The first recorded use of thermobiological diagnostics can be found in the writings of Hippocrates around 480 B.C. [1]. Wet mud spread over the patient was observed for areas that would dry first and was thought to indicate underlying organ pathology. The first use of diagnostic thermography came in 1957 when R. Lawson discovered that the skin temperature over a cancer in the breast was higher than that of normal tissue [2].

In 1982, the Food and Drug Administration published its approval and classification of thermography as an adjunctive diagnostic screening procedure for the detection of breast cancer. Since the late 1970´s, numerous medical centres and independent clinics have used thermography for a variety of diagnostic purposes and since 2000 there has been a surge in health professionals entering the field.

All objects with a temperature above absolute zero emit infrared radiation from their surface. Measurements of infrared radiation emitted by the skin can be converted directly into accurate temperature values, and a law of physics called the Stefan-Boltzmann Law defines this relationship. Human skin emits infrared radiation mainly in the 2 - 20 micron wavelength range, with an average peak at 9-10 microns. State-of-the-art infrared radiation detection systems utilize ultra-sensitive infrared cameras and sophisticated computers to detect, analyze, and produce high-resolution diagnostic images of these infrared emissions. The problems encountered with first generation infrared camera systems (such as improper detector sensitivity, thermal drift, calibration, analogue interface, etc) have been solved for almost two decades. The strict environmental control that is essential whilst performing a thermal image e.g. 1 degree C of change during the examination, is necessary to produce a physiologically neutral image free from artefact.

Breast thermography therefore, is a clinical diagnostic procedure, which uses highly specialised infra red cameras to measure the heat coming from the body, in this case, the breast. Thermography as a test of physiology is not capable of, and will never be capable of detecting breast cancer. Anatomical testing such as mammography can also not detect breast cancer. Both procedures demonstrate abnormalities indicating the possibility of the presence of cancer, as well as a host of other breast conditions. These clinical findings require differential diagnosis. Only laboratory confirmation of abnormal cell morphology can make the correct diagnosis of cancer.

Thermography of the human breast is not a stand-alone tool as some have suggested in the screening and diagnosis of breast cancer. It is adjunctive. We cannot ignore thermographys´ tremendous role as an early risk indicator or as a monitor for treatment. In this way changes in tumour angiogenesis can be evaluated and other procedures can be performed to aid in the earliest possible diagnosis. The procedure is non-ionizing and safe and there is no reason to simply "wait and see" any longer.

It is very important that proper protocols are used when performing breast thermograms. These include adequate cooling down procedures prior to imaging (for 10 to 15 minutes), no windows or open doors, exclusion of outside light, controlled climate and humidity, no air blowing directly on the patient and maintained room temperature of 18C-22C range.

It is critical to the outcome of quality thermal imaging, that the patient be given adequate instructions and protocols prior to their examination date as there are many factors, which can create false findings on the thermogram. This includes instruction on: timing of baths, no prior underarm shaving or use of lotions or creams, no alcohol or caffeine for 24 hours, no sunburn, no physical or massage therapy for 24 hours prior.

This test is often used to assist in the determination if a malignancy is present during routine breast thermography. The procedure involves performing a baseline thermogram of the breast (fig 1) and then to expose the patient’s hands or feet to ice cold for 1 minute. This challenges the autonomic nervous system and creates a "fight or flight" response under sympathetic nervous system control.

When an area of the breast is suspect, the challenge helps to determine whether the heat source may be of benign or malignant nature. By placing the patient’s hands in very cold water (10 C) a sympathetic induced vasoconstriction occurs in healthy tissue. Malignant regions do not cool. This important step in the process of breast thermal imaging is the step that has finally produced significant increases in detection using this screening methodology. This form of dynamic thermography has been reported to decrease the false-positive rate to 3.5% (96.5% sensitivity) after a study on 10,834 patients [3-6].

Some patients in the past have complained about the cold challenge, and in some cases, patients can become light headed. One manufacturer in particular is telling its doctor users that they no longer need to perform this test because their equipment is custom built for the human range. This is preposterous and extremely dangerous. The cold challenge stress test is a test of human physiology, which is independent of the type of thermal imaging camera utilized. In not performing a cold challenge there is potential for incorrect interpretation, malpractice and wrongful death.

