Tag: prostate cancer

Cochrane Pivots on Prostate Screening

Posted on by Brian Casey

Prostate cancer screening is getting new support from an unlikely source – the Cochrane group, which historically has been skeptical of population-based screening. Cochrane researchers last week published a new report supporting prostate screening, a sharp change from the group’s previous guidance. 

Prostate cancer screening hasn’t achieved the generally accepted status of other cancer screening tests like breast, cervical, colorectal, and lung. 

  • One of the main sticking points has been overdiagnosis. Prostate cancer can often be slow-growing, and many men live for years with prostate disease before dying of other causes.

But that dynamic has been changing in recent years, in large measure due to the ability of MRI to differentiate aggressive prostate cancer from more indolent disease. 

  • Clinicians are incorporating MRI into prostate screening protocols, using it to determine which men with elevated PSA levels should be biopsied and which ones can be followed with active surveillance. 

For its part, Cochrane is an international non-profit research consortium that periodically analyzes the peer-reviewed evidence behind new medical exams and technologies. 

  • But Cochrane’s work has occasionally been controversial: The group last month published a negative review of Alzheimer’s drugs that included treatments that never made it to market. Also, a Cochrane research center in Denmark for years was one of the most vociferous opponents of mammography screening. 

So that’s why last week’s statement on prostate screening is so surprising, especially given that Cochrane’s 2013 review found no evidence to support the claim that screening reduced prostate cancer mortality. 

In the new review, Cochrane analyzed data from six clinical trials in Europe and North America that included 800k men, finding that screening with PSA blood tests…

  • Detected 30% more prostate cancers overall, most at an early stage. 
  • Reduced the relative risk of a metastatic prostate cancer diagnosis by 35%.
  • Reduced prostate cancer mortality by 2 deaths for every 1k men screened (for comparison, mammography’s benefit is estimated to be 6-8 deaths). 
  • For every 1-2 deaths prevented, 36 additional cancers were diagnosed – a possible sign of overdiagnosis. 

What changed? Cochrane researchers said that we now have longer-term data that makes it easier to detect screening’s subtle mortality benefit.

  • They also cited the success of technologies like MRI in reducing unnecessary biopsies – and the harms of overdiagnosis.

The Takeaway

Last week’s news suggests that the ground is shifting under prostate cancer screening in favor of broader use of the exam, potentially with MRI follow-ups. If you can convince a screening-skeptical group like Cochrane of prostate screening’s value, you can convince anyone. 

Support for Prostate Cancer Screening Grows

Posted on by Brian Casey

Routine prostate cancer screening currently isn’t supported by clinical guidelines. But that could be changing, especially given research presented this week finding that prostate screening – aided by MRI to reduce unnecessary biopsies – was as effective as mammography screening. 

Prostate cancer is one of the leading causes of cancer death, killing some 360k men worldwide every year. 

  • But efforts to develop effective prostate cancer screening programs have been hampered by the challenges inherent in PSA testing, which often identifies indolent disease that may never pose a health risk to patients – the classic definition of overdiagnosis. 

That could be starting to change, however. Researchers are discovering that using MRI to work up patients with rising PSA levels could help identify men with high-risk disease who should be sent to biopsy, while lower-risk patients are monitored with surveillance.

  • New research presented at the European Association of Urology meeting on Sunday supports this idea, showing that – if done right – prostate cancer screening can be as effective as mammography screening.

Researchers from Germany compared prostate cancer screening data from 39.4k men who got PSA tests as part of the PROBASE trial to over 2.8M women who participated in the country’s national breast cancer screening program. 

  • Under the PROBASE protocol, men with confirmed PSA levels ≥ 3 ng/mL underwent MRI and biopsy, while those with lower PSA levels got repeat PSA testing in an effort to keep biopsy rates lower.

Major findings of the study included…

  • Both breast and prostate screening detected a high rate of clinically significant, invasive cancers (73% for mammography vs. 69% for 45-year-old men and 74% for 50-year-old men).
  • False-positive rates were much lower for breast screening (10% vs. 42% and 37%).
  • And fewer indolent cancers were detected with mammography (22% vs. 31% and 26%). 
  • But biopsy rates were comparable (1.1% vs. 0.8% and 2.4%), as the study’s active surveillance protocol limited over-treatment.

While the PROBASE study didn’t use AI as part of its protocol, other research has found that AI analysis of MRI scans can make the modality even more precise, with the PI-CAI study just one worth noting.

