FDG PET scan strategies and long-term outcomes after first-line therapy in Hodgkin's disease.
BACKGROUND
The use of positron emission tomography with fluoro-deoxy-glucose (FDG PET) in Hodgkin's disease (HD) is continuing to expand worldwide, with response assessment after completion of therapy being its most widely utilized application. A positive scan has been associated with high relapse rates and disease progression.


METHODS
A decision analysis was performed to determine the long-term impact of FDG PET restaging both with and without computed tomography (CT) in terms of the 5-year progression-free survival (5yrPFS). Outcomes and utilities were based on published data. The first strategy involved CT restaging after first-line therapy, with or without subsequent FDG PET, while the second strategy used FDG PET scan alone. All positive test required histological examination. Upon histological confirmation of active lymphoma, patients were considered candidates for autologous transplantation and long-term outcomes were retrieved. The expected clinical benefit of the two strategies was calculated and depicted, along with the mean costs. One-way and two-way sensitivity analyses were performed to ensure the validity of the results.


RESULTS
CT restaging plus FDG PET when residual mass is detected, results in a 2% benefit at 5yrPFS at baseline compared to FDG PET-alone restaging and remains positive for a wide range of probabilities. This strategy reduces the average cost by euro 1863 per patient, including costs of biopsy and autologous transplantation.


CONCLUSIONS
A more conservative approach that includes CT restaging after first-line therapy and FDG PET scan only on residual mass, is the preferred strategy in HD. Furthermore it appears to confer the maximal diagnostic yield along with a substantial reduction in the mean cost.
Poulou
Loukia S
LS
Department of Computed Tomography, Sotiria General Hospital for Chest Diseases, Athens, Greece.
Karianakis
George
G
Ziakas
Panayiotis D
PD
D019788:Fluorodeoxyglucose F18; D006689:Hodgkin Disease / Q000000981:diagnostic imaging* / Q000401:mortality / Q000628:therapy*; D006801:Humans; D008137:Longitudinal Studies; D049268:Positron-Emission Tomography / Q000706:statistics & numerical data*; D015995:Prevalence; D011379:Prognosis; D019275:Radiopharmaceuticals; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D016019:Survival Analysis; D015996:Survival Rate; D016896:Treatment Outcome
D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18