Cardiac PET has been used as a diagnostic imaging tool for a number of years, but has recently seen an increase in interest among cardiologists. When evaluating a considerable investment, such as Cardiac PET, it’s critical to look beyond the buzz and know for sure if it’s the right choice for your practice. Let’s take a look at Cardiac PET and some ways to see if it makes sense for you and your practice.
The Basics of Cardiac PET
Although most commonly used when imaging certain Oncology patients, PET cameras can potentially be of benefit to cardiologists for a segment of patients needing myocardial perfusion imaging. Supporters of PET MPI suggest higher diagnostic accuracy when compared to SPECT MPI, especially when Attenuation Correction is not available on the SPECT system.
Cardiac PET imaging must be performed on a PET or PET/CT system as SPECT imaging systems cannot image these higher energy agents. Instead of using readily available unit doses of Thallium or Technetium based MPI agents, Cardiac PET utilizes a Rubidium (Rb 82) Generator or an Ammonia (N-13) cyclotron for onsite production of the patient doses. Rubidium generators and Ammonia cyclotrons require a significant and ongoing investment, so a considerable volume of patients is necessary to support the overhead.
The working assumption is that PET MPI can reduce downstream costs by creating less false positives. While reducing false positives can lower costs, the total expense of providing PET MPI testing is considerable to both the practice and the patient.
Benefits of Cardiac PET
Cardiac PET is an excellent tool to diagnose patients who may have CAD. PET MPI benefits patients with a high likelihood of interventional needs because of its ability to calculate estimated blood flow and flow reserve. For patients who fit this profile, data from a PET MPI scan can be used to gauge the potential success of intervention (angioplasty, CABG, etc).
Images from Cardiac PET cameras typically offer excellent clarity and resolution due to the high-count rates and high Kev level of the PET MPI agents. Additionally, PET systems all have Attenuation Correction (either source based or CT based), further increasing reader confidence when interpreting images.
Though Cardiac PET is a useful tool in diagnosing coronary artery disease, a very small percentage of cardiac practices own a PET imaging system. The most recent estimates suggest less than 200 dedicated Cardiac PET facilities are operational in the U.S.
Drawbacks and Risks of Cardiac PET
One of the limiting factors in the growth of Cardiac PET is the cost of offering the modality. PET systems, whether refurbished, used, or new, are significantly more expensive than SPECT systems in terms of purchase price and in terms of ongoing repair, maintenance, and upkeep.
Outside of the known camera costs, the ongoing expenses and consumables are a considerable jump from SPECT. The nature of the radiotracers requires costly, long-term contracts that must be committed to before the first scan is provided.
For practices and hospital systems with the right panel size, Cardiac PET can be a profit center that offers a real benefit to patients. However, for groups that have clinical volume in the gray area, it can be a financial burden.
Because of this dynamic, it’s essential to know what imaging volume is needed to cover your overhead. While vendors may provide a pro forma, they often minimize cost factors, so the decision requires more due diligence as compared to other modalities.
Additionally, there is growing uncertainty about the future of reimbursement for Cardiac PET scans. Today, Medicare does not require prior authorization or pre-certification in order to be reimbursed for performing PET MPI. This stance on PET reimbursement has driven very modest growth over the last 18 months. Most Medicare Advantage plans currently require the same prior authorization or pre-certification for payment as is mandated by private insurance payers. The scrutiny will undoubtedly increase as study volumes grow. Even a slight change in reimbursements could move the camera from being a profit producer to a financial loss.
The Bottom Line
There is no question that Cardiac PET imaging offers high-quality images, may increase reading confidence for interpreting physicians, and provides information that may prove invaluable for some patients. Current estimates are that between 15% and 25% of MPI studies may be more appropriately performed as PET MPI rather than SPECT MPI (if PET MPI is available).
Even considering possible reimbursement instability, with the right panel size it’s a beneficial modality to add to your diagnostic imaging department. That said, it should be explored with a mindful approach that takes the full cost into account.
Ultimately, you want to perform the right test, for the right patient, at the right time, and for the right reason. Gaining a thorough understanding of the required investment, technology, and reimbursement dynamics is the first step in the process to determine if and how a Cardiologist might add PET MPI to their diagnostic toolkit.