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Lund, Eva
Publications (10 of 51) Show all publications
Adolfsson, E., White, S., Landry, G., Lund, E., Gustafsson, H., Verhaegen, F., . . . Alm Carlsson, G. (2015). Measurement of absorbed dose to water around an electronic brachytherapy source: Comparison of two dosimetry systems: lithium formate EPR dosimeters and radiochromic EBT2 film. Physics in Medicine and Biology, 60(9), 3869-3882
Open this publication in new window or tab >>Measurement of absorbed dose to water around an electronic brachytherapy source: Comparison of two dosimetry systems: lithium formate EPR dosimeters and radiochromic EBT2 film
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2015 (English)In: Physics in Medicine and Biology, ISSN 0031-9155, E-ISSN 1361-6560, Vol. 60, no 9, p. 3869-3882Article in journal (Refereed) Published
Abstract [en]

Interest in high dose rate (HDR) electronic brachytherapy operating at 50 kV is increasing. For quality assurance it is important to identify dosimetry systems that can measure the absorbed doses in absolute terms which is difficult in this energy region. In this work a comparison is made between two dosimetry systems, EPR lithium formate dosimeters and radiochromic EBT2 film.

Both types of dosimeters were irradiated simultaneously in a PMMA phantom using the Axxent EBS. Absorbed dose to water was determined at distances of 10 mm, 30 mm and 50 mm from the EBS. Results were traceable to different primary standards as regards to absorbed dose to water (EPR) and air kerma (EBT2). Monte Carlo simulations were used in absolute terms as a third estimate of absorbed dose to water.

Agreement within the estimated expanded (k = 2) uncertainties (5% (EPR), 7% (EBT2)) was found between the results at 30 mm and 50 mm from the x-ray source. The same result was obtained in 4 repetitions of irradiation, indicating high precision in the measurements with both systems. At all distances, agreement between EPR and Monte Carlo simulations was shown as was also the case for the film measurements at 30mm and 50mm. At 10mm the geometry for the film measurements caused too large uncertainty in measured values depending on the exact position (within sub-mm distances) of the EBS and the 10 mm film results were exculded from comparison.

This work has demonstrated good performance of the lithium formate EPR dosimetry system in accordance with earlier experiments at higher photon energies (192Ir HDR brachytherapy). It was also highlighted that there might be issues regarding the energy dependence and intrinsic efficiency of the EBT2 film that need to be considered for measurements using low energy sources.

Place, publisher, year, edition, pages
Institute of Physics Publishing (IOPP), 2015
Keywords
Electronic brachytherapy, EPR, lithium formate, radiochromic film, intrinsic efficiency
National Category
Radiology, Nuclear Medicine and Medical Imaging
Identifiers
urn:nbn:se:liu:diva-111090 (URN)10.1088/0031-9155/60/9/3869 (DOI)000354104700030 ()
Available from: 2014-10-07 Created: 2014-10-07 Last updated: 2017-12-05Bibliographically approved
Adolfsson, E., Gustafsson, H., Lund, E., Alm Carlsson, G., Olsson, S. & Carlsson Tedgren, Å. (2014). A system for remote dosimetry audit of 3D-CRT, IMRT and VMAT based on lithium formate dosimetry. Radiotherapy and Oncology, 113(2), 279-282
Open this publication in new window or tab >>A system for remote dosimetry audit of 3D-CRT, IMRT and VMAT based on lithium formate dosimetry
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2014 (English)In: Radiotherapy and Oncology, ISSN 0167-8140, E-ISSN 1879-0887, Vol. 113, no 2, p. 279-282Article in journal (Refereed) Published
Abstract [en]

The aim of this work was to develop and test a remote end-to-end audit system using lithium formate EPR dosimeters. Four clinics were included in a pilot study, absorbed doses determined in the PTV agreed with TPS calculated doses within ±5% for 3D-CRT and ±7% (k=1) for IMRT/VMAT dose plans.

