- The evolving role of the dynamic thermal analysis in the early detection of breast cancer
- Evaluation of digital infra-red thermal imaging as an adjunctive screening method for breast carcinoma: A pilot study.
- Effectiveness of a non-invasive digital infrared thermal imaging system in the detection of breast cancer.
- Thermal detection of embedded tumors using infrared imaging.
- Beating Breast Cancer.
- Overview: Beyond Mammography, Len Saputo. MD
- Medical Devices and Systems.
The evolving role of the dynamic thermal analysis in the early detection of breast cancer
M Salhab, W Al Sarakbi and K Mokbel*
It is now recognized that the breast exhibits a circadian rhythm which reflects its physiology. There is increasing evidence that rhythms associated with malignant cells proliferation are largely non-circadian and that a circadian to ultradian shift may be a general correlation to neoplasia.
Cancer development appears to generate its own thermal signatures and the complexity of these signatures may be a reflection of its degree of development.
The limitations of mammography as a screening modality especially in young women with dense breasts necessitated the development of novel and more effective screening strategies with a high sensitivity and specificity. Dynamic thermal analysis of the breast is a safe, non invasive approach
that seems to be sensitive for the early detection of breast cancer.
This article focuses on dynamic thermal analysis as an evolving method in breast cancer detection in pre-menopausal women with dense breast tissue. Prospective multi-center trials are required to validate this promising modality in screening.
The issue of false positives require further investigation using molecular genetic markers of malignancy and novel techniques such as mammary ductoscopy.
Breast cancer is one of the most common cancers, it is estimated that one in eight women in the USA will develop breast cancer during their lifetime. Furthermore, 25–30% of breast cancers are found in pre-menopausal women . Currently mammography is the best available
approach for the early detection of breast cancer in the general population with a sensitivity of 75–90%. However, the positive predictive value is only 25%. In addition to mammography, non invasive new modalities have been developed to allow the early detection of breast cancer in all age groups and more importantly in young women with dense breast tissue and women who have high risk of developing breast cancer such as, women with strong family history and carriers of BRCA1 and/or BRCA2 genes.
Currently, magnetic resonance imaging (MRI) is being studied for the early detection of breast cancer. Its sensitivity in high risk women has been found to be much higher than mammography but with a lower specificity. Kriege et al observed a higher sensitivity for MRI in detection of breast cancer in women with a genetic predisposition or at high risk compared to (71% vs. 41 %) but with lower specificity (90% vs. 95%).
Electrical impedance scanning (EIS) is another modality under development for breast cancer detection especially in young women with dense breasts. The basic science behind its use is the fact that malignant tumors have lower electrical impedance than the surrounding normal
tissue. However, separation between malignant and benign lesions needs further investigations.
Furthermore, mammary ductoscopy (MD) and visualization of mammary ducts and proteomics of nipple aspirate fluid (NAF) and serum are promising screening modalities that require further evaluation.
The limitations of mammography as a screening modality especially in young women with dense breasts necessitated the development of novel and more effective screening strategies with a high sensitivity and specificity. This article focuses on the dynamic thermal analysis as an evolving non invasive and a safe method in breast cancer detection in pre-menopausal women with dense breast tissue and women at high risk due to family history or genetic predisposition.
BREAST AND CIRCADIAN RHYTHM 
It is now recognized that the establishment and growth of a tumor depend on neovascularization. This successful recruitment of new blood vessels into a tumor; also known as angiogenesis is dependent on angiogenic growth factors produced by the tumor cells. Such
new vessels grow adjacent to the tumor presumably to increase its nutrient supply. These new vessels lack smooth muscles rendering them unreceptive to control by epinephrine. The lack of receptivity produce a more constant blood flow, thus increasing the local temperature.
Earlier technology for assessing thermal abnormalities in the breast focused on the presence of the abnormal temperature as a crucial marker. In a study conducted by Gantherine et al, 21.3% of patients who had abnormal thermograms but no abnormality on physical examination
and mammography developed breast cancer within the next 3 years. In another study of women who had thermal abnormalities on initial examination using infrared technology, long term follow up (2–10 years) revealed that 33% of these women developed breast cancer, a rate
six times higher than that expected in the normal population. This relationship between breast skin temperature and breast cancer was thoroughly examined by Gros et al. They found that the differences between the characteristics of rhythmic changes in skin temperature of clinically healthy and cancerous breasts were real and measurable. Despite these interesting observations thermography as a general screening tool for the detection of women at risk of breast cancer did not find a wide spread acceptance due to low sensitivity of the test and the subjective nature of the test interpretations.
The superficial thermal patterns measured on the surface of the breast seem to be related to tissue metabolism and vascularization within the underlying tissue. Such thermal patterns change significantly as a result of normal phenomena including menstrual cycle, pregnancy and more
importantly the pathologic process itself. Additionally, cancer development represents the summation of a large number of mutations that occur over years, each with its own particular histologic phenotype.
Such changes appear to generate their own thermal signature and the complexity of these signatures may be a reflection of their degree of development.
