title: SUV-measurements and patient-specific corrections in pediatric Hodgkin-lymphoma: is there a benefit for PPV in early response assessment by FDG-PET?
abstract: BACKGROUND
  To evaluate the influence of different SUV-measurements and patient-specific corrections thereof on the positive predictive value (PPV) of FDG-PET in pediatric Hodgkin lymphoma (pHL) using SUV-based response assessment.
  
  
  METHODS
  PET-datasets of 33 children [female, n = 13, male, n = 20; range of age, 8.0-17.8 (mean, 15.0) years; follow-up, 44.5-83.3 (mean 63.0) months] with HL were analyzed retrospectively. PET-scans were obtained baseline (PET1) and after two cycles of chemotherapy (PET2). Within the leading lesion maximal SUV (SUVmax) and mean SUVs were generated by using isocontur-thresholds for different volumes of interest: Absolute, SUV2.5; relative to SUVmax, SUVmean40% to SUVmean70%. Generated SUVs were adjusted to body weight (SUV) and corrected for body surface area (SUV_BSA), patient's blood glucose and a combination thereof. The decrease in SUV or respective derivates thereof between PET1 and PET2 (ΔSUV) was assessed for response prediction using receiver operating characteristics (ROC)-analysis.
  
  
  RESULTS
  Three patients had recurrence of disease. ROC-analysis showed the most accurate differentiation of responders and non-responders for ΔSUVmax_BSA [AUC, 0.97; P = 0.0026; sensitivity, 100%; specificity, 93.3%; PPV, 60.0%; negative predictive value (NPV), 100%; accuracy, 93.3%]. However, comparable results were obtained for conventional ΔSUVmax-determination (AUC, 0.96; P = 0.0112; sensitivity, 100%; specificity, 90.0%; PPV, 50.0%; NPV, 100%; accuracy, 90.9%). Threshold-based approaches were less effective or technically not performable in all patients.
  
  
  CONCLUSIONS
  At early response assessment by FDG-PET, patient-specific correction of ΔSUVmax by BSA improves PPV without impairment of excellent NPV in pHL. However, it is not statistically superior to simple ΔSUVmax-analyses. Larger cohorts are needed to investigate this observation.
authors.affiliation: Department of Radiology and Nuclear Medicine, Medical School, Otto-von-Guericke University Magdeburg A.ö.R., Magdeburg, Germany. christian.furth@med.ovgu.de
authors.forename: Christian
authors.initials: C
authors.lastname: Furth
authors.forename: Robert M
authors.initials: RM
authors.lastname: Meseck
authors.forename: Ingo G
authors.initials: IG
authors.lastname: Steffen
authors.forename: Stefan
authors.initials: S
authors.lastname: Schoenberger
authors.forename: Timm
authors.initials: T
authors.lastname: Denecke
authors.forename: Günter
authors.initials: G
authors.lastname: Henze
authors.forename: Hubertus
authors.initials: H
authors.lastname: Hautzel
authors.forename: Frank
authors.initials: F
authors.lastname: Hofheinz
authors.forename: Oliver
authors.initials: O
authors.lastname: Großer
authors.forename: Patrick
authors.initials: P
authors.lastname: Hundsdoerfer
authors.forename: Holger
authors.initials: H
authors.lastname: Amthauer
authors.forename: Juri
authors.initials: J
authors.lastname: Ruf
mesh_terms: D000293:Adolescent; D002648:Child; D005260:Female; D019788:Fluorodeoxyglucose F18 / Q000378:metabolism; D006689:Hodgkin Disease / Q000175:diagnosis*; D006801:Humans; D008297:Male; D049268:Positron-Emission Tomography / Q000379:methods*; D011237:Predictive Value of Tests; D011379:Prognosis; D012189:Retrospective Studies
chemical_list: D019788:Fluorodeoxyglucose F18