Place, publisher, year, edition, pages
Elsevier, 2014
Keywords
Dosimetry audit; remote audit; end-to-end; EPR; ESR; lithium formate
National Category
Radiology, Nuclear Medicine and Medical Imaging
Identifiers
urn:nbn:se:liu:diva-111089 (URN)10.1016/j.radonc.2014.11.027 (DOI)000347657200021 ()
Available from: 2014-10-07 Created: 2014-10-07 Last updated: 2017-12-05Bibliographically approved
Fattibene, P., Trompier, F., Wieser, A., Brai, M., Ciesielski, B., De Angelis, C., . . . Tuner, H. (2014). EPR dosimetry intercomparison using smart phone touch screen glass. Radiation and Environmental Biophysics, 53(2), 311-320
Open this publication in new window or tab >>EPR dosimetry intercomparison using smart phone touch screen glass
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2014 (English)In: Radiation and Environmental Biophysics, ISSN 0301-634X, E-ISSN 1432-2099, Vol. 53, no 2, p. 311-320Article in journal (Refereed) Published
Abstract [en]

This paper presents the results of an interlaboratory comparison of retrospective dosimetry using the electron paramagnetic resonance method. The test material used in this exercise was glass coming from the touch screens of smart phones that might be used as fortuitous dosimeters in a large-scale radiological incident. There were 13 participants to whom samples were dispatched, and 11 laboratories reported results. The participants received five calibration samples (0, 0.8, 2, 4, and 10 Gy) and four blindly irradiated samples (0, 0.9, 1.3, and 3.3 Gy). Participants were divided into two groups: for group A (formed by three participants), samples came from a homogeneous batch of glass and were stored in similar setting; for group B (formed by eight participants), samples came from different smart phones and stored in different settings of light and temperature. The calibration curves determined by the participants of group A had a small error and a critical level in the 0.37-0.40-Gy dose range, whereas the curves determined by the participants of group B were more scattered and led to a critical level in the 1.3-3.2-Gy dose range for six participants out of eight. Group A were able to assess the dose within 20 % for the lowest doses (< 1.5 Gy) and within 5 % for the highest doses. For group B, only the highest blind dose could be evaluated in a reliable way because of the high critical values involved. The results from group A are encouraging, whereas the results from group B suggest that the influence of environmental conditions and the intervariability of samples coming from different smart phones need to be further investigated. An alongside conclusion is that the protocol was easily transferred to participants making a network of laboratories in case of a mass casualty event potentially feasible.

Place, publisher, year, edition, pages
Springer-Verlag New York, 2014
Keywords
EPR dosimetry, Radiological emergency, Retrospective dosimetry, Glass
National Category
Radiology, Nuclear Medicine and Medical Imaging
Identifiers
urn:nbn:se:liu:diva-111969 (URN)10.1007/s00411-014-0533-x (DOI)000334998200011 ()24671362 (PubMedID)
Available from: 2014-11-12 Created: 2014-11-12 Last updated: 2017-12-05Bibliographically approved
Lund, E., Adolfsson, E., Kolbun, N. & Gustafsson, H. (2014). EPR imaging of dose distributions aiming at applications in radiation therapy. Radiation Protection Dosimetry, 159(1-4), 130-136
Open this publication in new window or tab >>EPR imaging of dose distributions aiming at applications in radiation therapy
2014 (English)In: Radiation Protection Dosimetry, ISSN 0144-8420, E-ISSN 1742-3406, Vol. 159, no 1-4, p. 130-136Article in journal (Refereed) Published
Abstract [en]

A one-dimensional electron paramagnetic resonance (EPR) imaging method for visualisation of dose distributions in photon fields has been developed. Pressed pellets of potassium dithionate were homogeneously irradiated in a Co-60 radiation field to 600 Gy. The EPR analysis was performed with an X-Band (9.6 GHz) Bruker E540 EPR and EPR imaging spectrometer equipped with an E540 GC2X two-axis X-band gradient coil set with gradients along the y axis (along the sample tube) and z axis (along B-0) and an ER 4108TMHS resonator. Image reconstruction, including deconvolution, baseline corrections and corrections for the resonator sensitivity, was performed using an in-house-developed Matlab code for the purpose to have a transparent and complete algorithm for image reconstruction. With this method, it is possible to visualise a dose distribution with an accuracy of similar to 5 % within +/- 5 mm from the centre of the resonator.