Thermography´s role in breast cancer and other breast disorders is one of early detection and monitoring of aberrant (abnormal) physiology and the establishment of risk factors for the development or existence of cancer. While prone to misinterpretation by "untrained" clinicians, its diagnostic accuracy and yield are unparalleled. With respect to breast thermal imaging, a great number of studies by researchers in different parts of the world, utilizing different technology have still demonstrated the usefulness and clinical utility of the procedure. (when utilized appropriately).

In worldwide retrospective studies, thermograms were positive in a minimum of 71% to a maximum of 93% in patients with breast cancer as reported by Nyirjesy [7] (Also see Table 1 below). There are literally thousands of pages of discussion in print regarding the benefits of thermography as it relates to breast cancer. Despite the wide variety of protocols and equipment utilized, a tremendously high statistical correlation of accuracy prevails. This is likely to increase even further as technology and training become more standardized.

Sensitivity = positive thermograms in patients with known breast carcinoma, and Specificity = the reliability of a negative thermogram in the absence of disease.

* This was remarkable considering the stage of development of the technology utilized in those studies.

** Furthermore, Jones indicated in a study of patients at Royal Masden Hospital that 70% of Stage I and Stage II cancers and up to 90% of Stage III and IV cancers had abnormal thermographic findings.

ª 35% of whom were under 35 years of age

Breast thermography is very accurate (as demonstrated in Table 1), but only in the hands of trained personnel using the correct type of thermography cameras. The accuracy of the examination varies around the world but varies from 87%-96%. Numerous studies have been published demonstrating that patients reported to have false positive thermograms i.e. positive thermograms and negative mammograms who were told the thermography was wrong, were determined by long term follow-up to have developed breast cancer in exactly the location thermography had demonstrated its positive finding 5-10 years earlier.

We have a wonderful and exciting opportunity to at last change the incidence of this horrible disease, by screening younger women utilizing high resolution thermal imaging technology and then placing those women with positive findings into the appropriate lifestyle modification and treatment model which may be able to prevent or minimize not only cancer, but all breast disease.

Breast thermography has undergone extensive research since the late 1950´s. Over 1,000 peer-reviewed studies on breast thermography exist in the medical literature. Some of these studies have followed patients up to 12 years. Strict standardized interpretation protocols have been established for over 15 years.

Historically, thermography has been around from a very early technological basis with quite remarkable results for more than three decades. Williams and Handley reported in the Lancet (1961) that 54 of 57 patients with breast cancer could be determined with a crude hand held thermographic instrument [8]. The authors reported 1-2 degree centigrade changes in abnormal tissue and also stated that there was excellent discrimination between benign and malignant tissue.

These findings corroborate the concept that thermography of the breast provide for a very early screening platform allowing for rapid intervention. Also, the concept of stability of thermographic images from year to year in otherwise healthy patients with negative thermograms further support the concept of using thermal imaging as a monitoring tool for those patients with positive findings in an attempt to assess the validity and effectiveness of various breast cancer therapies.

The empirical evidence that underlying breast cancer alters regional skin surface temperatures was investigated early on. In 1963, Lawson and Chughtai, two McGill University surgeons, published an elegant intra-operative study demonstrating that the increase in regional skin surface temperature associated with breast cancer was related to venous convection [9]. This early quantitative experiment added credence to previous research suggesting that infrared findings were related to both increased vascular flow and increased metabolism. Gamagami studied angiogenesis by infrared imaging and reported that hypervascularity and hyperthermia could be shown in 86% of non-palpable breast cancers. He also noted that in 15% of these cases infrared imaging helped to detect cancers that were not visible on mammography [10]. The increased vascularity and neoangiogenesis seems to be necessary to maintain the increased metabolism of cellular growth and multiplication.

Spitalier and associates screened 61,000 women using thermography over a 10 year period. 91% of the nonpalpable cancers were detected by thermography. Of all the patients with cancer, thermography alone was the first alarm in 60% of the cases. The authors also noted "in patients having no clinical or radiographic suspicion of malignancy, a persistently abnormal breast thermogram represents the highest known risk factor for the future development of breast cancer" [11].

