Improved diagnostic methods for detection of breast cancer

The National Cancer Institute (NCI) supports several research projects to conventional mammography (X-ray technology to improve, to make the internal structure of breast is visible) and to recognize the other imaging procedures to diagnose and characterize tumors in the breast.

High-quality mammography is the most effective technology available today to detect breast cancer. Efforts to improve the alignment of mammography to improve the technology and improve how it manages and X-ray films are interpreted. National Cancer Institute supports research to reduce the radiation dose and mammography improve low, the quality of mammography images, statistical methods developed for computer interpretation of images, so that remote transmission electronic Image Technology (telemammography / teleradiology) for clinical consultations, and improve the imaging techniques with biopsies. (A biopsy is the removal of cells or tissue for examination under a microscope for signs of disease). NCI also supports research on technologies that are incompatible with X-ray and magnetic resonance imaging (MRI), ultrasound and positron emission tomography breast specific (PET) shows, to breast cancer. The following information describes the advanced imaging techniques are in use or under consideration.

Ultrasound

Ultrasound, and ultrasound is an imaging technique, in which high-frequency sound waves that can be heard by humans, are bounced off tissues and internal organs. Their echoes produce a picture called sonogram. Ultrasound is used for solid tumors and cysts filled with fluid to be distinguished. Ultrasound can also be used to evaluate the items, which are difficult to see on a mammogram. Sometimes ultrasound is used in conjunction with other diagnostic procedures such as fine-needle aspiration (aka needle biopsy). Fine-needle aspiration is the removal of tissue or fluid to check with a needle for examination under a microscope for signs of disease.

During an ultrasound, the doctor spread a thin layer of lubricant to explore the area, improve the management of sound waves. A handheld device called a transducer directs sound waves through the skin in certain tissues. When sound waves are reflected by the tissue in the chest, the pattern of the waves create a two-dimensional image of the breast formed on a computer.

Ultrasound is not used in routine screening for breast cancer, detect if not always, early signs of cancer such as microcalcifications (small calcium deposits in the breast that can not be felt, but can be seen in a conventional mammography.) A group of microcalcifications may indicate that cancer is present.

Digital mammography

Digital mammography is a technique for recording x-ray images in computer code instead of the film X-ray, as conventional mammography. The images will be displayed on a computer screen improved (to be bright or dark) before they are printed on film. Images can be manipulated, the radiologist (a doctor who specializes in creating and interpreting pictures of areas inside the body), you can zoom in or in an area. From the perspective of the patient, the procedure for a mammogram with a digital system is the same as for conventional mammography.

Digital mammography may have advantages over conventional mammography. Images can be stored and retrieved electronically, which makes remote consultation with specialists from other mammography easier. Because images by the radiologist, subtle differences between the tissues may be adjusted can be observed. Improving the accuracy of digital mammography, the number of monitoring procedures. Despite these advantages, studies have not shown that digital mammography is more effective in detecting cancer of conventional mammography.

Computer-aided detection

Computer-Aided Detection (CAD) provides for the use of computers for suspicious areas on mammograms radiologists attention. It is used after the radiologist has done the initial review of mammography.

In 1998, the FDA approved a breast imaging device that uses CAD technology. Others are in development. An example of breast imaging device that uses CAD technology, the Image Checker. This device scans the mammogram with a laser and converts it into a digital signal that is generated by a computer. The image is displayed on a screen, with suspicious areas highlighted for the radiologist to examine. The radiologist can compare the picture with the digital mammography, to see if one of the selected fields were detected in the initial review and require further evaluation. CAD technology, the accuracy of mammography screening. The integration of CAD technology to digital mammography is under evaluation.

RM

Magnetic resonance imaging (MRI), a magnet attached to a computer creates detailed pictures of areas inside the body without radiation. Each MRI produces hundreds of images in the chest from left to right, from top to bottom and from front to back. The images are then interpreted by a radiologist.

During a breast MRI, the patient lies on the examination in the prone position. The breast hangs into a depression or a hole in the table, the coils that detect the magnetic signal contains. The table moves in a machine that contains the magnet tube. Date After a first series of images was the patient, a contrast agent intravenously (to receive an injection into a vein). The contrast is not radioactive, but is sometimes used to improve the visibility of a tumor. Other images are purchased. The imaging session lasted about an hour.

Breast MRI is not used for the routine detection of breast cancer, but clinical trials (human studies) are under way to determine if MRI is useful for the detection of some women, like young women at high risk for breast cancer. NMR is not always accurately distinguish between cancer and benign (not cancerous) breast. Such as ultrasound, MRI can not detect microcalcifications.

MRI is used primarily to evaluate breast implants for leaks or cracks, and seen to abnormal areas on a mammogram or felt evaluate following breast surgery or radiation therapy. May, after breast cancer is diagnosed are used to determine the extent of the tumor in the chest. MRI is also sometimes in the images of dense breast tissue, which is often found in young women, useful, and see that breast abnormalities felt but not seen in conventional mammography or ultrasound can.

