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Blomqvist, Lennart
Publications (7 of 7) Show all publications
Rutegård, M., Båtsman, M., Axelsson, J., Brynolfsson, P., Brännström, F., Rutegård, J., . . . Riklund, K. (2019). PET/MRI and PET/CT hybrid imaging of rectal cancer - description and initial observations from the RECTOPET (REctal Cancer trial on PET/MRI/CT) study. Cancer Imaging, 19, Article ID 52.
Open this publication in new window or tab >>PET/MRI and PET/CT hybrid imaging of rectal cancer - description and initial observations from the RECTOPET (REctal Cancer trial on PET/MRI/CT) study
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2019 (English)In: Cancer Imaging, ISSN 1740-5025, E-ISSN 1470-7330, Vol. 19, article id 52Article in journal (Refereed) Published
Abstract [en]

PurposeThe role of hybrid imaging using F-18-fluoro-2-deoxy-D-glucose positron-emission tomography (FDG-PET), computed tomography (CT) and magnetic resonance imaging (MRI) to improve preoperative evaluation of rectal cancer is largely unknown. To investigate this, the RECTOPET (REctal Cancer Trial on PET/MRI/CT) study has been launched with the aim to assess staging and restaging of primary rectal cancer. This report presents the study workflow and the initial experiences of the impact of PET/CT on staging and management of the first patients included in the RECTOPET study.MethodsThis prospective cohort study, initiated in September 2016, is actively recruiting patients from Region Vasterbotten in Sweden. This pilot study includes patients recruited and followed up until December 2017. All patients had a biopsy-verified rectal adenocarcinoma and underwent a minimum of one preoperative FDG-PET/CT and FDG-PET/MRI examination. These patients were referred to the colorectal cancer multidisciplinary team meeting at Umea University Hospital. All available data were evaluated when making management recommendations. The clinical course was noted and changes consequent to PET imaging were described; surgical specimens underwent dedicated MRI for anatomical matching between imaging and histopathology.ResultsTwenty-four patients have so far been included in the study. Four patients were deemed unresectable, while 19 patients underwent or were scheduled for surgery; one patient was enrolled in a watch-and-wait programme after restaging. Consequent to taking part in the study, two patients were upstaged to M1 disease: one patient was diagnosed with a solitary hepatic metastasis detected using PET/CT and underwent metastasectomy prior to rectal cancer surgery, while one patient with a small, but metabolically active, lung nodulus experienced no change of management. PET/MRI did not contribute to any recorded change in patient management.ConclusionsThe RECTOPET study investigating the role of PET/CT and PET/MRI for preoperative staging of primary rectal cancer patients will provide novel data that clarify the value of adding hybrid to conventional imaging, and the role of PET/CT versus PET/MRI.Trial registrationNCT03846882.

Place, publisher, year, edition, pages
BMC, 2019
Keywords
Rectal neoplasm, Rectal tumour, Staging, Lymph nodes, Tumour deposits, PET, CT, FDG-PET, CT, PET
National Category
Cancer and Oncology
Identifiers
urn:nbn:se:umu:diva-161991 (URN)10.1186/s40644-019-0237-1 (DOI)000477054900002 ()31337428 (PubMedID)
Available from: 2019-08-13 Created: 2019-08-13 Last updated: 2019-08-13Bibliographically approved
Jäderling, F., Akre, O., Aly, M., Björklund, J., Olsson, M., Adding, C., . . . Carlsson, S. (2019). Preoperative staging using magnetic resonance imaging and risk of positive surgical margins after prostate-cancer surgery. Prostate Cancer and Prostatic Diseases, 22(3), 391-398
Open this publication in new window or tab >>Preoperative staging using magnetic resonance imaging and risk of positive surgical margins after prostate-cancer surgery
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2019 (English)In: Prostate Cancer and Prostatic Diseases, ISSN 1365-7852, E-ISSN 1476-5608, Vol. 22, no 3, p. 391-398Article in journal (Refereed) Published
Abstract [en]

Background: It is unclear whether preoperative staging using Magnetic Resonance Imaging (MRI) reduces the risk of positive margins in prostate cancer. We aimed to assess the effect on surgical margins and degree of nerve sparing of a pelvic MRI presented at a preoperative MRI conference. Methods: Single institution, observational cohort study including 1037 men that underwent robot assisted radical prostatectomy between October 2013 and June 2015. Of these, 557 underwent a preoperative MRI combined with a preoperative MRI conference and 410 did not. With whole-mount prostate specimen histopathology as gold standard we assessed the ability of MRI in finding the index tumor and the sensitivity and specificity for extra prostatic extension. We calculated relative risks for positive surgical margins and non-nerve sparing procedure, adjusting for preoperative risk factors using stabilized inverse-probability weighting. Results: MRI detected the index tumor in 80% of the cases. Non-organ confined disease (pT3) at histology was present in the MRI and the non-MRI group in 42% and 24%, respectively. Rate of positive surgical margins comparing the MRI and non-MRI groups was 26.7% and 33.7%, respectively, relative risk 0.79 [95% CI 0.65-0.96], weighted relative risk (wRR) 0.69 [95% CI 0.55-0.86]. The wRR of extensive positive surgical margins was 0.45 [95% CI 0.31-0.67]. Undergoing MRI was also associated with an increased risk of being operated with a non-nerve sparing technique (wRR, 1.84 [95% CI 1.11-3.03]). Conclusions: Our study suggests that preoperative prostate MRI in combination with a preoperative MRI conference affects the degree of nerve-sparing surgery and reduces positive surgical margins.

