SPECT/CT Roundtable: Experts Speak Out about Quality, Efficiency and Technology

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Advanced SPECT imaging hardware and software, as well as quantitative processing techniques, will ensure the modality remains a major clinical workhorse. Source: David Wolinsky, MD, Albany Associates in Cardiology, Albany, N.Y.
Moderator:  C.P. Kaiser, Editor, Cardiovascular Business

Cardiovascular Business invited four luminaries in the field of nuclear cardiology to discuss SPECT and SPECT/CT, including advanced technology, utilization in hospital- and office-based settings and reimbursement challenges. Participants in the roundtable discussion are:

Daniel S. Berman, MD, chief of cardiac imaging and nuclear cardiology at the S. Mark Taper Foundation Imaging Center at Cedars-Sinai Medical Center and a professor of medicine at the David Geffen School of Medicine at UCLA in California.

Gary V. Heller, MD, PhD, a professor of medicine and nuclear medicine at the University of Connecticut School of Medicine and associate director of the division of cardiology and director of the nuclear cardiology laboratory at Hartford Hospital, Harford, Conn.

Terrence D. Ruddy, MD, head of the division of cardiology, director of nuclear cardiology and a professor of medicine and radiology at the University of Ottawa Heart Institute and head of nuclear medicine at The Ottawa Hospital, Canada.

Leslee J. Shaw, PhD, an outcomes research scientist and a professor of medicine at Emory University School of Medicine, Atlanta, and program chair for the 2009 American Society of Nuclear Cardiology meeting.



How do the financial considerations differ for providing hospital- or office-based SPECT imaging?


Gary V. Heller, MD, PhD: The main consideration for the hospital-based setting is that if the test is ordered, we must image those patients. The reimbursement is extremely different from the office-based setting depending on DRGs, insurance companies, etc. The challenges for an imaging laboratory in the hospital are quite enormous, leading to hospitals trying to be as efficient as possible.

Terrence D. Ruddy, MD:
In Canada, we have the same reimbursement for clinics outside the hospital as for patients done in the hospital. But an outside clinic pays rent and buys its own equipment. They tend to have older cameras and run simple, inexpensive tests to save money. In the hospital, we have access to more capital and tend to have state-of-the-art equipment. In fact, when my academic center buys a new camera, we typically sell the old one to the outside clinic.

Dr. Shaw, is there any research to indicate differences in quality between hospital-and office-based settings in the U.S. that would impact financial considerations?


Leslee J. Shaw, PhD: Dr. Ruddy alluded to some of the differences which may occur if there are disparities in the advanced imaging techniques that are available, but there is no hard evidence showing this. At least in the U.S., it appears the quality of the equipment is fairly equivalent between the outpatient and hospital setting.

What can cardiologists do to increase revenues regarding SPECT imaging?


Heller: I am worried about the words “increase revenues.” I think the message should be “increase efficiency and reduce cost.” There is an enormous effort in the field of SPECT imaging to reduce acquisition time and improve image quality.

Daniel S. Berman, MD:
Many vendors are producing new software approaches to reduce acquisition time without losing image quality. They include UltraSPECT, Philips Healthcare (Astonish), Siemens Healthcare (Flash 3D), GE Healthcare (Evolution) and Digirad (nSPEED). There also are advanced cameras with faster acquisition times such as the CardiArc SPECT system and D-SPECT (Spectrum Dynamics). In addition, the PET imaging protocol is extremely efficient, allowing for a rest/stress exam in 30 minutes, compared to two to three hours for conventional rest/stress SPECT.

Is it possible that advanced SPECT technology would close the timing gap with PET?


Ruddy: Attenuation correction works really well with PET, especially in obese patients or women with large breasts. We also use quantitative blood flow analysis with either 13N-ammonia ?or rubidium-82 and find it helpful in patients who have diabetes or multivessel disease. The ischemia is more accurately quantified with PET.

Berman: The absolute flow measurement analysis techniques and looking at coronary flow reserve with PET are likely to become widely disseminated soon. We should acknowledge, though, that SPECT/CT systems are able to do attenuation correction as well as PET, and that some newer SPECT systems have the potential to measure coronary flow reserve.

What cost-effectiveness data are available for SPECT/CT?


Shaw: We don’t have any direct evidence on the cost-effectiveness of SPECT/CT, but we do have a large body of evidence on how selective use of SPECT plus CT for calcium scoring in certain patient populations can be very efficient at identifying at-risk patients.

