Description
Thermography is a noninvasive imaging technique intended to measure temperature distribution in organs and tissues. The visual display of this temperature information is known as a thermogram. Thermography has been proposed as a diagnostic tool, for treatment planning and for evaluation of treatment effects for a variety of conditions.

For individuals who have an indication for breast cancer screening or diagnosis who receive thermography, the evidence includes diagnostic accuracy studies and systematic reviews. Relevant outcomes are overall survival, disease-specific survival, test accuracy and test validity. Systematic reviews of studies evaluating the accuracy of thermography to screen and/or to diagnose breast cancer found wide ranges of sensitivities and specificities. Studies to date have not demonstrated that thermography is sufficiently accurate to replace or supplement mammography for breast cancer diagnosis. Moreover, there are no studies on the impact of thermography on patient management or health outcomes for patients with breast cancer. The evidence is insufficient to determine the effects of the technology on health outcomes.

For individuals who have musculoskeletal injuries who receive thermography, the evidence includes diagnostic accuracy studies and a systematic review. Relevant outcomes are test accuracy and validity, symptoms and functional outcomes. A systematic review of studies on thermography for diagnosing musculoskeletal injuries has found moderate levels of accuracy compared with other diagnostic imaging tests. This evidence does not permit conclusions whether thermography is sufficiently accurate to replace or supplement standard testing. Moreover, there are no studies on the impact of thermography on patient management or health outcomes for patients with musculoskeletal injuries. The evidence is insufficient to determine the effects of the technology on health outcomes.

For individuals who have miscellaneous conditions (e.g., herpes zoster, pressure ulcers, temporomandibular joint disorder) who receive thermography, the evidence includes diagnostic accuracy studies and a systematic review. Relevant outcomes are test accuracy and validity, symptoms and functional outcomes. There are 1 or 2 preliminary studies each from outside the United States on various miscellaneous potential indications for thermography. Most studies assessed temperature gradients or the association between temperature differences and the clinical condition. Studies have not adequately evaluated the diagnostic accuracy or clinical utility of thermography for any of these conditions. The evidence is insufficient to determine the effects of the technology on health outcomes.

Background
Interpretation of the color patterns is thought to assist in the diagnosis of many disorders such as complex regional pain syndrome (previously known as reflex sympathetic dystrophy), breast cancer, Raynaud phenomenon, digital artery vasospasm in hand-arm vibration syndrome, peripheral nerve damage following trauma, impaired spermatogenesis in infertile men, degree of burns, deep vein thrombosis, gastric cancer, tear-film layer stability in dry-eye syndrome, Frey syndrome, headaches, low back pain, and vertebral subluxation.

Infrared radiation from the skin or organ tissue reveals temperature variations by producing brightly colored patterns on a liquid crystal display. Thermography involves the use of an infrared scanning device and can include various types of telethermographic infrared detector images and heat-sensitive cholesteric liquid crystal systems. 

Thermography may also assist in treatment planning and procedure guidance by accomplishing the following tasks: identifying restricted areas of perfusion in coronary artery bypass grafting, identifying unstable atherosclerotic plaque, assessing response to methylprednisone in rheumatoid arthritis, and locating high undescended testicles.

Regulatory Status
A number of thermographic devices have been cleared for marketing by the Food and Drug Administration through the 510(k) process. Food and Drug Administration product codes: LHQ, FXN. Devices with product code LHQ may only be marketed for adjunct use. Devices with product code FXN do not provide a diagnosis or therapy. Examples of these devices are shown in Table 1.

Table 1. Thermography Devices Cleared by the Food and Drug Administration

Policy:
The use of all forms of thermography (temperature gradient studies) is investigational and/or unproven and is therefore considered NOT MEDICALLY NECESSARY because the available medical literature indicates thermography to be an ineffective diagnostic technique.

The use of dynamic infrared perfusion imaging (DIRI) is investigational and /or unproven and is therefore considered NOT MEDICALLY NECESSARY because of a lack of evidence of its clinical utility.

Policy Guidelines
Coding
Please see the Codes table for details.

Benefit Application
BlueCard/National Account Issues
State or federal mandates (e.g., FEP) may dictate that all devices approved by the U.S. Food and Drug Administration (FDA) may not be considered investigational. Therefore, FDA-approved devices may only be assessed on the basis of their medical necessity.

Rationale  
This evidence review was created in March 1996 and has been updated regularly with searches of the PubMed database. The most recent literature update was performed through July 12, 2022.

Evidence reviews assess whether a medical test is clinically useful. A useful test provides information to make a clinical management decision that improves the net health outcome. That is, the balance of benefits and harms is better when the test is used to manage the condition than when another test or no test is used to manage the condition.