The Takeaway

Is it finally time for prostate cancer screening to join breast, colorectal, cervical, and lung among the major population-based cancer screening tests? Results from the PROBASE study at EAU 2026 suggest the time may finally be right.

Prostate AI Improves Biparametric MRI

Posted on by Brian Casey

Researchers continue to hone in on the best way to use MRI for patients suspected of having prostate cancer, and AI is helping the effort. A new study in AJR shows that AI can improve the diagnostic accuracy and consistency of prostate MRI – while making it easier to perform.

Multiparametric MRI is the gold standard for prostate cancer imaging, but requires the use of three different MRI sequences as well as contrast administration, making it more complex and time-intensive to perform. 

  • On the other hand, biparametric MRI uses just two sequences – T2-weighted and diffusion-weighted imaging – and omits the contrast entirely, leading to shorter scan times and lower cost.

But what are you losing with bpMRI – and can AI help you get it back? Researchers addressed this question in the new study in which six radiologists interpreted bpMRI scans of 180 patients from multiple centers. 

  • Radiologists used a deep learning algorithm developed at the NIH to interpret bpMRI scans acquired on 3T scanners. The open-source algorithm generates binary prostate cancer prediction maps that are overlaid on T2-weighted images.

Researchers found that radiologists using the bpMRI AI algorithm to detect clinically significant prostate cancer had…

  • An increase in lesion-level positive predictive value (77% vs. 67%).
  • But lower lesion-level sensitivity (44% vs. 48%). 
  • And no statistically significant difference in patient-level AUC (0.82 vs. 0.83, p = 0.61).
  • While inter-reader agreement scores improved for lesion-level and patient-level PI-RADS scores and lesion size measurements. 

What to make of the numbers? The authors pointed out that the study design – in which AI was used as a first reader – may have reduced AI’s performance.

  • In real clinical practice, AI would most likely be used as a sort of clinical spell checker, with AI results overlaid on images that radiologists had already seen. 

The researchers said the results on improved positive predictive value and inter-reader agreement show that AI can improve the diagnostic accuracy and consistency of bpMRI for prostate cancer. 

The Takeaway

The new findings echo other research like the PI-CAI study highlighting the growing role of AI in prostate cancer detection. If validated with other studies, they show AI-assisted bpMRI could be ready to take on mpMRI for a broader role.

All-Star AI for Prostate MRI

Posted on by Brian Casey

An AI model for prostate MRI that combines the best features of five separate algorithms helped radiologists diagnose clinically significant prostate cancer in a new study in JAMA Network Open. 

The Prostate Imaging-Cancer AI consortium was formed to address a nagging problem in prostate cancer screening.

  • Studies have shown that MRI can reduce biopsies and minimize workup of clinically insignificant disease, but it also has high inter-reader variability and requires a high level of expertise. 

The PI-CAI challenge brought together researchers from multiple countries with a single goal: develop an AI algorithm for prostate MRI that would improve radiologists’ performance.

  • Results were presented at RSNA and ECR conferences, as well as in a 2024 paper in Lancet Oncology that showed that individually the algorithms improved radiologist performance and generated fewer false positives.

But what if you combined the best of the PI-CAI algorithms into a single all-star AI model? 

  • Researchers did just that in the new study, combining the top five algorithms from the PI-CAI challenge into a single AI model in which each algorithm’s results were pooled to create an average detection map indicating the presence of prostate cancer. 

To test the new algorithm, 61 readers from 17 countries interpreted 360 prostate MRI scans with and without the model. 

  • Patients in the test cohort had a median age of 65 years and a median PSA level of 7.0 ng/mL; 34% were eventually diagnosed with clinically significant prostate cancer.

Results of PI-CAI-aided prostate MRI were as follows …

  • Radiologists using the algorithm had higher diagnostic performance than those who didn’t (AUROC=0.92 vs. 0.88).
  • PI-CAI working on its own had the highest performance (AUROC=0.95).
  • Sensitivity improved for cases rated as PI-RADS 3 or higher (97% vs. 94%).
  • Specificity also improved (50% vs. 48%).
  • AI assistance improved the performance of non-expert readers more than expert readers, with greater increases in sensitivity (3.7% vs. 1.5%) and specificity (4.3% vs. 2.8%).

The Takeaway

The new PI-CAI study is an important advance not only for prostate cancer diagnosis but also for the broader AI industry. It points to a future where multiple AI algorithms could be combined to tackle clinical challenges with better diagnostic performance than any model working alone.

