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Several private institutions along with government-supported agencies such as The National Cancer Institute (NCI) are financing the development of several new technologies to detect breast tumors. This research ranges from technologies under development in research labs to those that have reached the stage of testing in humans, known as clinical trials. Breast cancer kills fewer women each year than lung cancer, however statistics show that 1 in 8 women will be diagnosed with breast cancer in their lifetime. The risk increases with age, as an 80-year-old is many times more likely to develop breast cancer than a 20-year-old woman. About three-quarters of all breast cancers occur in women over 50; only 5% develop in women under 40. A woman's family history, weight, alcohol use, and when she first had children may also play a role -- though Dr. Lisa Bailey, a Berkeley oncologist, notes that "at least half of all breast cancers occur in women who do not have any of these risk factors." Julia Knight, Ph.D., a Canadian researcher who has worked on developing a more realistic model for calculating breast cancer risk states, "The one-in-eight statistic comes from looking at large groups of women over a lifetime ... it doesn't say anything about any one woman's specific situation right now, given her environment, and personal risk factors." The most important factor of this statistic is that one in eight refers to diagnosis, not death. So while many women will indeed develop breast cancer (175,000 in 1999, estimates the American Cancer Society) the vast majority of those women, especially those who find the cancer early, will beat the disease and live on. The five-year survival rate for breast cancer found before it has spread outside the breast is 97%. The five-year survival rate for all breast cancers, including those found after they've spread throughout the body, is somewhat lower, at 85%. Efforts to improve conventional mammography include digital mammography, where computers assist in the interpretation of the x-rays. Other studies are aimed at developing teleradiology, sending x-rays electronically, for long-distance clinical consultations. A non-X-ray based technology under development is magnetic resonance imaging (MRI). In addition to imaging technologies, NCI-supported scientists are exploring methods to detect markers of breast cancer in blood, urine, or nipple aspirates that may serve as early warning signals for breast cancer. A screening mammogram is an x-ray of the breast used to detect breast changes in women who have no signs of breast cancer. It usually involves two x-rays of each breast. Using a mammogram, it is possible to detect a tumor that cannot be felt. A diagnostic mammogram is an x-ray of the breast used to diagnose unusual breast changes, such as a lump, pain, nipple thickening or discharge, or a change in breast size or shape. A diagnostic mammogram is also used to evaluate abnormalities detected on a screening mammogram. It is a basic medical tool and is appropriate in the workup of breast changes, regardless of a woman's age. A mammogram is merely a conventional X-ray that implements equipment designed to scan a highly specific area: the breast tissue. The procedure is performed by placing the breast between two plates and applying pressure to ensure a clear picture. The area of compression is a very sensitive area and thus the pressure is found by the majority of women who undergo the test to be very uncomfortable. The test only lasts a few minutes however in many cases, post-test bruising is reported. Two x-rays are taken of each breast, one from the top and one from the side. Although some women are concerned about the risk of cancer posed by radiation during mammography, the actual risk is very small. The American Cancer Society and the American Medical Association, have always recommended women have routine mammograms every one or two years after age 40 and annually after age 50. Several studies have shown that regular screening mammograms can help to decrease the chance of dying from breast cancer. The benefits of regular screening are greater for women over age 50. For women in their forties, there is recent evidence that having mammograms on a regular basis reduces their chances of dying from breast cancer by about 17 percent. For women between the ages of 50 and 69, there is strong evidence that screening with mammography on a regular basis reduces breast cancer deaths by about 30 percent. Imaging Diagnostic Systems is seeking Pre-Market Approval (PMA) from the Food and Drug Administration for its Computed Tomography Laser Mammography (CTLM®) system to be used as an adjunct to mammography to aid in the detection of breast abnormalities. Under the new Modular submission approach, the Company's PMA application has been divided into different modules, each of which will contain documentation required for the FDA review. The Company has submitted two modules and is currently completing the next set of modules to be submitted. Imaging Diagnostic Systems, Inc., has developed the world's first patented, laser-based breast imaging system that utilizes state-of-the-art laser technology and proprietary and patented algorithms to create three-dimensional cross sectional images of the breast. The CTLM is a non-invasive, painless examination