Early and late therapy response assessment with [18F] fluorodeoxyglucose positron emission tomography in pediatric Hodgkin's lymphoma: Analysis of a prospective multicenter trial

Abstract

Purpose: In adult Hodgkin's lymphoma (HL) risk stratification after early therapy response assessment with [18F]fluorodeoxyglucose (FDG) positron emission tomography (PET) seems to allow tailoring therapy with less toxicity for patients with adequate metabolic response. This study delivers the first prospective data on the potential of FDG-PET for response assessment in pediatric HL. Patients and Methods: FDG-PET was performed in 40 pediatric HL patients before polychemotherapy (PET-1), after two cycles of polychemotherapy (PET-2), and after completion of polychemotherapy (PET-3). Mean follow-up was 46 months (range, 26 to 72 months). Results: At early and late response assessment, the proportion of PET-negative patients was significantly higher compared with those patients with negative findings in conventional imaging methods (CIMs; PET-2, 26 of 40 v CIM-2, one of 40; P < .001; PET-3, 21 of 29 v CIM-3, four of 29; P < .001). Specificity of early therapy response assessment by PET was improved to 97% by quantitative analysis of maximal standardized uptake value reduction using a cutoff value of 58%. Conclusion: Pediatric HL patients with a negative PET in response assessment have an excellent prognosis while PET-positive patients have an increased risk for relapse. © 2009 by American Society of Clinical Oncology.