The first step in assessing a medical test is to formulate the clinical context and purpose of the test. The test must be technically reliable, clinically valid, and clinically useful for that purpose. Evidence reviews assess the evidence on whether a test is clinically valid and clinically useful. Technical reliability is outside the scope of these reviews, and credible information on technical reliability is available from other sources.

Breast Cancer Screening or Diagnosis
Clinical Context and Test Purpose
The purpose of using thermography in patients undergoing breast cancer screening or diagnosis is to inform decisions on diagnosis and treatment.

The question addressed in this portion of the evidence review is: Does thermography when used to screen or diagnose breast cancer improve the net health outcome compared with standard mammographic techniques? Specifically, does the use of thermography improve diagnostic accuracy compared with standard screening mammography methods and is this increase in accuracy likely to improve health outcomes by leading to earlier diagnosis and treatment?

The following PICO was used to select literature to inform this review.

Populations
The relevant populations of interest are asymptomatic individuals being screened for breast cancer or individuals undergoing testing to diagnose breast cancer.

Interventions
The intervention of interest is thermography.

Comparators
The following test is currently being used to make decisions about breast cancer diagnosis: mammography.

Outcomes
The outcome of interest for diagnostic accuracy is test validity (ie, sensitivity, specificity). The primary outcomes of interest for clinical utility are overall survival and breast cancer-specific survival rates.

The potential beneficial outcomes of primary interest in the case of a true-negative would be the avoidance of unnecessary surgery and associated consequences (e.g., morbidity, mortality, resource utilization, patient anxiety). The potential harms from a false-positive could be inappropriate assessment and improper management of patients with breast malignancies, which could result in the following: inappropriate surgical decisions, high frequency of unnecessary further testing, and unnecessary patient anxiety. The potential harms from a false-negative could be a determination that the patient does not have malignancy, which would lead to a delay in surgery and tumor diagnosis.

The timing for routine screening can be guided by national guidelines on breast cancer screening. The timing for diagnosis would be after an initial screening test or clinical examination.

Study Selection Criteria
For the evaluation of clinical validity of thermography for breast cancer, studies that meet the following eligibility criteria were considered:

• Reported on the accuracy of the marketed version of the technology (including any algorithms used to calculate scores)
• Included a suitable reference standard
• Patient/sample clinical characteristics were described
• Patient/sample selection criteria were described.

Clinically Valid
A test must detect the presence or absence of a condition, the risk of developing a condition in the future, or treatment response (beneficial or adverse).

Review of Evidence
Systematic Reviews
Several systematic reviews of the published literature on the diagnostic accuracy of thermography were identified. A systematic review by Vreugdenburg et al. (2013) identified 8 studies on thermography for diagnosis of breast cancer that included a valid reference standard (eg, biopsy with histopathologic confirmation).¹ A previous systematic review by Fitzgerald and Berentson-Shaw (2012) identified 6 studies, 1 using thermography for breast cancer screening and the others using thermography to diagnose breast cancer among symptomatic women or those with a positive mammogram.² A summary of the characteristics of clinical validity for these systematic reviews is provided in Table 2. A summary of the clinical validity results is provided in Table 3. Study findings were not pooled due to heterogeneity in data reporting and assessment methodology utilized.

Table 2. Systematic Reviews: Characteristics of Clinical Validity of Thermography in Breast Cancer Screening or Diagnosis

N/A: not available; NR: not reported.
a Note 2 aspects of design: prospective, retrospective or nonconcurrent prospective; sample selection random or consecutive.
b Note other characteristics that could bias or limit relevance such as use of historical data, evolution of technology, or practice setting.

Table 3. Systematic Reviews: Clinical Validity of Thermography in Breast Cancer Screening or Diagnosis

Study; Subgroup Initial N (Range) Final N (Range) Excluded N Prevalence of Condition Clinical Validity Sensitivity Specificity PPVNPV Vreugdenberg et al. (2013)¹

Diagnostic Studies
Several studies have been published since the systematic reviews. Morales-Cervantes et al. (2018) compared the accuracy of automated or manual thermography screening in 206 women scheduled for mammography in Mexico.³ A retrospective study conducted in the U.S. by Neal et al. (2018) assessed outcomes in 38 women referred for further breast imaging following abnormal thermography testing.⁴ Omranipour et al. (2016) compared the accuracy of thermography and mammography in 132 patients in Iran who had breast lesions and were candidates for breast biopsy.⁵ Rassiwala et al. (2014) in India reported on 1008 women being screened for breast cancer.⁶ Summaries of characteristics and results of clinical validity for these diagnostic studies are provided in Tables 4 and 5.

