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Asklund, Thomas
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Publications (10 of 29) Show all publications
Malmstrom, A., Akesson, L., Asklund, T., Kinhult, S., Werlenius, K., Hesselager, G., . . . Henriksson, R. (2018). GENDER DIFFERENCES IN GLIOMA - FINDINGS FROM THE SWEDISH NATIONAL QUALITY REGISTRY FOR PRIMARY BRAIN TUMORS. Paper presented at 13th Meeting of the European-Association-of-Neurooncology (EANO), OCT 10-14, 2018, Stockholm, SWEDEN. Neuro-Oncology, 20, 267-267
Open this publication in new window or tab >>GENDER DIFFERENCES IN GLIOMA - FINDINGS FROM THE SWEDISH NATIONAL QUALITY REGISTRY FOR PRIMARY BRAIN TUMORS
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2018 (English)In: Neuro-Oncology, ISSN 1522-8517, E-ISSN 1523-5866, Vol. 20, p. 267-267Article in journal, Meeting abstract (Other academic) Published
Abstract [en]

Background

An often debated topic in neuro-oncology are the differences in incidence and survival between men and women with glioma. To the Swedish National Quality Registry for Primary Brain Tumors (SNQR) over 90% of all Swedish patients with primary brain tumor have been reported since 1999. We therefore conducted a study of clinical factors in relation to gender in patients registered with high grade glioma using data from the SNQR.

Methods

The SNQR was searched for patients diagnosed with high grade glioma from 1999 through 2016 and clinical data were analyzed for gender differences regarding prognostic factors, tumor location and survival.

Results

In all 5470 patients were identified, 2268 women and 3202 men, giving a ratio of 1:1.4. We found a survival benefit for women when analyzing the whole time period. While there was no difference in median survival (315 versus 326 days for women versus men), there were significantly more long term survivors among women, with mean survival being 742 versus 628 days (p=0.03). The survival benefit for women was also only present in those being younger than 50 years at diagnosis. We looked at the prognostic factors age, performance status (PS) and surgery in relation to gender. We found that median age for being diagnosed with high grade glioma was significantly higher in women than men (63 versus 62 years, p=0.002) and the ratio of women in relation to men increases with increasing age, the ratios for younger than 50 years being 1:1.5 and over 50 years 1:1.39. A higher fraction of the women are over 60 years when diagnosed compared to men (57% vs 53%, p=0.002). For PS we identified that significantly more women were reported to have PS 3 and for men more PS 0 was registered. For type of surgery we found no gender differences. For tumor location more women had tumors in the frontal and less in the temporal lobe as compared to men.

Conclusion

In the Swedish National Quality Registry for Primary Brain Tumors we identified differences in incidence and survival between men and women related to age and also a disparity regarding PS and tumor location. If the cause of these clinical differences is due to molecular background or has other causes warrants further study.

Place, publisher, year, edition, pages
OXFORD UNIV PRESS INC, 2018
National Category
Cancer and Oncology
Identifiers
urn:nbn:se:umu:diva-157545 (URN)000460645600195 ()
Conference
13th Meeting of the European-Association-of-Neurooncology (EANO), OCT 10-14, 2018, Stockholm, SWEDEN
Note

Supplement 3

Available from: 2019-04-05 Created: 2019-04-05 Last updated: 2019-04-05Bibliographically approved
Brynolfsson, P., Löfstedt, T., Asklund, T., Nyholm, T. & Garpebring, A. (2018). Gray-level invariant Haralick texture features. Paper presented at 37th Meeting of the European-Society-for-Radiotherapy-and-Oncology (ESTRO), APR 20-24, 2018, Barcelona, SPAIN. Radiotherapy and Oncology, 127, S279-S280
Open this publication in new window or tab >>Gray-level invariant Haralick texture features
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2018 (English)In: Radiotherapy and Oncology, ISSN 0167-8140, E-ISSN 1879-0887, Vol. 127, p. S279-S280Article 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-150493 (URN)10.1016/S0167-8140(18)30837-5 (DOI)000437723401139 ()
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
Sandstrom, M., Laudius, M., Lindqvist, T., Asklund, T. & Johansson, M. (2017). A Retrospective Evaluation of Bevacizumab Treatment in Patients with Progressive Malignant Glioma in Northern Sweden. Anticancer Research, 37(4), 1869-1874
Open this publication in new window or tab >>A Retrospective Evaluation of Bevacizumab Treatment in Patients with Progressive Malignant Glioma in Northern Sweden
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2017 (English)In: Anticancer Research, ISSN 0250-7005, E-ISSN 1791-7530, Vol. 37, no 4, p. 1869-1874Article in journal (Refereed) Published
Abstract [en]

