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Nyholm, Tufve
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Publications (10 of 81) 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
Fetty, L., Kuess, P., Nesvacil, N., Nyholm, T., Georg, D. & Furtado, H. (2019). Evaluating different generator networks of a conditional generative adversarial network. Paper presented at 38th Annual Meeting of the European-Society-for-Radiotherapy-and-Oncology (ESTRO), Milan, ITALY, April 26-30, 2019. Radiotherapy and Oncology, 133, S555-S555
Open this publication in new window or tab >>Evaluating different generator networks of a conditional generative adversarial network
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2019 (English)In: Radiotherapy and Oncology, ISSN 0167-8140, E-ISSN 1879-0887, Vol. 133, p. S555-S555Article 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-160314 (URN)10.1016/S0167-8140(19)31425-2 (DOI)000468315602270 ()
Conference
38th Annual Meeting of the European-Society-for-Radiotherapy-and-Oncology (ESTRO), Milan, ITALY, April 26-30, 2019
Available from: 2019-06-17 Created: 2019-06-17 Last updated: 2019-06-17Bibliographically approved
Löfstedt, T., Brynolfsson, P., Nyholm, T. & Garpebring, A. (2019). Gray-level invariant Haralick texture features. PLoS ONE
Open this publication in new window or tab >>Gray-level invariant Haralick texture features
2019 (English)In: PLoS ONE, ISSN 1932-6203, E-ISSN 1932-6203Article in journal (Refereed) Epub ahead of print
Abstract [en]

Haralick texture features are common texture descriptors in image analysis. To compute the Haralick features, the image gray-levels are reduced, a process called quantization. The resulting features depend heavily on the quantization step, so Haralick features are not reproducible unless the same quantization is performed. The aim of this work was to develop Haralick features that are invariant to the number of quantization gray-levels. By redefining the gray-level co-occurrence matrix (GLCM) as a discretized probability density function, it becomes asymptotically invariant to the quantization. The invariant and original features were compared using logistic regression classification to separate two classes based on the texture features. Classifiers trained on the invariant features showed higher accuracies, and had similar performance when training and test images had very different quantizations. In conclusion, using the invariant Haralick features, an image pattern will give the same texture feature values independent of image quantization.

National Category
Medical Biotechnology
Identifiers
urn:nbn:se:umu:diva-134995 (URN)10.1371/journal.pone.0212110 (DOI)000459709100037 ()30794577 (PubMedID)
Note

Originally included in thesis in manuscript form

Available from: 2017-05-15 Created: 2017-05-15 Last updated: 2019-04-08
Daniel, M., Kuess, P., Andrzejewski, P., Nyholm, T., Helbich, T., Polanec, S., . . . Baltzer, P. (2019). Impact of androgen deprivation therapy on apparent diffusion coefficient and T2w MRI for histogram and texture analysis with respect to focal radiotherapy of prostate cancer. Strahlentherapie und Onkologie (Print), 195(5), 402-411
Open this publication in new window or tab >>Impact of androgen deprivation therapy on apparent diffusion coefficient and T2w MRI for histogram and texture analysis with respect to focal radiotherapy of prostate cancer
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2019 (English)In: Strahlentherapie und Onkologie (Print), ISSN 0179-7158, E-ISSN 1439-099X, Vol. 195, no 5, p. 402-411Article in journal (Refereed) Published
Abstract [en]

Purpose: Accurate prostate cancer (PCa) detection is essential for planning focal external beam radiotherapy (EBRT). While biparametric MRI (bpMRI) including T2-weighted (T2w) and diffusion-weighted images (DWI) is an accurate tool to localize PCa, its value is less clear in the case of additional androgen deprivation therapy (ADT). The aim of this study was to investigate the value of a textural feature (TF) approach on bpMRI analysis in prostate cancer patients with and without neoadjuvant ADT with respect to future dose-painting applications.

Methods: 28 PCa patients (54–80 years) with (n = 14) and without (n = 14) ADT who underwent bpMRI with T2w and DWI were analyzed retrospectively. Lesions, central gland (CG), and peripheral zone (PZ) were delineated by an experienced urogenital radiologist based on localized pre-therapeutic histopathology. Histogram parameters and 20 Haralick TF were calculated. Regional differences (i. e., tumor vs. PZ, tumor vs. CG) were analyzed for all imaging parameters. Receiver-operating characteristic (ROC) analysis was performed to measure diagnostic performance to distinguish PCa from benign prostate tissue and to identify the features with best discriminative power in both patient groups.

