Dr. Mahesh Bandemegal Senior Surgical Oncologist, HCG Cancer Hospital, Bengaluru
Breast cancer, a disease involving abnormal growth of cells in the breasts, is the most common kind of cancer affecting women and very rarely, men. It can initiate in any of the breasts and can be identified by some presentable symptoms which includes a lump in the breast, bloody discharge from the nipple and changes in the shape or texture of the nipple or breast. While it is one of the leading form of cancer in the country, it can be effectively cured when detected at the initial stages. It is essential to detect breast cancer at the early stages as it significantly improves the prognosis and also reduces fatality due to breast cancer in the long run. The lesser the time taken to identify it, the higher is the chance of cure. In recent times, technological advances have made several breakthroughs in diagnosing and treating breast cancer. One such advance is breast tomosynthesis.
Breast Tomosynthesis also known as three-dimensional (3-D) mammography and digital breast tomosynthesis (DBT), an advanced form of breast imaging or mammography using a low-dose X-ray system and computer reconstructions and creating a three-dimensional image of the breasts. Tomosynthesis is known to play a vital role in early detection and diagnosis of breast cancer thereby significantly enhancing the probability of cure.
This is how tomosynthesis aids in early detection
The information culled out from the 3-D images captured by Tomosynthesis is used to put together 3D images of the layers of breast tissues. It has been observed that digital tomosynthesis makes it easier to find breast cancers in dense tissues, improving the accuracy of the test. While mammograms are only 2 dimensional and take only two images of the breasts – top to bottom and a side-to-side view from an angle, tomosynthesis takes multiple images of the breasts from several angles. A mammogram may fail to view breast cancer hidden in between overlapping breast tissues as it appears normal. A tomosynthesis can easily go between layers and detect hidden abnormal tumours. This way tomosynthesis detects more cancers than mammograms alone.
Merits of digital breast tomosynthesis (DBT)
Digital breast tomosynthesis is especially useful in examining dense breasts and is known to improve the radiologist’s ability to find breast cancer. It comes with these advantages.
● It brings down the rate of false positive readings – a reading that identifies normal tissue as an abnormality.
● It reduces the need for follow-up tests and ensures that fewer women need to come back for another mammogram.
● It reduces the need to do a biopsy – an examination of tissue removed from a living body to discover the presence, cause, or extent of a disease.
● It enables a radiologist to detect the exact location of the abnormality in the breast with more precision.
● It also reduces anxiety among patients related to longer waiting time before getting the results.
Working of tomosynthesis
A mammogram requires one’s breasts to be positioned on a flat support and compressed between two plates. The X-ray tube takes a single image. During a tomosynthesis, the breasts are positioned and compressed in the same manner as it is done during a mammogram. However, the X-ray tube moves in an arc over the breasts taking pictures as it moves. Digital breast tomosynthesis is performed at the same time during mammogram and thus it takes a little longer, about 45 minutes. The total radiation dose used for tomosynthesis is under three times that of a mammogram and is considered as an acceptable and safe amount of radiation.
Before tomosynthesis, one is advised to not use deodorant, talc, oils or lotions on the upper body. Above the waist jewelleries and clothing need to be taken off too.
During the exam, one is made to stand in front of a mammography X-ray machine and the breasts are put between two plates. This could be uncomfortable for some, but the test lasts only for a couple of seconds. The patient must be still and hold breath until the X-ray is done. During the procedure, a special tube rotates around the breasts and takes pictures. On completion of the test, the compression on the breasts is released.
Women experiencing a lump in the breasts or change in the texture and shape of nipples and breasts must immediately reach out for clinical help and may be recommended to go for a tomosynthesis. This procedure helps in early detection of any abnormality and can significantly amp up the chance of cure from breast cancer.