Dosimetric Comparison between Three-Dimensional Magnetic Resonance Imaging-Guided and Conventional Two-Dimensional Point A-Based Intracavitary Brachytherapy Planning for Cervical Cancer.
OBJECTIVE
The purpose of this study was to comprehensively compare the 3-dimensional (3D) magnetic resonance imaging (MRI)-guided and conventional 2-dimensional (2D) point A-based intracavitary brachytherapy (BT) planning for cervical cancer with regard to target dose coverage and dosages to adjacent organs-at risk (OARs).


METHODS
A total of 79 patients with cervical cancer were enrolled to receive 2D point A-based BT planning and then immediately to receive 3D planning between October 2011 and April 2013 at the First Hospital Affiliated to Xi'an Jiao Tong University (Xi'an, China). The dose-volume histogram (DVH) parameters for gross tumor volume (GTV), high-risk clinical target volume (HR-CTV), intermediate-risk clinical target volume (IR-CTV) and OARs were compared between the 2D and 3D planning.


RESULTS
In small tumors, there was no significant difference in most of the DVHs between 2D and 3D planning (all p>0.05). While in big tumors, 3D BT planning significantly increased the DVHs for most of the GTV, HR-CTV and IR-CTV, and some OARs compared with 2D planning (all P<0.05). In 3D planning, DVHs for GTV, HR-CTV, IR-CTV and some OARs were significantly higher in big tumors than in small tumors (all p<0.05). In contrast, in 2D planning, DVHs for almost all of the HR-CTV and IR-CTV were significantly lower in big tumors (all p<0.05). In eccentric tumors, 3D planning significantly increased dose coverage but decreased dosages to OARs compared with 2D planning (p<0.05). In tumors invading adjacent tissues, the target dose coverage in 3D planning was generally significantly higher than in 2D planning (P<0.05); the dosages to the adjacent rectum and bladder were significantly higher but those to sigmoid colon were lower in 3D planning (all P<0.05).


CONCLUSIONS
3D MRI image-guided BT planning exhibits advantages over 2D planning in a complex way, generally showing advantages for the treatment of cervical cancer except small tumors.
Department of Radiotherapy, Oncology Center, First Affiliated Hospital of Xi'an Jiaotong University, Xi'an, Shaanxi, P.R. China.
Juan
J
Ren
Department of Radiotherapy, Oncology Center, First Affiliated Hospital of Xi'an Jiaotong University, Xi'an, Shaanxi, P.R. China.
Wei
W
Yuan
Department of Radiotherapy, Oncology Center, First Affiliated Hospital of Xi'an Jiaotong University, Xi'an, Shaanxi, P.R. China.
Ruihua
R
Wang
Department of Imaging, First Affiliated Hospital of Xi' an Jiaotong University, Xi'an, Shaanxi, P.R. China.
Qiuping
Q
Wang
Department of Radiotherapy, Oncology Center, First Affiliated Hospital of Xi'an Jiaotong University, Xi'an, Shaanxi, P.R. China.
Yi
Y
Li
Medical School, Xi' an Jiaotong University, Xi'an, Shaanxi, P.R. China.
Chaofan
C
Xue
Medical School, Xi' an Jiaotong University, Xi'an, Shaanxi, P.R. China.
Yanli
Y
Yan
Medical School, Xi' an Jiaotong University, Xi'an, Shaanxi, P.R. China.
Xiaowei
X
Ma
Medical School, Xi' an Jiaotong University, Xi'an, Shaanxi, P.R. China.
Li
L
Tan
Department of Radiotherapy, Oncology Center, First Affiliated Hospital of Xi'an Jiaotong University, Xi'an, Shaanxi, P.R. China.
Zi
Z
Liu
D000328:Adult; D000368:Aged; D001918:Brachytherapy; D005260:Female; D006801:Humans; D021621:Imaging, Three-Dimensional; D008279:Magnetic Resonance Imaging; D008875:Middle Aged; D011446:Prospective Studies; D011880:Radiotherapy Planning, Computer-Assisted; D016896:Treatment Outcome; D002583:Uterine Cervical Neoplasms / Q000473:pathology / Q000532:radiotherapy*