Background/Aim: Overall survival for glioblastoma patients is short. Standard treatment is surgery followed by radiochemotherapy and adjuvant temozolomide. The aim of this study was to evaluate the outcome for all patients with progressive disease treated with bevacizumab-based treatment combinations in the northern region of Sweden. Patients and Methods: This was a single-center retrospective analysis after bevacizumab-based second-line treatment for malignant glioma. All patients treated with bevacizumab, between 2007 and 2011 in our Center were retrospectively evaluated. Results: Progression-free survival after the start of bevacizumab-based treatment was 20 weeks and overall survival was 31 weeks. Treatment was well tolerated, but 9% of patients (n=6) suffered from serious adverse events. In 68% of patients, a >= 25% decrease in contrast enhancement was seen at best response. Conclusion: Results from this retrospective study are comparable with earlier phase-II. studies and motivate randomized trials of bevacizumab-based treatment in the second-line setting.

Place, publisher, year, edition, pages
INT INST ANTICANCER RESEARCH, 2017
Keywords
Malignant glioma, bevacizumab, anti-angionenesis treatment
National Category
Cancer and Oncology
Identifiers
urn:nbn:se:umu:diva-137012 (URN)10.21873/anticanres.11524 (DOI)000402167700042 ()28373454 (PubMedID)
Available from: 2017-06-29 Created: 2017-06-29 Last updated: 2018-06-09Bibliographically approved
Brynolfsson, P., Nilsson, D., Torheim, T., Asklund, T., Thellenberg Karlsson, C., Trygg, J., . . . Garpebring, A. (2017). Haralick texture features from apparent diffusion coefficient (ADC) MRI images depend on imaging and pre-processing parameters. Scientific Reports, 7, Article ID 4041.
Open this publication in new window or tab >>Haralick texture features from apparent diffusion coefficient (ADC) MRI images depend on imaging and pre-processing parameters
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2017 (English)In: Scientific Reports, ISSN 2045-2322, E-ISSN 2045-2322, Vol. 7, article id 4041Article in journal (Refereed) Published
Abstract [en]

In recent years, texture analysis of medical images has become increasingly popular in studies investigating diagnosis, classification and treatment response assessment of cancerous disease. Despite numerous applications in oncology and medical imaging in general, there is no consensus regarding texture analysis workflow, or reporting of parameter settings crucial for replication of results. The aim of this study was to assess how sensitive Haralick texture features of apparent diffusion coefficient (ADC) MR images are to changes in five parameters related to image acquisition and pre-processing: noise, resolution, how the ADC map is constructed, the choice of quantization method, and the number of gray levels in the quantized image. We found that noise, resolution, choice of quantization method and the number of gray levels in the quantized images had a significant influence on most texture features, and that the effect size varied between different features. Different methods for constructing the ADC maps did not have an impact on any texture feature. Based on our results, we recommend using images with similar resolutions and noise levels, using one quantization method, and the same number of gray levels in all quantized images, to make meaningful comparisons of texture feature results between different subjects.

Place, publisher, year, edition, pages
Nature Publishing Group, 2017
National Category
Radiology, Nuclear Medicine and Medical Imaging
Identifiers
urn:nbn:se:umu:diva-134993 (URN)10.1038/s41598-017-04151-4 (DOI)000403874900024 ()28642480 (PubMedID)
Note

Originally included in thesis in manuscript form.

Available from: 2017-05-15 Created: 2017-05-15 Last updated: 2018-06-09Bibliographically approved
Jonsson, J. H., Akhtari, M. M., Karlsson, M. G., Johansson, A., Asklund, T. & Nyholm, T. (2015). Accuracy of inverse treatment planning on substitute CT images derived from MR data for brain lesions. Radiation Oncology, 10, Article ID 13.
Open this publication in new window or tab >>Accuracy of inverse treatment planning on substitute CT images derived from MR data for brain lesions
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2015 (English)In: Radiation Oncology, ISSN 1748-717X, E-ISSN 1748-717X, Vol. 10, article id 13Article in journal (Refereed) Published
Abstract [en]