Place, publisher, year, edition, pages
Oxford University Press, 2014
National Category
Clinical Medicine
Identifiers
urn:nbn:se:liu:diva-109275 (URN)10.1093/rpd/ncu142 (DOI)000338829100018 ()24757173 (PubMedID)
Available from: 2014-08-12 Created: 2014-08-11 Last updated: 2017-12-05Bibliographically approved
Kolbun, N., Adolfsson, E., Gustafsson, H. & Lund, E. (2014). High-resolution mapping of 1D and 2D dose distributions using X-band electron paramagnetic resonance imaging. Radiation Protection Dosimetry, 159(1-4), 182-187
Open this publication in new window or tab >>High-resolution mapping of 1D and 2D dose distributions using X-band electron paramagnetic resonance imaging
2014 (English)In: Radiation Protection Dosimetry, ISSN 0144-8420, E-ISSN 1742-3406, Vol. 159, no 1-4, p. 182-187Article in journal (Refereed) Published
Abstract [en]

Electron paramagnetic resonance imaging (EPRI) was performed to visualise 2D dose distributions of homogenously irradiated potassium dithionate tablets and to demonstrate determination of 1D dose profiles along the height of the tablets. Mathematical correction was applied for each relative dose profile in order to take into account the inhomogeneous response of the resonator using X-band EPRI. The dose profiles are presented with the spatial resolution of 0.6 mm from the acquired 2D images; this value is limited by pixel size, and 1D dose profiles from 1D imaging with spatial resolution of 0.3 mm limited by the intrinsic line-width of potassium dithionate. In this paper, dose profiles from 2D reconstructed electron paramagnetic resonance (EPR) images using the Xepr software package by Bruker are focussed. The conclusion is that using potassium dithionate, the resolution 0.3 mm is sufficient for mapping steep dose gradients if the dosemeters are covering only +/- 2 mm around the centre of the resonator.

Place, publisher, year, edition, pages
Oxford University Press, 2014
National Category
Clinical Medicine
Identifiers
urn:nbn:se:liu:diva-109276 (URN)10.1093/rpd/ncu134 (DOI)000338829100025 ()24748487 (PubMedID)
Available from: 2014-08-12 Created: 2014-08-11 Last updated: 2017-12-05Bibliographically approved
Adolfsson, E., Carlsson Tedgren, Å., Alm Carlsson, G., Gustafsson, H. & Lund, E. (2014). Optimisation of an EPR dosimetry system for robust and high precision dosimetry. Radiation Measurements, 70, 21-28
Open this publication in new window or tab >>Optimisation of an EPR dosimetry system for robust and high precision dosimetry
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2014 (English)In: Radiation Measurements, ISSN 1350-4487, E-ISSN 1879-0925, Vol. 70, p. 21-28Article in journal (Refereed) Published
Abstract [en]

Clinical applications of electron paramagnetic resonance (EPR) dosimetry systems demand high accuracy causing time consuming analysis. The need for high spatial resolution dose measurements in regions with steep dose gradients demands small sized dosimeters. An optimization of the analysis was therefore needed to limit the time consumption. The aim of this work was to introduce a new smaller lithium formate dosimeter model (diameter reduced from standard diameter 4.5 mm to 3 mm and height from 4.8 mm to 3 mm). To compensate for reduced homogeneity in a batch of the smaller dosimeters, a method for individual sensitivity correction suitable for EPR dosimetry was tested. Sensitivity and repeatability was also tested for a standard EPR resonator and a super high Q (SHQE) one. The aim was also to optimize the performance of the dosimetry system for better efficiency regarding measurement time and precision. A systematic investigation of the relationship between measurement uncertainty and number of readouts per dosimeter was performed. The conclusions drawn from this work were that it is possible to decrease the dosimeter size with maintained measurement precision by using the SHQE resonator and introducing individual calibration factors for dosimeter batches. It was also shown that it is possible reduce the number of readouts per dosimeter without significantly decreasing the accuracy in measurements.

