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Jonsson, Joakim
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Publications (10 of 22) Show all publications
Adjeiwaah, M., Bylund, M., Lundman, J. A., Söderström, K., Zackrisson, B., Jonsson, J. H., . . . Nyholm, T. (2019). Dosimetric Impact of MRI Distortions: A Study on Head and Neck Cancers. International Journal of Radiation Oncology, Biology, Physics, 103(4), 994-1003
Open this publication in new window or tab >>Dosimetric Impact of MRI Distortions: A Study on Head and Neck Cancers
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2019 (English)In: International Journal of Radiation Oncology, Biology, Physics, ISSN 0360-3016, E-ISSN 1879-355X, Vol. 103, no 4, p. 994-1003Article in journal (Refereed) Published
Abstract [en]

Purpose: To evaluate the effect of magnetic resonance (MR) imaging (MRI) geometric distortions on head and neck radiation therapy treatment planning (RTP) for an MRI-only RTP. We also assessed the potential benefits of patient-specific shimming to reduce the magnitude of MR distortions for a 3-T scanner.

Methods and Materials: Using an in-house Matlab algorithm, shimming within entire imaging volumes and user-defined regions of interest were simulated. We deformed 21 patient computed tomography (CT) images with MR distortion fields (gradient nonlinearity and patient-induced susceptibility effects) to create distorted CT (dCT) images using bandwidths of 122 and 488 Hz/mm at 3 T. Field parameters from volumetric modulated arc therapy plans initially optimized on dCT data sets were transferred to CT data to compute a new plan. Both plans were compared to determine the impact of distortions on dose distributions.

Results: Shimming across entire patient volumes decreased the percentage of voxels with distortions of more than 2 mm from 15.4% to 2.0%. Using the user-defined region of interest (ROI) shimming strategy, (here the Planning target volume (PTV) was the chosen ROI volume) led to increased geometric for volumes outside the PTV, as such voxels within the spinal cord with geometric shifts above 2 mm increased from 11.5% to 32.3%. The worst phantom-measured residual system distortions after 3-dimensional gradient nonlinearity correction within a radial distance of 200 mm from the isocenter was 2.17 mm. For all patients, voxels with distortion shifts of more than 2 mm resulting from patient-induced susceptibility effects were 15.4% and 0.0% using bandwidths of 122 Hz/mm and 488 Hz/mm at 3 T. Dose differences between dCT and CT treatment plans in D-50 at the planning target volume were 0.4% +/- 0.6% and 0.3% +/- 0.5% at 122 and 488 Hz/mm, respectively.

Conclusions: The overall effect of MRI geometric distortions on data used for RTP was minimal. Shimming over entire imaging volumes decreased distortions, but user-defined subvolume shimming introduced significant errors in nearby organs and should probably be avoided.

Place, publisher, year, edition, pages
Elsevier, 2019
National Category
Radiology, Nuclear Medicine and Medical Imaging
Identifiers
urn:nbn:se:umu:diva-157192 (URN)10.1016/j.ijrobp.2018.11.037 (DOI)000459153600031 ()30496879 (PubMedID)
Available from: 2019-04-15 Created: 2019-04-15 Last updated: 2019-04-15Bibliographically approved
Zborayova, K., Antti, H., Blomqvist, L., Flygare, L., Gebre-Medhin, M., Jonsson, J., . . . Zackrisson, B. (2019). Early changes in multiparametric imaging parameters during radiotherapy of squamous carcinoma. Paper presented at 7th International Congress on Innovative Approaches in Head and Neck Oncology (ICHNO), Barcelona, SPAIN, MAR 14-16, 2019.. Radiotherapy and Oncology, 132, 63-63
Open this publication in new window or tab >>Early changes in multiparametric imaging parameters during radiotherapy of squamous carcinoma
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2019 (English)In: Radiotherapy and Oncology, ISSN 0167-8140, E-ISSN 1879-0887, Vol. 132, p. 63-63Article in journal, Meeting abstract (Other academic) Published
Place, publisher, year, edition, pages
Elsevier, 2019
National Category
Radiology, Nuclear Medicine and Medical Imaging
Identifiers
urn:nbn:se:umu:diva-158753 (URN)10.1016/S0167-8140(19)30289-0 (DOI)000463820400107 ()
Conference
7th International Congress on Innovative Approaches in Head and Neck Oncology (ICHNO), Barcelona, SPAIN, MAR 14-16, 2019.
Note

Supplement 1.

