Can Digital Thermal Imaging Detect Breast Cancer?

Digital Infrared Thermal Imaging (DITI) has the potential to be a helpful tool in the detection of cancerous tissue in the human body. Advocates suggest that it could be used in addition to mammography (using x-ray images) because it does not emit radiation and can spot problem areas long before an x-ray image can reveal cancerous activity.
Let's be clear; it is not possible to diagnose cancer with thermal imaging, x-ray mammography or an ultrasound scan. Each imaging method is used as a means of detection, though DITI does not have the support of the US Food and Drug Administration (FDA) or the UK National Institute for Health and Clinical Excellence (NICE) for this clinical application. Only a surgically invasive biopsy can currently provide an accurate diagnosis. Self-examination, along with mammography, are the officially accepted methods of detection.
Cancerous activity in the body changes the metabolic activity in that area, since tumours use angiogenesis to feed themselves with blood. Vascular activity becomes abnormal and heat is created. It is possible to interpret hot-spots in a thermal image as what appears to be increased vascular activity in a subject breast and this may indicate abnormal activity. However, I would speculate that the NHS seems to think that thermography is inaccurate because there are lots of other harmless conditions that can appear as an "abnormal" result on the thermograph.
Opposition to thermal imaging in cancer detection has been based (not exclusively) on the insensitivity of images to thermal differences. Cancerous areas are warmer, but they need to be significantly warmer for infrared cameras to indicate usable information. One method, used by Angott Medical Products, suggests that cooling the body prior to examination will give a better, more readable, result. They suggest that the abnormal metabolic activity in the cancerous area does not cool as quickly as the surrounding body tissue, so it should be more evident on the thermal image.
Advocates of DITI for breast cancer detection are keen to suggest that it can depict potential cancers long before x-ray images because x-rays can only show larger - and therefore more advanced - cancerous fibroids. This is only valid if we are totally sure that thermal images are clearly pinpointing cancerous activity. Cancer Active, "Britain´s Number 1 holistic cancer information charity", make strong claims for the unique characteristics of DITI as an additional breast cancer detection tool, especially for younger women where higher breast tissue density makes both x-ray and ultrasound less useful as predictive tools.
At least two cases suggest that official bodies are more than circumspect when it comes to claims made by commercial interests. Recently the Advertising Standards Authority upheld a claim against The Homeopathic Clinic who had claimed, perhaps misleadingly, that thermography could detect the early signs of breast cancer in women under fifty. In the USA, a similar case was brought against Meditherm, Inc by the FDA.
No official US or UK source currently backs DITI as a breast cancer detection tool, anyone who suspects they have breast cancer is best relying on the advice of their doctor. Private firms operating DITI detection procedures may have trained clinicians who can decipher thermal images but there is no official quality control applied to their analysis and advice.
Thermal imaging is being used successfully as a clinical tool by veterinary surgeons, particularly in the detection of animal injury. It is also entering the world of sports medicine. At the moment the growth areas for thermal imaging are still in areas such as fire-fighting, and electrical and building safety inspection.