Systematic evaluation of MRI findings in different stages of treatment of cervical cancer: potential of MRI on delineation of target, pathoanatomic structures, and organs at risk.
OBJECTIVE
To compare magnetic resonance imaging (MRI) findings at different stages of cervix cancer treatment and to define the potential of MRI to delineate the gross tumor volume (GTV), clinical target volume (CTV), pathoanatomic structures, and organs at risk (OAR) in brachytherapy.


METHODS
Forty-nine patients underwent MRI at diagnosis and at brachytherapy. The ability to discriminate anatomic structures on MRI was assessed (quality factor: 0 = inability to discriminate; 1 = fair discrimination; 2 = good discrimination; 3 = excellent discrimination). The overall ability to visualize (percentage of patients with quality factors greater than 0) and the overall discrimination quality score (mean quality factors of all patients) were estimated for the applicator, GTV at diagnosis (GTV(D)), GTV at brachytherapy (GTV(BT))/"gray zones," cervix rim/uterine corpus, OAR, vaginal wall, and parametria.


RESULTS
The overall ability to visualize the applicator on MRI at brachytherapy was 100%; for the GTV(BT)/"gray zones," cervix rim/uterine corpus, OAR, and vaginal wall, visualization was 98% (overall discrimination quality factors: 1.2, 2.9, 2.1, 1.9, 1.7, and 2.6). Three of 4 borders of parametrial space were defined in more than 98% (discrimination quality factors: 2.9, 2.1, and 1.2).


CONCLUSIONS
Magnetic resonance imaging provides appropriate information for definition of the applicator, GTV, CTV, pathoanatomic structures, and OAR that enables precise delineation for cervix cancer brachytherapy.
Dimopoulos
Johannes C A
JC
Department of Radiotherapy and Radiobiology, Medical University of Vienna, Vienna, Austria. johannes.dimopoulos@akhwien.at
Schard
Gerdi
G
Berger
Daniel
D
Lang
Stefan
S
Goldner
Gregor
G
Helbich
Thomas
T
Pötter
Richard
R
D000328:Adult; D000368:Aged; D001918:Brachytherapy; D012809:Colon, Sigmoid / Q000033:anatomy & histology; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008875:Middle Aged; D001743:Urinary Bladder / Q000033:anatomy & histology; D002583:Uterine Cervical Neoplasms / Q000473:pathology* / Q000532:radiotherapy*