Place, publisher, year, edition, pages
Elsevier, 2014
Keywords
EPR; ESR; Lithium formate; High precision dosimetry; High spatial resolution dosimetry
National Category
Radiology, Nuclear Medicine and Medical Imaging
Identifiers
urn:nbn:se:liu:diva-111088 (URN)10.1016/j.radmeas.2014.08.013 (DOI)000345110700005 ()
Available from: 2014-10-07 Created: 2014-10-07 Last updated: 2017-12-05Bibliographically approved
Gerdle, B., Forsgren, M., Bengtsson, A., Dahlqvist Leinhard, O., Sören, B., Karlsson, A., . . . Lundberg, P. (2013). Decreased muscle concentrations of ATP and PCR in the quadriceps muscle of fibromyalgia patients – A 31P-MRS study. European Journal of Pain, 17(8), 1205-1215
Open this publication in new window or tab >>Decreased muscle concentrations of ATP and PCR in the quadriceps muscle of fibromyalgia patients – A 31P-MRS study
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2013 (English)In: European Journal of Pain, ISSN 1090-3801, E-ISSN 1532-2149, Vol. 17, no 8, p. 1205-1215Article in journal (Refereed) Published
Abstract [en]

BACKGROUND AND METHODS:

Fibromyalgia (FMS) has a prevalence of approximately 2% in the population. Central alterations have been described in FMS, but there is not consensus with respect to the role of peripheral factors for the maintenance of FMS. 31P magnetic resonance spectroscopy (31P-MRS) has been used to investigate the metabolism of phosphagens in muscles of FMS patients, but the results in the literature are not in consensus. The aim was to investigate the quantitative content of phosphagens and pH in resting quadriceps muscle of patients with FMS (n = 19) and in healthy controls (Controls; n = 14) using (31) P-MRS. It was also investigated whether the concentrations of these substances correlated with measures of pain and/or physical capacity.

RESULTS:

Significantly lower concentrations of adenosine triphosphate (ATP) and phosphocreatinine (PCr; 28-29% lower) were found in FMS. No significant group differences existed with respect to inorganic phosphate (Pi), Pi/PCr and pH. The quadriceps muscle fat content was significantly higher in FMS than in Controls [FMS: 9.0 ± 0.5% vs. Controls: 6.6 ± 0.6%; (mean ± standard error); P = 0.005]. FMS had significantly lower hand and leg capacity according to specific physical test, but there were no group differences in body mass index, subjective activity level and in aerobic fitness. In FMS, the specific physical capacity in the leg and the hand correlated positively with the concentrations of ATP and PCr; no significant correlations were found with pain intensities.

CONCLUSIONS:

Alterations in intramuscular ATP, PCr and fat content in FMS probably reflect a combination of inactivity related to pain and dysfunction of muscle mitochondria.

Place, publisher, year, edition, pages
John Wiley & Sons, 2013
National Category
Medical and Health Sciences
Identifiers
urn:nbn:se:liu:diva-90364 (URN)10.1002/j.1532-2149.2013.00284.x (DOI)000322723600012 ()23364928 (PubMedID)
Available from: 2013-03-25 Created: 2013-03-25 Last updated: 2019-06-14Bibliographically approved
Israelsson, A., Gustafsson, H. & Lund, E. (2013). Dose response of xylitol and sorbitol for EPR retrospective dosimetry with applications to chewing gum. Radiation Protection Dosimetry, 154(2), 133-141
Open this publication in new window or tab >>Dose response of xylitol and sorbitol for EPR retrospective dosimetry with applications to chewing gum
2013 (English)In: Radiation Protection Dosimetry, ISSN 0144-8420, E-ISSN 1742-3406, Vol. 154, no 2, p. 133-141Article in journal (Refereed) Published
Abstract [en]

The purpose of this investigation was to study the radiation-induced electron paramagnetic resonance signal in sweeteners xylitol and sorbitol for use in retrospective dosimetry. For both sweeteners and chewing gum, the signal changed at an interval of 1–84 d after irradiation with minimal changes after 4–8 d. A dependence on storage conditions was noticed and the exposure of the samples to light and humidity was therefore minimised. Both the xylitol and sorbitol signals showed linearity with dose in the measured dose interval, 0–20 Gy. The dose-response measurements for the chewing gum resulted in a decision threshold of 0.38 Gy and a detection limit of 0.78 Gy. A blind test illustrated the possibility of using chewing gums as a retrospective dosemeter with an uncertainty in the dose determination of 0.17 Gy (1 SD).

