Imaging for the selection and monitoring of men on active surveillance for prostate cancer

The Diagnostic Value of bpMRI in Prostate Cancer: Benefits and Limitations Compared to mpMRI

Prostate cancer is the second most common cancer in men and a leading cause of death worldwide. Early detection is vital, as it often presents with vague symptoms such as nocturia and poor urinary stream. Diagnostic tools like PSA tests, ultrasound, PET-CT, and mpMRI are essential for prostate cancer management. The PI-RADS system helps assess malignancy risk based on imaging. While mpMRI, which includes T1, T2, DWI, and dynamic contrast-enhanced imaging (DCE), is the standard, bpMRI offers a contrast-free alternative using only T2 and DWI. This reduces costs, acquisition time, and the risk of contrast-related side effects but has limitations in detecting higher-risk PI-RADS 3 and 4 lesions. This study compared bpMRI's diagnostic accuracy to mpMRI, focusing on prostate volume and PI-RADS scoring. Both methods showed strong inter-rater agreement for prostate volume (ICC 0.9963), confirming bpMRI's reliability in this aspect. However, mpMRI detected more complex conditions, such as periprostatic fat infiltration and iliac lymphadenopathy, which bpMRI missed. While bpMRI offers advantages like reduced cost and no contrast use, it is less effective for higher-risk lesions, making mpMRI more comprehensive.

AI-based automated evaluation of image quality and protocol tailoring in patients undergoing MRI for suspected prostate cancer

PURPOSE

To develop and validate an artificial intelligence (AI) application in a clinical setting to decide whether dynamic contrast-enhanced (DCE) sequences are necessary in multiparametric prostate MRI.

METHODS

This study was approved by the institutional review board and requirement for study-specific informed consent was waived. A mobile app was developed to integrate AI-based image quality analysis into clinical workflow. An expert radiologist provided reference decisions. Diagnostic performance parameters (sensitivity and specificity) were calculated and inter-reader agreement was evaluated.

RESULTS

Fully automated evaluation was possible in 87% of cases, with the application reaching a sensitivity of 80% and a specificity of 100% in selecting patients for multiparametric MRI. In 2% of patients, the application falsely decided on omitting DCE. With a technician reaching a sensitivity of 29% and specificity of 98%, and resident radiologists reaching sensitivity of 29% and specificity of 93%, the use of the application allowed a significant increase in sensitivity.

CONCLUSION

The presented AI application accurately decides on a patient-specific MRI protocol based on image quality analysis, potentially allowing omission of DCE in the diagnostic workup of patients with suspected prostate cancer. This could streamline workflow and optimize time utilization of healthcare professionals.

Could Biparametric MRI Replace Multiparametric MRI in the Management of Prostate Cancer?

Prostate cancer (PCa) is a worldwide epidemiological problem, since it is one of the most prevalent types of neoplasia among men, and the third-leading cause of cancer-related deaths, after lung and colorectal tumors. Unfortunately, the early stages of PCa have a wide range of unspecific symptoms. For these reasons, early diagnosis and accurate evaluation of suspicious lesions are crucial. Multiparametric MRI (mpMRI) is currently the imaging modality of choice for diagnostic screening and local staging of PCa, but also has a leading role in guiding biopsies and in treatment biparametric MRI (bpMRI) could partially replace mpMRI due to its lack of adverse reactions caused by contrast agents, relatively lower costs, and shorter acquisition time. Further, 31 relevant articles regarding the advantages and disadvantages of the aforementioned imaging techniques were scanned. As a result, while bpMRI has comparable accuracy in detecting PCa, its roles in the other steps of PCa management are limited.

Active Surveillance of Grade Group 1 Prostate Cancer: Long-term Outcomes from a Large Prospective Cohort

BACKGROUND

Active surveillance (AS) is the preferred management option for most men with grade group (GG) 1 prostate cancer (PCa). Questions persist regarding long-term outcomes and the optimal approach to AS.

OBJECTIVE

To determine survival and metastatic outcomes in AS patients. Secondary objectives were to measure the cumulative incidence and association of patient-level factors on biopsy grade reclassification.

DESIGN, SETTING, AND PARTICIPANTS

A prospective, active, open-enrollment cohort study was conducted from 1995 through July 2018 at a tertiary-care academic institution. Patients with very-low-risk or low-risk PCa were enrolled.

INTERVENTION

AS with semiannual prostate-specific antigen (PSA) and digital rectal examination, serial prostate biopsy, and multiparametric magnetic resonance imaging (mpMRI).

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

The 10- and 15-yr cumulative incidences of primary and secondary outcomes were determined.

RESULTS AND LIMITATIONS

Overall, 1818 men were monitored on AS for a median of 5.0yr (interquartile range 2.0-9.0). There were 88 non-PCa deaths, four PCa deaths, and one additional case of metastasis. The cumulative incidence of PCa-specific mortality or metastasis was 0.1% (95% confidence interval, 0.04-0.6%) at both 10 and 15yr. The 5-, 10-, and 15-yr cumulative incidences of biopsy grade reclassification were 21%, 30%, and 32%, respectively. On multivariable analysis, biopsy grade reclassification was associated with older age, African-American race, PSA density, and increased cancer volume on biopsy, and men who underwent mpMRI prior to enrollment were less likely to undergo grade reclassification. Our selection and monitoring are more stringent than many other contemporary AS programs.

CONCLUSIONS

In a large, single-institution, prospective AS cohort, the risk of cancer death or metastasis was <1% over long-term follow-up. Consistent with clinical guidelines, these data support the use of AS for the management of most men diagnosed with GG1 PCa.

PATIENT SUMMARY

This study investigated long-term outcomes in patients with grade group 1 prostate cancer managed with active surveillance (AS). Ten years after enrolling in AS, the risk of metastasis or death from prostate cancer was <1%, while 48% of men switched to treatment. Patients who underwent multiparametric magnetic resonance imaging (mpMRI)/ultrasound-fusion targeted biopsy prior to enrollment were less likely to experience biopsy grade reclassification during follow-up, suggesting a role for mpMRI as part of a comprehensive risk assessment to confirm AS eligibility. These findings support the safety of AS in most men with grade group 1 prostate cancer, but specific outcomes may differ in programs with less intensive monitoring.

Multiparametric MRI for prostate cancer diagnosis: current status and future directions

The current diagnostic pathway for prostate cancer has resulted in overdiagnosis and consequent overtreatment as well as underdiagnosis and missed diagnoses in many men. Multiparametric MRI (mpMRI) of the prostate has been identified as a test that could mitigate these diagnostic errors. The performance of mpMRI can vary depending on the population being studied, the execution of the MRI itself, the experience of the radiologist, whether additional biomarkers are considered and whether mpMRI-targeted biopsy is carried out alone or in addition to systematic biopsy. A number of challenges to implementation remain, such as ensuring high-quality execution and reporting of mpMRI and ensuring that this diagnostic pathway is cost-effective. Nevertheless, emerging clinical trial data support the adoption of this technology as part of the standard of care for the diagnosis of prostate cancer.

Entering an era of radiogenomics in prostate cancer risk stratification

Radiogenomics is a field that amalgamates data from genomics and imaging techniques in order to derive clinically meaningful trends. In this article, we discuss the importance of prostate cancer risk classification and how data derived from genomic testing and multi-parametric magnetic resonance imaging (mpMRI) can be integrated into clinical decision-making processes with a focus on active surveillance (AS). Finally, we describe an ongoing prospective trial (Miami MAST trial) which incorporates imaging (mpMRI) and radiomics data in patients who are on AS for prostate cancer.