AI Helps Radiologists Read Prostate MRI

Posted on by Brian Casey

MRI is changing how prostate cancer is detected, diagnosed, and followed up. But even a technology as powerful as MRI could use a little help, as evidenced by a new study in Radiology showing that a commercially available AI algorithm could help radiologists diagnose clinically significant prostate cancer. 

Workup of suspicious prostate lesions is being reshaped by MRI in meaningful ways.

  • For example, MRI-guided biopsy is replacing systemic prostate biopsy without guidance, especially for patients with low to intermediate risk of prostate cancer. 

But prostate MRI isn’t perfect – yet. Radiologist performance can vary due to differences in experience, as well as variations in MRI acquisitions, tumor location, and cancer prevalence. Could AI help even out these variations? 

  • To find out, researchers from South Korea tested Siemens Healthineers’ syngo.via Prostate MR algorithm in 205 patients suspected of prostate cancer who were scheduled for biopsy based on clinical information (including previous MRI scans).

The AI algorithm’s performance was compared to that of experienced radiologists, and researchers also estimated its impact on radiologist interpretation if used as a reading aid, finding that for clinically significant prostate cancer… 

  • AI had lower sensitivity versus radiologists (80% vs. 93%).
  • But higher positive predictive value (58% vs. 48%).
  • Adding AI to radiologists’ interpretation more than doubled specificity (44% vs. 21%).
  • There were no cancer cases among lesions rated by both the algorithm and radiologists as not likely to be cancer (PI-RADS 1 or 2).

AI’s higher PPV indicates that it could help reduce unnecessary prostate biopsies, while also detecting clinically significant cancer that might have been missed by radiologists.  

The Takeaway

The new findings echo previous studies that demonstrate the value of AI for MRI of prostate cancer, but differ in that they investigate a commercially available algorithm – indicating that tools for better prostate MRI are becoming accessible to radiologists. 

PSMA-PET Reduces Prostate Deaths

Posted on by Brian Casey

Using PSMA-PET instead of conventional imaging to stage patients with recurrent prostate cancer could reduce deaths by 13% and lead to improved quality of life. The new paper in JAMA Network Open confirms the value of PSMA imaging compared to traditional imaging approaches. 

Recurrent prostate cancer is one of the trickiest cancers to manage, especially as biochemical recurrence can occur in up to half of patients getting local treatment. 

  • PSA tests work well for detecting rising prostate antigen levels that could signify recurrence, but it can be difficult to locate recurrent cancer with existing imaging tools like CT and bone scans.

PET using a new generation of PSMA tracers offers a better solution thanks to tracers that target the PSMA protein that builds up on the surface of prostate cancer cells.

  • Previous studies have shown that PSMA-PET is more sensitive and specific for detecting recurrent prostate cancer, especially at lower PSA levels – but the modality’s long-term effects haven’t been explored. 

In the new study, researchers wanted to investigate the impact of switching to PSMA-PET on mortality and quality of life using statistical modeling to predict outcomes from three imaging approaches …

  • Conventional imaging with CT and bone scan.
  • CT and bone scan followed by PSMA-PET for negative or equivocal cases.
  • PSMA-PET alone.

They then projected outcomes for a hypothetical population of 1k patients with biochemically recurrent prostate cancer, defined as a persistent or rising PSA of 0.20 ng/mL after prostatectomy or PSA 2.0 ng/mL or higher following radiation therapy. They found …

  • PSMA-PET had the lowest number of prostate cancer deaths at 512, compared to conventional imaging plus PSMA-PET (520) or just conventional imaging (587).
  • PSMA-PET diagnosed 611 patients with metastasis compared to 630 with conventional imaging plus PSMA-PET and 297 with only conventional imaging.
  • PSMA-PET yielded 824 more quality-adjusted life years per 1k patients than conventional imaging.

The Takeaway

The findings are not only good news for patients with recurrent prostate cancer, they are also a boon for developers of commercially available PSMA-PET radiotracers like Lantheus Medical Imaging’s Pylarify (approved in 2021), Telix Pharmaceuticals’ Illuccix (approved in 2021), and Blue Earth Diagnostics’ Posluma (approved in 2023). 

MRI Reduces Prostate Biopsies

Posted on by Brian Casey

New research provides additional support for MRI’s role in making prostate screening more effective. In a new study in NEJM, researchers found that MRI can help reduce unnecessary biopsies more than 50%, with a very low chance of missing high-risk disease. 

