Biopsy vs. MRI guided Biopsy

An older friend - 71 yrs old - with a rising PSA has been scheduled by his urologist to have a biopsy. A standard biopsy, not first an MRI and then a guided biopsy based on MRI findings. Which is what I had done, and what I would've recommended.

The friend just wants to do what his doctor says, and the doctor is older and conservative, and so the friend will have the standard biopsy.

My thinking has been that the standard biopsy is looking for the needle(s) in the haystack. But should I be thinking of this differently based on age - if you're 71 and a standard biopsy doesn't find cancer that it means either (1), you don't have cancer, or (2), that any cancer you may have that is not detected is so un advanced that it is not likely to affect your longevity anyway?

Thinking the same as you hrpufnstuf. But the standard 12 core biopsy is what he's going to do.

There really is no evidence that an MR-guided biopsy is any better than a TRUS biopsy on a first biopsy. If suspicion remains after the first negative biopsy, or if it's positive and active surveillance is on the table, then a second MRI-targeted biopsy has a distinct diagnostic advantage over the TRUS. I think his doctor is right to wait.

There have been several studies, all with inconsistent results. It depends where you look. My guess is that in the hands of Jelle Berentz, the results are superior. That's why I always mention the importance of a great radiologist to interpret the findings.

You can see the lack of benefit in some of the studies:

"Magnetic resonance imaging guided in-bore and systematic transrectal ultrasound guided biopsies achieved equally high detection rates in biopsy naïve patients with increased prostate specific antigen."

Prospective Evaluation of Magnetic Resonance Imaging Guided In-bore Prostate Biopsy versus Systematic Transrectal Ultrasound Guided Prostate Biopsy in Biopsy Naïve Men with Elevated Prostate Specific Antigen

"MP-MRI/TRUS-fusion targeted biopsy did not improve PCa detection rate compared with TRUS-guided biopsy alone in patients with suspected PCa based on PSA values."

Prebiopsy Multiparametric Magnetic Resonance Imaging for Prostate Cancer Diagnosis in Biopsy-naive Men with Suspected Prostate Cancer Based on Elevated Prostate-specific Antigen Values: Results from a Randomized Prospective Blinded Controlled Trial

"In the first set of transrectal prostate biopsies, mp-MRI guidance did not increase the diagnostic yield significantly."

Multiparametric MRI guidance in first-time prostate biopsies: what is the real benefit?

As you see, results are inconsistent. I guess that's partly because of the experience of the radiologist.

The other key things we notice about all of these studies are that:
• All of these studies are from outside of the US
• Cancer is detected in about half to two-thirds of the cases, in both TRUS and MRI-targeted.

In the US, cancer is only detected in about one-third of cases. Because of the lack of PSA screening in Europe and elsewhere, and perhaps better biopsy protocols, PC is detected there more often on biopsy. Also, over-biopsying is rampant in the US. Because of this, MRI-targeting on a first biopsy in the US is expected to give a lower return here - most men will be negative. MRI-targeting in Europe also costs a good deal less. MRI increases the cost increase tremendously. Less diagnostic yield for a vastly increased cost doesn't sound like a good idea to me or any of the major cancer care centers in the US. I'd save it for when it's really needed.

- Allen

My comments in red. You dropped an important sentence, see below.

Tall Allen said...
There have been several studies, all with inconsistent results. It depends where you look. My guess is that in the hands of Jelle Berentz, the results are superior. That's why I always mention the importance of a great radiologist to interpret the findings.

You can see the lack of benefit in some of the studies:

"Magnetic resonance imaging guided in-bore and systematic transrectal ultrasound guided biopsies achieved equally high detection rates in biopsy naïve patients with increased prostate specific antigen. Magnetic resonance imaging guided in-bore biopsies required significantly fewer cores and revealed a significantly higher percent of cancer involvement per biopsy core."

Prospective Evaluation of Magnetic Resonance Imaging Guided In-bore Prostate Biopsy versus Systematic Transrectal Ultrasound Guided Prostate Biopsy in Biopsy Naïve Men with Elevated Prostate Specific Antigen

- Allen

For the second study, my comments again in red.

