Peter E. Valk

Conventional imaging and 2-deoxy-2-[18F]fluoro-D-glucose positron emission tomography for predicting the clinical outcome of previously treated non-Hodgkin's lymphoma patients.

PURPOSE The aim of this study was to determine the impact of positron emission tomography (PET) with 2-deoxy-2-[18F]fluoro-D-glucose (FDG) and combined conventional imaging on clinical stage and their ability to predict the clinical outcome of previously treated lymphoma patients. PROCEDURES Seventy-eight patients with Non-Hodgkins Lymphoma (NHL) were studied with PET within a median interval of 5.3 months after treatment. Conventional imaging performed after treatment and within three months before PET included 3.3+/-1.3 imaging tests/patient. To determine the independent ability of PET for predicting clinical outcome, PET images were re-read in a blinded fashion. Study endpoints were disease-free survival, or clinical evidence of disease or death. RESULTS PET downstaged 18 patients, upstaged nine and revealed the same stage as conventional imaging in 51 patients. Using the clinical outcome as gold standard, the positive and negative predictive values of PET were 95% and 83% versus 72% and 67% for conventional imaging (P<0.05). The prognostic accuracy of PET was superior to that of conventional imaging (90 vs. 71%; P<0.05). Kaplan-Meier analysis for disease-free survival showed a significant difference between PET negative and PET positive results (P<0.0001). CONCLUSION Whole-body FDG-PET imaging modified the clinical stage in 35% of lymphoma patients who were reevaluated after treatment. Moreover, FDG-PET predicted patient outcome with a higher predictive accuracy than conventional imaging. This superior prognostic accuracy was achieved with a single FDG-PET study versus multiple conventional imaging procedures/patient.

Reimbursement and Technology Assessment for Positron Imaging.

The lack of consistent reimbursement for positron imaging has hampered the growth of this modality, thereby denying patients access to this important technology. Reimbursement has improved dramatically over the past three to five years with the most significant step occurring in January, 1998, which is when Medicare reimbursement was approved for staging lung cancer and characterizing indeterminate pulmonary nodules. The decision to reimburse for positron imaging for oncologic applications would not have occurred if clinical data were not available, and if the clinical effectiveness of positron imaging were not validated through technology assessments conducted by qualified research organizations. Even with the reality of reimbursement, the process by which positron imaging studies are reimbursed needs to be explored and standardized. On the Medicare front, each Medicare carrier will need help from the positron imaging community in implementing the Medicare National Coverage Instructions. The rate of reimbursement for positron imaging is a constant concern, especially with the variation of positron imaging devices and their associated capital and operational costs. This article summarizes the process involved in reimbursement for positron imaging, i.e., contracting with third-party payers and obtaining the support of referring physicians for positron imaging. The process of technology assessment for new procedures is integral to the growth, development and acceptance of positron imaging procedures by government and private-payer entities. We have made a significant step forward in reimbursement, but there is tremendous work to be done in establishing the process of reimbursement for positron imaging.