Table 4. Diagnostic Study Characteristics of Clinical Validity of Thermography in Breast Cancer Screening or Diagnosis

BI-RADS: breast imaging reporting and data system; NR: not reported; ΔT: temperature gradient.
a Note 2 aspects of design: prospective, retrospective or nonconcurrent prospective; sample selection random or consecutive.
b Note other characteristics that could bias or limit relevance such as use of historical data, evolution of technology, or practice setting.
c Thermal score is defined as the sum of the surface temperature difference at the site of the lesion compared to that of the contralateral breast and the vascularity score, based on the following scale: 1) absence of vascular patterns; 2) symmetrical or moderate vascular patterns; 3) significant vascular asymmetry; 4) vascular asymmetry extended in at least one-third of breast area.

Table 5. Clinical Validity of Thermography in Breast Cancer Screening or Diagnosis

NA: not applicable; NPV: negative predictive value; NR: not reported; PPV: positive predictive value.
* Clinical validity results for this subgroup must be interpreted with caution as subjects with normal mammograms did not undergo histopathologic reference testing for diagnostic confirmation.
** Clinical validity results for this subgroup must be interpreted with caution as subjects with normal thermograms did not undergo radiologic and histopathologic reference testing for diagnostic confirmation, only clinical assessment.

The diagnostic accuracy of automated thermography in the study by Morales-Cervantes et al. (2018) was 69.9%.³ The authors did not report on the diagnostic accuracy of manual thermography. While automated thermographic screening improved the sensitivity and specificity of the test compared to a manual, qualitative approach, reported values must be interpreted with caution as only patients with positive mammograms were subjected to diagnostic reference testing. Neal et al. (2018) indicated that 95% of patients referred for follow-up imaging evaluation following abnormal thermography testing did not have breast cancer, concluding that conventional breast imaging appears sufficient to manage patients.⁴ According to Omranipour et al. (2016),⁵ the diagnostic accuracy of thermography (67.7%) was lower than for mammography (76.9%; p values not reported). The reported false-negative rate was not accurately calculated in Rassiwala et al. (2014) because women who had normal thermograms only had a clinical examination and did not undergo radiologic and histopathologic reference tests for confirmation, highlighting a major limitation of this study.⁶ For patients with positive or abnormal thermograms, 8 results were considered false-positive. One false-negative was reported, but it is unclear which subgroup this patient belonged to or how this was determined, given that patients with normal thermograms were only assessed with a clinical examination. Tables 6 and 7 display further notable limitations identified in each study. This information is synthesized as a summary of the body of evidence following each table and provides the conclusions on the sufficiency of the evidence supporting the position statement.

Table 6. Study Relevance Limitations: Breast Cancer Screening or Diagnosis

The study limitations stated in this table are those notable in the current review; this is not a comprehensive gaps assessment.
BI-RADS: breast imaging reporting and data system.
a Population key: 1. Intended use population unclear; 2. Clinical context is unclear; 3. Study population is unclear; 4. Study population not representative of intended use.
b Intervention key: 1. Classification thresholds not defined; 2. Version used unclear; 3. Not intervention of interest.
c Comparator key: 1. Classification thresholds not defined; 2. Not compared to credible reference standard; 3. Not compared to other tests in use for same purpose.
d Outcomes key: 1. Study does not directly assess a key health outcome; 2. Evidence chain or decision model not explicated; 3. Key clinical validity outcomes not reported (sensitivity, specificity and predictive values); 4. Reclassification of diagnostic or risk categories not reported; 5. Adverse events of the test not described (excluding minor discomforts and inconvenience of venipuncture or noninvasive tests).
e Follow-Up key: 1. Follow-up duration not sufficient with respect to natural history of disease (true positives, true negatives, false positives, false negatives cannot be determined).

Table 7. Study Design and Conduct Limitations: Breast Cancer Screening or Diagnosis

The study limitations stated in this table are those notable in the current review; this is not a comprehensive gaps assessment.
a Selection key: 1. Selection not described; 2. Selection not random or consecutive (i.e., convenience).
b Blinding key: 1. Not blinded to results of reference or other comparator tests.
c Test Delivery key: 1. Timing of delivery of index or reference test not described; 2. Timing of index and comparator tests not same; 3. Procedure for interpreting tests not described; 4. Expertise of evaluators not described.
d Selective Reporting key: 1. Not registered; 2. Evidence of selective reporting; 3. Evidence of selective publication.
e Data Completeness key: 1. Inadequate description of indeterminate and missing samples; 2. High number of samples excluded; 3. Highbr loss to follow-up or missing data.
f Statistical key: 1. Confidence intervals and/or p values not reported; 2. Comparison with other tests not reported.

Clinically Useful
A test is clinically useful if the use of the results informs management decisions that improve the net health outcome of care. The net health outcome can be improved if patients receive correct therapy, more effective therapy, or avoid unnecessary therapy or testing.

