Breast Thermal Imaging,
the paradigm shift
by William Cockburn, DC., FIACT, FABFE
Article for IRIE 99'
(f) Associate Professor of Clinical Sciences Department Chairman Thermographic Sciences CCC-LA
(reprint) original published in Thermologie Oesterreich,
ISSN-1021-4356
April 95'
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SUMMARY
Infrared thermal imaging of the breast, a non-invasive adjunctive diagnostic
methodology has become all but non-existent in the United States. This is
in large part due to extensive debate concerning thermography in the trial
courts, related to spinal injury cases and also due to the model or basis
used for breast thermal imaging. This paper attempts to identify possible
factors which will bring thermal breast imaging back into serious mainstream
consideration as a valid adjunct to overall breast pathology diagnosis.
KEY WORDS:
Breast thermal imaging, protocol, technology, quantification, paradigm
shift, prevention, risk assessment.
INTRODUCTION:
For purposes of this paper, I define the word "paradigm" to mean "model".
The paradigm, or model for breast thermal imaging must change.
The initial use of thermography was for breast cancer screening and diagnosis.
This was error. 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.
This is a paradox. Both procedures, thermography and mammography, 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'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.
This is breast thermography's only role at the current time in history.
After large scale clinical trial under appropriate protocols and further
development of the procedure, equipment, protocol and certification it is
hoped that certain thermal "markers" may become more generally accepted and
pathognomonic of various breast disorders, including types and location of
cancer.
APPROPRIATE TRAINING
Since thermography is a non-invasive (no radiation) procedure there is
no specific legislation or regulatory act under which thermography can be
scrutinized in the United States. Early thermographic pioneers created entrepreneurial
training and certification programs for both physicians and technicians.
These programs cultivated a host of new course instructors and a variety
of organizations and certifications became available.
Some courses offered thermographic certification to people with no medical
background or formal medical education. For example, injured workers in California
could under vocational rehabilitation laws to become certified as thermographic
technicians and open their own labs.
These individuals needed an interpreting physician, so they found doctors
who were willing to review and "read" the examinations performed, although
few of those physicians themselves had training or certification in the field
of thermography.
To avoid a deluge of poor quality and inadequate thermographic study as
well as faulty interpretation of the studies, university based training programs
must be established. With the electronic super highway in existence, a global
network can be aimed at creating such standards and uniformity of study,
worldwide.
APPROPRIATE EQUIPMENT
There are essentially two types of thermographic equipment utilized in
medical practice.
One is LCT (liquid crystal thermography). These are essentially latex
plates embedded with liquid crystals which react to surface heat of the body
by giving off visible color. The mix of crystals used in the detector
determines the detectors ability to differentiate heat ranges.
The other is Electronic Thermography also known as telethermography. The
latter are camera\computer based systems which are highly accurate and function
in real time with no contact to the subjects skin.
Many manufacturers modified thermographic equipment utilized for night
vision or military applications. Some of these detectors were not of adequate
quality to read heat patterns emitted from human skin. For example, a system
with a sensitivity above 0.5 degrees C, did not provide consistent quantification
(numeric measurement).
Systems which sensitivity of 1.0 degrees centigrade provide for errors
ranging between 0.1 and 1.9 degrees. With pathology found at the .4 to 1.0
C range, it is obvious that such equipment is not appropriate for utilization,
but none the less, these inappropriate systems were heavily utilized in the
70's and 80's for this purpose.
Early electronic thermographic systems utilized detectors made from indium
antimonide which had a spectral range of 2-5 millimicrons. As heat patterns
detectable from breast tissue fall into the 8-13 millimicron range the 2-5
millimicron detectors were not adequate and the more expensive mercury cadmium
telluride detectors should have been used.(1). These
detectors were much more costly to the average clinician or research facility
and so they were not used. (focal plane array cameras in the modern
era are aiding in the correction of this divergence.
Unaware physicians, who desired to use thermography in their practices
purchased the less expensive systems and thus the basis for many of the false
positive findings reported in the literature. Had they used the appropriate
systems with the correct optical wave band, these false positives would have
been eliminated or significantly reduced.
Many of the manufacturers of computer based systems designed software that
caused the images to look fantastic, but these images were displaying information
that was not necessarily complete and thus, the unwary physician found inconsistency
in his studies as well as a high false positive rate which would not have
occurred had the appropriate systems been utilized in breast cancer screening.
As with any medical device the appropriate technology, performed according
to a consistent and established protocol by board certified individuals will
result in more accurate studies and satisfactory scientific yields.
REGULATION:
Though medicine as a whole cries out for less governmental control, the
lack of regulation within the field of thermography is a significant problem.
For example, in the United States, medical, chiropractic and podiatric licensing
boards have adopted position statements regarding clinical utility of thermography
and some have "accepted" various protocols for implementation, but that is
all.
