Positron Emission Tomography (PET) Scans, Miscellaneous Applications

Medical Policy: 06.01.12 
Original Effective Date: June 2004 
Reviewed: November 2011 
Revised: April 2008 

Benefit Application
Benefit determinations are based on the applicable contract language in effect at the time the services were rendered. Exclusions, limitations or exceptions may apply. Benefits may vary based on contract, and individual member benefits must be verified. Wellmark determines medical necessity only if the benefit exists and no contract exclusions are applicable. This medical policy may not apply to FEP. Benefits are determined by the Federal Employee Program.

This Medical Policy document describes the status of medical technology at the time the document was developed. Since that time, new technology may have emerged or new medical literature may have been published. This Medical Policy will be reviewed regularly and be updated as scientific and medical literature becomes available.

Description: 

Positron Emission Tomography (PET) measures the level of metabolic activity and perfusion of radioactive chemicals in various organs or organ systems of the body. Radiopharmaceuticals are introduced into the body by intravenous injection or inhalation. PET scanners produce computerized mathematical models of physiologic functions and use tracer kinetics to generate images.

PET results may assist in avoiding an invasive diagnostic procedure, or the results may assist in determining optimal anatomic location to perform a diagnostic procedure.

Research continues on efforts to use PET to identify Alzheimer’s disease and differentiate it from other types of dementia, with much of it focusing on alternative radiotracers to PET. In particular, there is interest in amyloid PET tracers because beta amyloid is the principal component of Alzheimer’s disease plaques in the brain. 

One of the challenges in evaluating the use of PET to distinguish among dementias is to identify what serves as the reference standard. The sensitivity of clinical diagnosis has been documented to vary between 75% and 98%, with an average of 82%. Therefore, comparing PET results to clinical diagnosis can be confounded by the fact that the clinical diagnosis itself may not be accurate.

Another research interest is the potential use of PET scan results as a biomarker for progression to Alzheimer’s disease. It is difficult to evaluate treatments that may prevent or delay the onset of dementia in individuals with mild cognitive impairment because a relatively small number of study participants will progress to Alzheimer’s disease during the follow up period. A 2011 study by Herholz et al in the United Kingdom used a previously devised quantitative PET score to evaluate disease progression; a software program was available to calculate the score. This prospective study included 94 patients with mild cognitive impairment (MCI), 40 patients with mild Alzheimer’s disease and 44 healthy controls. Participants received 4 PET scans and clinical assessments over 2 years. By the 2-year follow-up, 30 of 94 (32%) had progressed to MCI, 7 (7%) reverted to normal cognitive function and 57 (61%) remained mildly cognitively impaired. Two of 44 (4.5%) healthy controls had progressed to MCI. All of the individuals with Alzheimer’s disease at baseline remained in that category. The proportion of patients with abnormal PET scores at baseline was 85% in the Alzheimer’s group, 40% in the MCI group and 11% in the control group. An abnormal PET score at baseline had a sensitivity to predict disease progression of 0.57 and a specificity of 0.67. The area under the receiver-operating characteristic (ROC) curve was 0.75 for PET scores. Areas under the ROC curve for predicting disease progression for the outcome measures Mini-Mental State Examination (MMSE) and the Alzheimer’s Disease Assessment Scale-Cognitive (ADAS-cog), were 0.66 and 0.68 respectively. Conclusions about the utility of using this PET score in clinical practice cannot be drawn from the Herholz study.

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Prior Approval: 

Not applicable

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Policy: 

PET scan may be considered medically necessary to identify or localize seizure foci in patients undergoing evaluation for neurosurgical treatment of epilepsy.

PET scan may be considered medically necessary in the diagnosis of chronic osteomyelitis.