Available from: 2019-05-15 Created: 2019-05-15 Last updated: 2019-05-15Bibliographically approved
Sandgren, K., Johansson, L., Axelsson, J., Jonsson, J., Ögren, M., Ögren, M., . . . Widmark, A. (2019). Radiation dosimetry of [Ga-68]PSMA-11 in low-risk prostate cancer patients. EJNMMI Physics, 6, Article ID 2.
Open this publication in new window or tab >>Radiation dosimetry of [Ga-68]PSMA-11 in low-risk prostate cancer patients
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2019 (English)In: EJNMMI Physics, ISSN 2197-7364, E-ISSN 2191-219X, Vol. 6, article id 2Article in journal (Refereed) Published
Abstract [en]

Background: 68Ga-labeled Glu-NH-CO-NH-Lys(Ahx)-HBED-CC ([68Ga]PSMA-11) has been increasingly used to image prostate cancer using positron emission tomography (PET)/computed tomography (CT) both during diagnosis and treatment planning. It has been shown to be of clinical value for patients both in the primary and secondary stages of prostate cancer. The aim of this study was to determine the effective dose and organ doses from injection of [68Ga]PSMA-11 in a cohort of low-risk prostate cancer patients.

Methods: Six low-risk prostate cancer patients were injected with 133–178 MBq [68Ga]PSMA-11 and examined with four PET/CT acquisitions from injection to 255 min post-injection. Urine was collected up to 4 h post-injection, and venous blood samples were drawn at 45 min, 85 min, 175 min, and 245 min post-injection. Kidneys, liver, lungs, spleen, salivary and lacrimal glands, and total body where delineated, and cumulated activities and absorbed organ doses calculated. The software IDAC-Dose 2.1 was used to calculate absorbed organ doses according to the International Commission on Radiological Protection (ICRP) publication 107 using specific absorbed fractions published in ICRP 133 and effective dose according to ICRP Publication 103. We also estimated the absorbed dose to the eye lenses using Monte Carlo methods.

Results: [68Ga]PSMA-11 was rapidly cleared from the blood and accumulated preferentially in the kidneys and the liver. The substance has a biological half-life in blood of 6.5 min (91%) and 4.4 h (9%). The effective dose was calculated to 0.022 mSv/MBq. The kidneys received approximately 40 mGy after an injection with 160 MBq [68Ga]PSMA-11 while the lacrimal glands obtained an absorbed dose of 0.12 mGy per administered MBq. Regarding the eye lenses, the absorbed dose was low (0.0051 mGy/MBq).

Conclusion: The effective dose for [68Ga]PSMA-11 is 0.022 mSv/MBq, where the kidneys and lacrimal glands receiving the highest organ dose.