Background: In this pilot study we evaluated the performance of a substitute CT (s-CT) image derived from MR data of the brain, as a basis for optimization of intensity modulated rotational therapy, final dose calculation and derivation of reference images for patient positioning. Methods: S-CT images were created using a Gaussian mixture regression model on five patients previously treated with radiotherapy. Optimizations were compared using D-max, D-min, D-median and D-mean measures for the target volume and relevant risk structures. Final dose calculations were compared using gamma index with 1%/1 mm and 3%/3 mm acceptance criteria. 3D geometric evaluation was conducted using the DICE similarity coefficient for bony structures. 2D geometric comparison of digitally reconstructed radiographs (DRRs) was performed by manual delineation of relevant structures on the s-CT DRR that were transferred to the CT DRR and compared by visual inspection. Results: Differences for the target volumes in optimization comparisons were small in general, e.g. a mean difference in both D-min and D-max within similar to 0.3%. For the final dose calculation gamma evaluations, 100% of the voxels passed the 1%/1 mm criterion within the PTV. Within the entire external volume between 99.4% and 100% of the voxels passed the 3%/3 mm criterion. In the 3D geometric comparison, the DICE index varied between approximately 0.8-0.9, depending on the position in the skull. In the 2D DRR comparisons, no appreciable visual differences were found. Conclusions: Even though the present work involves a limited number of patients, the results provide a strong indication that optimization and dose calculation based on s-CT data is accurate regarding both geometry and dosimetry.

Keywords
Radiotherapy, Treatment planning, MRI, Substitute CT, s-CT
National Category
Cancer and Oncology Radiology, Nuclear Medicine and Medical Imaging
Identifiers
urn:nbn:se:umu:diva-102308 (URN)10.1186/s13014-014-0308-1 (DOI)000350027400001 ()25575414 (PubMedID)
Available from: 2015-06-24 Created: 2015-04-23 Last updated: 2018-06-07Bibliographically approved
Asklund, T., Malmström, A., Bergqvist, M., Björ, O. & Henriksson, R. (2015). Brain tumors in Sweden: Data from a population-based registry 1999-2012. Acta Oncologica, 54(3), 377-384
Open this publication in new window or tab >>Brain tumors in Sweden: Data from a population-based registry 1999-2012
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2015 (English)In: Acta Oncologica, ISSN 0284-186X, E-ISSN 1651-226X, Vol. 54, no 3, p. 377-384Article in journal (Refereed) Published
Abstract [en]

Background. The Swedish brain tumor registry has, since it was launched in 1999, provided significant amounts of data on histopathological diagnoses and on important aspects of surgical and medical management of these patients. The purpose is mainly quality control, but also as a resource for research.

Methods. Three Swedish healthcare regions, constituting 40% of the Swedish population, have had an almost complete registration. The following parameters are registered: diagnosis according to SNOMED/WHO classification, symptoms, performance status, pre- and postoperative radiology, tumor size and localization, extent of surgery and occurrence of postoperative complications, postoperative treatment, such as radiotherapy and/or chemotherapy, other treatments, complications and toxicity, occurrence of reoperation/s, participation in clinical trials, multidisciplinary conferences and availability of a contact nurse.

Results. Surgical radicality has been essentially constant, whereas the use of early (within 72 hours) postoperative CT and MRI has increased, especially for high-grade glioma, which is a reflection of quality of surgery. Survival of patients with high-grade glioma has increased, especially in the age group 60-69. Patients aged 18-39 years had a five-year survival of 40%. Waiting times for the pathological report has been slightly prolonged. Geographical differences do exist for some of the variables.

Conclusion. Population-based registration is valuable for assessment of clinical management, which could have impact on patient care. As a result of short survival and/or the propensity to affect cognitive functions this patient group has considerable difficulties to make their voices heard in society. We therefore believe that a report like the present one can contribute to the spread of knowledge and increase the awareness for this patient group among caregivers and policy makers.

