No one wants to go through an invasive clinical procedure if they don’t need it. Who wouldn’t prefer to be spared from simple invasions like blood draws or enemas, let alone major surgeries like replacing a heart valve or removing a lung? From the viewpoint of an individual, we’d like to avoid these if we can.

From the perspective of the healthcare system, it’s also important to be conservative about performing procedures. Not only does this improve healthcare delivery, it also saves healthcare costs. Among the key principles of a top-quality health system are:

• Avoid or reduce risks of side effects
• No needless pain (both physical and emotional)
• Provide care based on the best available evidence
• Don’t waste a patient’s time or money
• Don’t waste society’s money

Prostate biopsy: the big picture

Let’s consider prostate biopsies, most of which are done using the conventional transrectal ultrasound (TRUS) 12-14 needle method. Almost 90% of prostate cancers (PCa) are found as the result of screening by an inexpensive PSA blood test. A suspiciously high result leads to a prostate biopsy; in turn, there are costs associated with sending the slides to a pathology lab for analysis, and potential outpatient and inpatient costs incurred by post-biopsy infections. Thus, “screening” can be more broadly defined as the blood test, biopsy, pathology and any other downstream costs per patient. Using this definition, a 2014 analysis of 94,652 SEER-Medicare case records from 2007-2009 produced the following data:

✔ The annual screening cost to Medicare was $447 million
✔ PSA tests accounted for 28% of the total cost
✔ Biopsy-related costs accounted for 72% of the total cost
✔ 50% of the biopsy-related costs came from the procedure itself
✔ 19% of the biopsy-related costs came from pathology fees
✔ 3% of the biopsy-related costs came from hospitalization due to biopsy complications

The authors of the analysis suggest, “Given the high percentage of screening cost that is attributable to biopsy, it would be important to test the utility of alternative, lower-cost approaches for downstream workup after detection of an elevated PSA.”^[i] They enumerate PSA variants (velocity, density), artificial neural networks, models and nomograms, and biomarkers taken from blood, urine and semen as information that can help doctors and patients discuss if a biopsy is needed. However, when their paper was published, there was not yet the quickly growing body of studies on MRI before biopsy.

A picture is worth a thousand tests

I want to share a retrospective study out of the well-respected Radboud University Medical Center, Nijmegen, the Netherlands. Our Dutch colleagues specialize in clinical studies involving 3T multiparametric MRI (mpMRI) for the detection, diagnosis and image-guided treatment of prostate tumors. This study is an important contribution in how to reduce the number of unnecessary biopsies.

In order to determine whether mpMRI results can help avoid an unnecessary biopsy, they analyzed the records of 4259 patients who had mpMRI between Jan. 2012 – Dec. 2017. The patients either had a previous TRUS-guided biopsy that was negative for PCa, or had never had a biopsy. The PI-RADS classification system was used to score the probability of PCa (where 1 is most probably benign and 5 is most probably malignant). For purposes of their analysis, negative mpMRI was defined as an index (largest) lesion of PI-RADS score lesser than or equal to 2 (≤ 2), while clinically significant PCa was defined as Gleason score ≥ 3 + 4. Follow-up was completed through Oct. 2018.^[ii]

According to their mpMRI findings, 2281 patients (53.6%) had a lesion scored as PI-RADS ≤2. In 320 of them, a follow-up mpMRI was performed at an average of nearly 5 years (41-63 months). The rate of freedom from clinically significant prostate cancer was 99.6% after 3 years. They concluded that more than half of the men were able to avoid a biopsy because their initial mpMRI did not show clinically significant PCa, and 3 years later 99.6% of them had not progressed any further.

mpMRI shows if a biopsy is needed

It’s encouraging that noninvasive imaging after a suspicious PSA result can clarify whether a prostate biopsy is justified. Avoiding an unnecessary procedure spares a man from needless risk, and it has the added economic benefit of sparing society from spending needless healthcare dollars. Men whose mpMRI was negative for significant PCa but whose PSA remains high or continues to rise can have repeat scans without the risks involved in repeat biopsy. If the scan reveals significant PCa, a real-time mpMRI-guided targeted biopsy reduces the risks of conventional TRUS biopsy by using fewer needles while it offers the advantages of superior diagnostic accuracy.

Wouldn’t it be great to know if you really needed a biopsy? Isn’t it great to know that mpMRI tells you what you need to know?

NOTE: This content is solely for purposes of information and does not substitute for diagnostic or medical advice. Talk to your doctor if you are experiencing pelvic pain, or have any other health concerns or questions of a personal medical nature.

References

[i] Ma X, Wang R, Long JB, Ross JS et al. The Cost Implications of Prostate Cancer Screening in the Medicare Population. Cancer. 2014 Jan 1; 120(1): 10.1002/cncr.28373.
[ii] Venderink W, van Luijtelaar A, van der Leest M, Barentsz JO et al. Multiparametric magnetic resonance imaging and follow-up to avoid prostate biopsy in 4259 men. BJU Int. 2019 Nov;124(5):775-784. doi: 10.1111/bju.14853. Epub 2019 Jul 23. https://www.ncbi.nlm.nih.gov/pubmed/31237388