Diagnostic Imaging
August 2003

VIEWPOINT

Say no to peers who weaken mammography

Missing a breast cancer does not indicate incompetence, but limitations of technology

An event that occurred during my first year of radiology residency remains excruciatingly clear in my memory. I had spent an afternoon reading a stack of plain films. The next morning I was approached by the director of the residency program, a scholarly man who possessed not only extensive knowledge but, even more impressively, great wisdom.

"Mark," he said, motioning for me to follow him into the main reading area, "I want to show you a case."

He proceeded to hang a series of rib films on the viewboxes.

"What do you see?" he asked.

I studied the films and told him that I thought there were three fractures of the right ribs.

"Interesting," he replied. "You didn't think so yesterday."

I don't need to tell any radiologist how I felt at that moment. I had seen the same set of films less than 24 hours earlier and thought they looked just fine. As I lamented the fact that I was completely worthless and should find a job with the sanitation department as soon as possible, the residency director looked at me kindly, smiled, and said the following words, which I have never forgotten.

"There are two kinds of radiologists: those who make mistakes and those who don't read any films," he said.

We have all learned the wisdom of that statement. We all make mistakes and, hopefully, we learn from them. Since that day, I look at rib films as if searching for hidden gold.

Recent studies on mammography have documented that up to 67% of mammographically detected breast cancers are retrospectively visible on prior studies. More interesting, studies have also shown that as many as 21% of breast cancers are flat-out missed by experienced mammographers. It is one thing to say that hindsight can identify the origin of most breast cancers and quite another to say that even very good mammographers miss breast cancer. This is not incompetence; this is a limitation of technology.

My practice performs in excess of 85,000 mammograms annually, and each of our mammographers obviously reads a great number of films. We take our work very seriously, and we are very good at what we do. But as good as we are, we can't beat the statistics; we all miss some cancers. Every day we make judgments, most of them correct, but some, unfortunately, miss the mark. It's a fact of life in mammography and in all of radiology.

Yet the standard of care for mammography is not 79% correct, 21% incorrect; the de facto standard of care has become 100%. The reason is plaintiff's attorneys, and worse, radiologists who help them.

Plaintiff's attorneys will tell you that they are simply protecting the public and that tort law encourages better care and more attention to detail. Their cause is just, righteous, and beneficial to those who would otherwise be victimized by the powerful medical community. Radiologists who testify for the plaintiff preach the same gospel.

You might be surprised by the identity of some of these radiologists. Not a few are academic mammographers, some retired from active practice and some not. Some are people with whom many of us are well acquainted. All too often, members of this group are willing to hold our feet to the fire for misses they might have been guilty of in clinical practice themselves.

The following hypothetical example, a composite that is not unlike many cases from around the country, illustrates the situation. A mammogram of a woman in her 60s is interpreted by a highly respected mammographer. An area of asymmetric density is present on a single view, for which additional views are obtained that suggest the absence of a true mass. Two years later, having had no interval mammography or breast exam, the patient returns with an obvious cancer at a location just inferior to the site of the earlier asymmetric density. The density present two years earlier most likely represented an induced response to something brewing in the neighborhood. Hindsight is always 20/20.

The patient sues for failure to diagnose breast cancer. She has undergone surgery, radiation therapy, and chemotherapy and is doing well clinically. The plaintiff's attorney retains a highly credentialed mammographer as an expert witness. During a deposition, the defense asks the expert if he had ever retrospectively reviewed a mammogram that he had previously read and found a missed a breast cancer that he had originally overlooked on a mammogram. He answers honestly, of course, "Yes."

The defense then asks him if he had ever missed a breast cancer on a mammogram that in retrospect he felt he should have seen. Again, he answers yes. Finally, he is asked if he had ever missed a breast cancer on a mammogram and that miss was below what would be considered the standard of care. Once again he answers yes, to which he smiled and volunteered that it had happened on more than one occasion.

Well, of course it had. If he has read thousands of mammograms, he had to have missed these and more. The irony is that the expert and the defendant could just as easily have been on opposite sides of the table.

Experienced mammographers do read thousands of mammograms annually, find a good many cancers, and make a positive impact on the lives of many women. Each one of us who practices this art takes every case of breast cancer personally, and we try to care for every patient the best we can, medically, emotionally, even spiritually.

We certainly did not choose mammography for the compensation; it pays a lot less than MRI or CT or interventional radiology. But a distinct feeling of fulfillment and satisfaction results from knowing that what we do makes a big difference to many women every day. From the moment we find a lesion we become part of that woman's life's history forever.

For the plaintiff's attorneys, mammography is "lawyer candy." With a retrospective visibility rate of 67% and a "miss" rate of 21%, all a plaintiff's attorney has to do is camp out at the entrance to a breast cancer clinic, ask to see a woman's mammogram, tell her there is an excellent chance her cancer could have been detected earlier if only the incompetent radiologist had done his job, and have her sign on the bottom line. All that remains is to find a radiologist to say, "Oh sure, any decent radiologist would have seen that one."

It is the willingness of radiologists to testify against their colleagues that perpetuates this madness. Some of these individuals will claim they do so to protect the specialty, to make certain that only qualified radiologists read mammograms. If that is true, why do they turn up so often testifying against well-trained, highly experienced mammographers?

And, certainly, the courts are not the place to practice quality assurance in mammography. Plaintiff's attorneys are not interested in making improvements in mammography. Their livelihood involves picking off radiologists one by one to fill their personal coffers, so the last thing they want is perfect mammography. Continuing education, periodic recredentialing, and appropriate compensation for mammographers are what is needed, not another round in the courtroom.

Radiologists who profit from testifying against their colleagues are shameful, and it's past the time to let them know it is not OK. Boycott lectures and meetings at which these people speak. Shun them at professional society meetings. Let them and their colleagues know that you know what they do. I am not recommending that we as a profession allow the incompetent to continue; that would be an even greater crime. We are talking about a flawed system that demands 100% perfection when only 79% is possible. We are talking about those who besmirch the reputations of people who are doing the best that is possible.

The number of radiologists willing to read mammograms is diminishing, and who can blame those who quit? Litigation against radiologists for failure to diagnose breast cancer is now number one on the list of malpractice cases. Make $10, get sued for $25 million is not what most people would consider a great business proposition.

It is time to step up to the plate and let these radiologist consultants know that such behavior will no longer be tolerated. Vote with your dollars; refuse to attend meetings in which they participate and raise your voice against this small but deadly group who threaten our ability to do our jobs.

History has repeatedly taught us the fate of those who see injustice and stand by silently.

Dr. Klein is a radiologist at Washington Radiology Associates in Washington, DC.