PMID- 27788953
OWN - NLM
STAT- MEDLINE
DCOM- 20170710
LR  - 20200225
IS  - 1879-355X (Electronic)
IS  - 0360-3016 (Print)
IS  - 0360-3016 (Linking)
VI  - 96
IP  - 4
DP  - 2016 Nov 15
TI  - Prospective Validation of a High Dimensional Shape Model for Organ Motion in 
      Intact Cervical Cancer.
PG  - 801-807
LID - S0360-3016(16)33100-5 [pii]
LID - 10.1016/j.ijrobp.2016.08.015 [doi]
AB  - PURPOSE: Validated models are needed to justify strategies to define planning 
      target volumes (PTVs) for intact cervical cancer used in clinical practice. Our 
      objective was to independently validate a previously published shape model, using 
      data collected prospectively from clinical trials. METHODS AND MATERIALS: We 
      analyzed 42 patients with intact cervical cancer treated with daily fractionated 
      pelvic intensity modulated radiation therapy and concurrent chemotherapy in one 
      of 2 prospective clinical trials. We collected online cone beam computed 
      tomography (CBCT) scans before each fraction. Clinical target volume (CTV) 
      structures from the planning computed tomography scan were cast onto each CBCT 
      scan after rigid registration and manually redrawn to account for organ motion 
      and deformation. We applied the 95% isodose cloud from the planning computed 
      tomography scan to each CBCT scan and computed any CTV outside the 95% isodose 
      cloud. The primary aim was to determine the proportion of CTVs that were 
      encompassed within the 95% isodose volume. A 1-sample t test was used to test the 
      hypothesis that the probability of complete coverage was different from 95%. We 
      used mixed-effects logistic regression to assess effects of time and patient 
      variability. RESULTS: The 95% isodose line completely encompassed 92.3% of all 
      CTVs (95% confidence interval, 88.3%-96.4%), not significantly different from the 
      95% probability anticipated a priori (P=.19). The overall proportion of missed 
      CTVs was small: the grand mean of covered CTVs was 99.9%, and 95.2% of misses 
      were located in the anterior body of the uterus. Time did not affect coverage 
      probability (P=.71). CONCLUSIONS: With the clinical implementation of a 
      previously proposed PTV definition strategy based on a shape model for intact 
      cervical cancer, the probability of CTV coverage was high and the volume of CTV 
      missed was low. This PTV expansion strategy is acceptable for clinical trials and 
      practice; however, we recommend daily image guidance to avoid systematic large 
      misses in select patients.
CI  - Copyright (c) 2016 Elsevier Inc. All rights reserved.
FAU - Williamson, Casey W
AU  - Williamson CW
AD  - Department of Radiation Medicine and Applied Sciences, University of California, 
      San Diego, La Jolla, California.
FAU - Green, Garrett
AU  - Green G
AD  - Department of Radiation Medicine and Applied Sciences, University of California, 
      San Diego, La Jolla, California.
FAU - Noticewala, Sonal S
AU  - Noticewala SS
AD  - Department of Radiation Medicine and Applied Sciences, University of California, 
      San Diego, La Jolla, California.
FAU - Li, Nan
AU  - Li N
AD  - Department of Radiation Medicine and Applied Sciences, University of California, 
      San Diego, La Jolla, California.
FAU - Shen, Hanjie
AU  - Shen H
AD  - Department of Radiation Medicine and Applied Sciences, University of California, 
      San Diego, La Jolla, California.
FAU - Vaida, Florin
AU  - Vaida F
AD  - Division of Biostatistics and Bioinformatics, Department of Family Medicine and 
      Public Health, University of California, San Diego, La Jolla, California.
FAU - Mell, Loren K
AU  - Mell LK
AD  - Department of Radiation Medicine and Applied Sciences, University of California, 
      San Diego, La Jolla, California. Electronic address: lmell@ucsd.edu.
LA  - eng
GR  - TL1 TR001443/TR/NCATS NIH HHS/United States
GR  - UL1 TR001442/TR/NCATS NIH HHS/United States
PT  - Journal Article
PT  - Validation Study
DEP - 20160822
PL  - United States
TA  - Int J Radiat Oncol Biol Phys
JT  - International journal of radiation oncology, biology, physics
JID - 7603616
SB  - IM
MH  - Adult
MH  - Brachytherapy
MH  - *Cone-Beam Computed Tomography
MH  - Dose Fractionation, Radiation
MH  - Female
MH  - Humans
MH  - Middle Aged
MH  - Motion
MH  - *Movement
MH  - Observer Variation
MH  - Prospective Studies
MH  - Radiotherapy Planning, Computer-Assisted/*methods
MH  - Radiotherapy, Image-Guided/methods
MH  - *Radiotherapy, Intensity-Modulated
MH  - Uterine Cervical Neoplasms/*diagnostic imaging/drug 
      therapy/pathology/*radiotherapy
PMC - PMC6369704
MID - NIHMS1009335
COIS- Conflict of interest: none.
EDAT- 2016/10/30 06:00
MHDA- 2017/07/14 06:00
PMCR- 2019/02/11
CRDT- 2016/10/30 06:00
PHST- 2016/05/27 00:00 [received]
PHST- 2016/07/31 00:00 [revised]
PHST- 2016/08/15 00:00 [accepted]
PHST- 2016/10/30 06:00 [pubmed]
PHST- 2017/07/14 06:00 [medline]
PHST- 2016/10/30 06:00 [entrez]
PHST- 2019/02/11 00:00 [pmc-release]
AID - S0360-3016(16)33100-5 [pii]
AID - 10.1016/j.ijrobp.2016.08.015 [doi]
PST - ppublish
SO  - Int J Radiat Oncol Biol Phys. 2016 Nov 15;96(4):801-807. doi: 
      10.1016/j.ijrobp.2016.08.015. Epub 2016 Aug 22.