E x V/ΓD: the formula for breast tomosynthesis?

January 16, 2007

It's the new year -- time for me to come up with some resolutions. Some might consider this late, or something that should have been done a couple of weeks ago. I consider it prudent.

It's the new year - time for me to come up with some resolutions. Some might consider this late, or something that should have been done a couple of weeks ago. I consider it prudent.

Those heady days right after Christmas are hardly the time for me to make life-altering decisions. I'm high on the holiday and the drop of the Times Square ball. Even now it's a little hard to concentrate. This morning I saw gas prices a few cents above two bucks. I've begun thinking about driving long distances when I should be thinking about long-term planning.

It's a lot like what's going on in breast imaging. Sales of full-field digital mammography (FFDM) systems are flying off the assembly line. If I were heading a company with this kind of demand for my product, I'd have a hard time changing gears. But if I could get past the moment, stick my head above the fog, and look around, I'd see change might not be such a bad thing.

Clinical evidence is accumulating that tomosynthesis offers distinct advantages in breast cancer diagnosis. Business factors are aligning in favor of a move to tomography, as computed radiography has started a low-cost run at the market.

Some wrinkles have yet to be ironed out, such as how many images, over how big an arc, need to be acquired to construct a 3D tomograph of the breast and even whether two arcs along different planes should be performed. But GE, Hologic, and Siemens have developed technology for putting any such approach in place.

So what's holding tomography back? Is it perfectionism, the need to get the technology just right? Is it the kind of prudence I exercise in making my New Year's resolutions? Or is it something else? Dr. Piers Steel at the Haskayne School of Business at the University of Calgary may have the means for calculating an answer.

After a decade of scrupulously meta-analyzing research into procrastination, the world's foremost expert on putting off until tomorrow what should be done today has come up with a formula that determines when things will finally get done.

His temporal motivational theory factors in the expectancy a person has of succeeding with a given task (E), the value of completing the task (V), the desirability of the task (Utility), its immediacy or availability (the Greek letter Gamma - who knows why) and the person's sensitivity to delay (D) or, simply, Utility = E x V/ΓD.

When the numbers all work out - bang! That's it.

This may be what happened in CT a few years ago. Elscint commercialized the first dual-slice CT in 1992. Six years passed before quad-slice came along, but when it did, GE, Siemens, and Toshiba were there with scanners within months of each other.

Each had introduced spiral scanning about the same time Elscint tried to popularize its CT-Twin and it may be that the major vendors wanted to stretch out single-slice spiral CT for as long as possible to get as much return from their investment as they could. Personally, I think procrastination is just as likely to have been at the root of the problem, just as it might be now for tomo.

Steel said it's not clear why people procrastinate. It might be genetic. Obviously, this question screams for more attention.

"Continued research into procrastination should not be delayed, especially because its prevalence seems to be growing," Steel said.

Let's hope, for the sake of women's health, that the makers of tomosynthesis are among the unaffected.

Editor's note: Steel's paper, "The nature of procrastination: A meta-analytic and theoretical review of quintessential self-regulatory failure," appears in the American Psychological Association's Psychological Bulletin this month. I plan to read it first chance I get.