CTbased HDR Brachytherapy For Uterine Cervical Cancer: Correlation Between Dose Volume Parameters An

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CT-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)