Frequently Asked Questions

What are the approved clinical indications for PET?

PET scans have been approved for reimbursement under Medicare for the following:

Clinical Condition
Coverage – is subject to additional guidelines set forth below and in the conditions and requirements of the CMS National Coverage Determination described below.
Breast Cancer* Staging, re-staging, and monitoring response to therapy
Colorectal Cancer Diagnosis, staging and re-staging
Esophageal Cancer Diagnosis*, staging* and restaging*
Head & Neck Cancers
(excluding CNS and thyroid)
Diagnosis*, staging* and restaging*
Lung Cancer
(Non-Small Cell)
Diagnosis*, staging* and restaging*
Lymphoma Diagnosis*, staging* and restaging*
(Excludes evaluation of regional nodes)
Diagnosis*, staging* and restaging*
Myocardial Viability* Primary or initial diagnosis, or following an inconclusive SPECT prior to revascularization*
Refractory Seizures


Covered for pre-surgical evaluation only
Solitary Pulmonary Nodule Characterization of indeterminate single pulmonary nodule
Thyroid Cancer* Restaging
Cervical Cancer* Staging as an adjunct to conventional imaging
Dementia Differential diagnosis of fronto-temporal dementia (FTD) and Alzheimer’s disease (AD) – or – CMS approved practical clinical trial
Clinical Condition
Coverage – is subject to additional guidelines set forth below and in the conditions and requirements of the CMS National Coverage Determination described below
Perfusion of the heart using Rubidium 82** tracer* Covered for noninvasive imaging of the perfusion of the heart*
Perfusion of the heart using ammonia N-13** tracer* Covered for noninvasive imaging of the perfusion of the heart*

* Not FDG

Approved Under the Following Conditions:

For all uses of PET relating to malignancies the following conditions apply:

*Diagnosis: PET is covered only in clinical situations in which: (1) the PET results may assist in avoiding an invasive diagnostic procedure, or in which, (2) the PET results may assist in determining the optimal anatomical location to perform an invasive diagnostic procedure. In general, for most solid tumors, a tissue diagnosis is made prior to the performance of PET scanning. PET scans following a tissue diagnosis are generally performed for staging rather than diagnosis.

PET is not covered as a screening test (i.e. testing of patients without specific signs and symptoms of disease).

*Staging: PET is covered for staging in clinical situations in which: (1)(a) the stage of the cancer remains in doubt after completion of a standard diagnostic workup, including conventional imaging (computed tomography(CT), magnetic resonance imaging(MRI), or ultrasound), or (1)(b) if it could potentially replace one or more conventional imaging studies when it is expected that conventional study information is insufficient for the clinical management of the patient; and (2) clinical management of the patient would differ depending on the stage of the cancer identified.

*Restaging: PET is covered for restaging: (1) after completion of treatment for the purpose of detecting residual disease, (2) for detecting suspected recurrence or metastasis, (3) to determine the extent of a known recurrence, or (4) if it could potentially replace one or more conventional imaging studies when it is expected that conventional study information is insufficient for the clinical management of the patient. Restaging applies to testing after a course of treatment is completed, and is covered subject to the conditions above.

Monitoring: This refers to the use of PET to monitor tumor response to treatment during the planned course of therapy (i.e., when a change in therapy is anticipated)

*Breast Cancer: Medicare covers FDG PET as an adjunct to standard imaging modalities for staging patients with distant metastasis, or restaging patients with locoregional recurrence or metastasis. Monitoring treatment of a breast cancer tumor when a change in therapy is contemplated is also covered as an adjunct to other imaging modalities.

*Thyroid Cancer: Medicare covers the use of FDG PET for thyroid cancer only for restaging of recurrent or residual thyroid cancers of follicular cell origin that have been previously treated by thyroidectomy and radioiodine ablation and have a serum thyroglobulin >10ng/ml and negative I-131 whole body scan performed.

