The use of positron emission tomography (PET) has been increasing since the mid 1980s [1]. PET is primarily used in oncology, cardiology, and neuropsychiatry. Oncologic uses of PET include the evaluation of lung, breast, brain, head and neck, and colorectal cancer; melanoma; and lymphoma (Hodgkin's and non-Hodgkin's) [2–5]. Although a variety of radionuclides can be used to perform PET, FDG is the most commonly used radionuclide for applications in oncology. In cardiology, the use of PET is focused on the assessment of coronary artery disease to differentiate viable from nonviable ischemic myocardial tissue [6]. Patients with neuropsychiatric disorders, such as epilepsy and dementia, are also examined using PET [6]. PET is also potentially useful in evaluating the response of cancer patients to chemotherapy and radiation treatments [4, 5, 7].

The Centers for Medicare & Medicaid Services have approved Medicare reimbursement for PET scans obtained for a variety of indications. These indications include the assessment of myocardial viability; presurgical evaluation of refractory seizures; diagnosis of solitary pulmonary nodules; and evaluation of patients with non–small cell lung cancer, colorectal cancer, esophageal cancer, breast cancer, lymphoma, and melanoma. The Centers for Medicare & Medicaid Services are reviewing Medicare reimbursement of PET for the diagnosis of Alzheimer's disease, dementia, soft-tissue sarcoma, and thyroid cancer [8].

The accuracy of FDG PET in characterizing solitary pulmonary nodules [9–11] and in staging non–small cell lung cancer is well documented [3, 11–15]. In addition, several groups have evaluated the cost effectiveness of PET in the management of lung cancer [2, 16–22]. Most of these studies used decision analysis models to evaluate the projected cost effectiveness of PET for pulmonary nodule diagnosis [18, 21] or staging in patients with non–small cell lung cancer [16–18, 20–22]. The models suggest that more accurate diagnosis or staging of non–small cell lung cancer will lead to more effective treatment and to improved patient outcomes. Prospective evidence to support this view is emerging [23]. A recently concluded randomized controlled trial found that PET not only is more accurate than traditional methods for staging non–small cell lung cancer, but also results in improved patient outcomes in the clinical setting [24]. The costs of PET for these models were estimated using Medicare reimbursement rates [21, 22], hospital charges [16, 20], insurance reimbursement rates [2], or German national reimbursement rates [17, 18]. Additional cost-effectiveness studies using accurate estimates of costs, performed in conjunction with prospective trials, are needed to assess the true benefit and determine the appropriate role of PET in clinical applications.

Operating a PET center is expensive. In 1983, the annual operating expense of a PET and cyclotron center was $2.1 million (adjusted to 2000 dollars) [25]. Scan volume is reported to be the most critical factor in determining scanner profitability [25, 26]. Most previously published cost estimates were based on hospital charges, Medicare reimbursement rates, or estimates found in the literature. One study modeled the cost of PET and projected patient volume on the basis of interviews with key informants such as PET center managers and nuclear medicine physicians, evidence from prior studies, and financial information from one PET center. In that study, the estimated annual operating cost of a PET and cyclotron center was between $0.9 and $2.6 million (in 2000 dollars) per year over a 7-year period [26]. In 1998, ECRI (formerly the Emergency Care Research Institute) used previously published charge and reimbursement estimates to calculate that the cost of a PET scan was between $1901 and $2535 (in 2000 dollars) [19]. A 1983 analysis of financial information from two PET centers over a 5-year period estimated that PET costs ranged from $1059 to $4787 (adjusted to 2000 dollars) per scan [25].

We present a survey-based analysis that includes direct, indirect, and capital costs from eight PET centers participating in a clinical trial. This convenience sample is not necessarily representative of all PET centers; however, it allowed us to capitalize on the fact that the directors of the centers were willing to participate in research and to share potentially sensitive cost data with us. Because these centers are functioning PET centers, our study is an improvement over previous modeling studies and provides more up-to-date information than the prior estimates. The sensitivity of the cost analysis to four different methods of calculating indirect costs is also examined.

This analysis was performed as a substudy of VA Cooperative Study 27, “18-F-Fluorodeoxyglucose (FDG) Positron Emission Tomography (PET) Imaging in the Management of Patients with Solitary Pulmonary Nodules.” Therefore, the respondents to our survey are not a random sample; we sent a survey to each of the 10 sites participating in the clinical trial. Sites included eight Veterans Affairs (VA) and two non-VA hospitals. All sites were at teaching hospitals where research is conducted. The two non-VA hospitals in the survey were both academic medical centers, with 450 and 1020 beds, respectively. Two hospitals did not complete the survey. Both are similar in size to the hospitals that did respond.

We determined the annual cost of operating a PET scanner with and without a dedicated FDG facility from the perspective of the hospital. We used information about whole-body, lung, heart, and brain PET scans at eight sites to calculate costs per scan.

We conducted two separate analyses: one of sites that manufacture FDG and another of sites that purchase FDG. The data provided by sites that both manufacture and purchase FDG were entered into both of these analyses.

We estimated the direct, indirect, and total costs associated with PET. We performed a survey to estimate direct costs and used data from Decision Support System reports and Medicare reports to estimate indirect costs. We found that the mean per-scan costs of PET was $1885 for sites that manufacture FDG and $1898 for PET centers that purchase FDG. These estimates are consistent with the results of previous analyses, which reported a PET scan costs between $1059 and $4787 [19, 25, 26].

