All eligibility criteria and coverage guidelines that apply to PET studies will also apply to PET/CT fusion imaging based on the anatomic area imaged. This policy focuses on PET/CT fusion imaging in diagnosing and treating various malignancies. For information on PET imaging as the sole imaging modality for oncologic applications, refer to Medical Policy Bulletin R-9.

All eligible diagnosis codes for covered PET studies will also apply to PET/CT fusion imaging. PET/CT fusion imaging reported with a diagnosis code other than those listed as eligible will be denied as not medically necessary. A participating, preferred, or network provider cannot bill the member for the denied service.

Codes 78814-78816 represent the concurrent acquisition of PET and CT imaging data on a hybrid scanner. The CT component of these codes refers to limited CT acquisition for attenuation correction and anatomic localization. As such, the CT component of the test is considered to be of non-diagnostic quality.

Separate diagnostic CT studies should not be reported with the PET/CT codes (78814-78816) unless medically necessary and ordered by the referring physician. Similarly, if a PET scan is performed with a full diagnostic quality CT scan, both services may be reported separately, using the appropriate PET and CT codes.

Guidelines for PET/CT performed with or without a separate distinct diagnostic CT

Example A:
The referring physician orders a PET/CT study and a diagnostic CT scan requiring a separate and distinct CT acquisition (image data set). These studies should be reported as PET/CT (78814-78816) and the appropriate separate diagnostic CT code.

Example B:
The referring physician orders a PET/CT study. If this leads to a suspicious finding requiring further study, the radiologist may obtain an order from the referring physician for an additional diagnostic CT scan. It is appropriate to report PET/CT (78814-78816) and the full diagnostic CT study separately.

Example C:
In some cases when a PET/CT scan and a separate diagnostic CT study are ordered, it may be possible to use the diagnostic CT data set for the attenuation correction and anatomic localization portion of the PET/CT study. When the physician is interpreting a diagnostic CT and the attenuation plus anatomic localization from the same CT data set, the studies may be reported as a distinct and separate PET scan (78811-78813) in addition to a separate diagnostic CT study.

Description

Multi-modality image co-registration (also known as fusion or co-registered imaging) is useful in certain clinical situations because data acquired from CT and PET studies yields complementary information. In PET/CT fusion imaging, the anatomic information from the CT images is combined or "fused" with the physiologic information obtained from the PET images to localize tumors or lesions especially in regions of complex anatomy, such as in the head, neck, chest, abdomen and pelvis. 

There are two methods of PET/CT co-registered or fusion imaging. One method involves the use of special computer software that combines or "fuses" the anatomic information from previously acquired CT images with the physiologic or functional information obtained from a separate PET study. This software fusion method is more labor intensive and at times unsuccessful, because the patient is imaged by two different modalities during two different imaging sessions. The patient is not in the same position or alignment for both studies or patient movement is different during two separate imaging sessions, including the involuntary and uncontrollable motion of internal organs. 

The other method uses a hybrid PET/CT scanner that takes both PET and CT images at the same imaging session. When compared to PET studies performed alone, the co-registered images of a single combined PET/CT study improves lesion classification and staging performance and reduces scanning time. In this situation, the patient remains positioned on the same bed for both imaging modalities, minimizing both temporal motion and spatial differences between the images acquired. In addition, using the hybrid PET/CT scanning system for both modalities makes the images available for viewing while the patient is still in the scanner.

See Glossary for definitions of PET/CT related terms.

For additional information on CT scans, refer to Medical Policy Bulletin X-3.

For additional information on PET tumor localization, refer to Medical Policy Bulletin R-9.

NOTE:

This policy is designed to address medical guidelines that are appropriate for the majority of individuals with a particular disease, illness, or condition. Each person's unique clinical circumstances may warrant individual consideration, based on review of applicable medical records.

This medical policy may not apply to FEP. Medical policy is not an authorization, certification, explanation of benefits, or a contract. Benefits are determined by the Federal Employee Program.

PET/CT Fusion Proves Its Value, Diagnostic Imaging, Vol. 24, No. 6, June 2002

Staging of Non-small Cell Lung Cancer with Integrated Positron-Emission Tomography and Computed Tomography, The New England Journal of Medicine, Vol. 348, No. 25, June 2003

PET/CT Today and Tomorrow, The Journal of Nuclear Medicine, Vol. 45, No.1 (Suppl), January 2004

Head and neck cancer: clinical usefulness and accuracy of PET/CT image fusion, Radiology, Vol. 231, No. 1, April 2004

Radiology Rounds: A Newsletter for Referring Physicians Massachusetts General Hospital, Department of Radiology, Vol. 2, No. 5, May 2004

PET and PET-CT for evaluation of colorectal carcinoma, Seminars in Nuclear Medicine, Vol. 34, No. 3, July 2004

Image-guided cancer therapy using PET/CT, The Cancer Journal, Vol. 10, No. 4, July-August 2004

Positron emission tomography/computerized tomography functional imaging of esophageal and colorectal cancer, The Cancer Journal, Vol. 10, No. 4, July-August 2004

PET-CT fusion imaging in differentiating physiologic from pathologic FDG uptake, Radiographics, Vol. 24, No. 5, September-October 2004

Eligible Diagnosis Codes by Anatomic Area

Brain

Breast

Colorectal

Esophageal

Gynecological

Head & Neck

Lung

Lymphoma

Melanoma

Pancreas

Thyroid