University of Chicago researchers provided solid evidence that hybrid multidimensional MRI (HM-MRI) might be superior to multiparametric MRI (mpMRI) for diagnosing clinically significant prostate cancer.
That’s a big statement after nearly two decades of prostate MRI exams, but mpMRI’s continued variability challenges still leave room for improvement, and some believe HM-MRI’s quantitative approach could help add objectivity.
To test that theory, the researchers had four radiologists with different career experience (1 to 20yrs) interpret HM-MRI and mpMRI exams from 61 men with biopsy-confirmed prostate cancer, finding that the HM-MRI exams produced:
- Higher AUCs among three of the four readers (0.61 vs. 0.66; 0.71 vs. 0.60; 0.59 vs. 0.50; 0.64 vs. 0.46), with the least experienced rad achieving the greatest AUC improvement
- Higher specificity among all four readers (48% vs. 37%; 78% vs. 26%; 48% vs. 0%; 46% vs. 7%)
- Significantly greater interobserver agreement rates (Cronbach alpha: 0.88 vs. 0.26; >0.60 indicates reliability)
- Far shorter average interpretation times (73 vs. 254 seconds)
As the study’s editorial put it, HM-MRI appears to be a “quantitative step in the right direction” for prostate MRI, and has the potential to address mpMRI’s variability, accuracy, and efficiency challenges.
A new Lancet study out of the UK provided the strongest evidence yet that multiparametric ultrasound might deserve a core role in prostate cancer screening, either as a complement or alternative to multiparametric MRI. That could be a big deal given mpMRI’s cost, time, and accessibility challenges, and makes this study worth a deeper look.
The Study – The researchers performed mpUS and mpMRI exams on 306 patients with signs of prostate cancer (either elevated PSAs or abnormal rectal exams), and then conducted targeted biopsies on the 257 patients who had positive imaging findings.
The biopsy results revealed cancer in 133 patients, including 83 clinically significant cancers, while showing how mpUS might contribute to prostate cancer diagnosis:
- mpUS was positive in 272 patients (89%)
- mpMRI was positive in 238 patients (78%)
- mpUS identified 66 clinically significant cases (79%)
- mPMRI identified 77 clinically significant cases (93%)
- mpMRI and mpUS combined to detect all 83 clinically significant cancers
- mpUS exclusively detected 6 clinically significant cancers
- mpMRI exclusively detected 17 clinically significant cancers
In other words, mpUS was only slightly less accurate than mpMRI for clinically significant cancer detection (-4.3%), but led to far more biopsies (+11.1%), while the combined modalities notably improved clinically significant cancer detection (+7.2%).
mpMRI’s role in prostate cancer screening is still secure, but this study shows that mpUS could improve cancer detection if the modalities are used together. Perhaps more importantly, it suggests that mpUS could be a valid prostate cancer detection option for the half of the world that doesn’t have access to advanced imaging or for the many patients who can’t/won’t undergo MRI (orthopedic implants, claustrophobia etc.).