Concordance between four European centres of PET reporting criteria designed for use in multicentre trials in Hodgkin lymphoma.
OBJECTIVE
To determine if PET reporting criteria for the Response Adapted Treatment in Hodgkin Lymphoma (RATHL) trial could enable satisfactory agreement to be reached between 'core' laboratories operating in different countries.


METHODS
Four centres reported scans from 50 patients with stage II-IV HL, acquired before and after two cycles of Adriamycin/bleomycin/vinblastine/dacarbazine. A five-point scale was used to score response scans using 'normal' mediastinum and liver as reference levels. Centres read scans independently of each other. The level of agreement between centres was determined assuming (1) that uptake in sites involved at diagnosis that was higher than liver uptake represented disease (conservative reading), and (2) that uptake in sites involved at diagnosis that was higher than mediastinal uptake represented disease (sensitive reading).


RESULTS
There was agreement that the response scan was 'positive' or 'negative' for lymphoma in 44 patients with a conservative reading and in 41 patients with a sensitive reading. Kappa was 0.85 (95% CI 0.74-0.96) for conservative reading and 0.79 (95% CI 0.67-0.90) for sensitive reading. Agreement was reached in 46 and 44 patients after discussion for the conservative and sensitive readings, respectively.


CONCLUSIONS
The criteria developed for reporting in the RATHL trial are sufficiently robust to be used in a multicentre setting.
Barrington
Sally F
SF
PET Imaging Centre at St Thomas', Kings College London Division of Imaging, Lambeth Palace Road, London SE1 7EH, UK. sally.barrington@kcl.ac.uk
Qian
Wendi
W
Somer
Edward J
EJ
Franceschetto
Antonella
A
Bagni
Bruno
B
Brun
Eva
E
Almquist
Helén
H
Loft
Annika
A
Højgaard
Liselotte
L
Federico
Massimo
M
Gallamini
Andrea
A
Smith
Paul
P
Johnson
Peter
P
Radford
John
J
O'Doherty
Michael J
MJ
D005060:Europe; D006689:Hodgkin Disease / Q000000981:diagnostic imaging*; D006801:Humans; D007090:Image Interpretation, Computer-Assisted / Q000592:standards; D007753:Laboratories / Q000592:standards; D015337:Multicenter Studies as Topic / Q000592:standards*; D049268:Positron-Emission Tomography / Q000592:standards*; D012107:Research Design / Q000592:standards*