Temperature in a normal breast increases from the skin into the deep tissue and heat conductivity in the healthy breasts is constant in most cases and generally can be characterized in terms of circadian rhythm periodicity. In contrast, the rhythms associated with malignant cells proliferation are largely non circadian and suggest that a circadian to ultradian shift may be a general correlation to neoplasia. Heat production by the tumor under the influence of angiogenesis should be therefore re-examined in terms of absence of normal circadian fluctuations. Due to the increased blood flow and the lack of receptivity in the newly formed vessels in malignancy, temperature production exhibits circadian rhythmic variations to a far lesser degree than is evident in the healthy breasts. It has been found that independent of a tumor’s size, relatively
small tumors (>/= 0.5 cm in diameter), poorly vascularized rapidly growing tumors can produce increases in regional heat. The explanation for this effect is unclear but it may be due to the chronic inflammatory response around developing breast tumors. With increasing evidence that inflammation can enhance tumor growth and is associated with a poor prognosis, this suggestion implies that thermal analysis may have considerable value.
Furthermore, the unique relationship between the thermal circadian rhythm and mitotic activity could be considered as a first warning of tumor development, which can be detected using a safe and non-invasive technology. The genes that drive the circadian rhythm are emerging as
central players in gene regulation throughout the organism, particularly for cell-cycle regulatory genes and the genes of apoptosis.
DYNAMIC THERMAL ANALYSIS
Recent technological advances have facilitated the recording of circadian rhythm variations of the breast and analyzing the recorded data using highly complicated computer statistical software. A miniaturized microprocessor has been developed to record and store thermal information collected from eight separate sites of each breast. Sensors are placed in anatomically critical positions elicited by data obtained from tumor registries as to where cancers are most likely to develop.
In the First Warning System (FWS, Lifeline Biotechnologies, Florida, USA), thermal data are collected every five minutes for a period of 48 hours during which time women are encouraged to maintain their daily activities. 9000 pieces of data are recorded by microprocessors during
the test period and analyzed using specially developed statistical software. Temperature points from each contralateral sensor are plotted against each other to form a thermal motion picture of a lesion’s physiological activity.
Such a technology was first used by Farrar et al who examined a cohort of 138 women who had been scheduled for open breast biopsies based on the finding of physical examination and mammography. A total of 23 women (17%) were found to have breast cancer, of these, 20 (87%) were characterized by the monitor as being high risk. The other 3 patients (13%) who were missed by the monitor had ductal carcinoma. Mammography was positive or suspicious in only 19 patients (83%). Of the 4 cancers missed by mammography (3 of them were pre menopausal), the monitor correctly characterized 3 women as being high risk. A neural net algorithm was subsequently developed and evaluated by the
authors because of its value in analyzing the non-linear data such as these recorded by the breast’s monitors. Using this neural net algorithm reduced the number of false positives (18% vs. 30%)) and improved sensitivity (91% vs. 87%).
One of the main challenges to this technology is the false positive cases; confusion could be created in these women who are characterized as being positive or high risk by dynamic thermal analysis in the absence of physical and mammographical signs. This group of women may or
may not have cancer in its earliest stages. Further retrospective analysis of the thermal data using a refined neural net algorithm may increase the sensitivity and reduce the number of false positives. Also this group of patients may well benefit from the new advances in the nipple aspirate
fluid analysis and proteomic profiling technologies. Research is currently ongoing on this subject and the initial results are promising.
Dynamic thermal analysis of the breast is a safe, non invasive approach that seems to be sensitive for the early detection of breast cancer especially in young women where the conventional mammography is of limited value. Such a technology could become the initial breast
screening test in pre-menopausal women and those who are classified as positive can then be selected for anatomical imaging with mammography, MRI and/or ultrasonography. Further refinement of the neural net algorithm is required in order to shorten the period of data recording
and improve specificity. Prospective multi-centre trials are then required to validate these promising observations. The issue of false positives require further investigation using molecular genetic markers of malignancy and novel techniques such as mammary ductoscopy.
Finally, a better understanding of the circadian rhythm biology and clearer definition of the thermal activity boundaries for various pathological conditions of the breast will open the door to a new and more precise screening method for breast cancer.
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Evaluation of digital infra-red thermal imaging as an adjunctive screening method for breast carcinoma: A pilot study.
Rassiwala M1, Mathur P2, Mathur R3, Farid K3, Shukla S3, Gupta PK4, Jain B4.
Early screening plays a pivotal role in management of breast cancer. Given the socio-economic situation in India, there is a strong felt need for a screening tool which reaches the masses rather than waiting for the masses to reach tertiary centers to be screened. Digital infra-red thermal imaging (DITI) or breast thermography as a screening test offers this possibility and needs to be carefully assessed in Indian scenario.
The study involved 1008 female patients of age 20-60 years that had not been diagnosed of cancer of breast earlier. All the subjects in this population were screened for both the breasts using DITI. Based on the measured temperature gradients (ΔT) in thermograms, the subjects were classified in one of the three groups, normal (ΔT ≤ 2.5), abnormal (ΔT > 2.5, <3) and potentially having breast cancer (ΔT ≥ 3). All those having (ΔT > 2.5) underwent triple assessment that consisted of clinical examination, radiological and histopathological examination. Those with normal thermograms were subjected to only clinical examination.
Forty nine female breasts had thermograms with temperature gradients exceeding 2.5 and were subjected to triple assessment. Forty one of these which had ΔT ≥ 3 were proven to be having cancer of breast and were offered suitable treatment. Eight thermograms had temperature gradients exceeding 2.5 but less than 3. Most of these were lactating mothers or had fibrocystic breast diseases. As a screening modality, DITI showed sensitivity of 97.6%, specificity of 99.17%, positive predictive value 83.67% and negative predictive value 99.89%.
