Advanced

Improvements in absorbed dose measurements for external radiation therapy using ferrous dosimeter gel and MR imaging (FeMRI)

Bäck, Sven LU ; Magnusson, Peter LU ; Fransson, A; Olsson, L E LU ; Montelius, A; Holmberg, O LU ; Andreo, P and Mattsson, S LU (1998) In Physics in Medicine and Biology 43(2). p.76-261
Abstract

A ferrous gel, based on ferrous (Fe) sulphate and agarose, was used with a clinical magnetic resonance imaging (MRI) scanner to obtain relative dose distribution data from therapeutic photon and electron beams. The FeMRI gel was scanned using a new MRI acquisition protocol optimized for T1 measurements. Thorough comparisons with silicon semiconductor detector and ionization chamber measurements, as well as with Monte Carlo calculations, were performed in order to quantify the improvements obtained using FeMRI for dose estimations. Most of the relative doses measured with FeMRI were within 2% of the doses measured with other methods. The larger discrepancies (2-4%) found at shallow depths are discussed. The uncertainty in relative dose... (More)

A ferrous gel, based on ferrous (Fe) sulphate and agarose, was used with a clinical magnetic resonance imaging (MRI) scanner to obtain relative dose distribution data from therapeutic photon and electron beams. The FeMRI gel was scanned using a new MRI acquisition protocol optimized for T1 measurements. Thorough comparisons with silicon semiconductor detector and ionization chamber measurements, as well as with Monte Carlo calculations, were performed in order to quantify the improvements obtained using FeMRI for dose estimations. Most of the relative doses measured with FeMRI were within 2% of the doses measured with other methods. The larger discrepancies (2-4%) found at shallow depths are discussed. The uncertainty in relative dose measurements using FeMRI was significantly improved compared with previously reported results (5-10%, one standard deviation, 1 SD), and is today between 1.6% and 3.3% (depending on dose level, 2 SD). This corresponds to an improvement in the minimum detectable dose (3 SD above background) from approximately 2 Gy to better than 0.6 Gy. The results obtained in this study emphasize the importance of obtaining basic FeMRI dose data before the method is extended to complicated treatment regimes.

(Less)
Please use this url to cite or link to this publication:
author
organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
Electrons, Ferrous Compounds, Gels, Magnetic Resonance Imaging, Phantoms, Imaging, Photons, Radiotherapy Dosage, Radiotherapy Planning, Computer-Assisted, Radiotherapy, High-Energy, Reproducibility of Results, Sepharose
in
Physics in Medicine and Biology
volume
43
issue
2
pages
16 pages
publisher
IOP Publishing
external identifiers
  • Scopus:2642703476
ISSN
0031-9155
DOI
10.1088/0031-9155/43/2/004
language
English
LU publication?
yes
id
d747af00-9128-43de-8f94-81bf482d3aa7
date added to LUP
2016-08-16 12:15:27
date last changed
2016-10-13 05:12:19
@misc{d747af00-9128-43de-8f94-81bf482d3aa7,
  abstract     = {<p>A ferrous gel, based on ferrous (Fe) sulphate and agarose, was used with a clinical magnetic resonance imaging (MRI) scanner to obtain relative dose distribution data from therapeutic photon and electron beams. The FeMRI gel was scanned using a new MRI acquisition protocol optimized for T1 measurements. Thorough comparisons with silicon semiconductor detector and ionization chamber measurements, as well as with Monte Carlo calculations, were performed in order to quantify the improvements obtained using FeMRI for dose estimations. Most of the relative doses measured with FeMRI were within 2% of the doses measured with other methods. The larger discrepancies (2-4%) found at shallow depths are discussed. The uncertainty in relative dose measurements using FeMRI was significantly improved compared with previously reported results (5-10%, one standard deviation, 1 SD), and is today between 1.6% and 3.3% (depending on dose level, 2 SD). This corresponds to an improvement in the minimum detectable dose (3 SD above background) from approximately 2 Gy to better than 0.6 Gy. The results obtained in this study emphasize the importance of obtaining basic FeMRI dose data before the method is extended to complicated treatment regimes.</p>},
  author       = {Bäck, Sven and Magnusson, Peter and Fransson, A and Olsson, L E and Montelius, A and Holmberg, O and Andreo, P and Mattsson, S},
  issn         = {0031-9155},
  keyword      = {Electrons,Ferrous Compounds,Gels,Magnetic Resonance Imaging,Phantoms, Imaging,Photons,Radiotherapy Dosage,Radiotherapy Planning, Computer-Assisted,Radiotherapy, High-Energy,Reproducibility of Results,Sepharose},
  language     = {eng},
  number       = {2},
  pages        = {76--261},
  publisher    = {ARRAY(0xa887700)},
  series       = {Physics in Medicine and Biology},
  title        = {Improvements in absorbed dose measurements for external radiation therapy using ferrous dosimeter gel and MR imaging (FeMRI)},
  url          = {http://dx.doi.org/10.1088/0031-9155/43/2/004},
  volume       = {43},
  year         = {1998},
}