Results: The obtained sensitivities were equivalent or superior when utilizing the TF in the no-ADT group, while specificity was higher for the histogram parameters. However, in the ADT group, TF outperformed the conventional histogram parameters in both specificity and sensitivity. Rule-in and rule-out criteria for ADT patients could exclusively be defined with the aid of TF.

Conclusions: The TF approach has the potential for quantitative image-assisted boost volume delineation in PCa patients even if they are undergoing neoadjuvant ADT.

Place, publisher, year, edition, pages
Springer Berlin/Heidelberg, 2019
Keywords
Radiomics, Tissue characterization, Boost volume, Quantitative imaging, ADC
National Category
Radiology, Nuclear Medicine and Medical Imaging
Identifiers
urn:nbn:se:umu:diva-159876 (URN)10.1007/s00066-018-1402-3 (DOI)000466399900005 ()30478670 (PubMedID)
Available from: 2019-06-10 Created: 2019-06-10 Last updated: 2019-06-10Bibliographically approved
Daniel, M., Kuess, P., Andrzejewski, P., Nyholm, T., Nyholm, T., Heilmann, M., . . . Georg, D. (2019). Pilot study: Textural features of mpMRI for response assessment in prostate cancer patients. Paper presented at 38th Annual Meeting of the European-Society-for-Radiotherapy-and-Oncology (ESTRO), Milan, ITALY, April 26-30, 2019. Radiotherapy and Oncology, 133, S1113-S1113
Open this publication in new window or tab >>Pilot study: Textural features of mpMRI for response assessment in prostate cancer patients
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2019 (English)In: Radiotherapy and Oncology, ISSN 0167-8140, E-ISSN 1879-0887, Vol. 133, p. S1113-S1113Article 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-160313 (URN)10.1016/S0167-8140(19)32448-X (DOI)000468315605227 ()
Conference
38th Annual Meeting of the European-Society-for-Radiotherapy-and-Oncology (ESTRO), Milan, ITALY, April 26-30, 2019
Available from: 2019-06-17 Created: 2019-06-17 Last updated: 2019-06-17Bibliographically 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
Fetty, L., Buschmann, M., Heilemann, G., Kuess, P., Nyholm, T., Herrmann, H., . . . Nesvacil, N. (2019). Solutions for MR-based RT planning with an open low field scanner using neural network tools. Paper presented at 38th Annual Meeting of the European-Society-for-Radiotherapy-and-Oncology (ESTRO), Milan, ITALY, April 26-30, 2019. Radiotherapy and Oncology, 133, S567-S568
Open this publication in new window or tab >>Solutions for MR-based RT planning with an open low field scanner using neural network tools
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2019 (English)In: Radiotherapy and Oncology, ISSN 0167-8140, E-ISSN 1879-0887, Vol. 133, p. S567-S568Article 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-160315 (URN)10.1016/S0167-8140(19)31444-6 (DOI)000468315602288 ()
Conference
38th Annual Meeting of the European-Society-for-Radiotherapy-and-Oncology (ESTRO), Milan, ITALY, April 26-30, 2019
Available from: 2019-06-17 Created: 2019-06-17 Last updated: 2019-06-17Bibliographically 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
Engvall, G., Lindh, V., Mullaney, T., Nyholm, T., Lindh, J. & Ångström-Brännström, C. (2018). Children's experiences and responses towards an intervention for psychological preparation for radiotherapy. Radiation Oncology, 13, Article ID 9.
Open this publication in new window or tab >>Children's experiences and responses towards an intervention for psychological preparation for radiotherapy
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2018 (English)In: Radiation Oncology, ISSN 1748-717X, E-ISSN 1748-717X, Vol. 13, article id 9Article in journal (Refereed) Published
Abstract [en]

Background: Children can experience distress when undergoing radiotherapy as a reaction to being scared of and unfamiliar with the procedure. The aim was to evaluate children's experiences and responses towards an intervention for psychological preparation for radiotherapy.