Based on the results of this study involving 1008 subjects for screening of breast cancer, thermography turns out to be a very useful tool for screening. Because it is non-contact, pain-free, radiation free and comparatively portable it can be used in as a proactive technique for detection of breast carcinoma.
International Seminars in Surgical Oncology
Effectiveness of a non-invasive digital infrared thermal imaging system in the detection of breast cancer.
Arora N, Martins D, Ruggerio D, Tousimis E, Swistel AJ, Osborne MP, Simmons RM
Department of Surgery, New York Presbyterian Hospital-Cornell, New York, NY, USA.
Digital infrared thermal imaging (DITI) has resurfaced in this era of modernized computer technology. Its role in the detection of breast cancer is evaluated.
In this prospective clinical trial, 92 patients for whom a breast biopsy was recommended based on prior mammogram or ultrasound underwent DITI. Three scores were generated: an overall risk score in the screening mode, a clinical score based on patient information, and a third assessment by artificial neural network.
Sixty of 94 biopsies were malignant and 34 were benign. DITI identified 58 of 60 malignancies, with 97% sensitivity, 44% specificity, and 82% negative predictive value depending on the mode used. Compared to an overall risk score of 0, a score of 3 or greater was significantly more likely to be associated with malignancy (30% vs 90%, P < .03).
DITI is a valuable adjunct to mammography and ultrasound, especially in women with dense breast parenchyma.
Thermal detection of embedded tumors using infrared imaging.
Mital M, Scott EP.
Department of Mechanical Engineering, Virginia Tech, Blacksburg, VA 24060, USA.
Breast cancer is the most common cancer among women. Thermography, also known as thermal imaging or infrared imaging, is a procedure to determine if an abnormality is present in the breast tissue temperature distribution. This abnormality in temperature distribution might indicate the presence of an embedded tumor. Although thermography is currently used to indicate the presence of an abnormality, there are no standard procedures to interpret these and determine the location of an embedded tumor. This research is a first step towards this direction. It explores the relationship between the characteristics (location and power) of an embedded heat source and the resulting temperature distribution on the surface. Experiments were conducted using a resistance heater that was embedded in agar in order to simulate the heat produced by a tumor in the biological tissue. The resulting temperature distribution on the surface was imaged using an infrared camera. In order to estimate the location and heat generation rate of the source from these temperature distributions, a genetic algorithm was used as the estimation method. The genetic algorithm utilizes a finite difference scheme for the direct solution of the Pennes bioheat equation. It was determined that a genetic algorithm based approach is well suited for the estimation problem since both the depth and the heat generation rate of the heat source were accurately predicted.
William Hobbins, MD, FABS, DABCT, FIACT
William Amalu, DC, DABCT, DIACT, FIACT
This year, over 192,000 women will be diagnosed with breast cancer in the US and 1.2 million worldwide (Source: American Cancer Society and WHO). As shocking as these numbers are, even worse is the number of cancers that won’t be detected until it’s too late. The consensus among experts is that early detection holds the key to survival. Although this is true, detection is not occurring early enough. Even though women are advised to begin having mammograms at 40, what they don’t know is that by the time most cancers are detected they have been growing for 10 years, and that 20% of all cancers can’t be seen by a mammogram. It is because of these factors, and others, that the number of women who die from this disease has gone relatively unchanged in the past 40 years.
If a significant change in breast cancer mortality is to be realized, we have to rethink how we are providing for early detection. Are we currently providing a system that includes an early warning? What if we had a system that would comprise a multi-modality approach that includes technologies that reflect the early cancerous process itself? If there were a method of very early detection, a procedure that may act as an early warning system, women would have an additional tool to give them the fighting chance they need to win this battle. What is needed is a risk marker. We may be able to turn these statistics around if a risk marker were added to a woman’s regular screening procedures. Women now have access to a unique technology that may give them this early risk marker; a procedure called Digital Infrared Imaging (DII)
DII is a technology that uses advanced high-resolution computerized medical infrared camera systems to detect and analyze thermovascular heat patterns from the surface of the breasts. When a cancer is forming it incorporates and develops its own blood supply in order to feed its growth (a process known as angiogenesis). Even more important, pre-cancerous tissues may start this process in advance of the cells becoming malignant. This increased blood supply causes an abnormal heat pattern in the breasts. DII can detect this abnormal heat pattern by using specialized infrared cameras and sophisticated computerized analysis under the guidance of a doctor who is board certified in the procedure. These abnormal heat patterns are among the earliest known signs of risk that a cancer may be a forming.
An increased level of early detection may be realized when DII is added to a woman’s regular breast health care. It has been found that an abnormal thermal image is the single most important sign of high risk for developing breast cancer, 10 times more significant than a first order family history of the disease. This gives DII the ability to act as a possible risk marker; thus, warning a woman about her own unique level of future risk for breast cancer.
Women who undergo the test find it to be fairly uneventful, since the procedure uses no radiation or contact with the breasts. Women with dense breasts, implants, and women who are pregnant or nursing can be imaged without any harm or reduction in the accuracy of the test. Normal images, like the one seen on the left, show evenly cool inactive breasts (dark colors represent cold areas). Abnormal images, as seen on the right, show highly active blood vessels giving off heat in one breast. Since the procedure does not pose any harm to the patient, women who are at higher risk can be monitored closely without adverse effects on their health.
