PMID- 23891341
OWN - NLM
STAT- MEDLINE
DCOM- 20140519
LR  - 20181202
IS  - 1873-1449 (Electronic)
IS  - 1538-4721 (Linking)
VI  - 12
IP  - 6
DP  - 2013 Nov-Dec
TI  - Commissioning of a grid-based Boltzmann solver for cervical cancer brachytherapy 
      treatment planning with shielded colpostats.
PG  - 645-53
LID - S1538-4721(13)00274-2 [pii]
LID - 10.1016/j.brachy.2013.04.007 [doi]
AB  - PURPOSE: We sought to commission a gynecologic shielded colpostat analytic model 
      provided from a treatment planning system (TPS) library. We have reported 
      retrospectively the dosimetric impact of this applicator model in a cohort of 
      patients. METHODS AND MATERIALS: A commercial TPS with a grid-based Boltzmann 
      solver (GBBS) was commissioned for (192)Ir high-dose-rate (HDR) brachytherapy for 
      cervical cancer with stainless steel-shielded colpostats. Verification of the 
      colpostat analytic model was verified using a radiograph and vendor schematics. 
      MCNPX v2.6 Monte Carlo simulations were performed to compare dose distributions 
      around the applicator in water with the TPS GBBS dose predictions. 
      Retrospectively, the dosimetric impact was assessed over 24 cervical cancer 
      patients' HDR plans. RESULTS: Applicator (TPS ID #AL13122005) shield dimensions 
      were within 0.4 mm of the independent shield dimensions verification. GBBS 
      profiles in planes bisecting the cap around the applicator agreed with Monte 
      Carlo simulations within 2% at most locations; differing screw representations 
      resulted in differences of up to 9%. For the retrospective study, the GBBS doses 
      differed from TG-43 as follows (mean value +/- standard deviation [min, max]): 
      International Commission on Radiation units [ICRU]rectum (-8.4 +/- 2.5% [-14.1, 
      -4.1%]), ICRUbladder (-7.2 +/- 3.6% [-15.7, -2.1%]), D2cc-rectum (-6.2 +/- 2.6% 
      [-11.9, -0.8%]), D2cc-sigmoid (-5.6 +/- 2.6% [-9.3, -2.0%]), and D2cc-bladder 
      (-3.4 +/- 1.9% [-7.2, -1.1%]). CONCLUSIONS: As brachytherapy TPSs implement 
      advanced model-based dose calculations, the analytic applicator models stored in 
      TPSs should be independently validated before clinical use. For this cohort, 
      clinically meaningful differences (>5%) from TG-43 were observed. Accurate 
      dosimetric modeling of shielded applicators may help to refine organ toxicity 
      studies.
CI  - Copyright (c) 2013 American Brachytherapy Society. Published by Elsevier Inc. All 
      rights reserved.
FAU - Mikell, Justin K
AU  - Mikell JK
AD  - The University of Texas Graduate School of Biomedical Sciences at Houston, 
      Houston, TX; Department of Radiation Physics, The University of Texas MD Anderson 
      Cancer, Houston, TX.
FAU - Klopp, Ann H
AU  - Klopp AH
FAU - Price, Michael
AU  - Price M
FAU - Mourtada, Firas
AU  - Mourtada F
LA  - eng
PT  - Journal Article
DEP - 20130724
PL  - United States
TA  - Brachytherapy
JT  - Brachytherapy
JID - 101137600
SB  - IM
MH  - Brachytherapy/*instrumentation
MH  - Colon, Sigmoid/radiation effects
MH  - Equipment Design
MH  - Female
MH  - Follow-Up Studies
MH  - Humans
MH  - *Models, Theoretical
MH  - Radiation Injuries/prevention & control
MH  - Radiometry/methods
MH  - Radiotherapy Planning, Computer-Assisted/*methods
MH  - Rectum/radiation effects
MH  - Retrospective Studies
MH  - Urinary Bladder/radiation effects
MH  - Uterine Cervical Neoplasms/*radiotherapy
OTO - NOTNLM
OT  - (192)Ir
OT  - Acuros
OT  - Cervical cancer
OT  - Dose calculation
OT  - Shielded applicator
EDAT- 2013/07/31 06:00
MHDA- 2014/05/20 06:00
CRDT- 2013/07/30 06:00
PHST- 2013/02/14 00:00 [received]
PHST- 2013/04/02 00:00 [revised]
PHST- 2013/04/05 00:00 [accepted]
PHST- 2013/07/30 06:00 [entrez]
PHST- 2013/07/31 06:00 [pubmed]
PHST- 2014/05/20 06:00 [medline]
AID - S1538-4721(13)00274-2 [pii]
AID - 10.1016/j.brachy.2013.04.007 [doi]
PST - ppublish
SO  - Brachytherapy. 2013 Nov-Dec;12(6):645-53. doi: 10.1016/j.brachy.2013.04.007. Epub 
      2013 Jul 24.