Consensus guidelines for delineation of clinical target volume for intensity-modulated pelvic radiotherapy for the definitive treatment of cervix cancer.
OBJECTIVE
Accurate target definition is vitally important for definitive treatment of cervix cancer with intensity-modulated radiotherapy (IMRT), yet a definition of clinical target volume (CTV) remains variable within the literature. The aim of this study was to develop a consensus CTV definition in preparation for a Phase 2 clinical trial being planned by the Radiation Therapy Oncology Group.


METHODS
A guidelines consensus working group meeting was convened in June 2008 for the purposes of developing target definition guidelines for IMRT for the intact cervix. A draft document of recommendations for CTV definition was created and used to aid in contouring a clinical case. The clinical case was then analyzed for consistency and clarity of target delineation using an expectation maximization algorithm for simultaneous truth and performance level estimation (STAPLE), with kappa statistics as a measure of agreement between participants.


RESULTS
Nineteen experts in gynecological radiation oncology generated contours on axial magnetic resonance images of the pelvis. Substantial STAPLE agreement sensitivity and specificity values were seen for gross tumor volume (GTV) delineation (0.84 and 0.96, respectively) with a kappa statistic of 0.68 (p < 0.0001). Agreement for delineation of cervix, uterus, vagina, and parametria was moderate.


CONCLUSIONS
This report provides guidelines for CTV definition in the definitive cervix cancer setting for the purposes of IMRT, building on previously published guidelines for IMRT in the postoperative setting.
Lim
Karen
K
Radiation Medicine Program, Princess Margaret Hospital/ Ontario Cancer Institute, University Health Network, Toronto, Ontario, Canada.
Small
William
W
Portelance
Lorraine
L
Creutzberg
Carien
C
Jürgenliemk-Schulz
Ina M
IM
Mundt
Arno
A
Mell
Loren K
LK
Mayr
Nina
N
Viswanathan
Akila
A
Jhingran
Anuja
A
Erickson
Beth
B
De los Santos
Jennifer
J
Gaffney
David
D
Yashar
Catheryn
C
Beriwal
Sushil
S
Wolfson
Aaron
A
Taylor
Alexandra
A
Bosch
Walter
W
El Naqa
Issam
I
Fyles
Anthony
A
D002584:Cervix Uteri / Q000033:anatomy & histology; D005260:Female; D006801:Humans; D008198:Lymph Nodes / Q000033:anatomy & histology; D008279:Magnetic Resonance Imaging / Q000379:methods / Q000592:standards*; D058958:Organs at Risk / Q000033:anatomy & histology; D010388:Pelvis / Q000033:anatomy & histology; D050397:Radiotherapy, Intensity-Modulated / Q000379:methods / Q000592:standards*; D012680:Sensitivity and Specificity; D047368:Tumor Burden; D002583:Uterine Cervical Neoplasms / Q000175:diagnosis* / Q000532:radiotherapy*; D014599:Uterus / Q000033:anatomy & histology; D014621:Vagina / Q000033:anatomy & histology