Another benefit of this technology is its possible role in prevention. Digital Infrared Imaging has the added ability to observe specific thermal signs that may indicate hormonal effects on the breasts. At this time, research has determined that the single greatest risk factor for the future development of breast cancer is lifetime exposure of the breasts to estrogen. In which case, controlling the influence of estrogen on the breasts may be the single greatest method of breast cancer prevention. When hormone activity in the breast is dominated by estrogen, a specific type of infrared image is produced; thus, warning the patient and her doctor that this condition may exist. With this information in hand, a woman’s doctor will run further tests to confirm the condition and its cause. Once this is identified, a woman and her doctor can take a pro-active role in prevention. A treatment program aimed at restoring the normal hormonal balance in the breasts would follow and be monitored by the patient’s doctor. Once the hormone balance has been restored to the breasts, a woman’s overall breast cancer risk may be greatly reduced.
With the incidence of breast cancer rising in women under 40, an effort to provide some form of additional test is needed in this age group. Very early detection is especially important since breast cancers in younger women are commonly more aggressive resulting in lower survival rates. Current screening procedures have proven to be inaccurate in women in this age group due to breast tissue density and other factors. These issues, however, do not affect Digital Infrared Imaging. With this technology, women under 40 now have a safe imaging procedure that they can add to their regular breast health check ups.
Digital Infrared Imaging is a high-tech non-invasive imaging procedure designed to be used by women of all ages. The technology has been thoroughly researched for over 30 years and is FDA approved for use as an adjunctive imaging tool. Its unique ability to play a possible role in prevention is an impressive added benefit. Unfortunately, at this time there are too few qualified DII centers worldwide. However, with an increasing demand for the technology, educational organizations such as the International Academy of Clinical Thermology, International Thermographic Society, and the American Academy of Thermology are providing training for certified technicians and thermologists. It is their goal to provide women with greater access to this lifesaving technology.
Currently, no single screening procedure can detect 100% of all breast cancers. Digital Infrared Imaging is designed to be used as an additional procedure with mammography, and other tests, and not as a replacement. Studies show that when DII is added to a woman’s regular breast health check ups (physical examination + mammography + DII), 95% of all early stage cancers may be detected. This would give the vast majority of women who are diagnosed with this disease the reality of returning to a normal healthy life.
What if we could add another procedure that may act as an early risk marker for this terrible disease? What if we could provide a multi-modal approach that includes technologies that increase the early detection process? Would this give women a better chance for survival? The number of women who die from this disease will change very little if nothing is done to provide a better system. Digital Infrared Imaging has the unique ability to warn some women far enough in advance to give them a fighting chance. Combined with its ability to play a possible role in prevention, the advantages are obvious. With the addition of DII to a woman’s regular breast health care, women of all ages are given an early detection edge in the battle against breast cancer.
About the authors:
William Hobbins, MD, a Fellow of the American Board of Surgeons and a board certified clinical thermologist, has been performing thermal breast imaging for over 40 years. As an internationally recognized authority in this field, he has sat on multiple medical and thermographic boards, authored numerous articles, and has contributed a significant amount of research to the medical database using this technology. He currently practices in Madison Wisconsin.
William Amalu, DC, a Fellow of the International Academy of Clinical Thermology and a board certified clinical thermologist, has utilized digital infrared imaging in practice for over 20 years. He is currently the President of the International Academy of Clinical Thermology and the Medical Director of the International Association of Certified Thermographers. Dr. Amalu is in private practice in Redwood City California. For more information, please go to www.breastthermography.com.
Overview: Beyond Mammography
Len Saputo MD
The most devastating loss of life from breast cancer occurs between the ages of 30 to 50. Fortunately, women today have more options available to them to help in the detection of breast cancer than in past decades. Unfortunately, education and awareness of these options and their effectiveness in detecting breast cancer at different stages in life are woefully deficient.
The first part of this in-depth article explores the latest findings on the effectiveness and
shortcomings of various detection methods used by the mainstream medical community, including mammography, clinical breast exams, and to a lesser extent, magnetic resonance imaging (MRIs) and PET scans.
The second part of this article goes beyond mammography, exploring a highly advanced but much maligned detection tool for breast cancer–breast thermography. Breast thermography, which involves using a heat-sensing scanner to detect variations in the temperature of breast tissue, has been around since the 1960s. However, early infrared scanners were not very sensitive and were insufficiently tested before being put into clinical practice, resulting in misdiagnosed cases.
Modern-day breast thermography boasts vastly improved technology and more extensive scientific clinical research. In fact, the article references data from major peer-reviewed journals and research on more than 300,000 women who have been tested using the technology. Combined with the successes in detecting breast cancer with greater accuracy than other methods, the technology is slowly gaining ground among more progressive practitioners.
“Beyond Mammography” concludes that breast thermography needs to be embraced more widely by the medical community and awareness increased among women. Not only has it demonstrated a higher degree of success in identifying women with breast cancer under the age of 55 in comparison to other technologies, but it is also an effective adjunct to clinical breast exams and mammography for women over 55. Finally, it provides a non-invasive and safe detection method, and if introduced at age 25, provides a benchmark that future scans can be compared with for even greater detection accuracy.