Direct Evidence
Direct evidence of clinical utility is provided by studies that have compared health outcomes for patients managed with and without the test. Because these are intervention studies, the preferred evidence would be from randomized controlled trials (RCTs).

No studies have demonstrated how the results of thermography could be used to enhance the management of breast cancer patients in a manner that would improve their health outcomes.

Chain of Evidence
Indirect evidence on clinical utility rests on clinical validity. If the evidence is insufficient to demonstrate test performance, no inferences can be made about clinical utility.

It is not possible to construct a chain of evidence for clinical utility due to the lack of sufficient evidence that the diagnostic accuracy of thermography is at least as high as mammographic techniques for breast cancer screening and diagnosis.

Section Summary: Breast Cancer Screening or Diagnosis
Systematic reviews of studies evaluating the accuracy of thermography for diagnosing breast cancer found wide ranges of sensitivities and specificities and, where data are available, relatively low diagnostic accuracy compared with mammography. To date, no study has demonstrated that thermography is sufficiently accurate to replace or supplement mammography for breast cancer diagnosis. Moreover, there are no studies on the impact of thermography on patient management or health outcomes for patients with breast cancer.

Musculoskeletal Injuries
Clinical Context and Test Purpose
The purpose of using thermography in patients who have a musculoskeletal injury is to inform a decision whether to proceed to appropriate treatment or not.

The question addressed in this portion of the evidence review is: Does thermography when used to diagnose musculoskeletal injuries, improve the net health outcome compared with standard approaches. Specifically, does the use of thermography improve diagnostic accuracy compared with standard approaches (e.g., clinical examination, imaging with radiography or magnetic resonance imaging), and is this degree of increased accuracy likely to improve health outcomes by leading to earlier diagnosis and treatment?

The following PICO was used to select literature to inform this review.

Populations
The relevant population of interest is individuals with musculoskeletal injuries.

Interventions
The intervention of interest is thermography.

Comparators
The following tests and practices are currently being used to make decisions about musculoskeletal injuries: standard care without imaging and other forms of imaging (e.g., with radiography, magnetic resonance imaging).

Outcomes
The outcomes of interest for diagnostic accuracy include test accuracy and test validity (i.e., sensitivity, specificity). The primary outcomes of interest for clinical utility are a reduction in pain symptoms and improvement in functional ability. The timing would be following a musculoskeletal injury.

Study Selection Criteria
For the evaluation of clinical validity of thermography, studies that meet the following eligibility criteria were considered:

• Reported on the accuracy of the marketed version of the technology (including any algorithms used to calculate scores)
• Included a suitable reference standard
• Patient/sample clinical characteristics were described
• Patient/sample selection criteria were described

Clinically Valid
A test must detect the presence or absence of a condition, the risk of developing a condition in the future, or treatment response (beneficial or adverse).

Review of Evidence
Systematic Reviews
A systematic review by Sanchis-Sanchez et al. (2014) evaluated the literature on thermography for diagnosing musculoskeletal injuries.⁷ Six studies met the eligibility criteria (N = 416); 3 included patients with suspected stress fractures (n = 119) and the remainder addressed other musculoskeletal injuries. Characteristics and results of clinical validity for stress fracture diagnostic studies were reported and summaries are provided in Tables 8 and 9. A systematic review by Vardasca et al. (2019) evaluated the literature on musculoskeletal applications of thermography specific to the arm and forearm. However, the review mainly focused on correlations between skin surface temperatures and physical condition or health recovery monitoring. As diagnostic accuracy data were not extracted or pooled from included studies, this review was not assessed for evidence of clinical validity.

Table 8. Systematic Review: Characteristics of Clinical Validity of Thermography in Musculoskeletal Injury

Table 9. Systematic Review: Clinical Validity of Thermography in Musculoskeletal Injury

Clinically Useful
A test is clinically useful if the use of the results informs management decisions that improve the net health outcome of care. The net health outcome can be improved if patients receive correct therapy, more effective therapy, or avoid unnecessary therapy or testing.

Direct Evidence
Direct evidence of clinical utility is provided by studies that have compared health outcomes for patients managed with and without the test. Because these are intervention studies, the preferred evidence would be from RCTs.

Longitudinal Studies
Côrte et al. (2019) published pilot data from a longitudinal prospective study on the screening and prevention of muscle injuries in 28 professional Brazilian soccer players.8, Players were monitored for musculoskeletal imaging during the 2015-2016 seasons with ultrasound. In the second season, a thermographic monitoring regimen was added twice-weekly 48 hours after matches, and an injury prevention protocol was followed based on the results of thermographic imaging. The number of musculoskeletal injuries was compared for both seasons based on these management protocols. The total number of muscle injuries reported decreased from 11 in 2015 to 4 in 2016 (p = .04). Seven players were on the team roster across both seasons. There was no statistically significant reduction in muscle injury in this subgroup (p = .06). Limitations of this study are addressed in Tables 10 and 11.