Tall Allen said...

Results and limitations

"Overall, 53 and 60 patients were evaluable in the MP-MRI and control groups, respectively. The overall PCa detection rate and the clinically significant cancer detection rate were similar between the MP-MRI and control groups, respectively (64% [34 of 53] vs 57% [34 of 60]; 7.5% difference [95% confidence interval (CI), −10 to 25],p = 0.5, and 55% [29 of 53] vs 45% [27 of 60]; 9.7% difference [95% CI, −8.5 to 27],p = 0.8). The PCa detection rate was higher than assumed during the planning of this single-center trial."

This result was not statistically significant, therefore the conclusion below, but that was most likely because of the small sample size. But still, MP-MRI detected cancer in 64% vs 57% with the TRUS biopsy. And MP-MRI detected clinically significant cancer in 55% of the sample vs 45% for TRUS. I would go for the MP-MRI if insurance would pay for it.
"MP-MRI/TRUS-fusion targeted biopsy did not improve PCa detection rate compared with TRUS-guided biopsy alone in patients with suspected PCa based on PSA values."

Prebiopsy Multiparametric Magnetic Resonance Imaging for Prostate Cancer Diagnosis in Biopsy-naive Men with Suspected Prostate Cancer Based on Elevated Prostate-specific Antigen Values: Results from a Randomized Prospective Blinded Controlled Trial


- Allen

For the third study, my comments again in red.

"METHODS

Charts of 140 patients, who underwent transrectal prostate biopsy after the adaptation of mp-MRI into our routine clinical practice, were reviewed retrospectively. Patients with previous negative biopsies (n=24) and digital rectal examination findings suspicious for ≥cT3 prostate cancer (n=16) were excluded. T2-weighted imaging, diffusion-weighted imaging, and dynamic contrast-enhanced imaging were included in mp-MRI. Cognitive fusion biopsies were performed after a review of mp-MRI data, whereas TRUS-guided biopsies were performed blinded to MRI information. In-bore biopsies were conducted by means of real-time targeting under MRI guidance.
RESULTS

Between January 2012 and February 2014, a total of 100 patients fulfilling the inclusion criteria underwent TRUS-guided (n=37), cognitive fusion (n=49), and in-bore (n=14) biopsies. Mean age, serum prostate specific antigen level, and prostate size did not differ significantly among the study groups. In TRUS-guided biopsy group, 51.3% were diagnosed with prostate cancer, while the same ratio was 55.1% and 71.4% in cognitive fusion and in-bore biopsy groups, respectively (P = 0.429). Clinically significant prostate cancer detection rate was 69.1%, 70.3%, and 90% in TRUS-guided, cognitive fusion, and in-bore biopsy groups, respectively (P = 0.31). According to histopathologic variables in the prostatectomy specimen, significant prostate cancer was detected in 85.7%, 93.3%, and 100% of patients in TRUS-guided, cognitive fusion, and in-bore biopsy groups, respectively."

Clinically significant PC was detected in 90% of the live MRI biopsies vs 69.1% and 70.3% in the TRUS and fusion biopsies. In this case, the live MRI beat the other two methods. I think it all boils down to insurance. If your insurance will pay for an MRI biopsy, go for it.

Tall Allen said...
"In the first set of transrectal prostate biopsies, mp-MRI guidance did not increase the diagnostic yield significantly."

Multiparametric MRI guidance in first-time prostate biopsies: what is the real benefit?- Allen

Tall Allen said...
Once again, you can't just ignore statistical significance. The differences were not statistically significant. It didn't "beat" the others - they were not different (p=.31).

- Allen

Three different studies the MRI results were much better but not statistically significant due (most likely) to small sample sizes. If I needed a biopsy and insurance would pay for either, I would definitely pick an MRI fusion over a TRUS based on these results.

There is a clinical trial underway that is supposed to determine if MRI biopsies are better, but the estimated sample size is only 100. Good luck on that.
https://clinicaltrials.gov/ct2/show/record/NCT02131207