Researchers from the Mayo Clinic in Rochester, Minnesota have just published a paper in the British Journal of Radiology entitled “Masses in the era of screening tomosynthesis: Is diagnostic ultrasound sufficient?” Led by radiologist Sadia Choudhury, their purpose was to compare diagnostic outcomes when suspicious lesions detected when screening with digital breast tomosynthesis (DBT) were worked up with full-field digital mammography (FFDM) versus hand-held ultrasound (HHUS). It’s important to recognise that screening is routinely administered to detect breast cancer in healthy women who have no apparent symptoms, whereas diagnosis is applied after the detection of suspicious results.
In a few countries such as the USA, DBT (a type of 3D mammography) has begun to replace FFDM (or 2D mammography) as the primary method of screening for breast cancer. However, there is some uncertainty about the next steps after a DBT-detected lesion has been identified. Should the patient be referred for an FFDM exam with specific diagnostic views – and with the attendant radiation exposure – or should she be examined with HHUS? See workflow illustrated below left.
Choudhury’s team studied 212 masses identified with screening DBT, 102 being worked up with FFDM and 110 with HHUS. They evaluated the size, shape, margins, visibility and pathology of all the masses, as well as each woman’s breast density. They found that 98% of the masses detected by DBT screening were adequately assessed when sent to HHUS first, suggesting that there was the potential for avoiding diagnostic FFDM as a follow-up procedure. A number of benefits were identified: “Eliminating diagnostic mammography can decrease cost and radiation to patients and increase diagnostic workflow efficiency for radiology practices.”
Although DBT has begun to make some inroads in South Africa, FFDM is still the primary screening modality. From a workflow perspective, the acquisition of the images takes about 10 minutes. Because breast screening is a prescribed medical benefit – i.e. covered by health insurance – and includes ultrasound, most women also undergo HHUS which takes a further 20 minutes (see upper diagram, below right).
One of the driving factors for CapeRay when developing our Aceso dual-modality system for breast screening was to optimise the workflow. By combining FFDM with automated breast ultrasound (ABUS) in a single device, it is possible to acquire a full set of images in just 10 minutes (see lower diagram, at right). There is also the added benefit that the likelihood of a missed cancer – a false negative – will be significantly diminished by having access to both FFDM and ABUS images that are co-registered.