Accuracy of dwell position detection with a combined electromagnetic tracking brachytherapy system for treatment verification in pelvic brachytherapy.
Electromagnetic tracking
HDR brachytherapy
Pelvic cancer
Quality assurance
Journal
Radiotherapy and oncology : journal of the European Society for Therapeutic Radiology and Oncology
ISSN: 1879-0887
Titre abrégé: Radiother Oncol
Pays: Ireland
ID NLM: 8407192
Informations de publication
Date de publication:
01 2021
01 2021
Historique:
received:
09
06
2020
revised:
10
09
2020
accepted:
29
09
2020
pubmed:
11
10
2020
medline:
24
4
2021
entrez:
10
10
2020
Statut:
ppublish
Résumé
To investigate the accuracy of dwell position detection with a combined electromagnetic tracking (EMT) brachytherapy (BT) system for treatment verification, by quantifying positional errors due to EM field interference in typical pelvic BT clinical settings. Dedicated prostate and cervix BT phantoms were imaged with CT. For the cervix phantom, the Utrecht applicator + interstitial catheters were used. The implants were reconstructed and treatment plans were created with 270/65 dwell positions for the prostate/cervix phantom. Next, EMT experiments were performed in clinical BT settings using a prototype of a combined EMT/BT system. We quantified positional errors due to EM field interference from surrounding equipment by comparing planned and EMT-measured dwell positions. The mean residual error between planned and EMT-measured dwell positions was calculated in the prostate interstitial catheters and in the whole cervix implant including the applicator. For the cervix phantom, the analysis was repeated for only the interstitial catheters. Mean residual errors of less than 0.5/0.4 mm in the prostate/cervix catheters were found. For the whole cervix implant including the applicator, large deviations up to 2.4 mm were found. Compared to the interference free set-up, the CT and patient bed environments showed larger residual errors in the interstitial catheters, but residual errors remained <1 mm in all cases. Dwell position detection with the combined system in interstitial catheters is sufficiently accurate to perform EMT-based treatment verification. The effect of EM interference from the surrounding equipment was limited.
Sections du résumé
BACKGROUND AND PURPOSE
To investigate the accuracy of dwell position detection with a combined electromagnetic tracking (EMT) brachytherapy (BT) system for treatment verification, by quantifying positional errors due to EM field interference in typical pelvic BT clinical settings.
MATERIALS AND METHODS
Dedicated prostate and cervix BT phantoms were imaged with CT. For the cervix phantom, the Utrecht applicator + interstitial catheters were used. The implants were reconstructed and treatment plans were created with 270/65 dwell positions for the prostate/cervix phantom. Next, EMT experiments were performed in clinical BT settings using a prototype of a combined EMT/BT system. We quantified positional errors due to EM field interference from surrounding equipment by comparing planned and EMT-measured dwell positions. The mean residual error between planned and EMT-measured dwell positions was calculated in the prostate interstitial catheters and in the whole cervix implant including the applicator. For the cervix phantom, the analysis was repeated for only the interstitial catheters.
RESULTS
Mean residual errors of less than 0.5/0.4 mm in the prostate/cervix catheters were found. For the whole cervix implant including the applicator, large deviations up to 2.4 mm were found. Compared to the interference free set-up, the CT and patient bed environments showed larger residual errors in the interstitial catheters, but residual errors remained <1 mm in all cases.
CONCLUSION
Dwell position detection with the combined system in interstitial catheters is sufficiently accurate to perform EMT-based treatment verification. The effect of EM interference from the surrounding equipment was limited.
Identifiants
pubmed: 33038356
pii: S0167-8140(20)30836-7
doi: 10.1016/j.radonc.2020.09.061
pii:
doi:
Types de publication
Journal Article
Research Support, Non-U.S. Gov't
Langues
eng
Sous-ensembles de citation
IM
Pagination
249-254Informations de copyright
Copyright © 2021 The Authors. Published by Elsevier B.V. All rights reserved.