3D breast imaging beats mammography but cost-effectiveness more important
Technological excellence is a highly satisfactory achievement, but one that does not necessarily lead to enormous market success. Siemens has submitted its 3D breast imaging system for the FDA’s blessing and has good reason to expect to get it, not least because just last week a study of Hologic’s similar device underlined the utility of the technique.
But clinical success and regulatory approval are not the same as money in the bank. Hologic’s system, approved in the US since 2011, has still not been granted reimbursement – standard mammography is much cheaper – and the company has run into grave financial difficulties as a result (Hologic adopts poison pill to combat takeover drive, November 26, 2013). Siemens needs to persuade payers and the market at large as well as the FDA.
3D mammography, also known as tomosynthesis, involves multiple X-rays being acquired as the camera moves in an arc around the breast. These are then assembled by computer, allowing overlapping tissues to be disregarded, making the morphology and extent of any tumours easier to see.
The big question for both companies is whether the huge trial of Hologic’s Selenia Dimensions system will help change the reimbursement situation – and ideally breast cancer screening guidelines too.
The trial, which involved comparing 281,187 digital mammograms and 173,663 digital mammograms plus 3D mammograms, concluded that the addition of 3D mammography to the traditional technique increased the invasive cancer detection rate from 2.9 to 4.1 per 1000, a relative increase of 41%. However, the researchers said that they were unable to calculate absolute sensitivity and specificity as data on interval cancers were not available.
Tomosynthesis was also more definitive, reducing the number of women who had to return for confirmatory biopsies by 15%.
But the technology has two drawbacks: its addition to digital mammography doubles the radiation dose, and the machines used to perform the scans cost around half a million dollars, nearly twice the $300,000 2D mammography price tag.
Medicare and many insurance companies have previously decided that the technology’s advantages are not worth the extra cost, though it should be pointed out that some hospitals still buy the systems, often passing along the cost to patients. Hologic, the only company to have reached the US so far, has been able to sell around 1,000 of the devices since approval.
One thing that could spur uptake is to use the same idea behind companion diagnostics: identifying the patients most likely to benefit. It is hard though, to know how this could be done. Tomosynthesis is better than mammography at detecting smaller tumours, for example, but identifying these patients beforehand would abrogate the need for mammography anyway.
Siemens is now in the race too, though it is behind GE Healthcare, which submitted its PMA application a year ago. The German group is seeking approval to add a tomosynthesis option to its Mammomat Inspiration mammography system whereas Thomas Edison’s company has a separate 3D system called SenoClaire.
If the trial can persuade the Centers for Medicare and Medicaid to reimburse the system Hologic’s sales would leap, and GE and Siemens would stand to gain too. But this technology was conceived in a time of plenty; in today’s straitened climate these three companies might have been better off developing cheaper, no-frills 2D devices instead.