Rectal and Bladder Dose Measurements in the Intracavitary Applications of Cervical Cancer Treatment with HDR Afterloading System: Comparison of TPS Data with MOSFET Detector.
Brachytherapy
ICRU
In Vivo Dosimetry
MOSFET
Radiation Dosimeters
TPS
Journal
Journal of biomedical physics & engineering
ISSN: 2251-7200
Titre abrégé: J Biomed Phys Eng
Pays: Iran
ID NLM: 101589641
Informations de publication
Date de publication:
Apr 2020
Apr 2020
Historique:
received:
05
12
2018
accepted:
28
12
2018
entrez:
28
4
2020
pubmed:
28
4
2020
medline:
28
4
2020
Statut:
epublish
Résumé
Intracavitary brachytherapy plays a major role in management of cervical carcinoma. Assessment of dose received by OAR's therefore becomes crucial for the estimation of radiation toxicities in HDR brachytherapy. Purpose of this study is to evaluate the role of in vivo dosimetry in HDR brachytherapy and to compare actual doses delivered to OAR' s with those calculated during treatment planning. In this retrospective study, 50 patients of cervical carcinoma were treated by Microselectron HDR. Out of 50 patients, 26 were treated with a dose of 7 Gy and 24 with a dose of 9 Gy, prescribed to point A. Brachytherapy planning and evaluation of dose to bladder and rectum was done on TPS & in vivo dosimetry was performed using portable MOSFET. Calibration factors calculated for both dosimeters are almost equal and are 0.984 cGy/mV and 1.0895 cGy/mV. For bladder, dose deviation was found to be within ± 5% in 28 patients, ± 5-10% in 14 patients, ± 10-15% in 4 patients. Deviation between TPS-calculated dose and dose measured by MOSFET for rectum was within ± 5% in 31 patients, ± 5-10% in 8 patients, and ± 10-15% in 7 patients. TPS calculated doses were slightly higher than that measured by MOSFET. The use of small size MOSFET dosimeter is an efficient method for accurately measuring doses in high-dose gradient fields typically seen in brachytherapy. Therefore, to reduce the risk of large errors in dose delivery, in vivo dosimetry can be done in addition to TPS computations.
Sections du résumé
BACKGROUND
BACKGROUND
Intracavitary brachytherapy plays a major role in management of cervical carcinoma. Assessment of dose received by OAR's therefore becomes crucial for the estimation of radiation toxicities in HDR brachytherapy.
OBJECTIVE
OBJECTIVE
Purpose of this study is to evaluate the role of in vivo dosimetry in HDR brachytherapy and to compare actual doses delivered to OAR' s with those calculated during treatment planning.
MATERIAL AND METHODS
METHODS
In this retrospective study, 50 patients of cervical carcinoma were treated by Microselectron HDR. Out of 50 patients, 26 were treated with a dose of 7 Gy and 24 with a dose of 9 Gy, prescribed to point A. Brachytherapy planning and evaluation of dose to bladder and rectum was done on TPS & in vivo dosimetry was performed using portable MOSFET.
RESULTS
RESULTS
Calibration factors calculated for both dosimeters are almost equal and are 0.984 cGy/mV and 1.0895 cGy/mV. For bladder, dose deviation was found to be within ± 5% in 28 patients, ± 5-10% in 14 patients, ± 10-15% in 4 patients. Deviation between TPS-calculated dose and dose measured by MOSFET for rectum was within ± 5% in 31 patients, ± 5-10% in 8 patients, and ± 10-15% in 7 patients.
CONCLUSION
CONCLUSIONS
TPS calculated doses were slightly higher than that measured by MOSFET. The use of small size MOSFET dosimeter is an efficient method for accurately measuring doses in high-dose gradient fields typically seen in brachytherapy. Therefore, to reduce the risk of large errors in dose delivery, in vivo dosimetry can be done in addition to TPS computations.
Identifiants
pubmed: 32337180
doi: 10.31661/jbpe.v0i0.1065
pii: JBPE-10-2
pmc: PMC7166216
doi:
Types de publication
Journal Article
Langues
eng
Pagination
141-146Informations de copyright
Copyright: © Journal of Biomedical Physics and Engineering.
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