The most devastating loss of life from breast cancer impacts women between the ages of 30 and 50. For women between the ages of 40 and 44, breast cancer is the leading cause of death, according to the American Cancer Society. Yet the November 10, 2003 issue of the AMA journal, American Medical News, reports little evidence documenting that mammography saves lives from breast cancer for premenopausal women, which are many of the women who fall into these age ranges. (1) Good evidence supports mammography as a valuable breast cancer screening tool for women in their late 50s and 60s, but reveals room for substantial improvement. For women over the age of 70, accumulated data documents limited value in doing mammograms since they do not significantly extend life. (2, 9, 10) Obviously, as a detection tool, mammography has a valued place in clinical practice; however, other technologies are proving to be more effective in breast cancer detection and should become part of mainstream clinical practice in order to save more lives.
THE PREVALENCE, FEAR AND RISK FACTORS OF BREAST CANCER
According to the American Cancer Society (ACS), breast cancer is the leading cause of death in women between the ages of 40 and 44. Although breast cancer has only 10% the morbidity and mortality of coronary heart disease, it is generally more feared. (3)
ACS statistics further document that every year in the United States there are approximately 200,000 new cases of breast cancer and more than 40,000 deaths. Not included in this number are more than 47,000 new cases of carcinoma in situ breast cancer, which is better known as DCIS (ductal carcinoma in situ) or LCIS (lobular carcinoma in situ) and is a very early form of breast cancer.
DCIS and LCIS are very mild cancerous lesions that only become malignant in about 2% of cases. For this reason many physicians do not consider DCIS and LCIS true cancers.
The risk of breast cancer at age 25 is less than one in 19,000 whereas by age 35 it is one in 217. (4) Yet, the statistic people are most familiar with is that one in eight women will eventually develop breast cancer. It is important to appreciate that this number is a cumulative risk that only applies to women who have reached the age of 90.
The hereditary breast cancer genes, referred to as BRCA 1 and 2 genes, are known to be associated with both breast and ovarian cancers, but only account for 5 to 10% of all breast cancer. Newer, less well-known factors are estimated to account for another 10% of all breast cancers. In at least 70% of cases, however, the cause of breast cancer is yet unknown. (5)
GENERALLY ACCEPTED RISK FACTORS
The risk for breast cancer is increased if you:
* Had your first period before age 12
* Went through menopause after age 50
* Had your first child after age 30 or never were pregnant
* Were on hormone replacement therapy or birth control pills
* Consume one or more alcoholic drinks per day
* Have a family history of breast cancer
* Are found to have inherited the breast cancer genes
* Are postmenopausal and gained weight (not so for premenopausal women)
* Have elevated levels of insulin as seen with syndrome X or type 2 diabetes, which are
conditions associated with central obesity and increased levels of insulin-like growth factor-1
* Are sedentary
Popular myths regarding what causes breast cancer include antiperspirants, wearing a wire bra, and having had an abortion.
MAINSTREAM BREAST CANCER SCREENING TECHNOLOGIES
The gold standard study that assesses breast cancer detection technologies stems from the “Breast Cancer Detection Demonstration Project: Five year summary report.” (7) This study reviewed 283,000 women between the ages of 35 and 74 who had undergone mammography and clinical breast examinations. Over a five-year period 4,400 women were found to have developed breast cancer. So, the purpose of the study was to see how well clinical breast exams and mammography worked in identifying women with breast cancer.
The BCDDP study documented that overall, clinical breast exams discovered only 60% of women who actually had breast cancer. When these women had tumors that were less than 1 centimeter, only 47% were identified. However, detection rates were 66% for tumors between one and two centimeters in size, and were 79% of tumors bigger than 2 centimeters. Clearly, clinical breast exams are important, but overall they miss nearly 40% of cancers.
MAMMOGRAPHY AND WOMEN UNDER 50
Mammography has been the state-of-the-art screening test for several decades. However, considerable controversy remains regarding its value, particularly in women under the age of 50. (1, 8-10) Results from the widely accepted BCDDP study documented that the overall ability of mammograms to detect cancer was only 70%. This means that 30% of mammograms found to be negative for potentially cancerous lesions are actually positive.
FALSE POSITIVE RATE HIGH
The false positive rate of mammograms–those patients without cancer but with a positive finding on testing–turned out to be another problem. Only one biopsy in six was found to be positive for cancer when done on the basis of a positive mammogram or breast examination. The combined false positive rate was determined to be as high as 89%. Identifying and performing biopsies on these clinically insignificant lesions represents over diagnosis and over treatment. Further, the physical and psychological stress associated with mammogram findings is not a small concern nor are the additional costs.
TOO MANY MAMMOGRAMS PERFORMED?
Recent data from the University of Washington and Harvard University reveals that over a period of a single decade, one out of every two women will have a false positive result as the result of mammography, and of those, nearly 20% will undergo an unnecessary breast biopsy. (9) Contrary to what many health-related agencies advise, recent findings seem to demonstrate that too many rather than too few mammograms are performed every year in the United States. Further, estimates show that for every $100 spent on the cost of mammograms, $33 goes to the unproductive and unnecessary expense of false positive results.
