From the Guidelines
A PI-RADS 2 score indicates a lesion that is likely benign with a very low probability of clinically significant prostate cancer, and routine follow-up is typically recommended rather than immediate biopsy. This scoring system ranges from 1 to 5, with higher scores indicating greater likelihood of clinically significant cancer 1. The Prostate Imaging-Reporting and Data System version 2 (PI-RADS v2) was designed to simplify and standardize the terminology and content of mpMRI prostate reports, and to develop assessment categories that summarize levels of suspicion for clinically significant prostate cancer (csPCa) 1.
Key Points to Consider
- A low PI-RADS assessment category of 2 does not completely exclude the possibility of csPCa, but rather indicates that it is unlikely 1.
- The radiologist has determined that the MRI findings show features that are probably benign based on specific imaging characteristics across different MRI sequences (T2-weighted, diffusion-weighted imaging, and dynamic contrast-enhanced imaging) 1.
- These lesions often represent benign conditions like inflammation, benign prostatic hyperplasia, or normal anatomical variants.
- Clinical correlation with PSA levels, digital rectal examination findings, and patient risk factors is still important for comprehensive management 1.
- If there are other concerning clinical factors, your doctor might still recommend additional monitoring or possibly biopsy despite the low PI-RADS score.
Management Recommendations
- Routine follow-up is typically recommended rather than immediate biopsy for a PI-RADS 2 lesion.
- MRI-targeted biopsy can be considered if there are other concerning clinical factors, but the evidence suggests that it may not be necessary for PI-RADS 2 lesions 1.
- The management of prostate cancer should be individualized based on the patient's specific clinical factors, including PSA levels, digital rectal examination findings, and patient risk factors 1.
From the Research
MRI PI-RADS 2
- The Prostate Imaging Reporting and Data System (PI-RADS) is a standardized system used to interpret multiparametric prostate magnetic resonance imaging (mpMRI) studies 2.
- A PI-RADS score of 1 indicates a low suspicion of prostate cancer, while a score of 5 indicates a high suspicion of prostate cancer 3.
- Studies have shown that a PI-RADS score of 1 has a high negative predictive value, meaning that a low score is associated with a low risk of prostate cancer 2.
- However, factors such as low T2 signal intensity in the peripheral zone and elevated prostate-specific antigen (PSA) levels can be associated with false-negative PI-RADS 1 assessments 2.
Active Surveillance Strategies
- Active surveillance is a management strategy for low-risk prostate cancer that involves regular monitoring with PSA tests, digital rectal exams, and periodic biopsies 4.
- The use of MRI with PI-RADS scoring can help identify patients who are at higher risk of prostate cancer progression and may benefit from more frequent monitoring or biopsy 4, 3.
- Studies have shown that annual MRI with biopsy for lesions with PI-RADS scores of 4 or greater is a cost-effective strategy for active surveillance 4.
Diagnostic Value of Digital Rectal Examination (DRE)
- Digital rectal examination (DRE) is a diagnostic tool used to evaluate the prostate gland, but its value in prostate cancer diagnostics is debated 5.
- Studies have shown that DRE is not significantly associated with prostate cancer diagnosis or clinically significant prostate cancer detection 5.
- A PSA- and MRI-based approach may be effective for prostate cancer diagnostics, even without DRE 5.
Effect of 5-Alpha Reductase Inhibitors on MRI and Prostate Cancer Detection
- 5-Alpha reductase inhibitors (5-ARIs) are medications used to treat benign prostatic hyperplasia, but their effect on prostate cancer detection is unclear 6.
- Studies have shown that 5-ARI exposure does not change the PI-RADS distribution or the detection rates of clinically significant prostate cancer and insignificant prostate cancer 6.