How does the attenuation correction between SPECT/CT and PET/CT compare?


Ruddy: We have one 4-slice and two 6-slice SPECT/CT scanners, which we use mainly for attenuation correction and it does improve reader confidence. But you can believe the attenuation correction on PET/CT 100 percent of the time, whereas SPECT/CT tends to mis-register. Our clinicians definitely prefer PET/CT to SPECT/CT.

Berman: Part of that might be due to the higher resolution of PET. Some of the new SPECT cameras will have both faster acquisition and higher resolution.

Ruddy: That’s true. We just got the new GE Discovery camera that uses CZT detectors and the images are amazing.

When should one consider using a 64-slice SPECT/CT scanner to combine coronary CT angiography (CTA) with SPECT MPI?


Ruddy: I think the direction will be to keep 64-slice CT and SPECT or PET imaging separate. It works a lot better that way for patient flow.

Heller: It’s rare that we know ahead of time that a patient needs both the CT and a stress nuclear study. Sometimes the information is complementary.

How has the utilization of coronary CTA impacted SPECT?


Shaw: At Emory, we see a favoring of CTA over SPECT. The clinicians love to use it in the emergency department as a quick test to determine whether a low- to intermediate-risk patient has coronary disease.

Heller: Insurance companies in Connecticut have refused to reimburse for CTA studies in most cases, including exams that are clearly clinically indicated. As a result, the volume of studies at our hospital is low, about one to two per day; whereas we are doing 20 SPECT studies a day.

Is there evidence that coronary CTA is a cost-effective gatekeeper for unnecessary SPECT or catheter angiography?


Berman: Proposed randomized trials comparing SPECT to CT in the diagnostic patient population are currently being evaluated by the National Institutes of Health for potential funding. We hypothesized that there will be cost savings using CT in intermediate-risk patients. But we don’t have the evidence yet and our experience is like Dr. Heller’s. We have an excellent CT service, but it’s underutilized.

Ruddy: We have a program that handles about 2000 CTAs annually. We found that our normalcy rate in the cath lab has decreased, which indicates more appropriate use of the cath lab. Clinicians use CTA because its high negative predictive value can effectively rule out the low-probability patients. About one-third of these patients, however, go on to SPECT because CTA reveals a significant stenosis. In terms of numbers, CTA has not adversely affected our SPECT volume, which has increased about 5 percent for each of the past three years.

Just so we can put this in perspective, what is the reimbursement for coronary CTA in Canada?


Ruddy: Coronary CTA is reimbursed as a CT with contrast of the thorax. It’s revenue neutral from a hospital perspective. The professional fees are poor, around $150 to $200, whereas the professional fee for SPECT is around $350. It takes more time to read a CT than a SPECT study, but CT is more lucrative than, say, reading treadmills. Overall, the reimbursement is encouraging, not discouraging. [Editor’s note: Global reimbursement in the U.S. for coronary CTA ranges between $500 to $1,000, depending on rates established by local carriers.]

How will new radiotracers influence SPECT utilization?


Berman: A promising fluorine-18 labeled PET agent, being developed by Lantheus Medical Imaging, showed good Phase I results and should have a much higher resolution than rubidium-82. In addition, it has a two-hour half-life, which means it could be used with exercise.

Heller: There are two SPECT agents that have reached Phase III trials. One is MIBG, which shows promise in predicting whether patients with heart failure are at low or high risk for cardiac events, particularly arrhythmias and sudden cardiac death. The second product, BMIPP, is an iodinated compound with an “ischemic memory” that potentially could be used in the emergency department for people who present 12 to 24 hours after resolution of chest pain.

SPECT imaging has been singled out for self-referral abuse. Do you think this criticism is fair?


Shaw: As we move into the era of appropriateness, we will be able to better differentiate which patients are appropriate and support some of the self-referral. But it’s not as straightforward as some say.

Berman: There will be a new set of SPECT appropriateness criteria coming out from the American College of Cardiology by the summer and the guidelines are considerably changed. They will broaden the inappropriate categories, hopefully leading to a decrease in the number of inappropriate studies. It’s my hope that the cardiology community can discipline itself and not have to be subject to external agencies such as radiology business managers that seem to be dedicated to cost-reduction rather than effectiveness.