Thursday, 31 January 2008

Viva Las Vegas!

Well today I was supposed to be travelling to Las Vegas, where the American Roentgen Ray Society (ARRS) are hosting a Practical Breast MRI session at the Westin, similar to that held by the Radiology Academy in Norwich last April.

Weather has conspired against this so far. In California the rain is teeming down and 2 runways have been closed at San Francisco International Airport, with the associated delays, I am now experiencing what most Americans have to put up with on a regular basis. Hopefully will get off before midnight as we have a 7am start tomorrow.

The mid-West are having serious arctic weather right now, just like the UK appear to be having a similar arctic blast for the end of the week.

Does this remind you of the film - 'the day after tomorrow'?

Tuesday, 29 January 2008

Latest analysis of the DMIST trial - subset of women under 50 years

In the February edition of Radiology, Eta Pisano reports on some of the sub-group analysis of the DMIST study data.
Radiology, February 2008, Vol. 246:2, pp. 376-383
The subgroup of pre- or perimenopausal women younger than 50 years old with dense breasts was the only one for which FFDM performed significantly better than FSM.
The AUC for digital mammography was 0.79 versus 0.54 for film-screen mammography. Sixteen cancers in this group were found with digital and missed with film-screen mammography, while only two were found with film-screen and missed with digital.

The results also showed a trend toward improved accuracy of FSM over FFDM in women age 65 or over with fatty breasts, but it was not significant, according to the researchers. In this group, 15 cancers were found with film-screen mammography and missed with digital, and four were found with digital and missed with film-screen mammography

Friday, 4 January 2008

Motile in-situ cancer cells (DCIS)

Reported in this month's edition of The Journal of Cell Biology, there is evidence that malignant epithelial cells become motile within their own environment, similar to that occurring in the development of organs during embyrogenesis.

Although the cancer cells are not yet invasive (they do not have the ability to pass through basement membranes), motile cells may indicate the development of a higher grade, or aggressive form of cancer that is developing.
These type of motile cell may require fewer mutations to become fully invasive. Further work needs to be done to see if we can identify what cell lines are developing this way, and devise a test that will differentiate the more aggressive form of DCIS which needs a more aggressive surgical treatment from the outset.

Tuesday, 1 January 2008

Cost-Effectiveness of Digital Mammography Breast Cancer Screening

A paper in the Annals of Internal Medicine published today 1 January 2008, Volume 148 Issue 1, Pages 1-10, was part of the economic analysis of implementing the move to digital mammography as part of the ACRIN 6652 DMIST study, which reported in October 2006.

The authors Dr. Anna Tosteson et al, from Dartmouth Medical School, performed a discrete event-simulation model to evaluate the cost effectiveness of Digital Mammography (FFDM) compared with analogue (film-screen) mammography. The headline result shows that there are NO cost savings by moving to digital unless breast screening is targeted to a higher risk population where digital mammography has been proven to have a better track record for detecting cancer like younger women with dense breasts.

While this study is useful as it relates to QALYs and cost per life year saved, there are other real world events that also have to be taken into consideration when deciding whether to upgrade your mammography machine to digital.

One of these factors is the decreasing production of medical x-ray film and chemicals, which will eventually be phased out. There are other benefits of moving to digital, which include the eventual elimination of film libraries, physical film hanging, along with the elimination of having to deal with dangerous chemicals and the environmental aspects of disposal of the used developer and fixer. Photographic emulsions are steadily being phased out, so in the medium to long term, there is no real question that digital mammography has to be the final solution.

Perhaps we were originally aiming too high in the original trials, as scientifically it is correct that there has to be a benefit compared with the gold standard examination. An economic evaluation was correctly performed but maybe the most important finding is that digital mammography in its 2003-4 iteration was as good as, and occasionally more accurate than conventional mammography.

Pragmatically, when replacing a mammography unit, a digital one should be purchased. Newer versions of FFDM are better quality, and can only improve our ability to diagnose breast cancer. Workstations and comparison with prior mammograms are now the current challenges facing us as we move forward in attempting to advance the diagnosis of breast cancer.