New Breast Cancer Screening Method Could Make Mammography Obsolete
A team of reseachers at the National Physical Laboratory (NPL), the UK’s National Measurement Institute, working with the University Hospitals Bristol NHS Foundation Trust is trying to implement a new screening method for breast cancer with the aid of ultrasonography. Tests conducted by researchers so far are very promising.
The screening method most widely used for breast cancer currently is mammography. Mammography uses ionizing radiation, X-rays to examine and assess the presence of mammary gland tumors. This type of investigation is not performed in women under 40 years firstly due to the fact that glandular breast tissue is not visible, and on the other hand due to the higher iradiation risk of still functional ovaries. Ionizing radiation can also lead to cancer onset, which limits this method to screening only older women. Each year, 46,000 UK women are diagnosed with breast cancer using mammography. On average only 30% of women with suspicious lesions observed after an mamography were indeed diagnosed with breast cancer (confirmed through biopsy).
All these facts lead to the necessity of developing other breast cancer screening methods ideally non invasive and non-ionizing. In addition, improving the diagnostic method of breast cancer would reduce unnecessary biopsies and also reduce possible trauma caused by wrong diagnosis.
Ultrasonography is non-invasive method used to visualize tissues and organs. Ultrasonography has several advantages: it is safe, non-invasive, very fast, allows guidance of maneuvers such as puncture-biopsy and it is very cheap compared with other tests. However, ultrasonography provides tissue immages that are not very accurate and does not provide a very reliable diagnosis.
Currently, the main problem encountered is represented by detectors. Different types of tissues that have different sound speed and different tissues reflect the sound waves at different speeds. This phenomenon can give birth to artifacts on ultrasound images thus leading to false positive results.
The new method works by detecting sound wave intensity. Afterwards, this particular intensity is converted into heat which will be sensed by a pyroelectric membrane, which will generate a voltage output proportional to the temperature rise. Used in a Computed Tomography (CT) configuration, the new method could provide accurate images of abnormal lesions of the mammary gland. Tomography produces a cross section map of the tissue, which describes how the acoustic properties of tissue vary.
Having so far only positive results, NPL team seeks funding for further research. They plan to produce a demonstrator that provide faster scanning and also to create a system to be used clinically. Moreover, they intend to collaborate with a manufacturer in order to market the technology.
Dr Bajram Zeqiri, who leads the project at the National Physical Laboratory, points out that outcomes are very promising and can have a huge impact in terms of cancer diagnosis.