Place, publisher, year, edition, pages
Springer, 2019
Keywords
Radiation dosimetry, [Ga-68]PSMA-11, PSMA, PET-tracer, Prostate cancer, Absorbed dose and effective dose, Glu-NH-CO-NH-Lys(Ahx)-HBED-CC
National Category
Cancer and Oncology Radiology, Nuclear Medicine and Medical Imaging
Identifiers
urn:nbn:se:umu:diva-155760 (URN)10.1186/s40658-018-0239-2 (DOI)000455503100001 ()30631980 (PubMedID)
Available from: 2019-01-28 Created: 2019-01-28 Last updated: 2019-01-28Bibliographically approved
Jonsson, J., Nyholm, T. & Söderkvist, K. (2019). The rationale for MR-only treatment planning for external radiotherapy. Clinical and Translational Radiation Oncology, 18, 60-65
Open this publication in new window or tab >>The rationale for MR-only treatment planning for external radiotherapy
2019 (English)In: Clinical and Translational Radiation Oncology, ISSN 2405-6308, Vol. 18, p. 60-65Article, review/survey (Refereed) Published
Place, publisher, year, edition, pages
Elsevier, 2019
National Category
Cancer and Oncology
Identifiers
urn:nbn:se:umu:diva-161875 (URN)10.1016/j.ctro.2019.03.005 (DOI)000475468400009 ()31341977 (PubMedID)
Available from: 2019-08-08 Created: 2019-08-08 Last updated: 2019-08-08Bibliographically approved
Jonsson, J. (2018). Different methods of creating pseudo-CT images. Paper presented at 37th Meeting of the European-Society-for-Radiotherapy-and-Oncology (ESTRO), APR 20-24, 2018, Barcelona, SPAIN. Radiotherapy and Oncology, 127, S349-S349
Open this publication in new window or tab >>Different methods of creating pseudo-CT images
2018 (English)In: Radiotherapy and Oncology, ISSN 0167-8140, E-ISSN 1879-0887, Vol. 127, p. S349-S349Article in journal, Meeting abstract (Other academic) Published
Place, publisher, year, edition, pages
Elsevier, 2018
National Category
Cancer and Oncology
Identifiers
urn:nbn:se:umu:diva-150490 (URN)10.1016/S0167-8140(18)30970-8 (DOI)000437723401262 ()
Conference
37th Meeting of the European-Society-for-Radiotherapy-and-Oncology (ESTRO), APR 20-24, 2018, Barcelona, SPAIN
Available from: 2018-11-01 Created: 2018-11-01 Last updated: 2018-11-01Bibliographically approved
Sandgren, K., Jonsson, J., Nyholm, T., Strandberg, S., Ögren, M., Axelsson, J., . . . Windmark, A. (2018). Histology correlation of in vivo [68Ga]PSMA-PET/MRI data of the prostate. Paper presented at 37th Meeting of the European-Society-for-Radiotherapy-and-Oncology (ESTRO), APR 20-24, 2018, Barcelona, SPAIN. Radiotherapy and Oncology, 127, S541-S541
Open this publication in new window or tab >>Histology correlation of in vivo [68Ga]PSMA-PET/MRI data of the prostate
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2018 (English)In: Radiotherapy and Oncology, ISSN 0167-8140, E-ISSN 1879-0887, Vol. 127, p. S541-S541Article in journal, Meeting abstract (Other academic) Published
Place, publisher, year, edition, pages
Elsevier, 2018
National Category
Cancer and Oncology
Identifiers
urn:nbn:se:umu:diva-150494 (URN)10.1016/S0167-8140(18)31288-X (DOI)000437723402226 ()
Conference
37th Meeting of the European-Society-for-Radiotherapy-and-Oncology (ESTRO), APR 20-24, 2018, Barcelona, SPAIN
Available from: 2018-11-01 Created: 2018-11-01 Last updated: 2018-11-01Bibliographically approved
Björeland, U., Jonsson, J., Alm, M., Beckman, L., Nyholm, T. & Thellenberg-Karlsson, C. (2018). Inter-fraction movements of the prostate and pelvic lymph nodes during IGRT. Journal of radiation oncology, 7(4), 357-366
Open this publication in new window or tab >>Inter-fraction movements of the prostate and pelvic lymph nodes during IGRT
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2018 (English)In: Journal of radiation oncology, ISSN 1948-7894, Vol. 7, no 4, p. 357-366Article in journal (Refereed) Published
Abstract [en]

Objectivities: The aim of this study was to evaluate inter-fraction movements of lymph node regions that are commonly included in the pelvic clinical target volume (CTV) for high-risk prostate cancer patients. We also aimed to evaluate if the movements affect the planning target volumes. Methods: Ten prostate cancer patients were included. The patients underwent six MRI scans, from treatment planning to near end of treatment. The CTV movements were analyzed with deformable registration technique with the CTV divided into sections. The validity of the deformable registration was assessed by comparing the results for individual lymph nodes that were possible to identify in all scans. Results: Using repetitive MRI, measurements showed that areas inside the CTV (lymph nodes) in some extreme cases were as mobile as the prostate and not fixed to the bones. The lymph node volumes closest to the prostate did not tend to follow the prostate motion. The more cranial lymph node volumes moved less, but still independently, and they were not necessarily fixed to the pelvic bones. In 95% of the cases, the lymph node motion in the R-L direction was 2-4mm, in the A-P direction 2-7mm, and in the C-C direction 2-5mm depending on the CTV section. Conclusion: Lymph nodes and prostate were most mobile in the A-P direction, followed by the C-C and R-L directions. This movement should be taken into account when deciding the margins for the planning target volumes (PTV).