MAMMOGRAMS FOR WOMEN OVER THE AGE OF 70
A recent article from Duke University Medical Center reports that women over 70 are over-screened for both breast and cervical cancers. (10) The authors estimated the cost in the year 2000 for women over the age of 70 for the unnecessary mammograms they received was approximately $460 million. The article went on to point out that clinical guidelines for women over the age of 70 are ambiguous and based on almost no clinical research.
MAMMOGRAPHY AND YOUNGER WOMEN
For younger women, mammography is more likely to miss breast cancers that are rapidly growing, especially in women with dense breast tissue who are at a significantly increased risk for developing breast cancer. (15) At least 10% of breast cancers cannot be identified by mammography, even when they are palpable. (8)
OTHER MAINSTREAM TECHNOLOGIES
Advances in technology now allow digitally enhanced mammograms to be taken alone or after injecting intravenous contrast, but they have not been proven to be significantly more sensitive than regular mammograms, and they have the added risk of the invasiveness of an injection that can cause other problems. Further, they come with a substantial increase in cost and still expose the patient to radiation. (11)
Similarly, MRIs with and without contrast are a step forward, but they involve similar risks and are even more costly. While their sensitivity is near 90%, their accuracy (specificity) in identifying cancer as opposed to some other benign finding is no better than mammograms. (12)
PET scans are useful in identifying metastatic lesions but have an overall sensitivity similar to mammography. Further, for breast tumors less than one centimeter, only 25% of breast cancers are identifiable using this technology. (13) The most useful application of PET scans are in discriminating between viable tumor, fibrotic scar, and necrosis. Radiologists do not recommend PET scanning as a screening tool in asymptomatic women for breast cancer. (14)
For women under the age of 40, no accurate or cost effective technology exists in mainstream medical practice that identifies lesions likely to be breast cancer with reasonable sensitivity and specificity. Given that breast cancer is the leading cause of death in women between the ages of 40 and 44, it is obvious that a pressing need exists for another test to identify these cancers when they are just starting to develop and still small enough to be cured.
Most breast cancers do not become palpable until they are greater than one centimeter in size by that time 25% have already metastasized. Because most lethal breast cancers take approximately 15 years from their beginning to the time of death, women need reliable testing that starts when the cancer is initially forming in their mid-twenties. Even though there is reliable technology existing today that is available, there is limited awareness and insufficient education that has resulted in its being greatly underused in clinical practice.
THE HISTORY OF BREAST THERMOGRAPHY
Breast thermography has been available in clinical practice since the 1960s. Initially, physicians were very excited when they learned that breast cancers emit more infrared heat than normal healthy tissues, and that they could be detected using infrared scanners. However, this technology was brought into practice prematurely–before clinical trials were completed, and before sufficient information about other health conditions that also emitted large amounts of infrared light were understood.
Unfortunately, this resulted in many women having breast surgeries that did not have breast cancer. Eventually, the high rate of unneeded surgeries led to the rejection of infrared breast imaging in the United States, with the entire technology being sidelined by mainstream medical practice for several decades.
Since the 1970s, however, clinical research has continued, especially in Canada and France where this technology is considered more mainstream. More than 800 research papers have been published on the subject of breast thermography, and a research data bank on more than 300,000 women who have been tested with infrared breast imaging now exists.
In addition, major advances in infrared imaging technology have been achieved that improve the sensitivity to 0.05 degrees centigrade, which makes identifying breast cancer much easier and more reliable. The combination of improved technology and scientific clinical research is sparking the return of breast thermography into clinical practice today.
HOW BREAST THERMOGRAMS WORK
Breast thermography measures differences in infrared heat emission from normal breast tissue, benign breast abnormalities–such as fibrocystic disease, cysts, infections and benign tumors—and from breast cancers. It does this with a high degree of sensitivity and accuracy. Breast thermography is a non-invasive measurement of the physiology of breast tissue. This technology is not meant to replace mammography or other diagnostic tests presently used in clinical practice that measure anatomical abnormalities in breast tissue. While breast cancer can only be diagnosed by tissue biopsy, breast thermography safely eliminates the need for most unnecessary biopsies as well as their associated high cost and emotional suffering, and it does so years sooner than any other test in modern medicine.
Modern infrared scanners have a thermal sensitivity of 0.05 degrees Centigrade. Because tumor tissue does not have an intact sympathetic nervous system, it cannot regulate heat loss. When the breast is cooled with small fans in a room kept at 68 degrees Fahrenheit, blood vessels of normal tissue respond by constricting to conserve heat while tumor tissue remains hot. Thus, tumors emit more heat than their surrounding tissues and are usually easily detected by heat-sensing infrared scanners. Over time, cancerous tissues stay hot or become even hotter–they do not cool down. In sharp contrast, however, other possible conditions such as fibrocystic breasts, infections, and other benign disorders cool down as they resolve.
Breast thermograms have highly specific thermal patterns in each individual woman. They provide a unique “thermal signature” that remains constant over years unless there is a change in an underlying condition. Thus, over time, it is possible to differentiate between cancers and benign conditions. Based on this ability to more accurately detect cancers over time, it becomes important to have a benchmark early on in a woman’s life. For this reason, women should have breast thermography performed beginning at age 25.