It was well documented that long-term observation (8-10 years or more) is necessary to determine a true false-positive rate. One study noted that 30% of the cancers found would not have been detected if it were not for thermography [12].

As early as 1976, at the Third International Symposium on Detection and Prevention of Cancer in New York, thermography was established by consensus as the highest risk marker for the possibility of the presence of an undetected breast cancer. It had also been shown to predict such a subsequent occurrence [13-15]. This has remained undisputed since[16]. Together with other reports, this has confirmed that thermography is the highest risk indicator for the future development of breast cancer and is 10 times as significant as a first order family history of the disease [17].

From a patient base of 58,000 women screened with thermography, Gros and associates followed 1,527 patients with initially healthy breasts and abnormal thermograms for 12 years. Of this group, 40% developed malignancies within 5 years. The study concluded that "an abnormal thermogram is the single most important marker of high risk for the future development of breast cancer" [18].

In another study of 1,416 patients with isolated abnormal breast thermograms, it was found that a persistently abnormal thermogram, as an isolated phenomenon, is associated with an actuarial breast cancer risk of 26% at 5 years. Within this study, 165 patients with non-palpable cancers were observed. In 53% of these patients, thermography was the only test, which was positive at the time of initial evaluation. It was concluded that a persistently abnormal thermogram, even in the absence of any other sign of malignancy, is associated with a high risk of developing cancer [19, 20]

Mammography is well-recognized to have a reported sensitivity rate often below 65% [21] with persistent false-negative rates ranging up to 30% [22, 23]. There is also decreasing sensitivity in patients on HRT [24]. In addition, there is recent data suggesting that denser and less informative mammography images are precisely those associated with an increased cancer risk [25]. A recent article in the BMJ [26], concluded that website material provided by professional advocacy groups and governmental organisations on breast screening by mammography was severely biased in favour of screening and failed to document important harms. Recent scientific peer-reviewed publications have led to several concerns over mammography. These are 1) it leads to no survival advantage [27-29] 2) it is late detection (a cancer can have been developing 8 years before it is detected) 3) one third of mammograms give false positive readings [30] 4) each mammogram increases a pre-menopausal woman’s cancer risk by 1 per cent [31]. There are also some published concerns over the compression of existing cancers at the time of screening.

Thermography is NOT an alternative to mammography. Anyone making this claim is seriously misinformed. While we all want to see the non-judicious use of any radiographic imaging eliminated, mammography is a valuable diagnostic tool in many cases. Thermography does not medically, scientifically, or legally replace mammography. It has an entirely different place in the monitoring of a woman´s breast health.

Dodd [32] concluded that using thermography as a screening device to determine if mammography were indicated would eliminate the need for mammography in 80-85% in the general female population over age 40. This may have been overzealous and created some scrutiny for the thermal imaging industry, however the notion of reducing radiation exposure in younger women by screening first with thermography is to be encouraged. A not too dissimilar conclusion was arrived at by Isard [33]. Isard concluded that, had there been a preliminary selection of his group of 4,393 asymptomatic patients by infrared imaging, mammographic examination would have been restricted to 23% of this cohort. This would have resulted in a cancer detection rate of 24.1 per 1000 combined infrared and mammographic examinations as contrasted to the expected 7 per 1000 by mammographic screening alone. He concluded that since infrared imaging is an innocuous examination, it could be utilized to focus attention upon asymptomatic women who should be examined more intensely.

It has been estimated that the incidence of breast cancer detection per 1,000-screened patients would increase from 2.72% using mammography to 19% utilizing thermography [34]. The same author repeated the concept that thermography uses no radiation, no physical contact and that as an innocuous technique and could concentrate on the sought population selecting patients that would require further study.

There is a distinct advantage of Thermography in younger pre-menopausal women who are often difficult to diagnose accurately because of the density of the breast tissue. Adding thermographic screening in a physiologic detection category to the current base of knowledge will assist in catching some cancers and other breast diseases much earlier, providing for earlier intervention and hopefully a better clinical outcome.