Table 10. Study Relevance Limitations: Musculoskeletal Injury

The study limitations stated in this table are those notable in the current review; this is not a comprehensive gaps assessment.
a Population key: 1. Intended use population unclear; 2. Clinical context is unclear; 3. Study population is unclear; 4. Study population not representative of intended use.
b Intervention key: 1. Classification thresholds not defined; 2. Version used unclear; 3. Not intervention of interest.
c Comparator key: 1. Classification thresholds not defined; 2. Not compared to credible reference standard; 3. Not compared to other tests in use for same purpose.
d Outcomes key: 1. Study does not directly assess a key health outcome; 2. Evidence chain or decision model not explicated; 3. Key clinical validity outcomes not reported (sensitivity, specificity and predictive values); 4. Reclassification of diagnostic or risk categories not reported; 5. Adverse events of the test not described (excluding minor discomforts and inconvenience of venipuncture or noninvasive tests).
e Follow-Up key: 1. Follow-up duration not sufficient with respect to natural history of disease (true positives, true negatives, false positives, false negatives cannot be determined).

Table 11. Study Design and Conduct Limitations: Musculoskeletal Injury

The study limitations stated in this table are those notable in the current review; this is not a comprehensive gaps assessment.
a Selection key: 1. Selection not described; 2. Selection not random or consecutive (i.e., convenience).
b Blinding key: 1. Not blinded to results of reference or other comparator tests.
c Test Delivery key: 1. Timing of delivery of index or reference test not described; 2. Timing of index and comparator tests not same; 3. Procedure for interpreting tests not described; 4. Expertise of evaluators not described.
d Selective Reporting key: 1. Not registered; 2. Evidence of selective reporting; 3. Evidence of selective publication.
e Data Completeness key: 1. Inadequate description of indeterminate and missing samples; 2. High number of samples excluded; 3. High loss to follow-up or missing data.
f Statistical key: 1. Confidence intervals and/or p values not reported; 2. Comparison with other tests not reported.
No high-quality or randomized studies have been published that evaluate health outcomes in patients with musculoskeletal injuries who were managed with and without thermography.

Chain of Evidence
Indirect evidence on clinical utility rests on clinical validity. If the evidence is insufficient to demonstrate test performance, no inferences can be made about clinical utility.

It is not possible to construct a chain of evidence for clinical utility due to the lack of sufficient evidence that the diagnostic accuracy of thermography is at least as high as standard techniques for diagnosing musculoskeletal injuries.

Section Summary: Musculoskeletal Injuries
A systematic review of studies on thermography for diagnosing musculoskeletal injuries found moderate levels of accuracy compared with other diagnostic imaging tests. There was a lack of a consistent reference standard. This evidence does not permit conclusions as to whether thermography is sufficiently accurate to replace or supplement standard testing. Moreover, there are insufficient studies on the impact of thermography on patient management or health outcomes for patients with musculoskeletal injuries.

Temporomandibular Joint Disorder
Clinical Context and Test Purpose
The purpose of using thermography in patients who have temporomandibular joint (TMJ) disorder is to inform a decision whether to proceed to appropriate treatment or not.

The question addressed in this portion of the evidence review is: Does thermography when used to diagnose TMJ disorder, improve the net health outcome compared with standard approaches. Specifically, does the use of thermography improve diagnostic accuracy compared with standard approaches (e.g., clinical examination, imaging with radiography or magnetic resonance imaging), and is this degree of increased accuracy likely to improve health outcomes by leading to earlier diagnosis and treatment?

The following PICO was used to select literature to inform this review.

Populations
The relevant population of interest is individuals with TMJ disorder.

Interventions
The intervention of interest is thermography.

Comparators
The following tests and practices are currently being used to make decisions about TMJ disorder: standard clinical examination without imaging, diagnostic scales (e.g., Research Diagnostic Criteria for Temporomandibular Disorders [RDC/TMD], Fonseca Anamnestic Index, Anamnestic Index), and other forms of imaging (e.g., with radiography, arthrotomography, magnetic resonance imaging).

Outcomes
The outcomes of interest for diagnostic accuracy include test accuracy and test validity (i.e., sensitivity, specificity). The primary outcomes of interest for clinical utility are a reduction in pain symptoms and improvement in functional ability.

Study Selection Criteria
For the evaluation of clinical validity of thermography for TMJ disorder, studies that meet the following eligibility criteria were considered:

• Reported on the accuracy of the marketed version of the technology (including any algorithms used to calculate scores)
• Included a suitable reference standard
• Patient/sample clinical characteristics were described
• Patient/sample selection criteria were described

Clinically Valid
A test must detect the presence or absence of a condition, the risk of developing a condition in the future, or treatment response (beneficial or adverse).