Thermograms are graded with a system much like pap smears with grades 1-5. Th1 and Th2 are normal, Th3 is moderately abnormal, and Th4 and Th5 are severely abnormal and require careful follow-up because many of them are caused by cancer. Of significance, one recent study documented that women with Th1 and Th2 scores can be reassured with a 99% level of confidence that they do not have breast cancer. (16)
CLINICAL RESEARCH SUPPORTING BREAST THERMOGRAPHY
At least five important studies published between 1980 and 2003 document that breast thermal imaging is a major advancement in identifying breast cancers not only with greater sensitivity and specificity, but also years earlier than with any other scientifically tested medical technology.
These scientific studies include:
* Cancer, 1980, Volume 56, 45-51. (17) Fifty-eight thousand patients with breast complaints were examined between 1965 and 1977. Twelve hundred and forty-five patients with abnormal Th3 mammotherms had normal breasts by mammography, ultrasound, physical exam, and biopsy. Thirty-eight percent of women with normal breasts and 44% of those with mastopathy developed biopsy proven breast cancer within five years. Ninety percent of patients with Th4 or 5 had diagnosis of cancer made on their first visit.
* Biomedical Thermology, 1982, 279-301, Alan Liss, Inc, New York. Michel Gautherie, MD, followed 10,834 women over 2 to 10 years by clinical examination, mammography and thermography. (15) The study followed 387 people with normal breast examinations and mammograms but Th3 thermographic scores for an average of less than three years. In those without symptoms, 33% developed cancer. In those with cystic mastitis, cancer developed in 41%. These were predominately women between 30 to 45 years of age where breast cancer is the leading cause of death.
* Thermology, 1986, Volume 1, 170-73. (18) The effectiveness of mammography, clinical palpation, and thermography were compared in the detection of breast cancer. Thermography had the best reliability, but the best results were found when all three were used together.
* The Breast Journal, Volume 4, 1998, 245-51. (19) Keyserlingk et al documented 85% sensitivity in diagnosing breast cancer using clinical examination and mammography together. This increased to 98% when breast thermography was added.
* American Journal of Radiology, January 2003, 263-69. (16) The journal reported that thermography has 99% sensitivity in identifying breast cancer with single examinations and limited views. Thus, a negative thermogram (Th1 or Th2) in this setting is powerful evidence that cancer is not present.
IMPORTANT HIGHLIGHTS FROM BREAST THERMOGRAPHY STUDIES
* Advances in infrared technology combined with data on 300,000 women with mammotherms document that breast thermography is highly sensitive and accurate. Today, this means that more than 95% of breast cancers can be identified, and that this is done with 90% accuracy. In women under the age of 50, where there is the most devastating loss of life from breast cancer, mammography, MRIs and PET scans cannot come close to matching the combined sensitivity and specificity (accuracy) of breast thermography.
* Breast thermography involves no radiation exposure or breast compression, is easy to do, is done in a private setting, and is affordable.
* The FDA approved breast thermography for breast cancer risk assessment in 1982.
* It is important to begin breast cancer screening long before age 40. It should begin at age 25 in order to identify young women who are already developing breast cancer since it takes approximately 15 years for a breast cancer to form and lead to death. Further, young women with dense breast tissue are the most difficult to evaluate using breast palpation, mammography, and ultrasound examinations, yet their significantly higher risk of developing breast cancer can be accurately detected with breast thermography.
* Mainstream procedures are not approved for breast cancer screening in women under age 40–it is widely known and accepted that they miss too many cancers and lead to too many false positive findings that result in far too many needless breast biopsies.
There is an abundance of scientific evidence supporting that breast thermography is the most sensitive and accurate way to identify women with breast cancer, especially in women under the age of 55, where it causes the most devastating loss of life. For women over 55, breast thermography is an important adjunct to clinical breast examination and mammography, as this combination has been documented to increase identification of breast cancers to 98%. Because of its low cost and high degree of sensitivity and accuracy, all women who want to be screened for breast cancer should begin having breast thermograms beginning at age 25. Clearly, there are situations that warrant the use of other modalities such as mammography, ultrasound, MRI, PET scanning, nipple aspirations, or biopsy, and these valuable tools should continue to be used in clinical practice along with breast thermography.
Many new technologies are on the horizon that may become mainstream in the near future. With the advent of highly sophisticated genetic technology, new proteins are constantly being discovered that offer promise as markers of early breast cancer. (20) Recently published reports also suggest that MRI technology may be blended with spectrophotometric measurements that could diagnose breast cancer without even doing a biopsy. (21)
The practice of medicine, just like everything in life, is in constant evolution–there is no guarantee that what is in the mainstream today will be here tomorrow. Yet, the advancement of all fields of endeavor often moves slowly and cautiously, sometimes at the expense of human life. We must remain open and alert as new, exciting, and safe strategies emerge, especially in situations where there is such a pressing need for new approaches.
1. Elliott, VS. Mammography debate: Who should get screened and when? American Medical News, an AMA publication. Volume 10, number 42, pages 35-37, November 10, 2003.
2. Kerlikowske, K. Use of mammograms in older women questionable. JAMA. December 10, 2003.
3. Time Magazine, April 28, 2003. Cover story: The No. 1 Killer of Women.
4. SEER, National Cancer Institute: Chances of developing breast cancer at a given age.
5. de Sanjose S, et al. Prevalence of BRCA1 and BRCA2 germline mutations in young breast cancer patients: a population-based study. Int J Cancer 2003; 106 (4): 588-93.