However, anyone can own and operate thermographic equipment. Only a licensed
health care providers with portal of entry status, (MD, DC, DPM, etc.) can
interpret or render a diagnostic opinion of the examination.
In addition, this also relates to the ability to bill an insurance carrier
and receive payment for services. Thus entrepreneurs with no formal medical
training often submitted studies to insurance companies which were of very
poor quality. This resulted in not only denial of payment, but a doubt was
rightfully cast on the legitimacy and quality of thermographic studies as
they were being performed by inadequate personnel.
With this lack of regulation, a great many poorly performed studies found
their way into the medical literature and the court system. (see personal
injury model below).
PROPER PROTOCOL
A major factor related to the inconsistency of published works in the thermographic
imaging field is the various protocols under which the procedures is performed.
Although not difficult, the protocol of the examination, a with x-ray or
any other diagnostic device, is essential to accurate and reliable outcome.
Some examples of thermographic protocols would be :
Factors Affecting Examination
|
the ambient room temperature at which the examination is performed
|
the length of time allowed for patient equilibration to the ambient
temperature |
the type of equipment utilized |
| the type of floor covering |
the presence or absence of windows which can alter room temperature |
the type of heating or air conditioning for thermal regulation of the
room. |
| the usage of lotions, deodorants and cosmetics on the skin |
the ingestion of vasodilator and vasoconstrictor substances (ie:caffeine) |
the medications taken by the patient |
While the scope of this paper can not devote a great deal of space to protocol,
it is important to note that most non-thermographic clinicians that the author
has had opportunity to oppose in the legal system, have had no idea that
such protocol exists or is important.
When I taught the diplomate course for thermography in California, physicians
were asked to submit thermographic studies as part of their completion requirements.
The vast majority of unacceptable studies (which incidentally, were used
for diagnosis of patients in these clinicians practices) were found to contain
errors created simply by poor protocol which would have been very easy and
inexpensive to correct. For example, performing the procedure on tile flooring
which by its cold temperature, caused abnormal sympathetic heating responses
in the subject under evaluation. A carpeted floor is required.
Protocol is everything. Without an internationally accepted protocol, no
comparison of accuracy, double blinded study, or evaluation of the technology
and its effectiveness can be made. With the wide ranging opinion of thermographers
and pseudo-thermographers concerning appropriate protocol, it is no wonder
that many studies performed worldwide do not correlate, while other studies
performed to a stringent protocol are so very consistent.
ANECDOTAL Vs SCIENTIFIC EVIDENCE
It is very important to differentiate scientific fact from anecdotal evidence.
For purposes of this paper I define anecdotal to mean a myth or a fable not
supported by fact, but accepted because of a common belief or usage.
Many physicians and investigative journalists use anecdotal data to support
their point of view. An example of this is the often published article in
a medical journal that uses 20-30 references by other authors who all have
just rewritten an original thesis or premise in order to get published without
contributing any new data.
Now the materia medica has a number of consistent articles or studies which
appear to be powerful when used as an argument for or against a given procedure
or point of view. In reality, anecdotal evidence is disastrous when not recognized.
Thermal imaging is pure science. 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 the United States, William Hobbins, MD(2) demonstrated in
a sample of 37,050 patients, a yield of 56 cancers per 1,000 abnormal thermograms
as compared to the 5.6 per 1,000 in the BCDDP studies utilizing mammography.
In France, Gauthrie et al(3) utilizing thermography determined
73% correct diagnosis in 486 breast cancer patients.
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
(4).
There are literally thousands of pages of discussion in print regarding
the benefits of thermography as it relates to breast cancer. The interesting
observation to this author is the wide variety of protocols and equipment
utilized and yet a tremendously high statistical correlation of accuracy prevails.
Think of what might happen if the technology and training were more standardized.
COMPARISON OF THERMAL IMAGING TO OTHER DIAGNOSTIC
PROCEDURES
Comparing anatomic (mammography) to physiologic (thermography) is a great
irony and source of confusion in medicine. Many radiologists I have spoken
to fear that their investment in mammographic equipment will be wasted because
they view thermography as competitive with mammography or that stereo-tactic
biopsy is better than thermography.
This is a classic example of the lack of training and anecdotal arguments
I have previously described. Mammography is anatomical. So are other beneficial
procedures such as ultrasound, diaphenoscopy and CT scanning.
Thermography is a test of physiology (function), and not of anatomy. One
can not compare apples to oranges. The procedures are most definitely correlative
and complimentary and not competitive. The view that thermography is competitive
is error, and one of the most significant detractors from its effective utilization
today.
When used adjunctively with other laboratory and outcome assessment tools,
the best possible evaluation of breast health is made.
Radiologists need to understand the tremendous potential of thermography
to detect the physiologic manifestation of disease that so often predate the
anatomical analysis of the condition. In my first paper on this subject
(5) I point out the danger in "over reading" thermograms and state
that we should utilize the data obtained from thermal imaging from a "screening"
standpoint only, not from a diagnostic one. (1987)
This "complimentary" nature of thermal imaging is of unparalleled significance
to this issue.