National Category
Cancer and Oncology
Identifiers
urn:nbn:se:umu:diva-102463 (URN)10.3109/0284186X.2014.975369 (DOI)000350646400011 ()25383446 (PubMedID)
Available from: 2015-05-19 Created: 2015-04-26 Last updated: 2018-06-07Bibliographically approved
Holgersson, G., Bergström, S., Liv, P., Nilsson, J., Edlund, P., Blomberg, C., . . . Bergqvist, M. (2015). Effect of Increased Radiotoxicity on Survival of Patients with Non-small Cell Lung Cancer Treated with Curatively Intended Radiotherapy. Anticancer Research, 35(10), 5491-5497
Open this publication in new window or tab >>Effect of Increased Radiotoxicity on Survival of Patients with Non-small Cell Lung Cancer Treated with Curatively Intended Radiotherapy
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2015 (English)In: Anticancer Research, ISSN 0250-7005, E-ISSN 1791-7530, Vol. 35, no 10, p. 5491-5497Article in journal (Refereed) Published
Abstract [en]

Aim: To elucidate the impact of different forms of radiation toxicities (esophagitis, radiation pneumonitis, mucositis and hoarseness), on the survival of patients treated with curatively intended radiotherapy for non-small cell lung cancer (NSCLC).

Patients and Methods: Data were individually collected retrospectively for all patients diagnosed with NSCLC subjected to curatively intended radiotherapy (>= 50 Gy) in Sweden during the time period 1990 to 2000.

Results: Esophagitis was the only radiation-induced toxicity with an impact on survival (hazard ratio=0.83, p=0.016). However, in a multivariate model, with clinical-and treatment-related factors taken into consideration, the impact of esophagitis on survival was no longer statistically significant (hazard ratio=0.88, p=0.17).

Conclusion: The effect on survival seen in univariate analysis may be related to higher radiation dose and to the higher prevalence of chemotherapy in this group. The results do not suggest that the toxicities examined have any detrimental effect on overall survival.

Keywords
NSCLC, radiotherapy, toxicity, esophagitis, survival
National Category
Cancer and Oncology
Identifiers
urn:nbn:se:umu:diva-121219 (URN)000361823200042 ()26408714 (PubMedID)
Available from: 2016-05-30 Created: 2016-05-30 Last updated: 2018-06-07Bibliographically approved
Brynolfsson, P., Nilsson, D., Henriksson, R., Hauksson, J., Karlsson, M., Garpebring, A., . . . Asklund, T. (2014). ADC texture-An imaging biomarker for high-grade glioma?. Medical physics (Lancaster), 41(10), 101903
Open this publication in new window or tab >>ADC texture-An imaging biomarker for high-grade glioma?
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2014 (English)In: Medical physics (Lancaster), ISSN 0094-2405, Vol. 41, no 10, p. 101903-Article in journal (Refereed) Published
Abstract [en]

Purpose:

Survival for high-grade gliomas is poor, at least partly explained by intratumoral heterogeneity contributing to treatment resistance. Radiological evaluation of treatment response is in most cases limited to assessment of tumor size months after the initiation of therapy. Diffusion-weighted magnetic resonance imaging (MRI) and its estimate of the apparent diffusion coefficient (ADC) has been widely investigated, as it reflects tumor cellularity and proliferation. The aim of this study was to investigate texture analysis of ADC images in conjunction with multivariate image analysis as a means for identification of pretreatment imaging biomarkers.

Methods:

Twenty-three consecutive high-grade glioma patients were treated with radiotherapy (2 Gy/60 Gy) with concomitant and adjuvant temozolomide. ADC maps and T1-weighted anatomical images with and without contrast enhancement were collected prior to treatment, and (residual) tumor contrast enhancement was delineated. A gray-level co-occurrence matrix analysis was performed on the ADC maps in a cuboid encapsulating the tumor in coronal, sagittal, and transversal planes, giving a total of 60 textural descriptors for each tumor. In addition, similar examinations and analyses were performed at day 1, week 2, and week 6 into treatment. Principal component analysis (PCA) was applied to reduce dimensionality of the data, and the five largest components (scores) were used in subsequent analyses. MRI assessment three months after completion of radiochemotherapy was used for classifying tumor progression or regression.

Results:

The score scatter plots revealed that the first, third, and fifth components of the pretreatment examinations exhibited a pattern that strongly correlated to survival. Two groups could be identified: one with a median survival after diagnosis of 1099 days and one with 345 days, p = 0.0001.

Conclusions:

By combining PCA and texture analysis, ADC texture characteristics were identified, which seems to hold pretreatment prognostic information, independent of known prognostic factors such as age, stage, and surgical procedure. These findings encourage further studies with a larger patient cohort. (C) 2014 Author(s).