Methods: A case control design with qualitative content analysis of semi-structured interviews and statistical analysis of anxiety ratings were used for evaluating a strategy for psychological preparation and distraction. Fifty-seven children aged 2 to 18 years and their parents participated - 30 children in the baseline group and 27 in the intervention group. Child interviews were performed and the child and their parents rated the child's anxiety.

Results: The intervention was most appropriate for the younger children, who enjoyed the digital story, the stuffed animal and training with their parents. There were some technical problems and the digital story was not detailed enough to fit exactly with various cancer diagnoses. Children described suggestions for improvement of the intervention. The ratings of the child's anxiety during radiation treatment showed no differences between the baseline group and the intervention group.

Conclusions: The children of all the age groups experienced their interventions as positive. The strength of the intervention was that it encouraged interaction within the family and provided an opportunity for siblings and peers to take part in what the child was going through. Future research on children's experiences to interventions should be encouraged. The intervention and the technical solutions could improve by further development.

Trial registration: The study design was structured as an un-matched case-control study, baseline group vs. intervention group. Trial registration: ClinicalTrials.gov NCT02993978 , Protocol Record 2012-113-31 M. Retrospectively registered - 21 November 2016.

Place, publisher, year, edition, pages
BioMed Central, 2018
Keywords
childhood cancer, children’s experiences, distraction, psychological preparation, radiotherapy
National Category
Nursing
Identifiers
urn:nbn:se:umu:diva-144573 (URN)10.1186/s13014-017-0942-5 (DOI)000423350200001 ()29357940 (PubMedID)
Available from: 2018-02-06 Created: 2018-02-06 Last updated: 2018-06-09Bibliographically approved
Garpebring, A., Brynolfsson, P., Kuess, P., Georg, D., Helbich, T. H., Nyholm, T. & Löfstedt, T. (2018). Density Estimation of Grey-Level Co-Occurrence Matrices for Image Texture Analysis. Physics in Medicine and Biology, 63(19), 9-15, Article ID 195017.
Open this publication in new window or tab >>Density Estimation of Grey-Level Co-Occurrence Matrices for Image Texture Analysis
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2018 (English)In: Physics in Medicine and Biology, ISSN 0031-9155, E-ISSN 1361-6560, Vol. 63, no 19, p. 9-15, article id 195017Article in journal (Refereed) Published
Abstract [en]

The Haralick texture features are common in the image analysis literature, partly because of their simplicity and because their values can be interpreted. It was recently observed that the Haralick texture features are very sensitive to the size of the GLCM that was used to compute them, which led to a new formulation that is invariant to the GLCM size. However, these new features still depend on the sample size used to compute the GLCM, i.e. the size of the input image region-of-interest (ROI).

The purpose of this work was to investigate the performance of density estimation methods for approximating the GLCM and subsequently the corresponding invariant features.

Three density estimation methods were evaluated, namely a piece-wise constant distribution, the Parzen-windows method, and the Gaussian mixture model. The methods were evaluated on 29 different image textures and 20 invariant Haralick texture features as well as a wide range of different ROI sizes.

The results indicate that there are two types of features: those that have a clear minimum error for a particular GLCM size for each ROI size, and those whose error decreases monotonically with increased GLCM size. For the first type of features, the Gaussian mixture model gave the smallest errors, and in particular for small ROI sizes (less than about 20×20).

In conclusion, the Gaussian mixture model is the preferred method for the first type of features (in particular for small ROIs). For the second type of features, simply using a large GLCM size is preferred.

Place, publisher, year, edition, pages
Institute of Physics and Engineering in Medicine, 2018
Keywords
Haralick features, invariant features, GLCM, density estimation, texture analysis, image analysis
National Category
Computer Vision and Robotics (Autonomous Systems) Other Mathematics
Identifiers
urn:nbn:se:umu:diva-152488 (URN)10.1088/1361-6560/aad8ec (DOI)000446205200005 ()30088815 (PubMedID)
Funder
Västerbotten County CouncilVINNOVA
Available from: 2018-10-08 Created: 2018-10-08 Last updated: 2018-10-31Bibliographically approved
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