Review of Evidence
Systematic Reviews
A systematic review by de Melo et al. (2019) evaluated the diagnostic accuracy of infrared thermography in TMJ disorder.⁹ Nine studies were identified utilizing a variety of comparators. The authors note that while no specific diagnostic tool is currently considered the gold standard for the diagnosis of TMJ disorder, the RDC/TMD diagnostic is commonly used with a reported sensitivity and specificity of 87% and 92%, respectively. Four out of 9 studies utilized RDC/TMD, whereas the remaining studies utilized clinical examination or other methods. Characteristics and results of clinical validity for TMJ disorder diagnostic accuracy in this systematic review are summarized in Tables 12 and 13.

Table 12. Systematic Review: Characteristics of Clinical Validity of Thermography in Temporomandibular Joint Disorder

NR: not reported; RDC/TMD: Research Diagnostic Criteria for Temporomandibular Disorders.
a Note 2 aspects of design: prospective, retrospective or nonconcurrent prospective; sample selection random or consecutive.
b Note other characteristics that could bias or limit relevance such as use of historical data, evolution of technology, or practice setting.

Table 13. Systematic Review: Clinical Validity of Thermography in Temporomandibular Joint Disorder

NPV: negative predictive value; NR: not reported; PPV: positive predictive value.

Clinically Useful
A test is clinically useful if the use of the results informs management decisions that improve the net health outcome of care. The net health outcome can be improved if patients receive correct therapy, more effective therapy, or avoid unnecessary therapy or testing.

Direct Evidence
Direct evidence of clinical utility is provided by studies that have compared health outcomes for patients managed with and without the test. Because these are intervention studies, the preferred evidence would be from RCTs.

No studies have been published that evaluate health outcomes in patients with TMJ disorder who were managed with and without thermography.

Chain of Evidence
Indirect evidence on clinical utility rests on clinical validity. If the evidence is insufficient to demonstrate test performance, no inferences can be made about clinical utility.

It is not possible to construct a chain of evidence for clinical utility due to the lack of sufficient evidence that the diagnostic accuracy of thermography is at least as high as standard techniques for diagnosing TMJ disorder.

Section Summary: Temporomandibular Joint Disorder
A systematic review of studies on thermography for diagnosing TMJ disorder found a wide variation in accuracy compared with other diagnostics. There was a lack of a consistent reference standard. This evidence does not permit conclusions as to whether thermography is sufficiently accurate to replace or supplement standard testing. Moreover, there are no studies on the impact of thermography on patient management or health outcomes for patients with TMJ disorder.

Miscellaneous Conditions
A number of studies have assessed a range of potential thermography applications. To date, no randomized study has examined the impact of thermography on patient management decisions or health outcomes. Examples of other studies on thermography, mainly conducted outside of the U.S., include those evaluating the association between thermographic findings and post-herpetic neuralgia in patients with herpes zoster,^10,11 surgical site healing in patients who underwent knee replacements,¹² predicting pressure ulcers¹³ and pressure ulcer healing,^14,15 post-treatment pain in patients with coccygodynia,¹⁶ evaluation of allergic conjunctivitis,¹⁷ evaluation of burn depth,^18,19 association between thermographic findings and burn treatment,²⁰ detecting cervical lymph node metastasis from oral cavity cancer,²¹ monitoring lesions or inflammation in patients with scleroderma,^22,23 detection of vascular obstruction²⁴ or perforator vessels during surgery,^25,26 diagnosis of lower extremity cellulitis,²⁷ prediction of infrainguinal bypass surgery,²⁸ detection of melanoma,²⁹ detection of contact dermatitis during allergy patch testing,³⁰ diagnosis of acute appendicitis,³¹ and measuring disease activity in patients with rheumatoid arthritis, osteoarthritis, or other rheumatic diseases.^32,33,34,35

Several studies evaluating the clinical validity of thermography to assess potential complications of the diabetic foot have been conducted. Thermographic images of nondiabetic feet, nonulcerated diabetic feet, and ulcerated diabetic feet have been compared.^{36,37,38,39,40} Another study used thermography to diagnose infections in patients admitted with diabetic foot complications.⁴¹ The only study to date to investigate the clinical utility of thermography compared with no thermography assessed diabetic foot ulcer incidence in 110 participants with a history of diabetic neuropathy and foot ulcers.⁴² After 12 months followup, the study found no significant difference between use of monthly thermography versus no thermography and foot ulcer incidence (62% vs. 56%; adjusted odds ratio, 0.55, 95% confidence interval [CI], 0.21 to 1.40) or time to ulcer recurrence (adjusted hazard ratio, 0.67, 95% CI, 0.34 to 1.3).