that does not expose the patient to radiation or require breast compression. Lasers have been developed that produce extremely short pulses of light. These bursts of photons only last for incredibly short intervals of time, picoseconds [10-12 (0.000000000001) second] to femtoseconds [10-15 (0.000000000000001) second]. This characteristic allows one technique for medical optical imaging to be possible. The speed of light is approximately 300,000,000 meters per second in a vacuum. The speed of light generally decreases when light passes through a media. The ratio of the speed of light in vacuum to the speed of light in a media is referred to as the index of refraction, n (n = cv / cm). The index of refraction of dry air is 1.00029. Thus, the speed of light in a vacuum is very similar to the speed of light in our atmosphere and will be used interchangeably in this presentation. The index of refraction of breast tissue is approximately 1.54, and therefore light travels more slowly in breast tissue than in air. A laser beam directed into a breast undergoes a unique phenomenon. Light photons do not travel in a straight-line through the breast and thus individual photons require different times to travel through the breast. This phenomenon cannot be seen unless short pulses of light are used. Figure 1 illustrates this phenomenon. Figure 1a illustrates a case where the light pulse traveled straight through the breast and the pulse shape was preserved when the pulse exits the breast. This does not happen in nature. Figure 1b illustrates a pulse stretching that the light pulse experiences as the photons pass through the breast. Photons might be expected to arrive at time (t) but none actually do. It has been calculated that detection of a photon that passed straight through will occur once in 1017 years, a time older than the age of the universe. The actual time required for a photon to pass through the breast will depend on the path taken through the breast. The speed of light in the breast is estimated to be approximately 200,000,000 meters per second, or approximately 2 mm per 10 picoseconds (ps). 2mm = 200,000,000 meters per second x 0.00000000001 seconds = 2 x 108 x 1 x 10-11 = 0.002 m = 2mm For example, for a breast 10 cm in size, the value for (t) in Figure 1b would be: 10cm = 100 mm , 10 ps = 2mm , 500 ps = t Photons that arrive later than 500 ps have traveled a longer path and thus cannot have traveled straight through the breast. The later the arrival of photons after 500 ps, the less useful the photons for breast imaging. Figure 2, below, illustrates this concept. Photons that travel Path 1 travel a shorter path than Path 2 and arrive sooner than photons that traveled Path 2. As can be seen, it is possible for photons to travel a path, such as Path 2 and completely miss a lesion. CTLM® has the capability to select the photons used for imaging and thereby increase the ability to detect small lesions. This capability is illustrated in Figure 3. The capability to select the photons used for imaging is called time-gated or time-resolved imaging and is the feature that allows medical optical imaging to become a valuable diagnostic imaging tool. A biopsy is the only sure way to know whether a breast lump or a suspicious area seen on a mammogram is, in fact, cancer. A biopsy is a microscopic analysis of cells taken from the lump to determine if they are cancerous. The cells can be obtained by fine-needle aspiration, in which a few cells are extracted using a thin needle and a syringe, or open biopsy, in which a larger sample of tissue is surgically removed. In conclusion, breast cancer is a dangerous and statistically prevalent disease that we are working hard to overcome. The level of research in progress on this disease is unsurpassable. New diagnostic methods such as digital mammography and computed laser mammography are forging ahead with the guidance of organizations such as the American Cancer Society, the National Cancer Institute, and private companies such as Imaging Diagnostic Systems. We are moving positively toward more effective treatments and diagnosis. The contribution of these organizations along with the enthusiastic public support that is now in place significantly improves our chances of one day finding a cure for this disease. Bibliography: BIBLIOGRAPHY 1. Grable, Richard “Time-Gated Optical Tomography” http://www.imds.com/timegated.htm 2. Pearlman, Eve “One in Eight: The Truth Behind the Breast Cancer Statistic” http://www.planetrx.com/ecenter/breast_cancer/features/oneineight.html 3. “Breast Cancer: Life-Saving Facts” http://my.webmd.com/content/article/1680.50642 4. "Breast Cancer Facts and Figures 1997: Who Gets Breast Cancer?" American Cancer Society website. http://www.cancer.org 5. "Cancer Survivorship." 8/10/99 press release, National Institutes of Health, National Cancer Institute. http://www.nci.nih.gov/ 6. "1999 Facts and Figures: Selected Cancers." American Cancer Society website. http://www.cancer.org 7. "1999 Facts and Figures: Five Year Relative Survival Rates by Stage at Diagnosis, 1989-1994." American Cancer Society website. http://www.cancer.org 8. "1999 Facts and Figures: Estimated New Cancer Cases and Deaths by Sex for All Sites, United States, 1999." American Cancer Society website. http://www.cancer.org Word Count: 1652
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