Why is thermal imaging not utilized more?

The answer probably lies in poor early thermography technology, an early exaggerated emphasis on thermography as a replacement to mammography and political opposition from competitive medical technologies.

It wasn’t until the early 1980’s that established and standardized reading protocols were introduced but these now incorporate an analysis of vascular patterns (12 secondary factors) in conjunction with thermal differences (8 major factors).

The large patient populations and long survey periods in many of the above clinical studies yield a high significance to the various statistical data obtained. There is no doubt that Thermography will prove one of the most invaluable tools in the early detection of breast cancer and in our war to conquer the disease.

It is here that the paradigm needs to shift. We can no longer accept the "wait and see" attitude just because a mammogram is negative. Hopefully in the near future with a more universal and a-political approach, thermal-imaging markers can be even further classified into more effective and even pathognomonic categories. This will require a team approach, worldwide. Until that time, one thing is certain. In the presence or absence of cancer, an abnormal thermogram is indicative of abnormal physiology, and this cannot be ignored any longer.

When a thermogram is positive, a closer look at the patient´s diet, exposure to environmental toxins and pollution and lifestyle is in order. Clinical blood work in addition to mammography is essential.

Thermography´s only error is that it is too right too early. It is our job as scientists, physicians and concerned patients, to identify the appropriate protocols once a thermogram is positive. It is in this capacity that the paradigm must shift and where preventative medicine must play a key role.

In conclusion, the case for the widespread introduction of breast thermal imaging is now overwhelming, especially for young women, based on the accumulated evidence. Its adoption as a routine procedure as part of all ongoing breast screening programs would allow a more optimal and targeted use of mammography but more importantly would allow for prevention and much earlier treatment with the consequence of reducing mortality from breast cancer with corresponding significant cost savings for the NHS.

[1] Adams, F.: The Genuine Works of Hippocrates. Baltimore: Williams and Wilkins, 1939.

[2] Lawson R.: Implications of Surface Temperatures in the Diagnosis of Breast Cancer. Can Med Assoc J 75: 309-310,1956.

[3] Sciarra, J.: Breast Cancer: Strategies for Early Detection. Thermal Assessment of Breast Health. (Proceedings of the International Conference on Thermal Assessment of Breast Health). MTP Press LTD. pp. 117-129, 1983.

[4] Gautherie, M.: Thermobiological Assessment of Benign and Malignant Breast Diseases. Am J Obstet Gynecol (8)147:861-869, 1983.

[5] Louis, K., Walter, J., Gautherie, M.: Long-Term Assessment of Breast Cancer Risk by Thermal Imaging. Biomedical Thermology. Alan R. Liss Inc. pp.279-301, 1982.

[6] Gros, C., Gautherie, M.: Breast Thermography and Cancer Risk Prediction. Cancer 45:51-56, 1980

[7] Nyirjesy, I., Ayme, Y., et al: Clinical Evaluation, Mammography, and Thermography in the Diagnosis of Breast Carcinoma. Thermology 1:170-173, 1986

[8] Lloyd-Williams K., Handley RS Infra-red thermometry in the diagnosis of breast disease. Lancet 2: 1378-1381, 1961

[9] Lawson RN and Chughtai MS: Breast cancer and body temperatures. Can Med Assoc J 88: 68-70,1963.

[10] Gamagami P: Indirect signs of breast cancer: Angiogenesis study. In: Atlas of Mammography, Cambridge, Mass.,Blackwell Science pp.231-26, 1996.

[11] Spitalier, H., Giraud, D., et al: Does Infrared Thermography Truly Have a Role in Present-Day Breast Cancer Management? Biomedical Thermology, Alan R. Liss New York, NY. pp. 269-278, 1982

[12] Haberman, J., Francis, J., Love, T.: Screening a Rural Population for Breast Cancer Using Thermography and Physical Examination Techniques. Ann NY Acad Sci 335:492-500,1980

[13] Amalric, R., Gautherie, M., Hobbins, W., Stark, A.: The Future of Women with an Isolated Abnormal Infrared Thermogram. La Nouvelle Presse Med 10(38):3153-3159, 1981

