Lena M Jönsson
Universitetslektor
Internal Dosimetry Development and Evaluation of Methods and Models
Författare
Summary, in English
This thesis presents new methodologies developed to investigate the accuracy of internal dosimetry. The main focus was on the use of detailed biokinetic data from animals combined with Monte Carlo simulations using anthropomorphic phantoms on macro level, and applied in the development and refinement of an intestinal dosimetry model on a small-scale level.
A novel approach is the generation of Monte Carlo simulated scintillation camera images of a computer patient using a radionuclide biodistribution obtained from an experimental animal study. The accuracy of the activity quantification based on planar scintillation camera imaging was investigated and in particular the corrections for attenuation and scatter with the presence of activity in overlapping tissues. The absorbed doses were calculated using phantom-specific dose factors (S values) and were compared with absorbed doses calculated from standard MIRD-phantom-based S values. The results demonstrate the potential inaccuracy of the calculated absorbed dose to an individual patient when using dose factors based on the MIRD phantom.
A dosimetry model for the small intestine was developed and refined in order to obtain a more accurate model and dose factors. Previous dosimetry models of the small intestine have been limited to calculating the absorbed dose to the intestinal wall from activity in the contents only. The work in this thesis included Monte Carlo calculations of dose factors for the radiation sensitive crypt cells as target organ. The activity in the contents as well as in the intestinal wall was taken into account, and dose factors were calculated for both self-dose and cross-dose from surrounding parts of the small intestine. Calculations of the absorbed dose to the crypt cells for a realistic activity distribution are presented and compared with results from the general absorbed dose calculation.
It is evident from the results in this thesis that improvements are necessary in the quantification procedure, as well as further development of more realistic, small-scale anatomy models.
Avdelning/ar
- Medicinsk strålningsfysik, Lund
Publiceringsår
2007
Språk
Engelska
Fulltext
Dokumenttyp
Doktorsavhandling
Förlag
Medical Radiation Physics, Lund University
Ämne
- Radiology, Nuclear Medicine and Medical Imaging
Nyckelord
- tomografi
- Klinisk fysiologi
- medical instrumentation
- tomography
- radiology
- Clinical physics
- crypt cells
- intestine
- radionuclide
- scintillation camera
- sestamibi
- activity quantification
- conjugate view method
- Monte Carlo simulation
- internal dosimetry
- Nuclear medicine
- radiobiology
- Nukleärmedicin
- radiobiologi
- medicinsk instrumentering
- radiologi
Status
Published
Handledare
- Sven-Erik Strand
- Michael Ljungberg
ISBN/ISSN/Övrigt
- ISBN: 978-91-628-7090-4
Försvarsdatum
23 mars 2007
Försvarstid
09:00
Försvarsplats
Föreläsningssal 4, Blocket, Lund University Hospital, Lund
Opponent
- Lars Jacobsson (Professor)