As we’ve discussed in previous newsletters, prostate cancer screening based on PSA levels is an imprecise test. 

  • Many men with suspiciously high PSA (typically 3-4 ng/mL or higher) undergo biopsies that detect clinically insignificant disease that would never present a health risk during their lifetimes – the classic definition of overdiagnosis. 

Adding MRI can help make prostate screening more precise by directing biopsy-based workup to only those men with clinically significant cancer – but questions still abound about exactly when it should be used. 

In new results from the GÖTEBORG-2 trial in Sweden, researchers compared prostate screening protocols in men with PSA levels 3 ng/mL and higher who got MRI scans:

  • One group automatically got systemic biopsy and then MRI-targeted biopsy based on MRI results.
  • The other group only got MRI-targeted biopsy if they had a suspicious MRI scan.

In 13.2k men who were followed up for a median of four years, researchers found that those in whom systemic biopsy was omitted …

  • Had 57% lower risk of clinically insignificant cancers.
  • Had lower relative risk of clinically insignificant cancers in subsequent screening rounds (RR=0.25 vs. 0.49).
  • Had 16% lower risk of detecting clinically significant cancers.
  • Had 35% lower risk of advanced or high-risk cancers.

On the down side, the protocol eliminating systemic biopsy could lead to later diagnoses for higher-risk disease for 3 in 1k men – but given the slow-growing nature of prostate cancer it’s not clear how significant this is. 

  • Also, the data indicate that “most prostate cancers become visible on MRI” before they are incurable, which increases the likelihood that they would at least be detected on subsequent screening rounds and could be treated effectively.

The Takeaway

The new findings should help clinicians hone in on the best prostate screening protocols for maximizing detection of clinically significant cancer while minimizing unnecessary workup. Hopefully, the addition of new technologies like AI can move this process along.

Better Prostate MRI with AI

Posted on by Brian Casey

A homegrown AI algorithm was able to detect clinically significant prostate cancer on MRI scans with the same accuracy as experienced radiologists. In a new study in Radiology, researchers say the algorithm could improve radiologists’ ability to detect prostate cancer on MRI, with fewer false positives.

In past issues of The Imaging Wire, we’ve discussed the need to improve on existing tools like PSA tests to make prostate cancer screening more precise with fewer false positives and less need for patient work-up.

  • Adding MRI to prostate screening protocols is a step forward, but MRI is an expensive technology that requires experienced radiologists to interpret.

Could AI help? In the new study, researchers tested a deep learning algorithm developed at the Mayo Clinic to detect clinically significant prostate cancer on multiparametric (mpMRI) scans.

  • In an interesting wrinkle, the Mayo algorithm does not indicate tumor location, so a second algorithm – called Grad-CAM – was employed to localize tumors.

The Mayo algorithm was trained on a population of 5k patients with a cancer prevalence similar to a screening population, then tested in an external test set of 204 patients, finding …

  • No statistically significant difference in performance between the Mayo algorithm and radiologists based on AUC (0.86 vs. 0.84, p=0.68)
  • The highest AUC was with the combination of AI and radiologists (0.89, p<0.001)
  • The Grad-CAM algorithm was accurate in localizing 56 of 58 true-positive exams

An editorial noted that the study employed the Mayo algorithm on multiparametric MRI exams.

  • Prostate cancer imaging is moving from mpMRI toward biparametric MRI (bpMRI) due to its faster scan times and lack of contrast, and if validated on bpMRI, AI’s impact could be even more dramatic.

The Takeaway
The current study illustrates the exciting developments underway to make prostate imaging more accurate and easier to perform. They also support the technology evolution that could one day make prostate cancer screening a more widely accepted test.

Better Prostate MRI Tools

Posted on by Brian Casey

In past issues of The Imaging Wire, we’ve discussed some of the challenges to prostate cancer screening that have limited its wider adoption. But researchers continue to develop new tools for prostate imaging – particularly with MRI – that could flip the script. 

Three new studies were published in just the last week focusing on prostate MRI, two involving AI image analysis.

In a new study in The Lancet Oncology, researchers presented results from AI algorithms developed for the Prostate Imaging—Cancer Artificial Intelligence (PI-CAI) Challenge.

  • PI-CAI pitted teams from around the world in a competition to develop the best prostate AI algorithms, with results presented at recent RSNA and ECR conferences. 

