Target volume delineation for preoperative radiotherapy of rectal cancer: inter-observer variability and potential impact of FDG-PET/CT imaging.
To analyze the inter-observer variability and the potential impact of (18)F-fluorodeoxyglucose (FDG)-positron emission tomography/computed tomography (PET/CT) imaging for target volume delineation in preoperative radiotherapy of rectal cancer. Gross tumor volume (GTV) and clinical target volume (CTV) in 2 cases of rectal cancer were contoured by 10 radiation oncologists, 5 on CT and 5 on PET/CT images. Resulting volumes were analyzed by coefficient of variation (CV) and concordance index (CI). Mean GTV was 120 cc +/- 20.4 cc in case A and 119 cc +/- 35.7 cc in case B. Mean CTV was 723 cc +/- 147.5 cc in case A and 739 cc +/- 195.6 cc in case B. CV was lower and CI was similar or higher across the observers contouring GTV on PET/CT. CTV variability was less influenced by the use of PET/CT. PET/CT may allow reducing inter-observer variability in GTV delineation.
Krengli
Marco
M
Radiotherapy, University Hospital Maggiore della Carita, via Solaroli 17, 28100 Novara, Italy. krengli@med.unipmn.it
Cannillo
Barbara
B
Turri
Lucia
L
Bagnasacco
Paolo
P
Berretta
Laura
L
Ferrara
Teresa
T
Galliano
Mario
M
Gribaudo
Sergio
S
Melano
Antonella
A
Munoz
Fernando
F
Sciacero
Piera
P
Tseroni
Vassiliki
V
Bassi
Maria Chiara
MC
Brambilla
Marco
M
Inglese
Eugenio
E
D019788:Fluorodeoxyglucose F18; D006801:Humans; D015588:Observer Variation; D049268:Positron-Emission Tomography; D011300:Preoperative Care; D011379:Prognosis; D019275:Radiopharmaceuticals; D011880:Radiotherapy Planning, Computer-Assisted / Q000379:methods*; D012004:Rectal Neoplasms / Q000000981:diagnostic imaging* / Q000532:radiotherapy; D014057:Tomography, X-Ray Computed
D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18