Breast cancer accounts for 14% of all new cancer cases in the US and is the second most frequent malignancy in women after skin cancer. Breast cancer is most commonly diagnosed in women between the ages of 55 and 64, and the...
Breast cancer accounts for 14% of all new cancer cases in the US and is the second most frequent malignancy in women after skin cancer. Breast cancer is most commonly diagnosed in women between the ages of 55 and 64, and the risk increases with age.
Early diagnosis increases the chances of patient recovery and reduces the morbidity of treatment. Breast cancer treatments continue to improve and help reduce mortality, but early detection through mammography screening has a significant impact on overall mortality reduction.
All women over the age of 40 who are at average risk should get screened for breast cancer, according to the American Radiological Society. Breast ultrasonography, magnetic resonance imaging (MRI), and mammography are a few of the methods used to diagnose breast cancer.
However, tissue sampling is required for definitive diagnosis. Breast cancer screening is performed with mammography, and patients with equivocal or suggestive mammography screening results require further imaging with diagnostic mammography, ultrasound, breast MRI, biopsy, or a combination thereof. This article describes techniques and considerations when performing breast screening mammograms.
Indications
Breast cancer screening is advised by several professional groups. The American College of Obstetrics and Gynaecology, the American Medical Association, the National Comprehensive Cancer Network, the American Cancer Society, the American Radiological Society, the Breast Imaging Society, and the United States Preventive Services Task Force (USPSTF) are a few of these.
A detailed discussion of the differences between these professional society recommendations is beyond the scope of this article. According to the American College of Radiology, annual mammography screening is recommended for all women at average risk of breast cancer starting at age 40, and for women with a life expectancy of at least 5 to 7 years.
Willingness to undergo further testing/biopsy and treatment. In particular, there is no age limit on when screening mammography should be stopped. Instead, the patient's medical condition should determine whether ongoing screening is necessary. Breast cancer is most commonly diagnosed in the 50-60 year old group, but risk increases with age.
Screening mammography offers an opportunity for early detection of malignant or even precancerous lesions before they become clinically apparent elsewhere. An average-risk patient is one whose lifetime risk of developing breast cancer is less than 15% of hers.
At-risk patients are those who
- Women with certain genetic mutations, including BRCA 1 and 2.
- People with a strong family history of breast cancer, even without a known genetic mutation.
- Patients aged 10 to 30 who received radiation therapy to the chest. Patients with a family history of breast cancer should begin mammography screening 10 years before the youngest first-degree relative develops breast cancer.
However, these patients may be more sensitive to the ionizing radiation that mammography relies on, so screening should not begin before age 30.
Contraindications
Although there are no absolute contraindications to screening mammography, there are relative contraindications. First, women who have signs and symptoms that worry them about breast cancer, such as: B. If the breast mass is palpable or enlarging, it may be a candidate for screening imaging as well as mammography and ultrasound imaging.
This may include dot compression, additional angles, or enlarged views. Breast ultrasound adds complementary information, especially when lesions of interest are identified by palpation.
As previously mentioned, mammography screening before age 40 is not recommended for asymptomatic patients with average risk of developing breast cancer. Patients in this age group generally have dense breasts and mammography has decreased sensitivity to detect breast cancer in this setting.
There is also the risk of false-positive mammograms, which may require follow-up and tissue biopsies. However, we recommend that all women undergo a risk assessment by age 30 to determine if early screening is appropriate.
Equipment
As mentioned earlier, mammography uses x-rays of her to assess various anatomic structures within the breast. Initially, mammograms were performed using conventional film-based X-ray techniques. However, film mammography has been superseded by systems that use phosphor storage techniques or direct digital acquisition.
Phosphor storage systems use crystals that convert X-rays to visible light and digitize visible light. A direct digital acquisition system uses a CCD array that can transfer an X-ray beam directly into a digital image.
These new techniques have many advantages over film mammography. Most notably, dynamic range and contrast resolution can be adjusted after image acquisition. This allows radiologists to better assess subtle tissue differences and optimize image reproduction in the workplace.
Recently, digital breast tomosynthesis (DBT, aka "3D mammography") has gained popularity. Briefly, DBT is performed by acquiring multiple mammographic projections per view, and these projections are acquired sequentially along an arc.
Moreover, this increased sensitivity will enable the identification of low-grade cancers, improving treatment options and prognosis.
Preparation
The mammography machine should be calibrated accordingly and checked for defects. Upon arrival, the patient should be identified and fully briefed about the mammography procedure. The patient's family, medical history, and surgical history should be examined to allow appropriate individual risk stratification for breast cancer.
Specifically, family history of breast cancer, breast-related changes (e.g. development of palpable nodules, tenderness, or skin changes), or previous surgical procedures (e.g. breast augmentation or mammoplasty, Needle/surgical biopsy) should be evaluated.
Patients should remove all upper body clothing and wear a bathrobe. Raised skin lesions, such as bruises or scars from previous surgical procedures, should be marked with radiopaque skin markers for easy identification and to reduce recall associated with misinterpretation as masses or suspicious structural distortions.
Finally, the technician must enter patient information into the mammography machine before starting the exam.
Technique
The two common viewpoints used in screening mammography are called after the paths taken by the x-ray beam as it travels from the source to the detector.Craniocaudal (CC) and medial-lateral oblique (MLO).
For CC view, the patient's breast is placed on the image detector and the paddle compresses the breast from top to bottom. At least a portion of the submammary tissue should be present in the detector, ideally the décolleté area and a portion of the pectoralis major muscle (approximately 30% visible) should be included in the image.
These landmarks help ensure that the appropriate tissue is imaged so as not to exclude portions of breast tissue that may harbor malignant lesions. Compression is adjusted taking into account several factors, including breast size and patient tolerance.
Without adequate compression, parenchymal tissue separation is poor, resulting in uneven exposure across the breast, increased dose, and increased mobility. No part of the chest should be cut off or excluded from view.
For MLO view, the machine is typically tilted 40-60 degrees. For routine screening, this is preferred over true lateral as it includes the axillary tail and axilla.
The breast is placed on the image detector in a similar manner to recover as much breast tissue as possible, including the crease under the breast and as much posterior tissue as possible. It is important to include as much breast tissue as possible within the axillary tail, as breast cancer can develop in this area.
Complications
Mammography screening is well tolerated and has few complications. Immediate and subacute complications can occur from excessive chest compression. These are limited to bruising, small hematomas, and temporary discomfort caused by pressure.