Keywords
texture analysis, glioma, multivariate image analysis, ADC
National Category
Medical and Health Sciences
Identifiers
urn:nbn:se:umu:diva-96625 (URN)10.1118/1.4894812 (DOI)000343032400019 ()
Available from: 2014-11-27 Created: 2014-11-24 Last updated: 2018-06-07Bibliographically approved
Johansson, A., Garpebring, A., Asklund, T. & Tufve, N. (2014). CT substitutes derived from MR images reconstructed with parallel imaging. Medical physics (Lancaster), 41(8), 474-480
Open this publication in new window or tab >>CT substitutes derived from MR images reconstructed with parallel imaging
2014 (English)In: Medical physics (Lancaster), ISSN 0094-2405, Vol. 41, no 8, p. 474-480Article in journal (Refereed) Published
Abstract [en]

Purpose: Computed tomography (CT) substitute images can be generated from ultrashort echo time (UTE) MRI sequences with radial k-space sampling. These CT substitutes can be used as ordinary CT images for PET attenuation correction and radiotherapy dose calculations. Parallel imaging allows faster acquisition of magnetic resonance (MR) images by exploiting differences in receiver coil element sensitivities. This study investigates whether non-Cartesian parallel imaging reconstruction can be used to improve CT substitutes generated from shorter examination times.

Methods: The authors used gridding as well as two non-Cartesian parallel imaging reconstruction methods, SPIRiT and CG-SENSE, to reconstruct radial UTE and gradient echo (GE) data into images of the head for 23 patients. For each patient, images were reconstructed from the full dataset and from a number of subsampled datasets. The subsampled datasets simulated shorter acquisition times by containing fewer radial k-space spokes (1000, 2000, 3000, 5000, and 10 000 spokes) than the full dataset (30 000 spokes). For each combination of patient, reconstruction method, and number of spokes, the reconstructed UTE and GE images were used to generate a CT substitute. Each CT substitute image was compared to a real CT image of the same patient.

Results: The mean absolute deviation between the CT number in CT substitute and CT decreased when using SPIRiT as compared to gridding reconstruction. However, the reduction was small and the CT substitute algorithm was insensitive to moderate subsampling (≥5000 spokes) regardless of reconstruction method. For more severe subsampling (≤3000 spokes), corresponding to acquisition times less than aminute long, the CT substitute quality was deteriorated for all reconstructionmethods but SPIRiT gave a reduction in the mean absolute deviation of down to 25 Hounsfield units compared to gridding.

Conclusions: SPIRiT marginally improved the CT substitute quality for a given number of radial spokes as compared to gridding. However, the increased reconstruction time of non-Cartesian parallel imaging reconstruction is difficult to motivate from this improvement. Because the CT substitute algorithm was insensitive to moderate subsampling, data for a CT substitute could be collected in as little as minute and reconstructed with gridding without deteriorating the CT substitute quality.

Keywords
magnetic resonance imaging, computed tomography substitute, ultrashort echo time, parallel imaging, radial imaging
National Category
Physical Sciences
Research subject
radiofysik
Identifiers
urn:nbn:se:umu:diva-93051 (URN)10.1118/1.4886766 (DOI)000341068100043 ()
Available from: 2014-09-11 Created: 2014-09-11 Last updated: 2018-06-07Bibliographically approved
Rosenlund, L., Henriksson, R., Asklund, T. & Petersson, L. (2014). Developing Patient Reported Outcome Measures (PRO) for Implementation in the Swedish National Quality Register for Primary Brain Tumors. Paper presented at 11th Congress of the European-Association-of-Neuro-Oncology, Turin, ITALY, OCT 09-12, 2014. Neuro-Oncology, 16(Suppl. 2), Meeting Abstract: P15.14
Open this publication in new window or tab >>Developing Patient Reported Outcome Measures (PRO) for Implementation in the Swedish National Quality Register for Primary Brain Tumors
2014 (English)In: Neuro-Oncology, ISSN 1522-8517, E-ISSN 1523-5866, Vol. 16, no Suppl. 2, p. Meeting Abstract: P15.14-Article in journal, Meeting abstract (Refereed) Published
Place, publisher, year, edition, pages
Oxford University Press, 2014
National Category
Cancer and Oncology
Identifiers
urn:nbn:se:umu:diva-96965 (URN)10.1093/neuonc/nou174 (DOI)000344235700294 ()
Conference
11th Congress of the European-Association-of-Neuro-Oncology, Turin, ITALY, OCT 09-12, 2014
Available from: 2014-12-09 Created: 2014-12-05 Last updated: 2018-06-07Bibliographically approved
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