• Autoimmune disorders with or without CNS manifestations, including:
  • Behçet’s syndrome
  • lupus erythematosus
• Cerebrovascular diseases, including:
  • arterial occlusive disease (arteriosclerosis, atherosclerosis)
  • carotid artery disease
  • cerebral aneurysm
  • cerebrovascular malformations (AVM and Moya Moya disease)
  • hemorrhage
  • infarct
  • ischemia
• Degenerative motor neuron disease, including:
  • Tourette syndrome
  • Parkinson disease
  • amyotrophic lateral sclerosis
  • Friedreich’s ataxia
  • olivopontocerebellar atrophy
  • progressive supranuclear palsy
  • Shy-Drager syndrome
  • spinocerebellar degeneration
  • Steele-Richardson-Olszewski disease
• Dementias, including but not limited to:
  • Alzheimer's disease
  • Pick syndrome
  • multi-infarct dementia
  • frontotemporal dementia
  • Lewy Body dementia
  • presenile dementia
• Demyelinating diseases, including
  • Multiple Sclerosis
• Developmental, congenital, or inherited disorders, including:
  • adrenoleukodystrophy
  • Down’s syndrome
  • Huntington’s chorea
  • Menkes’ syndrome
  • Sturge-Weber syndrome (encephalofacial angiomatosis) and the phakomatoses
• Nutritional or metabolic diseases and disorders, including:
  • acanthocytes
  • hepatic encephalopathy
  • hepatolenticular degeneration
  • metachromatic  leukodystrophy
  • mitochondrial disease
  • subacute necrotizing encephalomyelopathy
• Psychiatric diseases and disorders, including:
  • affective disorders
  • depression
  • obsessive-compulsive disorder
  • psychomotor disorders
  • post-traumatic stress disorder
  • schizophrenia
• Pyogenic infections, including:
  • Aspergillosis
  • encephalitis
• Substance abuse, including the CNS effects of alcohol, cocaine, and heroin
• Viral infections, including:
  • acquired immune deficiency syndrome (AIDS)
  • AIDS dementia complex
  • Creutzfeldt-Jakob syndrome
  • progressive multifocal leukoencephalopathy
  • progressive rubella encephalopathy
  • subacute sclerosing panencephalitis
• Migraine headache
• Musculoskeletal diseases
  • Spondylodiscitis
  • Joint replacement follow-up
• Pulmonary diseases, including:
  • adult respiratory distress syndrome (ARDS)
  • diffuse panbronchiolitis
  • emphysema
  • obstructive lung disease
  • pneumonia
• Vegetative versus “locked-in”state
• Other not identified above, including but not limited to:
  • Giant cell arteritis
  • vasculitis
  • chronic fatigue syndrome
  • sick-building syndrome
  • cerebral blood flow in newborns

There is insufficient evidence on the value of PET for the above indications. Studies are needed that demonstrate PET will result in a change in management that will improve patient outcomes in order to determine that it is a clinically useful test.

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Procedure Codes and Billing Guidelines: 

• To report provider services, use appropriate CPT* codes, Modifiers, Alpha Numeric (HCPCS level 2) codes, Revenue codes, and/or ICD-9 diagnostic codes.
• 78608 brain imaging, positron emission tomography (PET); metabolic evaluation 
• 78609 brain imaging, positron emission tomography (PET); perfusion evaluation
• 78811 Positron emission tomography (PET) imaging; limited area (eg, chest, head/neck)
• 78812 Positron emission tomography (PET) imaging; skull base to mid-thigh
• 78813 Positron emission tomography (PET) imaging; whole body
• 78814 Positron emission tomography (PET) with concurrently acquired computed tomography (CT) for attenuation correction and anatomical localization imaging; limited area (eg, chest, head/neck)
• 78815 Positron emission tomography (PET) with concurrently acquired computed tomography (CT) for attenuation correction and anatomical localization imaging; skull base to mid-thigh
• 78816 Positron emission tomography (PET) with concurrently acquired computed tomography (CT) for attenuation correction and anatomical localization imaging; whole body
• A9526 Nitrogen N-13 ammonia, diagnostic, per study dose, up to 40 millicuries        
• A9552 Fluorodeoxyglucose F-18 FDC, diagnostic, per study does, up to  45 millicuries
• A9580 Sodium fluoride F-18, diagnostic, per study dose, up to 30 millicuries  

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Selected References: 

