Title: CTbased HDR Brachytherapy For Uterine Cervical Cancer: Correlation Between Dose Volume Parameters An
1CT-based HDR Brachytherapy For Uterine Cervical
Cancer Correlation Between Dose Volume
Parameters And Telangiectasia
Woong Sub Koom, M.D., Dae Kyung Sohn, M.D., Sung
Yong Park, Ph.D., Jong Won Kim, R.T.T., Dae Yong
Kim, M.D., Kyung Hwan Shin, M.D., Kwan Ho Cho,
M.D., and Joo-Young Kim, M.D. Research Institute
and Hospital, National Cancer Center, Goyang,
Gyeonggi, South Korea
INTRODUCTION
CT-based Treatment planning
Endoscopic scoring
- CT scan with the applicators in place
- Brachytherapy planning system (PLATO, version
14.2) - Contouring CTV and OARs
- Uterine and vaginal direction limit up to
initial tumor infiltration - Parametrial direction cervix presumed
tumor extension based on pelvic exam and
MRI at brachytherapy - Rectum anorectal junction rectosigmoid
flexure - Sigmoid rectosigmoid flexure 2cm beyond
the uterine fundus - Prescription
- Point A (n44) or Dose optimization (n27)
- Dose volume constraints
- CTV, D90 gt prescribe dose, and V100 gt 90
OARs, lt 90 of - prescribe dose in rectum and sigmoid, lt 100
in bladder)
- Table 5. Distribution of the worst endoscopy
score according to the location (n71)
- Point A and ICRU reference points using 2-D
orthogonal radiographs are reproducible and
useful tools for reporting and comparison of the
treatment results. - With the advent of imaging modality, 3-D planning
in brachytherapy has been recently introduced. - From July 2003, we commenced a prospective
clinical study examining DVH parameters obtained
from the 3-D brachytherapy planning and the
rectal complications using a serial flexible
sigmoidoscopic examination. - This report is a preliminary analysis for dose
volume parameters and the rectosigmoid
telangiectasia for the first 6 months under our
clinical trial scheme.
Relation between rectosigmoid dose and
telangiectasia
- Table 6.
- Mean value of dose
- volume parameters
- according to
- telangiectasia grade
- after treatment
- (t-test)
- Figure 2.
- Dose response relation
- between dose volume
- parameters and
- telangiectasia ? Grade 2
- (logistic regression)
Grading and scoring system for endoscopy based on
Medical University of Vienna1 and OMED2
- Table 2. Graduation for endoscopic findings
- Table 3. Endoscopic score system
Patients characteristics
- Between January 2004 and July 2005, 71 patients
(table1.)
grade 2
grade 3
Telangiectasia grade 1
1 Wachter S, et al. Radiother Oncol.
20005411-19 2 Crespi M, et al. Am. J.
Gastroenterol. 199691191-216
Treatment scheme
- EBRT (external beam radiotherapy)
- median 54 Gy (45 63 Gy), 1.8 2.0 Gy / fx
- Midline Block at 36 50.4 Gy (median, 45 Gy)
- HDR ICBT (high-dose-rate intracavitary
brachytherapy) - 192 Ir (microSelectron HDR, Nucletron)
afterloading system - median 28 Gy (24 33 Gy), 4 5 Gy /
fraction, 5-7 fx - Concurrent chemotherapy mainly with cisplatin in
53 pts (91)
- Despite the inevitable inter- and intrafractional
uncertainties, 3D imaging based planning is
considered to be a clinically feasible method for
gynecological brachytherapy. - Our preliminary data revealed that the dose
volume parameters (D0.1cc, D1cc, D2cc, D5cc) were
reliable estimatiors of the telangiectasia of the
rectosigmoid mucosa compared to the ICRU point
dose. - Long-term endoscopic follow up with the analysis
of clinical outcome data will aid the
establishment of the radiobiological model
predicting the dose volume relationships for the
normal tissue complications in gynecologic
brahcytherapy.
Endoscopic finding
- Table 4. Distribution of the worst grade for
endoscopy finding through the whole rectosigmoid
(Necrosis 0)