Positron Emission Tomography Scanner Technology

CMS NCA document | source_status=Closed | review_type=New | public_comment_open=False | document_id=CAG-00090N

CMS’s December 15, 2000 decision memorandum was based on clinical data collected in patients using the full-ring systems with BGO crystals that were in service in the late 1990’s. CMS’s conclusion that FDG-PET is a reasonable and necessary service for the indications reviewed in the December 15, 2000 memorandum was therefore based on the imaging performance of full-ring systems compared to conventional imaging. Our review of all available published studies on gamma camera PET systems demonstrates that these devices perform as well as full-ring PET scanners for moderate and large lesions, but may not detect a significant percentage of smaller lesions (approximately 2 cm or less). In addition, available studies do not clearly show that gamma camera imaging can replace or add to the diagnostic information provided by conventional imaging. Newer gamma camera systems may have improved performance, but no clinical data are available on these most recently released systems. Studies used for FDA approval of gamma cameras were based on images produced by “phantoms” or artificial lesions, and therefore do not allow conclusions to be drawn about the clinical utility of these systems for specific clinical applications. Given this body of scientific information, gamma camera PET, even those systems with crystals at least 1-inch in thickness, will not be covered for the clinical indications which are newly-covered, based upon the December 15, 2000 decision memorandum. In addition, for those indications already covered prior to the December 15, 2000 decision memorandum, PET imaging must be performed on either FDA-approved full- or partial-ring scanners, or coincidence systems that have the following features: Crystal at least 5/8-inch thick Techniques to minimize or correct for scatter and/or randoms Digital detectors and iterative reconstruction Scans performed with gamma camera PET systems with crystals thinner than 5/8-inch will NOT be covered. In addition, scans performed with systems with crystals greater than or equal to 5/8-inch in thickness, which do not meet the other listed design characteristics, are NOT covered. CMS will formally reconsider these limitations on coverage for gamma cameras after December 31, 2002. Coverage would be provided for gamma cameras 1) if these systems can demonstrate performance equivalent to or better than the full-ring PET systems for which data was submitted in support of the December 15, 2000 decision memorandum; or 2) if their clinical utility is demonstrated by adequate clinical studies showing that the gamma camera provides diagnostic information that adds to or replaces information provided by conventional imaging. In the absence of such evidence, CMS will consider withdrawing all coverage for gamma camera systems. CMS is aware of the standards for PET performance measurement recently released by NEMA, called the NU 2-2001 standards. These standards may provide a mechanism for comparing the performance of PET systems with different design features. CMS will work with representatives of industry and the academic community over the next 18 months to explore whether these measurement standards could be reliably used to compare the performance of different PET systems.