• Tai YF, Piccini P. Applications of positron emission tomography (PET) in neurology. J Neurol Neurosurg Psychiatry. 2004 May; 75(5):669-76.
• Sandrini G, Friberg L, Janig W, et al. Neurophysiological tests and neuroimaging procedures in non-acute headache: guidelines and recommendations. Eur J Neurol. 2004 Apr; 11(4):217-24.
• Murphy MA, O'Brien TJ, Morris K, Cook MJ. Multimodal image-guided surgery for the treatment of medically refractory epilepsy. J Neurosurg. 2004 Mar; 100(3):452-62.
• Jahasz C, Chugani HT. Imaging the epileptic brain with positron emission tomography. Neuroimaging Clin N Am. 2003 Nov; 13(4):705-16, viii.
• Alavi A, Gupta N, Alberini JL, et al. Positron emission tomography imaging in nonmalignant thoracic disorders. Semin Nucl Med. 2002 Oct;32(4):293-321.
• Latchaw RE, Yonas H, Hunter GJ et al. Guidelines and recommendations for perfusion imaging in cerebral ischemia: a scientific statement for healthcare professionals by the Writing Group on Perfusion Imaging from the Council on Cardiovascular Radiology of the American Heart Association. Stroke 2003; 34(4): 1084-104.
• Parsey RV, Mann JJ. Applications of positron emission tomography in psychiatry. Semin Nucl Med 2003; 33(2):129-35.
• Strobel K, Strumpe KD. PET/CT in musculoskeletal infection. Semin Muscoloskelet Radiol. 2007 Dec;11(4):353-64.
• Kumar R, Basu S, Torigian D et al. Role of modern imaging techniques for diagnosis of infection in the era of 18F-fluorodeoxyglucose positron emission tomography. Clin Microbiol Rev. 2008 Jan;21(1):209-24.
• Bleeker-Rovers CP, Vos FJ, Corstens FH, et al. Imaging of infectious diseases using [18F] fluorodeoxyglucose PET. Q J Nucl Med Mol Imaging. 2008 Mar;52(1):17-29.
• Hartmann A, Eid K, Dora C et al. Diagnostic value of 18F-FDG PET/CT in trauma patients with suspected chronic osteomyelitis. Eur J Nucl Med Mol Imaging. 2007 May;34(5):704-14. Epub 2006 Nov 29.
• Berti V, Osorio RS, Mosconi L et al. Early detection of Alzheimer’s disease with PET imaging. Neurodegener Dis. 2010;7(1-3): 131-5. Epub 2010 Mar 3.
• Durand-Martel P, Tremblay D, Brodeur C et al. Autopsy as gold standard in FDG-PET studies in dementia. Can J Neurol Sci 2010;37(3):336-42.
• Mosconi L. Mistur R, Switalski R et al. FDG-PET changes in brain glucose metabolism from normal cognition to pathologically verified Alzheimer’s disease. Eur J Nucl Med Mol Imaging. 2009 May;36(5):811-22. Epub 2009 Jan 14.
• Li Y, Rinne JO, Mosconi L et al. Regional analysis of FDG and PIB-PET images in normal aging, mild cognitive impairment, and Alzheimer’s disease. Eur J Nucl Med Mol Imaging. 2008 Dec;35(12):2169-81. Epub 2008 Jun 20.
• Mosconi L, berti V, Glodzik L et al. Pre-clinical detection of Alzheimer’s disease using FDG-PET, with or without amyloid imaging. J Alzheimers Dis 2010; 20(3):843-54.
• Basu S, Zhuang H, Torigian DA et al. Functional imaging of inflammatory diseases using nuclear medicine techniques. Semin Nucl Med 2009;39(2):124-45.
• Meller J, Sahlmann CO, Gurocak O et al. FDG-PET in patients with fever of unknown origin: the importance of diagnosing large vessel vasculitis. Q J Nucl Med Mol Imaging 2009; 53(1):51-63.
• Herholz K, Westwood S, Haense C et al. Evaluation of a calibrated (18) F-FDG PET score as a biomarker for progression in Alzheimer disease and mild cognitive impairment. J Nucl Med. 2001 Aug; 52(8):1218-26. Epub 2011 Jul 15.
• Clark CM, Schneider JA, Bedell BJ et al. Use of Florbetapir-PET for imaging β-amyloid pathology. JAMA 2011 Janu 19; 305(3):275-83.
• Kiferle L, Politis M, Muraro PA et al. Positron emission tomography imaging in multiple sclerosis-current status and future applications. Eur J Neurol 2011; 18(2):226-31.
• Treglia G, Mattoli MV, Leccisotti L et al. Usefulness of whole-body fluorine-18-fluorodeoxyglucose positron emission tomography in patients with large-vessel vasculitis: a systematic review.
• Lehmann P, Buchtala S, Achajew N et al. 18F-FDG PET as a diagnostic procedure in large vessel vasculitis-a controlled, blinded re-examination of routine PET scans. Clin Rheumatol. 2011 Jan; 30(1):37-42. Epub 2010 Oct 23.
• Albert MS, DeKosky ST, Dickson D et al. The diagnosis of mild cognitive impairment due to Alzheimer’s disease: recommendations from the National Institute on Aging-Alzheimer’s Association workgroups on diagnostic guidelines for Alzheimer’s disease. Alzheimers Dement. 2011 May; 7(3):270-9. Epub 2011 Apr 21. 

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Policy History: 

Date                                         Reason                              Action

November 2010                      Annual review                    Policy renewed

November 2011                      Annual review                    Policy renewed

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Wellmark medical policies address the complex issue of technology assessment of new and emerging treatments, devices, drugs, etc.   They are developed to assist in administering plan benefits and constitute neither offers of coverage nor medical advice. Wellmark medical policies contain only a partial, general description of plan or program benefits and do not constitute a contract. Wellmark does not provide health care services and, therefore, cannot guarantee any results or outcomes. Participating providers are independent contractors in private practice and are neither employees nor agents of Wellmark or its affiliates. Treating providers are solely responsible for medical advice and treatment of members. Our medical policies may be updated and therefore are subject to change without notice.

*Current Procedural Terminology © 2010 American Medical Association. All Rights Reserved.