Place, publisher, year, edition, pages
Springer, 2018
Keywords
Prostate, Lymph nodes, CTV, Movements
National Category
Cancer and Oncology
Identifiers
urn:nbn:se:umu:diva-154896 (URN)10.1007/s13566-018-0366-3 (DOI)000452890500007 ()30595810 (PubMedID)
Available from: 2019-01-07 Created: 2019-01-07 Last updated: 2019-01-07Bibliographically approved
Nyholm, T., Svensson, S., Andersson, S., Jonsson, J., Sohlin, M., Gustafsson, C., . . . Gunnlaugsson, A. (2018). MR and CT data with multiobserver delineations of organs in the pelvic area: Part of the Gold Atlas project. Medical physics (Lancaster), 45(3), 1295-1300
Open this publication in new window or tab >>MR and CT data with multiobserver delineations of organs in the pelvic area: Part of the Gold Atlas project
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2018 (English)In: Medical physics (Lancaster), ISSN 0094-2405, Vol. 45, no 3, p. 1295-1300Article in journal (Refereed) Published
Abstract [en]

Purpose: We describe a public dataset with MR and CT images of patients performed in the same position with both multiobserver and expert consensus delineations of relevant organs in the male pelvic region. The purpose was to provide means for training and validation of segmentation algorithms and methods to convert MR to CT like data, i.e., so called synthetic CT (sCT).

Acquisition and validation methods: T1- and T2-weighted MR images as well as CT data were collected for 19 patients at three different departments. Five experts delineated nine organs for each patient based on the T2-weighted MR images. An automatic method was used to fuse the delineations. Starting from each fused delineation, a consensus delineation was agreed upon by the five experts for each organ and patient. Segmentation overlap between user delineations with respect to the consensus delineations was measured to describe the spread of the collected data. Finally, an open-source software was used to create deformation vector fields describing the relation between MR and CT images to further increase the usability of the dataset.

Data format and usage notes: The dataset has been made publically available to be used for academic purposes, and can be accessed from . Potential applicationsThe dataset provides a useful source for training and validation of segmentation algorithms as well as methods to convert MR to CT-like data (sCT). To give some examples: The T2-weighted MR images with their consensus delineations can directly be used as a template in an existing atlas-based segmentation engine; the expert delineations are useful to validate the performance of a segmentation algorithm as they provide a way to measure variability among users which can be compared with the result of an automatic segmentation; and the pairwise deformably registered MR and CT images can be a source for an atlas-based sCT algorithm or for validation of sCT algorithm.

Place, publisher, year, edition, pages
John Wiley & Sons, 2018
Keywords
CT, MRI, open dataset, organs at risk, radiotherapy
National Category
Medical Image Processing
Identifiers
urn:nbn:se:umu:diva-146581 (URN)10.1002/mp.12748 (DOI)000427129700032 ()29322528 (PubMedID)
Available from: 2018-06-26 Created: 2018-06-26 Last updated: 2018-06-26Bibliographically approved
Adjeiwaah, M., Bylund, M., Lundman, J. A., Thellenberg Karlsson, C., Jonsson, J. H. & Nyholm, T. (2018). Quantifying the effect of 3T MRI residual system and patient-induced susceptibility distortions on radiotherapy treatment planning for prostate cancer. International Journal of Radiation Oncology, Biology, Physics, 100(2), 317-324
Open this publication in new window or tab >>Quantifying the effect of 3T MRI residual system and patient-induced susceptibility distortions on radiotherapy treatment planning for prostate cancer
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2018 (English)In: International Journal of Radiation Oncology, Biology, Physics, ISSN 0360-3016, E-ISSN 1879-355X, Vol. 100, no 2, p. 317-324Article in journal (Refereed) Published
Abstract [en]

Purpose: To investigate the effect of magnetic resonance system- and patient-induced susceptibility distortions from a 3T scanner on dose distributions for prostate cancers.

