PI-RADS 3 lesions: Does the association of the lesion volume with the prostate-specific antigen density matter in the diagnosis of clinically significant prostate cancer? (2020)
"
Highlights• Clinically significant prostate cancer (csCaP) was defined as Gleason score ≥3 + 4 or ≥ISUP2.
• The prevalence of csCaP in Pi-RADS 3 lesions varies from 16% to 21%.
•
There is a new subclassification of Pi-RADS 3 lesions: 3a (indolent or low-risk lesions with volume <0.5 ml) and 3b (significant or high-risk lesions with volume ≥0.5 ml).
• The majority of Gleason score ≥4 + 3 tumors with volume <0.5 ml on pathology were not detectable on the magnetic resonance imaging of the prostate (MRI).• The prostate-specific antigen density (PSAd) with a cut-off point of 0.15 increases the negative predictive value (NPV) of MRI."
Abstract
IntroductionCurrently, a new subclassification of the Pi-RADS 3 lesions and subgroups is being used: 3a (indolent or low-risk lesions with volume <0.5 ml) and 3b (significant or high-risk lesions with volume ≥0.5 ml). The prostate-specific antigen density (PSAd) has been identified as a diagnostic tool that helps to predict clinically significant prostate cancer (csCaP). The aim of this study is to evaluate the association of the volume of the Pi-RADS 3 lesions and the PSAd in the diagnosis of csCaP.
Material and MethodsWe conducted a retrospective study that included prostate biopsies performed using a transperineal approach and guided by ultrasound between 2015 and 2020. csCaP was defined as Gleason score ≥3 + 4. The population was divided into groups according to the Pi-RADS 3 subclassification and the PSAd value. We calculated sensitivity, specificity, negative predictive value (NPV) and positive predictive value (PPV) of 3b lesions for the detection of high-grade prostate cancer, alone and combined with PSAD groups.
ResultsIn total, 99 patients with Pi-RADS 3 lesions were included. Forty-three patients were in group 3a and 56, in 3b. Mean PSA was 7.28 ± 2.6 ng/ml. Pi-RADS 3a lesion did not present csCaP but 17.8% of Pi-RADS 3b lesion did. In group 3b with PSAd > 0.15, 62.5% presented csCaP. In those Pi-RADS 3b with PSAd ≤ 0.15, all biopsies were insignificant prostate cancer (isCaP) and 40 biopsies could have been avoided. Considering 3b as positive for csCaP detection, sensitivity was 100%, specificity 48.3%, NPV 17.8%, and PPV 100%. When adding PSAd to group 3b, sensitivity was 100%, specificity was 86.9%, NPV was 62.5%, PPV was 100%. In total, only the subgroup 3b with PSAd > 0.15 presented csCaP and 83.8% biopsies could be avoided.
ConclusionsIn this series, the association of the volume of PIRADS 3 lesion and the PSAd improves specificity and PPV contributing to improve the management of csCaP."
[Emphasis mine]
_________________________________
The majority of studies previously concluded that PIRADS 3 lesions (which are in the gray, or intermediate zone) do warrant investigation by biopsy, especially for biopsy-naive men, Yes, this study makes a case for the seriousness of 3b lesions when the PSAd is > 0.15.
But even though the authors suggest how the subgrouping coupled with PSAd can avoid some biopsies, they confirm an equally important fact: most ≥4 + 3 tumors with a volume <0.5 m do not show up on mpMRI. (1) This only further emphasizes an important message emphasized by a number of studies: men who are biopsy-naive should refuse a targeted-only biopsy (whether fusion or not) and tell their uros that studies have shown that
targeted + systematic biopsies have a distinct advantage for finding clinically significant PCa over either type alone.
(2) A case has been made that men on AS with an MRI record, can be followed with targeted-only biopsies, but I think this is foolish: you are on the table, tush to the wind, with no place to go. So why not have samples taken in all zones? You know what they say about
the ultrasound probe: in for a penny, in for a pound. Many clinically significant lesions have been found in cores where the uro directed the needle either randomly in the zone or to an area that appeared suspicious on the ultrasound screen. That was my case: the cores taken in my new nodule at the apex were LL benign, but 2 cores in other prostate zones found a G10 and a G9 lesion!
(3) BTW, another study concluded that as far as MRI targets are concerned,
3 cores per target are statistically sufficient for finding clinically significant lesions.
I don't remember any Forum Brother reporting either a PIRADS 3a or 3b finding.
Djin