National Category
Medical and Health Sciences
Identifiers
urn:nbn:se:liu:diva-85528 (URN)10.1093/rpd/ncs174 (DOI)000316968200001 ()22908355 (PubMedID)
Available from: 2012-11-22 Created: 2012-11-22 Last updated: 2017-12-07
Forsgren, M., Bengtsson, A., Dahlqvist Leinhard, O., Sören, B., Brandejsky, V., Lund, E. & Lundberg, P. (2012). 31P MRS as a Potential Biomarker for Fibromyalgia. In: Proceedings of the 20th Annaal Meeting & Exhibition, 5-11 May, Melbourne, Australia: . Paper presented at ISMRM, 20th Annaal Meeting & Exhibition, 5-11 May, Melbourne, Australia (pp. 1493-1493).
Open this publication in new window or tab >>31P MRS as a Potential Biomarker for Fibromyalgia
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2012 (English)In: Proceedings of the 20th Annaal Meeting & Exhibition, 5-11 May, Melbourne, Australia, 2012, p. 1493-1493Conference paper, Published paper (Refereed)
Abstract [en]

Major clinical symptoms in fibromyalgia (FM) are muscle pain, stiffness and fatigue. Studies have shown reduced voluntary strength and exercise capacity, lower endurance and more muscular pain even at low workload. An impaired muscle energy metabolism has therefore been proposed as a result of the disease. An earlier study using magnetic resonance spectroscopy (MRS) showed that at maximal dynamic and static contractions the concentration of inorganic phosphate was lower in FM [1]. A decrease in ATP, ADP and PCr and an increase in AMP and creatine was found in FM biopsies [2]. The purpose of this study was to non-invasively analyze the quantitative content of  phosphagens in the resting muscle in FM in comparison to healthy controls using 31P MRS of the quadriceps muscle.

National Category
Medical and Health Sciences
Identifiers
urn:nbn:se:liu:diva-91387 (URN)
Conference
ISMRM, 20th Annaal Meeting & Exhibition, 5-11 May, Melbourne, Australia
Available from: 2013-04-23 Created: 2013-04-23 Last updated: 2019-06-14Bibliographically approved
Adolfsson, E., Karlsson, M., Alm Carlsson, G., Carlsson Tedgren, Å., Lund, E., Olsson, S. & Gustafsson, H. (2012). Investigation of signal fading in lithium formate EPR dosimeters using a new sensitive method. Physics in Medicine and Biology, 57(8), 2209-2217
Open this publication in new window or tab >>Investigation of signal fading in lithium formate EPR dosimeters using a new sensitive method
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2012 (English)In: Physics in Medicine and Biology, ISSN 0031-9155, E-ISSN 1361-6560, Vol. 57, no 8, p. 2209-2217Article in journal (Refereed) Published
Abstract [en]

The aim of this study was to investigate signal fading in lithium formate electron paramagnetic resonance (EPR) dosimeters used for clinical applications in radiotherapy. A new experimental method for determination of signal fading, designed to resolve small changes in signal from slowly decaying unstable radicals, was used. Possible signal fading in lithium formate due to different storage temperatures was also tested. Air humidity was kept at a constant level of 33% throughout the experiments. The conclusion drawn from the investigations was that the EPR signal from lithium formate is stable during at least 1 month after irradiation and is not sensitive to variations in storage temperature andlt;40 degrees C when kept at a relative air humidity of 33%. This makes lithium formate a suitable dosimeter for transfer dosimetry in clinical audits.

Place, publisher, year, edition, pages
Institute of Physics (IOP), 2012
National Category
Medical and Health Sciences
Identifiers
urn:nbn:se:liu:diva-77095 (URN)10.1088/0031-9155/57/8/2209 (DOI)000302567100008 ()22456424 (PubMedID)
Note

Funding Agencies|Swedish Cancer foundation (CF)|100443|FORSS|86231|

Available from: 2012-05-04 Created: 2012-05-04 Last updated: 2017-12-07Bibliographically approved
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