Three-dimensional imaging in gynecologic brachytherapy: a survey of the American Brachytherapy Society.
OBJECTIVE
To determine current practice patterns with regard to three-dimensional (3D) imaging for gynecologic brachytherapy among American Brachytherapy Society (ABS) members.


METHODS
Registered physician members of the ABS received a 19-item survey by e-mail in August 2007. This report excludes physicians not performing brachytherapy for cervical cancer.


RESULTS
Of the 256 surveys sent, we report results for 133 respondents who perform one or more implantations per year for locally advanced cervical cancer. Ultrasound aids 56% of physicians with applicator insertion. After insertion, 70% of physicians routinely obtain a computed tomography (CT) scan. The majority (55%) use CT rather than X-ray films (43%) or magnetic resonance imaging (MRI; 2%) for dose specification to the cervix. However, 76% prescribe to Point A alone instead of using a 3D-derived tumor volume (14%), both Point A and tumor volume (7%), or mg/h (3%). Those using 3D imaging routinely contour the bladder and rectum (94%), sigmoid (45%), small bowel (38%), and/or urethra (8%) and calculate normal tissue dose-volume histogram (DVH) analysis parameters including the D2cc (49%), D1cc (36%), D0.1cc (19%), and/or D5cc (19%). Respondents most commonly modify the treatment plan based on International Commission on Radiation Units bladder and/or rectal point dose values (53%) compared with DVH values (45%) or both (2%).


CONCLUSIONS
More ABS physician members use CT postimplantation imaging than plain films for visualizing the gynecologic brachytherapy apparatus. However, the majority prescribe to Point A rather than using 3D image based dosimetry. Use of 3D image-based treatment planning for gynecologic brachytherapy has the potential for significant growth in the United States.
Viswanathan
Akila N
AN
Department of Radiation Oncology, Brigham and Women's Hospital and Dana-Farber Cancer Institute, Harvard Medical School, Boston, MA 02115, USA. aviswanathan@lroc.harvard.edu
Erickson
Beth A
BA
D001918:Brachytherapy / Q000379:methods*; D005260:Female; D019538:Health Care Surveys; D006801:Humans; D021621:Imaging, Three-Dimensional / Q000379:methods / Q000706:statistics & numerical data*; D008279:Magnetic Resonance Imaging; D010818:Practice Patterns, Physicians' / Q000592:standards / Q000706:statistics & numerical data*; D018787:Radiation Oncology / Q000592:standards / Q000706:statistics & numerical data*; D011879:Radiotherapy Dosage; D012007:Rectum / Q000000981:diagnostic imaging; D012955:Societies, Medical; D014057:Tomography, X-Ray Computed / Q000379:methods / Q000706:statistics & numerical data; D047368:Tumor Burden; D018084:Ultrasonography, Interventional / Q000706:statistics & numerical data; D014481:United States; D001743:Urinary Bladder / Q000000981:diagnostic imaging; D002583:Uterine Cervical Neoplasms / Q000000981:diagnostic imaging / Q000473:pathology / Q000532:radiotherapy*