Evaluation of interim PET response criteria in paediatric Hodgkin's lymphoma--results for dedicated assessment criteria in a blinded dual-centre read.
BACKGROUND
The aim of this study was to evaluate the use and reliability of the new positron emission tomography (PET)-based response criteria for interim positron emission tomography (iPET) in patients with paediatric Hodgkin's lymphoma (pHL). Particular emphasis was put on interobserver variability and on identification of a visual cut-off defining patients with very low risk for relapse.


METHODS
The iPET scans of 39 pHL patients were evaluated in two independent centres by two PET-experienced specialists in nuclear medicine (blinded read, centre consensus) each. The iPET scans were interpreted using a 5-point scale and were compared with the outcome. Cohen's kappa-test (κ) was used to analyse the interobserver agreement.


RESULTS
Concordant ratings were assessed in 19 patients with iPET-negative findings, in 11 patients with iPET-positive findings and in 2 patients with inconclusive ratings. A 'substantial agreement' between attended centres was achieved (κ = 0.748). All patients suffering relapse were concordantly identified, taking mediastinal blood pool structures (MBPS) as visual cut-off between PET-positive and PET-negative findings, respectively. All pHL patients with uptake lower than or equal to MBPS remained in complete remission.


CONCLUSIONS
The iPET interpretation assured low interobserver variability. High sensitivity for identification of pHL patients suffering relapse is achieved if [18F]-fluorodeoxyglucose uptake above the MBPS value is rated as a PET-positive finding.
Furth
C
C
Department of Radiology and Nuclear Medicine, Medical School, Otto-von-Guericke University, Magdeburg. Electronic address: christian.furth@med.ovgu.de.
Amthauer
H
H
Department of Radiology and Nuclear Medicine, Medical School, Otto-von-Guericke University, Magdeburg; Department of Radiology and Nuclear Medicine, Charité Campus Virchow, Humboldt-University Berlin, Berlin.
Hautzel
H
H
Department of Nuclear Medicine (KME) at the Research Center Juelich, Heinrich-Heine-University Duesseldorf, Juelich.
Steffen
I G
IG
Department of Radiology and Nuclear Medicine, Medical School, Otto-von-Guericke University, Magdeburg; Department of Radiology and Nuclear Medicine, Charité Campus Virchow, Humboldt-University Berlin, Berlin.
Ruf
J
J
Department of Radiology and Nuclear Medicine, Medical School, Otto-von-Guericke University, Magdeburg.
Schiefer
J
J
Department of Radiology and Nuclear Medicine, Medical School, Otto-von-Guericke University, Magdeburg.
Schönberger
S
S
Department of Paediatric Oncology, Haematology and Clinical Immunology, University Children's Hospital, Heinrich-Heine-University, Duesseldorf.
Henze
G
G
Department of Paediatric Oncology/Haematology, Charité Campus Virchow, Humboldt-University Berlin, Berlin.
Grandt
R
R
Department of Nuclear Medicine (KME) at the Research Center Juelich, Heinrich-Heine-University Duesseldorf, Juelich.
Hundsdoerfer
P
P
Department of Paediatric Oncology/Haematology, Charité Campus Virchow, Humboldt-University Berlin, Berlin.
Dietlein
M
M
Department of Nuclear Medicine, University Hospital of Cologne, Cologne, Germany.
Kobe
C
C
Department of Nuclear Medicine, University Hospital of Cologne, Cologne, Germany.
D000293:Adolescent; D002648:Child; D019468:Disease Management; D018572:Disease-Free Survival; D005260:Female; D006689:Hodgkin Disease / Q000000981:diagnostic imaging* / Q000628:therapy; D006801:Humans; D008297:Male; D009364:Neoplasm Recurrence, Local / Q000517:prevention & control; D015588:Observer Variation; D010043:Outcome and Process Assessment, Health Care; D049268:Positron-Emission Tomography; D016896:Treatment Outcome