DR. KOPANS REPLY AND READER'S LETTER

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Thanks for your question.  Although I was Co-Chairman of the original BIRADS Committee, and BIRADS was based on the computer reporting system that I developed for my group at the Massachusetts General Hospital, I am no longer on the committee, so I posed it to Dr. Ed Sickles who was on the BIRADS committee and he wrote the following:

“Having been "on the inside" when the decision was made to replace "clustered" with "grouped", I can explain it to you. You may or may not agree with the rationale, but here it is.

There is very little difference between "grouped" and "clustered" in the English language.  The change in BI-RADS was made because over the many years of having used "clustered" as a descriptor of calcifications judged suspicious for malignancy, many referring clinicians and patients developed an inaccurately high estimate of the likelihood of malignancy for this mammographic finding, much more likely malignant than benign.  The actual likelihood is approximately 30%, hence these calcifications are much more likely benign than malignant, albeit sufficiently suspicious that tissue diagnosis is appropriate.  The BI-RADS Committee decided to change terminology so that when the actual percentage likelihoods of malignancy were published in BI-RADS for the first time (5th edition), misconceptions about "clustered" would be eliminated when this term was replaced with the term "grouped", explicitly stated to have a likelihood of malignancy of only about 30%.”

In other words Dr. Sickles is explaining that there is no real difference between the two words.  The Committee wanted to end the idea that “clustered” implied a very high risk of being due to cancer.  In fact, as he writes, most “grouped” or “clustered” calcifications are not related to cancer, but have a high enough risk (30%) that they need to be biopsied.  In the U.S. we would perform an image guided needle biopsy using local anesthesia.  I don’t know why the committee made the change since all they had to do was explain the risk when there are small calcifications “grouped” or “clustered” close together.  Of course, as I wrote back to Dr. Sickles, and he agreed, it is not just the grouping (or clustering) that determines the need for a biopsy, but the morphology of the calcifications.  For example: I have never seen a “group” or “cluster” of calcifications that were “round with lucent centers” that was associated with breast cancer. 

I personally like to use the term “a group” of calcifications if I feel it is important to describe 5 or more in a cubic centimeter of tissue, when I am NOT concerned about the “group” so that someone looking at the study will understand that I saw them and felt they could be left alone.  I would still use the term “clustered” when I am concerned that they need to be biopsied. 

BIRADS is very important to organize our thoughts, reports, and track our results, but there are some parts of it with which I do not agree.  I would continue to use “clustered” when I want a biopsy and “a group of round, lucent centered calcifications” when I just want to describe them, but leave them alone.

By the way, as one of my former fellows explained, “round” is like a ball.  When you bounce it, it comes back to your hand.  If a calcification will not come directly back, then it is not “round” and should not be described as “round”.

I hope this helps.  Let me know if you have any other questions. 

Dan Kopans