QUANTIFICATION
Technology, especially in light of the desk top PC and the Pentium processor,
has at last reached a stage of development and cost effectiveness that makes
the availability of dynamic quantitative and reliable thermography a definitive
reality.
In the past, the quantitative (or numbers) measurement of actual spot temperatures
was difficult. Many thermographer s' used liquid crystal imaging (much like
the temperature strips we use on our children's foreheads). While bright,
colorful and reliable images could be obtained, no precise measurement could
be made. This is called qualitative imaging. (quality of image)
While the quality of a properly performed thermogram can provide immediate
thermal imaging information to the unaided eye, (excluding the estimated 15%
of the population who are color blind), errors can be made in the interpretation
by assuming that a color change is significant when in fact it may not be.
(authors note: due to the email capabilities of this type of correspondence,
the original text and illustration presented below have been modified to meet
the standards available for download)
Qualitative thermography uses color or gray scale images for comparison
of left to right, as in the right nipple as compared to the left, or the full
breast, right compared to left. With qualitative imaging, a color scale is
presented as a crude marker for comparison to the patients actual temperatures.
It was assumed that a color change indicated a pathology as illustrated below.
This was based on a ten color scale, 1 degree centigrade between colors.
So as represented in the diagram, a shift from yellow to orange was assumed
to be a 1 degree centigrade increase in heat, left compared to right.
Sample Color Scale Representation .1 degree increments
| Pink |
Red |
Orange |
Yellow |
Olive |
Lime |
Dk Blue |
Blue |
Lavender |
Black |
| 31.0* |
30.0* |
29.0* |
28* |
27* |
26* |
25* |
24* |
23* |
22* |
X X
X-X = 1.0 degree centigrade difference
Y
Y Y-Y = 1.9 degree centigrade difference
Z Z
Z-Z = 0.1 degree centigrade difference
* degrees centigrade
So, if the right breast were orange on the qualitative image, and the left
breast were red, a pathology was assumed to exist as a 1 degree centigrade
increase in heat had occurred thus shifting the color scale..
WRONG! Please notice that the beginning of each color block has a temperature
selected. They increase in 1 degree centigrade increments. Also notice that
there is a "0" in the tenths position. This means the system is measuring
unit values of 1/10th degree centigrade. Because the color "scale" is assigning
only one color to a block of temperature, all temperatures falling within
that "block" are assigned by the computer, the same color.
Therefore, a difference as little as .1 degree centigrade or as much as
1.9 degrees centigrade could shift the color assignment. Obviously a .1 degree
centigrade shift is minimal and non diagnostic. A 1.9 degree centigrade shift
is quite severe and indicative of pathology. Both however, would assign with
these outdated systems, the same relative color shift and thus the reason
for misdiagnosis and the reporting of the so-called false positives.
In my thermography lecture series, I devote one hour with graphic slides
explaining this phenomenon, which is so easily corrected once the "concept"
is grasped
I have now designed software that differentially measures the actual spot
temperatures in the contralateral tissues so that this error can no longer
occur, yet many clinicians still utilize, and rely upon the outdated and
dangerous qualitative imaging techniques.
CONCLUSION: I would like to restate, that 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 can not ignore thermographys' tremendous
role as an early risk indicator or as a monitor for treatment.
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.
When mammography and blood work are negative or equivocal, thermographic
monitoring on a quarterly to semi-annual basis should be performed in those
patients with suspicious thermograms.
In this way changes in tumor angiogenesis can be evaluated and other procedures
can be ordered 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 here that the paradigm needs to shift. We can no longer accept the
"wait and see" attitude just because a mammogram is negative. Perhaps some
day 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 of cancer or not,
an abnormal thermogram is indicative of abnormal physiology, and this can
not be ignored any longer.
REFERENCES
1. Hardy, JD: The Radiation of Heat from the Human Body, J. Clinical Investigation,
13:539-615
2. Hobbins, Wm, Abplanalp. K., Barnes, C., Moner, B.: Analysis of Thermal
Class TH-V Examinations in 37,050 Breast Thermograms, Thermal Assessment of
Breast Health MTP Press Limited, 25: 249-255, 1984
3. Gross, C., Gauthries, M, Archer, F. et al: Classification Thermogaphique
des Cancers Mammaires, Bull Cancer (Paris), 58:351-362, 1971
4. Nyirijesy, J., Abernathy, MB., Billingsley, FS., Bruns, P.,: Thermography
and Detection of Breast Cancer, a review and comments, J. Reproductive Medicine,
18/4 165-175
5. Cockburn, Wm., Breast Thermography, to screen or not to screen: J International
Academy of Clinical Thermology, Vol1 No2, 17-44 1989
This article was first submitted for publication 24, October 1994
Accepted December 1994
Dr. Cockburn may be reached for comment or discussion at thermodoc@verizon.net
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