*Myocardial Viability: Medicare covers FDG PET for the determination of myocardial viability as a primary or initial diagnostic study prior to revascularization, or following an inconclusive SPECT. SPECT may not be used following an inconclusive PET scan.

*Cervical: Medicare covers FDG-PET as an adjunct test for the detection of pre-treatment metastases (i.e. staging) in newly diagnosed cervical cancer subsequent to conventional imaging that is negative for extra-pelvic metastasis.

*Dementia: Medicare covers FDG-PET scans for either the differential diagnosis of fronto-temporal dementia (FTD) and Alzheimer’s disease (AD) under specific requirements. Medicare has established specific requirements for coverage of the differential diagnosis of FTD and AD. These requirements are detailed in the NCD for Dementia and Neurodegenerative Diseases (220.6.1) and summarized in the attached Coverage Policy document and the PET Request Form below.

Alzheimer’s Coverage Policy
Alzheimer’s PET Request Form

*Myocardial Perfusion: PET scans performed at rest or stress (exercise or pharmacological)used for noninvasive imaging of the perfusion of the heart for the diagnosis and management of patients with known or suspected coronary artery disease using the FDA-approved radiopharmaceutical Ammonia N-13 or Rubidium 82 (Rb 82).

General Conditions: Regardless of any other terms or conditions, all uses of FDG PET scans, in order to be covered by the Medicare program, must meet the following general conditions as of July 1,2001:

  1. The provider of the PET scan should maintain on file the doctor’s referral and documentation that the procedure involved only FDA approved drugs and devices, as is normal business practice.
  2. The ordering physician is responsible for documenting the medical necessity of the study and that it meets the conditions specified in the instructions. The physician should have documentation in the beneficiary’s medical record to support the referral to the PET scan provider.

National Coverage
PET scans are covered by the Centers for Medicare and Medicaid Services (CMS), Medicare, for specific clinical conditions under a National Coverage Determination (NCD)*. The specific coverage criteria are available on the CMS web site for reference. (1) (2)

* What is a National Coverage Determination (NCD)?

“CMS makes NCDs granting, limiting, or excluding Medicare coverage for a specific medical service, procedure, or device. NCDs are made under section 1862(a) (1) of the Social Security Act (the Act) or other applicable provisions of the Act. The national coverage decisions apply nationwide and are binding on all Medicare carriers, fiscal intermediaries, quality improvement organizations, health maintenance organizations, competitive medical plans, and health care prepayment plans for purposes of Medicare coverage.”

NCD for Positron Emission Tomography (PET) Scans (220.6)
To view the entire NCD on the CMS website go to the link below

Or view the PET sections as a .pdf below
National Coverage Determination (PET sections only)

This information provided by CTI PETNET is based on published guidelines and on our experience, and is provided for general information only, as a service and at no charge to our customers. It is based on information found in published CMS National Coverage documents, but is not all-inclusive. We believe that the information set forth herein is generally accurate; however, we cannot provide assurance that it is complete, accurate or current. Always check with your local insurance carriers, as coverage may vary by region. The referring physician is responsible for pre-authorization and providing proof of medical necessity for any PET scan. CTI PETNET and its representatives hereby expressly disclaim any and all liability for claims, including bodily injury or death, arising from any reliance on the information set forth herein.


What is SUV?

SUV stands for standard uptake value. It is a way to normalize results across patients and in the same patient between scans. In normal muscle tissue the SUV is about 1.0. In liver it is about 2.0. It tumors it can range from 1-50. Click here for more information.


What is the normal distribution of FDG?

Shreve et al (1999) wrote an excellent review article on that topic in Radiographics.


How do I order a PET scan?

Please contact us to schedule your patient’s PET scans. We will assist you with forms and billing codes.


How and when will I get the PET scan results?

  • You may access your patient’s reports and PET/CT scans online by logging into PETLinQ. Please contact us to get an account on PETLinQ.
  • You can also receive a report and printed PET image delivered to your office within 24-48 hours.