Section Summary: Miscellaneous Conditions
For most of these potential indications, there are 1 or 2 preliminary studies on each of the indications. Several studies evaluated the clinical validity of thermography in assessing diabetic foot and related complications. For all indications, the studies described temperature gradients or the association between temperature differences and the clinical condition. Due to the small number of studies for each indication, the diagnostic accuracy could not adequately be evaluated. The clinical utility of thermography for these miscellaneous conditions was not investigated in any study.

Summary of Evidence
For individuals who have an indication for breast cancer screening or diagnosis who receive thermography, the evidence includes diagnostic accuracy studies and systematic reviews. Relevant outcomes are overall survival, disease-specific survival, and test validity. Using histopathologic findings compared to the reference standard, a series of systematic reviews of studies have evaluated the accuracy of thermography to screen and/or diagnose breast cancer and reported wide ranges of sensitivities and specificities. To date, no study has demonstrated that thermography is sufficiently accurate to replace or supplement mammography for breast cancer diagnosis. Moreover, there are no studies on the impact of thermography on patient management or health outcomes for patients with breast cancer. The evidence is insufficient to determine that the technology results in an improvement in the net health outcome.

For individuals who have musculoskeletal injuries who receive thermography, the evidence includes diagnostic accuracy studies, a longitudinal prospective study, and a systematic review. Relevant outcomes are test validity, symptoms, and functional outcomes. A systematic review of studies on thermography for diagnosing musculoskeletal injuries found moderate levels of accuracy compared with other diagnostic imaging tests. There is no consistent reference standard. This evidence does not permit conclusions as to whether thermography is sufficiently accurate to replace or supplement standard testing. Moreover, there are no high-quality or randomized studies on the impact of thermography on patient management or health outcomes for patients with musculoskeletal injuries. The evidence is insufficient to determine that the technology results in an improvement in the net health outcome.

For individuals who have TMJ disorder who receive thermography, the evidence includes a systematic review. Relevant outcomes are test validity, symptoms, and functional outcomes. A systematic review of studies on thermography for diagnosing TMJ disorder found a wide variation in accuracy compared to other diagnostics. There is no consistent reference standard. The evidence does not permit conclusions as to whether thermography is sufficiently accurate to replace or supplement standard testing. Moreover, there are no studies on the impact of thermography on patient management or health outcomes for patients with the TMJ disorder. The evidence is insufficient to determine that the technology results in an improvement in the net health outcome.

For individuals who have miscellaneous conditions (e.g., herpes zoster, pressure ulcers, diabetic foot) who receive thermography, the evidence primarily includes diagnostic accuracy studies. Outcomes in these studies are test validity, symptoms, and functional outcomes. Most studies assessed temperature gradients or the association between temperature differences and the clinical condition. Due to the small number of studies for each indication, diagnostic accuracy could not adequately be evaluated. The clinical utility of thermography has only been considered in a single study of diabetic foot ulcers. For other miscellaneous conditions, the clinical utility of thermography has not been investigated. The evidence is insufficient to determine that the technology results in an improvement in the net health outcome.

The purpose of the following information is to provide reference material. Inclusion does not imply endorsement or alignment with the evidence review conclusions.

Practice Guidelines and Position Statements
Guidelines or position statements will be considered for inclusion in Supplemental Information if they were issued by, or jointly by, a U.S. professional society, an international society with U.S. representation, or National Institute for Health and Care Excellence (NICE). Priority will be given to guidelines that are informed by a systematic review, include strength of evidence ratings, and include a description of management of conflict of interest.

European Society of Breast Imaging
A position paper by the European Society of Breast Imaging (2017) and 30 other national breast radiology bodies on screening for breast cancer stated that "screening with thermography or other optical tools as alternatives to mammography is discouraged."[Sardanelli F, Aase HS, Alvarez M, et al. Position ... 7(7): 2737-2743. PMID 27807699]

American College of Physicians
The American College of Physicians (2019) issued a guidance statement for breast cancer screening in average-risk women that reviews existing screening guidelines. While the use of thermography was not mentioned in this statement, the authors concluded that evidence is insufficient to understand the benefits and harms of primary or adjunctive screening strategies in women who are found to have dense breasts on screening mammography.⁴³

American College of Radiology
The American College of Radiology guidelines for breast cancer screening (revised 2017) do not mention the use of thermography for breast cancer screening.⁴⁴

National Comprehensive Cancer Network
National Comprehensive Cancer Network guideline on breast cancer screening and diagnosis (v.1.2022 ) states that: "Current evidence does not support the routine use of thermography as screening procedures."⁴⁵

U.S. Preventive Services Task Force Recommendations
The U.S. Preventive Services Task Force (2016) recommendations on breast cancer screening (currently undergoing an update) do not mention thermography. Additionally, there is insufficient evidence for the use of adjunctive screening methods for breast cancer (ultrasonography, magnetic resonance imaging, digital breast tomosynthesis, or other methods) in women identified to have dense breasts on a negative screening mammogram.⁴⁶

Ongoing and Unpublished Clinical Trials
Some currently ongoing and unpublished trials that might influence this review are listed in Table 14.

