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Reduction of the absorbed dose to the urinary bladder from radiopharmaceuticals -An investigation of influencing parameters

Schönbeck, Morgan (2007)
Medical Physics Programme
Abstract (Swedish)
Introduction: The main route of excretion of activity for most administered radiopharmaceuticals is via the urinary bladder and it is important to estimate the absorbed dose to the mucosal surface of the bladder wall, especially when radiopharmaceuticals are given for therapeutic purposes. The purpose of this thesis was to investigate how the absorbed dose varies with changes in the parameters, which control the volume in the bladder. Material and Methods: A dynamic bladder model was used, which makes it possible to evaluate what would be the optimal first void time after administration, and how the dose pattern changes with the variables that control the volume in the bladder at any time. The investigated parameters were initial bladder... (More)
Introduction: The main route of excretion of activity for most administered radiopharmaceuticals is via the urinary bladder and it is important to estimate the absorbed dose to the mucosal surface of the bladder wall, especially when radiopharmaceuticals are given for therapeutic purposes. The purpose of this thesis was to investigate how the absorbed dose varies with changes in the parameters, which control the volume in the bladder. Material and Methods: A dynamic bladder model was used, which makes it possible to evaluate what would be the optimal first void time after administration, and how the dose pattern changes with the variables that control the volume in the bladder at any time. The investigated parameters were initial bladder content volume, residual bladder content volume, voiding interval, urine flow rate and time of administration. For the voiding interval and the urine flow rate data from 30 healthy volunteers were used. The volunteers wrote down time of micturition and the amount of urine under a period of at least 24 hours. The bladder model was transferred to STELLA, which is an interactive program for modelling dynamic systems over time. The radiopharmaceuticals used in this study were 18F-FDG, 99mTc-MDP, 123I-NaI, 131I-NaI and 111In-DTPA Results: The best way of reducing the absorbed dose to the bladder wall surface is to increase the urine flow rate, and this is done by increasing the liquid consumption. The first void time is especially important after an administration with 18F-FDG. Another parameter that is easy to control is the initial bladder content volume, if the patients do not urinate directly before the administration this helps to reduce the absorbed dose. The absorbed doses calculated by ICRP differ from the results in this report and the largest difference is obtained for 131I-NaI. The value in this report is approximately 50% higher than that presented by ICRP. Conclusions: The result shows that it is possible to reduce the absorbed dose to the bladder wall surface after an administration of a radiopharmaceutical. The absorbed dose calculated by ICRP to the urinary bladder from 123I-NaI and 131I-NaI needs to be revised. (Less)
Please use this url to cite or link to this publication:
author
Schönbeck, Morgan
supervisor
organization
year
type
H2 - Master's Degree (Two Years)
subject
keywords
Nukleärmedicin
language
English
id
2157004
date added to LUP
2011-09-13 15:26:44
date last changed
2011-09-13 15:26:44
@misc{2157004,
  abstract     = {{Introduction: The main route of excretion of activity for most administered radiopharmaceuticals is via the urinary bladder and it is important to estimate the absorbed dose to the mucosal surface of the bladder wall, especially when radiopharmaceuticals are given for therapeutic purposes. The purpose of this thesis was to investigate how the absorbed dose varies with changes in the parameters, which control the volume in the bladder. Material and Methods: A dynamic bladder model was used, which makes it possible to evaluate what would be the optimal first void time after administration, and how the dose pattern changes with the variables that control the volume in the bladder at any time. The investigated parameters were initial bladder content volume, residual bladder content volume, voiding interval, urine flow rate and time of administration. For the voiding interval and the urine flow rate data from 30 healthy volunteers were used. The volunteers wrote down time of micturition and the amount of urine under a period of at least 24 hours. The bladder model was transferred to STELLA, which is an interactive program for modelling dynamic systems over time. The radiopharmaceuticals used in this study were 18F-FDG, 99mTc-MDP, 123I-NaI, 131I-NaI and 111In-DTPA Results: The best way of reducing the absorbed dose to the bladder wall surface is to increase the urine flow rate, and this is done by increasing the liquid consumption. The first void time is especially important after an administration with 18F-FDG. Another parameter that is easy to control is the initial bladder content volume, if the patients do not urinate directly before the administration this helps to reduce the absorbed dose. The absorbed doses calculated by ICRP differ from the results in this report and the largest difference is obtained for 131I-NaI. The value in this report is approximately 50% higher than that presented by ICRP. Conclusions: The result shows that it is possible to reduce the absorbed dose to the bladder wall surface after an administration of a radiopharmaceutical. The absorbed dose calculated by ICRP to the urinary bladder from 123I-NaI and 131I-NaI needs to be revised.}},
  author       = {{Schönbeck, Morgan}},
  language     = {{eng}},
  note         = {{Student Paper}},
  title        = {{Reduction of the absorbed dose to the urinary bladder from radiopharmaceuticals -An investigation of influencing parameters}},
  year         = {{2007}},
}