Researchers measured the ensemble performance of top-performing PI-CAI algorithms for detecting clinically significant prostate cancer against 62 radiologists who used the PI-RADS system in a population of 400 cases, finding that AI …

  • Had performance superior to radiologists (AUROC=0.91 vs. 0.86)
  • Generated 50% fewer false-positive results
  • Detected 20% fewer low-grade cases 

Broader use of prostate AI could reduce inter-reader variability and need for experienced radiologists to diagnose prostate cancer.

In the next study, in the Journal of Urology, researchers tested Avenda Health’s Unfold AI cancer mapping algorithm to measure the extent of tumors by analyzing their margins on MRI scans, finding that compared to physicians, AI … 

  • Had higher accuracy for defining tumor margins compared to two manual methods (85% vs. 67% and 76%)
  • Reduced underestimations of cancer extent with a significantly higher negative margin rate (73% vs. 1.6%)

AI wasn’t used in the final study, but this one could be the most important of the three due to its potential economic impact on prostate MRI.

  • Canadian researchers in Radiology tested a biparametric prostate MRI protocol that avoids the use of gadolinium contrast against multiparametric contrast-based MRI for guiding prostate biopsy. 

They compared the protocols in 1.5k patients with prostate lesions undergoing biopsy, finding…

  • No statistically significant difference in PPV between bpMRI and mpMRI for all prostate cancer (55% vs. 56%, p=0.61) 
  • No difference for clinically significant prostate cancer (34% vs. 34%, p=0.97). 

They concluded that bpMRI offers lower costs and could improve access to prostate MRI by making the scans easier to perform.

The Takeaway

The advances in AI and MRI protocols shown in the new studies could easily be applied to prostate cancer screening, making it more economical, accessible, and clinically effective.  

MRI Makes Prostate Screening More Precise

Posted on by Brian Casey

Prostate cancer screening isn’t a guideline-directed screening test yet, but this could change with the use of MRI and other tools. A series of papers published in several JAMA journals late last week indicates the progress that’s being made. 

As we’ve discussed in previous issues, prostate screening with PSA tests hasn’t met the threshold for clinical benefit achieved by other population-based screening exams.

  • PSA-based screening has been characterized by lower mortality benefits and relatively high rates of overdiagnosis and complications from follow-up procedures. 

But some researchers believe that PSA screening could be made more effective by using additional diagnostic tools like imaging and blood tests to focus on potentially high-risk disease for biopsy while active surveillance is used for less threatening prostate lesions. 

In the ProScreen trial in Finland, researchers tested the combination of PSA, a kallikrein four-panel blood test, and MRI in selecting patients for biopsy. 

  • Patients were sent to MRI if they had PSA scores of 3.0 ng/mL or higher and kallikrein scores of 7.5% or higher; those with abnormal MRI scans got targeted biopsy. 

The researchers tested the ProScreen protocol in a study of 61.2k men, with 15.3k invited to screening and 7.7k getting screened. Over a preliminary three-year follow-up period, researchers found …

  • 9.7% of men met the PSA threshold for a suspicious lesion; this fell to 6.8% after the kallikrein test and 2.7% after MRI, illustrating the protocol’s ability to reduce biopsies
  • Biopsy yield for high-grade cancer was 1.7%, which an editorial called a “remarkably high yield”
  • Overdetection of low-grade disease was 0.4%, compared to 3.2% in a comparable previous study

In a second study, this one in JAMA Oncology, researchers performed a meta-analysis of 80.1k men from 12 studies in which MRI was used to direct patients to prostate biopsy after PSA testing, finding that MRI-directed protocols had …

  • Higher odds of detecting clinically significant prostate cancer (OR=4.15) compared to PSA screening alone
  • Lower odds ratio for biopsy (OR=0.28)
  • Lower odds ratio for detecting clinically insignificant cancer (OR=0.34)

Finally, a secondary analysis in JAMA of a large UK trial illustrates the challenges of prostate screening without MRI guidance. Researchers reviewed 15-year outcomes of the Cluster Randomized Trial of PSA Testing for Prostate Cancer (CAP), a study of 415k men,196k of whom were screened from 2002 to 2009 without the use of MRI, finding … 

  • PSA screening increased detection of low-grade cancer (2.2% vs. 1.6%) but not intermediate or high-grade disease
  • Screening reduced prostate cancer mortality by a small amount (0.69% vs. 0.78%)

The Takeaway

Taken together, new studies offer a roadmap toward making MRI an integral part of prostate screening, such that perhaps in years to come it can join other cancer tests as a population-based screening tool.

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