Table 14. Summary of Key Trials

NCT: national clinical trial.

References: 

1. Vreugdenburg TD, Willis CD, Mundy L, et al. A systematic review of elastography, electrical impedance scanning, and digital infrared thermography for breast cancer screening and diagnosis. Breast Cancer Res Treat. Feb 2013; 137(3): 665-76. PMID 23288346
2. Fitzgerald A, Berentson-Shaw J. Thermography as a screening and diagnostic tool: a systematic review. N Z Med J. Mar 09 2012; 125(1351): 80-91. PMID 22426613
3. Morales-Cervantes A, Kolosovas-Machuca ES, Guevara E, et al. An automated method for the evaluation of breast cancer using infrared thermography. EXCLI J. 2018; 17: 989-998. PMID 30564079
4. Neal CH, Flynt KA, Jeffries DO, et al. Breast Imaging Outcomes following Abnormal Thermography. Acad Radiol. Mar 2018; 25(3): 273-278. PMID 29275941
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12. Romano CL, Logoluso N, Dell'Oro F, et al. Telethermographic findings after uncomplicated and septic total knee replacement. Knee. Jun 2012; 19(3): 193-7. PMID 21441031
13. Oliveira AL, Moore Z, O Connor T, et al. Accuracy of ultrasound, thermography and subepidermal moisture in predicting pressure ulcers: a systematic review. J Wound Care. May 02 2017; 26(5): 199-215. PMID 28475447
14. Nakagami G, Sanada H, Iizaka S, et al. Predicting delayed pressure ulcer healing using thermography: a prospective cohort study. J Wound Care. Nov 2010; 19(11): 465-6, 468, 470 passim. PMID 21135794
15. Bilska A, Stangret A, Pyzlak M, et al. Skin surface infrared thermography in pressure ulcer outcome prognosis. J Wound Care. Dec 02 2020; 29(12): 707-718. PMID 33320753
16. Wu CL, Yu KL, Chuang HY, et al. The application of infrared thermography in the assessment of patients with coccygodynia before and after manual therapy combined with diathermy. J Manipulative Physiol Ther. May 2009; 32(4): 287-93. PMID 19447265
17. Hara Y, Shiraishi A, Yamaguchi M, et al. Evaluation of allergic conjunctivitis by thermography. Ophthalmic Res. 2014; 51(3): 161-6. PMID 24603108
18. Singer AJ, Relan P, Beto L, et al. Infrared Thermal Imaging Has the Potential to Reduce Unnecessary Surgery and Delays to Necessary Surgery in Burn Patients. J Burn Care Res. Nov/Dec 2016; 37(6): 350-355. PMID 26720102
19. Dang J, Lin M, Tan C, et al. Use of Infrared Thermography for Assessment of Burn Depth and Healing Potential: A Systematic Review. J Burn Care Res. Jun 12 2021. PMID 34120173
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26. Chen R, Huang ZQ, Chen WL, et al. Value of a smartphone-compatible thermal imaging camera in the detection of peroneal artery perforators: Comparative study with computed tomography angiography. Head Neck. May 2019; 41(5): 1450-1456. PMID 30636085
27. Li DG, Dewan AK, Xia FD, et al. The ALT-70 predictive model outperforms thermal imaging for the diagnosis of lower extremity cellulitis: A prospective evaluation. J Am Acad Dermatol. Dec 2018; 79(6): 1076-1080.e1. PMID 30003987
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47. Centers for Medicare & Medicaid Services (CMS). National Coverage Determination for Thermography (220.11). 1992; https://www.cms.gov/medicare-coverage-database/details/ncd-details.aspx?NCDId = 164&ncdver = 1&DocID = 220.11. Accessed July 12, 2022.

Coding Section

Procedure and diagnosis codes on Medical Policy documents are included only as a general reference tool for each policy. They may not be all-inclusive.

This medical policy was developed through consideration of peer-reviewed medical literature generally recognized by the relevant medical community, U.S. FDA approval status, nationally accepted standards of medical practice and accepted standards of medical practice in this community, Blue Cross Blue Shield Association technology assessment program (TEC) and other nonaffiliated technology evaluation centers, reference to federal regulations, other plan medical policies, and accredited national guidelines.

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