Thermography (infrared imaging) is controversial and generally not recognized by the medical community, even though the FDA approved breast thermography for breast cancer screening in 1982. However, there are studies indicating a thermogram is effective, especially in women with dense breasts.
In a review of over 15 studies from 1967-1998, breast thermography has shown an average sensitivity and specificity of 90%. Breast cancer sensitivity refers to the actual cancers identified, while specificity the non-cancers correctly identified.
According to Dr. Len Saputo, breast thermography measures differences in infrared heat emission for normal breast tissue, benign breast abnormalities and breast cancers. This difference may be related to a tumor’s increased blood flow, due to vascular proliferation as a result of tumor associated angiogenesis. This causes tumors to emit more heat, which can be easily detected by heat-sensing infrared scanners. However, DCIS may be more difficult to detect because of its lack of mature vascular patterns.
During a thermogram the breasts are cooled in a room kept at 68 degrees Fahrenheit. Blood vessels of normal tissue respond by constricting to conserve heat, while tumor tissue remains hot. Suspicious areas are graded using 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 they may indicate the presence of cancer.
A study by Parisky in the 2003 January of the American Journal of Radiology documented that women with Th1 and Th2 scores can be reassured with a 99 percent level of confidence that they do not have breast cancer. He concludes that “infrared imaging offers a safe noninvasive procedure that would be valuable as an adjunct to mammography in determining whether a lesion is benign or malignant.”
Although breast thermography is affordable and involves no radiation exposure or breast compression, a 1986 study by Nyirjesy et al demonstrated that a multi-modal approach is best. This study compared clinical examination, mammography and thermography. Clinical examination had an average sensitivity of 75% in detecting all tumors and 50% in cancers less than 2 cm in size. Mammography had an average 80% sensitivity and 73% specificity, while thermography had an average sensitivity of 88% (85% in tumors less than 1 cm in size) and a specificity of 85%. From these findings, the authors concluded that “none of the techniques available for screening for breast carcinoma and evaluating patients with breast related symptoms is sufficiently accurate to be used alone.” However, when using clinical examination + mammography + thermography, 95% of early stage cancers were detected.
YouTube video of Dr. Ben Johnson discussing why mammograms are not a good test for “early detection” and why thermography is.
Find a Certified Thermography Clinic: The American College of Thermology