Methods and Materials: Combined displacement fields from the residual system and patient-induced susceptibility distortions were used to distort 17 prostate patient CT images. VMAT dose plans were initially optimized on distorted CT images and the plan parameters transferred to the original patient CT images to calculate a new dose distribution.

Results: Maximum residual mean distortions of 3.19 mm at a radial distance of 25 cm and maximum mean patient-induced susceptibility shifts of 5.8 mm were found using the lowest bandwidth of 122 Hz per pixel. There was a dose difference of <0.5% between distorted and undistorted treatment plans. The 90% confidence intervals of the mean difference between the dCT and CT treatment plans were all within an equivalence interval of (−0.5, 0.5) for all investigated plan quality measures.

Conclusions: Patient-induced susceptibility distortions at high field strengths in closed bore magnetic resonance scanners are larger than residual system distortions after using vendor-supplied 3-dimensional correction for the delineated regions studied. However, errors in dose due to disturbed patient outline and shifts caused by patient-induced susceptibility effects are below 0.5%.

Place, publisher, year, edition, pages
Elsevier, 2018
National Category
Radiology, Nuclear Medicine and Medical Imaging
Identifiers
urn:nbn:se:umu:diva-142319 (URN)10.1016/j.ijrobp.2017.10.021 (DOI)000423097500011 ()29229326 (PubMedID)
Available from: 2017-11-27 Created: 2017-11-27 Last updated: 2018-06-09Bibliographically approved
Brynolfsson, P., Axelsson, J., Holmberg, A., Jonsson, J., Goldhaber, D., Jian, Y., . . . Nyholm, T. (2018). Technical note: adapting a GE SIGNA PET/MR scanner for radiotherapy. Medical physics (Lancaster), 45(8), 3546-3550
Open this publication in new window or tab >>Technical note: adapting a GE SIGNA PET/MR scanner for radiotherapy
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2018 (English)In: Medical physics (Lancaster), ISSN 0094-2405, Vol. 45, no 8, p. 3546-3550Article in journal (Refereed) Published
Abstract [en]

Purpose: Simultaneous collection of PET and MR data for radiotherapy purposes are useful for, for example, target definition and dose escalations. However, a prerequisite for using PET/MR in the radiotherapy workflow is the ability to image the patient in treatment position. The aim of this work was to adapt a GE SIGNA PET/MR scanner to image patients for radiotherapy treatment planning and evaluate the impact on signal-to-noise (SNR) of the MR images, and the accuracy of the PET attenuation correction. Method: A flat tabletop and a coil holder were developed to image patients in the treatment position, avoid patient contour deformation, and facilitate attenuation correction of flex coils. Attenuation corrections for the developed hardware and an anterior array flex coil were also measured and implemented to the PET/MR system to minimize PET quantitation errors. The reduction of SNR in the MR images due to the added distance between the coils and the patient was evaluated using a large homogenous saline-doped water phantom, and the activity quantitation errors in PET imaging were evaluated with and without the developed attenuation corrections. Result: We showed that the activity quantitation errors in PET imaging were within ±5% when correcting for attenuation of the flat tabletop, coil holder, and flex coil. The SNR of the MRI images were reduced to 74% using the tabletop, and 66% using the tabletop and coil holders. Conclusion: We present a tabletop and coil holder for an anterior array coil to be used with a GE SIGNA PET/MR scanner, for scanning patients in the radiotherapy work flow. Implementing attenuation correction of the added hardware from the radiotherapy setup leads to acceptable PET image quantitation. The drop in SNR in MR images may require adjustment of the imaging protocols.

Place, publisher, year, edition, pages
Wiley-Blackwell Publishing Inc., 2018
Keywords
MRI, PET, PET, MR, quality assurance, radiotherapy
National Category
Radiology, Nuclear Medicine and Medical Imaging
Identifiers
urn:nbn:se:umu:diva-151405 (URN)10.1002/mp.13032 (DOI)000441292000009 ()29862522 (PubMedID)
Funder
VINNOVA
Available from: 2018-09-03 Created: 2018-09-03 Last updated: 2018-09-04Bibliographically approved
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