Multiparametric magnetic resonance imaging versus Partin tables and the Memorial Sloan-Kettering cancer center nomogram in risk stratification of patients with prostate cancer referred to external beam radiation therapy

Biparametric (bp) and multiparametric (mp) magnetic resonance imaging (MRI) approach to prostate cancer disease: a narrative review of current debate on dynamic contrast enhancement

Prostate cancer is the most common malignancy in male population. Over the last few years, magnetic resonance imaging (MRI) has proved to be a robust clinical tool for identification and staging of clinically significant prostate cancer. Though suggestions by the European Society of Urogenital Radiology to use complete multiparametric (mp) T2-weighted/diffusion weighted imaging (DWI)/dynamic contrast enhancement (DCE) acquisition for all prostate MRI examinations, the real advantage of functional DCE remains a matter of debate. Recent studies demonstrate that biparametric (bp) and mp approaches have similar accuracy, but controversial evidences remain, and the specific potential benefits of contrast medium administration are still poorly discussed in literature. The bp approach is in fact sufficient in most cases to adequately identify a negative test, or to accurately define the degree of aggressiveness of a lesion, especially if larger or with major characteristics of malignancy. This feature would give the DCE a secondary role, probably limited to a second evaluation of the lesion location, for detecting small cancer or in case of controversy. However, DCE has proved to increase the sensitivity of prostate MRI, though a less specificity. Therefore, an appropriate decision algorithm is needed to standardize the MRI approach. Aim of this review study was to provide a schematic description of bpMRI and mpMRI approaches in the study of prostatic anatomy, focusing on comparative validity and current DCE application. Additional theoretical considerations on prostate MRI are provided.

Multiparametric MRI in the management of prostate cancer: an update-a narrative review

The growing interest in multiparametric MRI is leading to important changes in the diagnostic process of prostate cancer. MRI-targeted biopsy is likely to become a standard for the diagnosis of prostate cancer in the next years. Despite it is well known that MRI has no role as a staging technique, it is clear that multiparametric MRI may be of help in active surveillance protocols. Noteworthy, MRI in active surveillance is not recommended, but a proper understanding of its potential may be of help in achieving the goals of a delayed treatment strategy. Moreover, the development of minimally invasive techniques, like laparoscopic and robotic surgery, has led to greater expectations as regard to the functional outcomes of radical prostatectomy. Multiparametric MRI may play a role in planning surgical strategies, with the aim to provide the highest oncologic outcome with a minimal impact on the quality of life. We maintain that a proper anatomic knowledge of prostate lesions may allow the surgeon to achieve a better result in planning as well as in performing surgery and help the surgeon and the patient engage in a shared decision in planning a more effective strategy for prostate cancer control and treatment. This review highlights the advantages and the limitations of multiparametric MRI in prostate cancer diagnosis, in active surveillance and in planning surgery.

PI-RADS score is associated with biochemical control and distant metastasis in men with intermediate-risk and high-risk prostate cancer treated with radiation therapy

BACKGROUND

Novel methods of risk stratification are needed for men with prostate cancer. The Prostate Imaging Reporting and Data System (PI-RADS) uses multiparametric MRI (mpMRI) to assign a score indicating the likelihood of clinically significant prostate cancer. We evaluated pretreatment mpMRI findings, including PI-RADS score, as a marker for outcome in patients treated with primary radiation therapy (RT).

METHODS

One hundred and twenty-three men, 64% and 36% of whom had National Comprehensive Cancer Network (NCCN) intermediate-risk and high-risk disease, respectively, underwent mpMRI prior to RT. PI-RADS score and size of the largest nodule were analyzed with respect to freedom from biochemical failure (FFBF) and freedom from distant metastasis.

RESULTS

A PI-RADS score of ≤3, 4, or 5 was defined in 7%, 49%, and 44%; with a median nodule size of 0, 8, and 18 mm, respectively (P < 0.001). Median follow-up was 67 months. Men with PI-RADS ≤ 3, 4, or 5 disease had 7-year FFBF of 100%, 92%, and 65% (P = 0.002), and a 7-year freedom from distant metastasis of 100%, 100%, and 82%, respectively (P = 0.014). PI-RADS (Hazard Ratio 5.4 for PI-RADS 5 vs. 4, P = 0.006) remained associated with FFBF when controlling for NCCN risk category (P = 0.063) and receipt of androgen deprivation therapy (P = 0.535). Nodule size was also associated with FFBF (Hazard Ratio 1.08 per mm, P < 0.001) after controlling for NCCN risk category (P = 0.156) and receipt of androgen deprivation therapy (P = 0.776).

CONCLUSION

mpMRI findings, including PI-RADS score and nodule size, may improve risk stratification in men treated with primary RT.