing and advancing existing technologies is essential in furthering this process.

Radio-pathomic mapping model generated using annotations from five pathologists reliably distinguishes high-grade prostate cancer

“…Reported ROC results vary from 0.77 to 0.99 comparing cancer with benign tissue. While it has been reported that cancers with a total volume >0.5 cm 2 on whole-mount slides are more likely to be significant, 33 we have found that our technique is sensitive to lesions as small as 0.1 cm 2 . No standard value for lesion exclusion exists in whole-mount rad-path studies, which may have implications for the comparison of ROC results between rad-path studies in prostate cancer.…”

Detection of clinically significant prostate cancer in biopsy‐naïve men: direct comparison of systematic biopsy, multiparametric MRI‐ and contrast‐ultrasound‐dispersion imaging‐targeted biopsy

“…At the same time, the CUDI-TBx strategy had more false positives than the mpMRI-TBx strategy (53% vs 18%) and the AUC of the CUDI-TBx strategy for GG ≥2 PCa was 0.71. These false-positive findings were mainly caused by the fact that CUDI, like DCE MRI, demonstrated difficulties in distinguishing prostatitis and BPH from csPCa [32]. Future research on CUDI is therefore foreseen.…”

Basic concepts and applications of functional magnetic resonance imaging for radiotherapy of prostate cancer

“…The assumption that neovascularization is a key element in the formation and growth of many cancers including prostate cancer has been the basis for DCE-MRI. Although DCE-MRI was introduced more than two decades ago, there is today much more knowledge about the limitations in differentiating prostatitis from cancer in the peripheral zone and benign prostatic hyperplasia from cancer in the transitional zone [31] .…”

“…CSI is both more technically challenging and demanding than DWI and DCE-MRI and the spatial resolution is inherently lower with this technique. Furthermore, most of the reported knowledge around CSI dates several years back during which time other functional imaging techniques, in particular DWI has significantly improved and further developed and being implemented in clinical routine [31] , [42] . Due to its complex nature, CSI is not listed as a mandatory functional technique according PI-RADS v.2 guidelines for multiparametric MRI of prostate cancer [1] .…”