6. Furstenberger et al. Insulin like growth factors mediate breast cancer growth and proliferation.
Onkologie, 2003. Volume 26, number 3, pages 290-94.
7. Baker L. Breast cancer detection demonstration project: Five year summary report. Cancer, 1982, volume 32, pages 194-225.
8. Sickles EA. Breast masses: mammographic evaluation. Radiology 1989. Pages 173-303.
9. Fletcher, S W, and Elmore, J G. Mammographic Screening for Breast Cancer. New England Journal of Medicine. Volume 348, no. 17, pages 1672-80. April 24, 2003.
10. Ostbye, T. Elderly women over-screened for cancers with little measurable benefit. Annals of
Family Practice. November/December issue, 2003.
11. Pisano, E. Digital Mammography Offers Better Breast Cancer Diagnoses. Presented at the
Radiologic Society of North America annual meeting, December 2003. Research conducted at
University of North Carolina School of Medicine. firstname.lastname@example.org.
12. Freidrich M. MRI of the breast: State of the art. European Radiology, 1998. Volume 8, pages 707- 725.
13. Avril N, Rose CA, Schelling M, et al. Breast imaging with positron emission tomography and fluorine-18 flourodeoxyglucose: use and limitations. Journal of Clinical Oncology, 2000. Volume 18, pages 3495-3502.
14. Avril N. Discussions in PET Imaging 2003. CMP Healthcare Media, DPI no. 621, PET and Breast Cancer.
15. Gautherie, M, Haehnel, P, Walter, J p, Keith, L. Long-Term Assessment of Breast Cancer Risk by Liquid-Crystal Thermal Imaging. Biomedical Thermology, pages 279-301. 1982 Alan R. Liss, Incl, 150 Fifth Avenue, New York, NY 10011.
16. Parisky, Y R, et al. Efficacy of Computerized Infrared Imaging Analysis to Evaluate
Mammographically Suspicious Lesions. American Journal of Roentgenology, January 2003, 263-69.
17. Gautherie, M, and Gros, C M. Breast Thermography and Cancer Risk Prediction. Cancer, 1980, volume 56, 45-51.
18. Nyirjesy, M D, et al. Clinical Evaluation, Mammography and Thermography in the Diagnosis of Breast Carcinoma. Thermology, 1986, volume 1, 170-73.
19. Keyserlingk, M D, et al. Infrared Imaging of the Breast: Initial Reappraisal Using High-Resolution Digital Technology in 100 successive cases of Stage I and II Breast Cancer. The Breast Journal, volume 4, 1998, 245-51.
20. Zangar, R. Breast Cancer Research and Treatment. July 3, 2003.
21. Bolan, P. In vivo quantification of choline compounds in the breast with 1H MR spectroscopy. Magnetic Resonance in Medicine. Volume 50, Issue 6, Date: December 2003, Pages: 1134-1143.
by Len Saputo, MD
Len Saputo, MD
Health Medicine Institute
3799 Mt. Diablo Blvd.
Lafayette, California 94549 USA
COPYRIGHT 2004 The Townsend Letter Group
COPYRIGHT 2004 Gale Group
Medical Devices and Systems
The following is Chapter 25 of the 2006 edition of The Biomedical Engineering Handbook, Third Edition, Medical Devices and Systems published by CRC Press.
Joseph D. Bronzino, editor of the handbook, comments that “Medical Devices and Systems” is an authoritative reference text and is considered the “bible” of biomedical engineering. This latest volume presents new and updated material contributed by a team of world-renowned experts. The text reflects the most recent advances in both research and practice, and authoritatively covers sensor and imaging technologies, signal analysis, and medical instrumentation. This Third Edition presents an excellent summary of the status of knowledge and activities of biomedical engineers in the beginning of the 21st century.”
The principle author of this chapter, Dr. William Amalu, is joined by three other world-renowned experts in this field to present the state-of-the-art in infrared breast imaging. The following chapter contains a review of the literature along with a presentation of infrared physics, imaging system standards, a brief historical background, laboratory and patient imaging standards and protocols, and a look at the future of this lifesaving technology.
The following is a brief highlight of the chapter that follows:
• In 1982, the FDA approved breast thermography as an adjunctive breast cancer
• Breast thermography has undergone extensive research since the late 1950’s.
• Over 30 years of research comprising over 800 peer-reviewed studies on breast
thermography exist in the index-medicus literature.
• In this database, well over 300,000 women have been included as study participants.
• The numbers of participants in many studies are very large — 10K, 37K, 60K, 85K …
• Some of these studies have followed patients up to 12 years.
• Strict standardized interpretation protocols have been established for over 15 years.
• Breast thermography has an average sensitivity and specificity of 90%.
• An abnormal thermogram is 10 times more significant as a future risk indicator for
breast cancer than a first order family history of the disease.
• A persistent abnormal thermogram caries with it a 22x higher risk of future breast
• An abnormal infrared image is the single most important marker of high risk for
developing breast cancer.
• Breast thermography has the ability to detect the first signs that a cancer may be
forming up to 10 years before any other procedure can detect it.
• Research has shown that breast thermography significantly augments the long-term
survival rates of its recipients by as much as 61%.
• When used as part of a multi-modal approach (clinical examination + mammography
+ thermography) 95% of early stage cancers will be detected.