In contrast to previous analyses, we did not find a cost advantage for facilities that purchase FDG over those that manufacture FDG on-site. This discrepancy may be caused by several factors. The survey included an open-ended question about equipment used to manufacture FDG (other than the cyclotron). Several sites answered this question in great detail, whereas others provided superficial information. Consequently, the costs attributable to FDG manufacturing may have been underestimated at some sites. Additionally, the centers that compound FDG use the cyclotron for activities other than FDG synthesis 43% of the time and use 15% of the synthesized FDG for research. Although these activities were accounted for when calculating total direct costs at each facility, we may have underestimated the extent to which the production of other radionuclides and research activities reduce the cost of FDG synthesis. On the other hand, previous studies may have overestimated economies of scope—that is, the cost savings resulting from an increase in the diversity of goods produced by one enterprise.

Our study is limited by its small sample size, possible nonresponse bias, and the possibility that VA hospitals are not typical of other providers. Nonresponse to individual survey questions may affect the validity of our study. The response rate to individual questions in the survey varied across sites, which required us to make assumptions about some costs. To ensure data quality, we contacted respondents for clarification if survey responses were incomplete or unclear. However, some respondents did not have enough information to provide complete cost data. It is unclear if the large variation in our results stems from incomplete information obtained by the survey and its small sample size or if it stems from a true variation in costs across centers. All hospitals, both respondents and nonrespondents, were teaching hospitals. Nonrespondents were similar in size to respondents. It is possible that the two centers that did not respond had differentially high or low costs. However, center-level nonresponse bias remains a smaller concern than the limited size of our sample.

Our study may also be limited by the pre-dominance of VA hospitals. This factor must be considered when assessing the generalizability of our findings. However, previous assessments of cost comparisons between VA and nonfederal hospitals have shown that there are no significant differences in their costs [29]. The salaries of VA physicians have in the past been lower than those of physicians working in the non-VA sector. However, a 1991 reform made salaries for VA physicians more competitive with those for physicians working in the private sector in most specialties and regions [30]. To determine unit cost, an analyst would also need to determine whether VA physicians are as productive as their private sector counterparts, an issue that we have not considered.

Figures 1 and 2 suggest that volume has a considerable impact on per-scan and per-dose costs. Both the PET and cyclotron facilities have high fixed costs (capital costs and staff costs account for 79% of the total direct costs of the PET facilities) and 66% of the total direct costs of cyclotron facilities. Increasing volume can decrease unit costs. There may also be a fixed component to staffing; a base level of staff is needed to operate the scanner and cyclotron regardless of patient volume. Moderate increases in patient volume will not automatically necessitate increases in staff. However, large increases in patient volume will lead to an increase in staffing needs. Therefore, increasing patient volume, up to a certain point, will reduce the per-scan costs attributable to staff. Our finding of a possible inverse association between scan volume and scanning cost agrees with other cost analyses, which have also shown that scan volume affects cost [1, 25, 26]. In our analysis, this relationship is largely defined by the center that produced approximately 2500 scans. Given the limitations of our study noted, this trend should be considered as a hypothesis for further research rather than as a firm result.

In 2000, Medicare reimbursement was $2185–2301 for a PET scan, depending on the indication and body part scanned. This value can be thought of as a breakeven point for PET centers. Figure 1 suggests that centers with higher scan volumes may be able to break even on Medicare reimbursement or perhaps make a profit. Centers with low scan volumes have difficulty keeping costs below Medicare reimbursement rates. From Figure 1, the break-even volume for a PET center appears to be approximately 700 scans annually, or approximately two scans per day. However, scan volume is not the only important factor in determining the cost per scan, as shown by one site that had costs above the Medicare reimbursement rate despite obtaining approximately 700 scans per year.

Like most technologies, PET is changing over time. Recent studies have examined FDG imaging with a modified, dual-detector gamma camera. It is unclear how the accuracy of coincidence imaging with a gamma camera, which is referred to as co-PET, compares with traditional PET. The main advantage of FDG imaging with a modified gamma camera is the lower acquisition cost. Adding coincident imaging capability to a standard gamma camera costs approximately $500,000. In contrast, according to our analysis, the average purchase price of a dedicated PET scanner is $1.9 million.

Another avenue for possible change is the development of scanners that obtain anatomic–metabolic fusion images with PET and CT, an integrated CT–PET system. The integrated CT–PET system is approximately 20% more expensive to acquire than a dedicated PET scanner [31]. The future clinical usefulness of the hybrid system is still uncertain. Another delivery option is the use of a mobile PET center. This setup could improve patient access and decrease overhead costs.

It is unclear how many PET centers are operating in the United States and what the age of equipment at these sites is. Thus, it is unclear how representative the sites in this study are of centers nationally. According to the Academy of Molecular Imaging, 173 PET centers are in the United States [32]. This total is an underestimate because only seven of the 10 centers in our study were listed among the 173 centers. Additionally, many of the centers listed appear to be free-standing PET facilities; these centers may avoid the extra costs of being hospital-based.

This analysis provides an improved estimate of the costs involved in operating a dedicated PET scanner with and without on-site FDG manufacturing. Additional cost analysis and cost-effectiveness studies are needed to determine the proper roles that dedicated PET scanners and cyclotrons are to play in clinical medicine.

We thank the VA Cooperative Studies Program Coordinating Center for funding and Chara Rydzak for help administering the survey.

Address correspondence to P. G. Barnett.

The views expressed in this article are those of the authors and are not necessarily the views of the Department of Veterans Affairs.

Supported by the VA Cooperative Studies Program Coordinating Center.

M. K. Gould received support from the VA Health Services Research and Development Service.