PET

Positron emission tomography (PET) creates computerized images of chemical changes that occur in the tissue. The patient receives an injection of a substance that is a combination sugar and a small amount of radioactive material. The radioactive sugar to help find a tumor, cancer cells absorb sugar or absorb faster than other body tissues.

After receiving the radioactive drug, the patient is still for about 45 minutes while the drug circulates in the body. If a tumor is present, the radioactive sugar accumulates in the tumor. The patient lies on a table that moves slowly through the PET scanner 6-7 times over a period of 45 minutes. The PET scanner is used to detect radiation. A computer translates this information into images that are interpreted by a radiologist.

PET may play a role in determining whether a breast cancer is to play. However, PET is accurate in the detection of larger tumors and more aggressive than those on the site of tumors that are smaller than 8 mm and / or less aggressive. It can also detect cancer when other imaging techniques show normal results. PET is in the evaluation and implementation of the recurrent disease (cancer has returned, which is helpful).

A clinical trial sponsored by NCI, to the benefit of the PET findings in women with breast cancer compared with the results of other imaging diagnostic methods and to evaluate. This paper examines the effectiveness of PET in monitoring tumor response to treatment.

Scanning electrical impedance

The different types of tissue have different electrical impedance (electrical impedance is a measure of the speed, moving with the flow through a given material). Some types of tissue have high electrical impedance, while others have low electrical impedance. Breast tissue that is cancer, has a much lower electrical impedance (conducts electricity much better) than in normal breast tissue. Electrical impedance scanning devices are used in conventional mammography for detecting breast cancer. The T-Scan 2000, also known as the T-Scan is an example of such a device. The FDA approved the T-Scan from 2000 to 1999.

The electrical impedance scanning device, which does not emit radiation consists of a scanning probe and handheld computer screen that shows a two-dimensional image of the breast. An electrode patch is used, similar to an electrocardiogram, is placed in the hands of patients. A very small amount of electricity, roughly the same amount by using a small flashlight battery, is transmitted through the patch and into the body. The current through the chest, which is measured by the scanning probe is placed on the chest. An image is generated from measurements of electrical impedance.
Because breast cancer cells conduct electricity better than normal cells and breast cancers tend to have lower electrical impedance, have succeeded in breast tumors as bright white spots appear on the screen.

This device can confirm the location of anomalous zones were detected by conventional mammography. The scanner sends the image directly to a computer, the radiologist who move the probe around the breast in order to obtain the best view of the area under study. The device reduces the number of biopsies necessary to determine whether a cancerous mass. It can also improve the identification of women who undergo a biopsy.

The scanner is not admitted as a screening device for breast cancer, and is not used when mammography or other findings clearly show the need for a biopsy. This equipment has not been studied in patients with implanted electronic devices such as pacemakers. Not for use in these patients is not recommended.

Image-guided breast biopsy techniques

Imaging techniques play an important role in doctors perform biopsies, especially of abnormal areas can not be felt, but you can see in a conventional mammography and ultrasound. A kind of needle biopsy, stereotactic biopsy, includes the exact location of the abnormal area in three dimensions with conventional mammography. (Stereotactic refers to the use of a computer and barcode scanners to create three-dimensional images.) A needle is inserted into the breast and a tissue sample is obtained. Additional samples can be achieved by moving the needle into the abnormal area.

Another type of needle biopsy uses a different system known as the Mammotome breast biopsy. The FDA approved Mammotome in 1996, the portable version of the Mammotome received FDA approval in September 1999. A long needle into the suspicious area with ultrasound or stereotactic guidance added. The Mammotome is used to suck gently on the fabric of the suspect area. Additional tissue samples can be obtained by rotating the needle. This procedure can be with the patient lying on his stomach out on a table. If the handheld device is used, the patient can be on your back or sitting.
There were no reports of serious complications of the Mammotome breast biopsy system. Women are interested in this procedure should talk to your doctor.

Ductal Lavage

Ductal lavage is a research technique for the sampling of breast duct cells for examination under a microscope. Saline (salt water) solution is introduced into a milk duct through a catheter (a thin tube and flexible) in the channel to the surface of the nipple is inserted. Fluid, which is the channel-containing cells removed through the catheter. The cells were microscopically for changes that cancer or changes that may increase the risk of breast cancer suggest may determine investigated. The utility of ductal lavage is still under study.

Images in clinical studies.

In March 1999 the NCI funding of the American College of Radiology Imaging Network (ACRIN) as part of Cooperative Group clinical trials NCIS program. (A cooperative is a group of doctors, hospitals or even working with NCI to important questions in cancer research to identify and design of clinical trials to answer these questions.) Applies to the group designed to promote and support cooperative clinical trials new cancer therapies, explore the methods of prevention and early diagnosis and study of life issues and rehabilitation during and after treatment. ACRIN is to increase the number and quality of clinical trials of imaging methods for the detection and diagnosis of cancer given. The NCI is actively involved in the planning, conducted testing and monitoring of clinical trials by ACRIN.