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-Hodgkin's 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.

The impact of PET on the management of lung cancer: the referring physician's perspective.

UNLABELLED: (18)F-FDG PET is a molecular whole-body imaging modality that is increasingly being used for diagnosing, staging, and restaging cancer. The objective of this study was to determine referring physicians' perspectives on the impact of (18)F-FDG PET on staging and management of lung cancer. METHODS: A questionnaire was sent to the 292 referring physicians of 744 consecutive patients with known or suspected lung cancer who were evaluated with PET. Questionnaires on 274 patients were returned (response rate, 37%). Management changes were categorized as intermodality (e.g., surgery to medical, surgery to radiation, and medical to no treatment) or intramodality (e.g., altered medical, surgical, or radiotherapy approach). RESULTS: The primary reasons for PET referral were staging of lung cancer in 61% of patients, diagnosis in 20%, and monitoring of therapy or the course of disease in 6%. Physicians reported that PET caused them to change their decision on clinical stage in 44% of all patients: The disease was upstaged in 29% and downstaged in 15%. PET resulted in intermodality management changes in 39% of patients, whereas 15% had an intramodality change. CONCLUSION: This survey-based study of referring physicians suggests that PET has a major impact on staging and management of lung cancer.

Whole-body (18)F-FDG PET and conventional imaging for predicting outcome in previously treated breast cancer patients.

UNLABELLED: This study was conducted to determine the ability of (18)F-FDG PET and conventional imaging (CI) to predict the outcomes in breast cancer patients who have previously undergone primary treatment. METHODS: The study population consisted of 61 female patients (median age, 54 y; range, 32--91 y) who were reevaluated with (18)F-FDG PET and CI after treatment. The median interval between the last treatment and PET was 0.4 y (range, 0--16 y). PET was performed within 3 mo of CI (median interval, 25 d; range, 2--84 d). To determine the independent impact of PET on outcome, PET images were reinterpreted in a blind fashion. Availability of clinical information after PET scanning (21 plus minus 12 mo) was required for study inclusion. Study endpoints were clinical evidence of progression of disease or death. RESULTS: Of 61 patients, 19 (31.1%) had no clinical evidence and 38 (62.3%) had evidence of residual or recurrent disease by the end of follow-up. Four patients (6.6%) had died. The positive and negative predictive values (PPV and NPV, respectively) of PET were 93% and 84%, respectively. CI yielded a PPV of 85% and an NPV of 59%. The prognostic accuracy of single whole-body PET was superior to that of multiple procedures with CI (90% vs. 75%; P < 0.05). Kaplan--Meier estimates of disease-free survival in patients with negative PET findings compared with those with positive PET findings revealed a significant difference between the 2 curves (log-rank test = 0.001). Kaplan--Meier estimates of disease-free survival stratified by CI results showed a marginally significant difference between CI-positive and CI-negative patients (log-rank test = 0.04). CONCLUSION: FDG PET can be used to improve prediction of the clinical outcome of previously treated breast cancer patients relative to what is achievable through CI alone.

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.