[14] Gautherie, M., Gros, C.: Contribution of Infrared Thermography to Early Diagnosis, Pretherapeutic Prognosis, and Post-irradiation Follow-up of Breast Carcinomas. Laboratory of Electroradiology, Faculty of Medicine, Louis Pasteur University, Strasbourg, France, 1976

[15] Hobbins, W.: Significance of an "Isolated" Abnormal Thermogram. La Nouvelle Presse Medicale 10(38):3153-3155, 1981

[16] Hobbins, W.: Thermography, Highest Risk Marker in Breast Cancer. Proceedings of the Gynecological Society for the Study of Breast Disease. pp. 267-282, 1977

[17] Louis, K., Walter, J., Gautherie, M.: Long-Term Assessment of Breast Cancer Risk by Thermal Imaging. Biomedical Thermology. Alan R. Liss Inc. pp.279-301, 1982.

[18] Gros, C., Gautherie, M.: Breast Thermography and Cancer Risk Prediction. Cancer 45:51-56, 1980

[19] Amalric, R., Giraud, D., et al: Combined Diagnosis of Small Breast Cancer. Acta Thermographica, 1984.

[20] Spitalier, J., Amalric, D., et al: The Importance of Infrared Thermography in the Early Suspicion and Detection of Minimal Breast Cancer. Thermal Assessment of Breast Health (Proceedings of an International Conference), MTP Press Ltd., pp.173-179, 1983

[21] Sickles EA: Mammographic features of "early" breast cancer. Am J Roentgenol 143:461, 1984.

[22] Moskowitz M: Screening for breast cancer. How effective are our tests? CA Cancer J Clin 33:26,1983.

[23] Elmore JG, Wells CF, Carol MPH et al. Variability in radiologists interpretation of mammograms. NEJM 331(22):1994;1493

[24] Laya MB: Effect on estrogen replacement therapy on the specificity and sensitivity of screening mammography. J Natl Cancer Inst 88:643-649, 1996.

[25] Boyd NF, Byng JW, Jong RA et al: Quantitative classification of mammographic densities and breast cancer risk. J Natl Cancer Inst 87:670-75,1995.

[26] Jorgensen & Gotzshe: Presentation on websites of possible benefits and harms from screening for breast cancer: a cross sectional study. British Medical Journal, 328, 148-151, 2004

[27] Lancet, 2002, 359: 909-19

[28] Lancet, 2002; 356: 1087

[29] BMJ, 2002; 324: 432

[30] N. Engl J Med, 1998; 338: 1089-96

[31] Lancet, 1992; 340:122

[32] Dodd, GD: Thermography in Breast Cancer Diagnosis, In: Abstracts for the Seventh National Cancer Conference. Proceedings, Los Angeles, Calif. Sept. 27-29, Lippincott Philadelphia, Toronto: pp.267, 1972

[33] Isard HJ, Becker W, Shilo R et al: Breast thermography after four years and 10,000 studies. Am J Roentgenol 115: 811-821,1972.

[34] Wallace JD: Thermographic examination of the breast: In: An assessment of its present capabilities: In Gallagher HS (Ed):Early Breast Cancer: Detection and Treatment. American College of Radiology, Wiley, New York pp. 13-19, 1975

[35] Gershen-Cohen J, Haberman J, Brueschke EE: Medical thermography: A summary of current status. Radiol Clin North Am 3:403-431, 1965.

[36] Jones CR: Thermography of the Female Breast, in C.A. Pasons (Ed) Diagnosis of Breast Disease, University Park Press, Baltimore, pp. 214-234, 983, 1978

[37] Hoffman, R.: Thermography in the Detection of Breast Malignancy. Am J Obstet Gynecol 98:681-686, 1967

[38] Stark, A., Way, S.: The Screening of Well Women for the Early Detection of Breast Cancer Using Clinical Examination with Thermography and Mammography. Cancer 33:1671-1679, 1974

[39] Useki H: Evaluation of the thermographic diagnosis of breast disease: relation of thermographic findings and pathologic findings of cancer growth. Nippon Gan Chiryo Gakkai Shi 23: 2687-2695, 1988.