Place, publisher, year, edition, pages
Nature Publishing Group, 2019
National Category
Cancer and Oncology Urology and Nephrology
Identifiers
urn:nbn:se:umu:diva-162837 (URN)10.1038/s41391-018-0116-z (DOI)000480651400005 ()30504811 (PubMedID)
Available from: 2019-09-13 Created: 2019-09-13 Last updated: 2019-09-13Bibliographically approved
Jäderling, F., Nyberg, T., Öberg, M., Carlsson, S., Skorpil, M. & Blomqvist, L. (2018). Accuracy in local staging of prostate cancer by adding a three-dimensional T2-weighted sequence with radial reconstructions in magnetic resonance imaging. Acta radiologica open, 7(2)
Open this publication in new window or tab >>Accuracy in local staging of prostate cancer by adding a three-dimensional T2-weighted sequence with radial reconstructions in magnetic resonance imaging
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2018 (English)In: Acta radiologica open, E-ISSN 2058-4601, Vol. 7, no 2Article in journal (Refereed) Published
Abstract [en]

Background: The evidence supporting the use of magnetic resonance imaging (MRI) in prostate cancer detection has been established, but its accuracy in local staging is questioned. Purpose: To investigate the additional value of multi-planar radial reconstructions of a three-dimensional (3D) T2-weighted (T2W) MRI sequence, intercepting the prostate capsule perpendicularly, for improving local staging of prostate cancer. Material and Methods: Preoperative, bi-parametric prostate MRI examinations in 94 patients operated between June 2014 and January 2015 where retrospectively reviewed by two experienced abdominal radiologists. Each patient was presented in two separate sets including diffusion-weighted imaging, without and with the 3D T2W set that included radial reconstructions. Each set was read at least two months apart. Extraprostatic tumor extension (EPE) was assessed according to a 5-point grading scale. Sensitivity and specificity for EPE was calculated and presented as receiver operating characteristics (ROC) with area under the curve (AUC), using histology from whole-mount prostate specimen as gold standard. Inter-rater agreement was calculated for the two different reading modes using Cohen's kappa. Results: The AUC for detection of EPE for Readers 1 and 2 in the two-dimensional (2D) set was 0.70 and 0.68, respectively, and for the 2D+3D set 0.62 and 0.65, respectively. Inter-rater agreement (Reader 1 vs. Reader 2) on EPE using Cohen's kappa for the 2D and 2D+3D set, respectively, was 0.42 and 0.17 (i.e. moderate and poor agreement, respectively). Conclusion: The addition of 3D T2W MRI with radial reconstructions did not improve local staging in prostate cancer.

Place, publisher, year, edition, pages
Sage Publications, 2018
Keywords
Prostate cancer, magnetic resonance imaging, staging, three-dimensional T2-weighted imaging
National Category
Radiology, Nuclear Medicine and Medical Imaging
Identifiers
urn:nbn:se:umu:diva-145137 (URN)10.1177/2058460118754607 (DOI)000424787300001 ()
Available from: 2018-03-05 Created: 2018-03-05 Last updated: 2018-06-09Bibliographically 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
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
Sandgren, K., Westerlinck, P., Jonsson, J. H., Blomqvist, L., Thellenberg Karlsson, C., Nyholm, T. & Dirix, P. (2017). Imaging for the Detection of Locoregional Recurrences in Biochemical Progression After Radical Prostatectomy: A Systematic Review. European Urology Focus
Open this publication in new window or tab >>Imaging for the Detection of Locoregional Recurrences in Biochemical Progression After Radical Prostatectomy: A Systematic Review
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2017 (English)In: European Urology Focus, ISSN 2405-4569Article, review/survey (Refereed) In press
Abstract [en]

Context: Local and regional recurrence after radical prostatectomy (RP) can be treated using salvage radiotherapy (SRT). If the recurrence can be delineated on diagnostic imaging, this could allow for increasingly individualized SRT.

Objective: This systematic review aimed at evaluating the evidence regarding the usefulness of positron emission tomography (PET) and magnetic resonance imaging (MRI) in identifying local and regional recurrences, with the aim to further individualize the SRT treatment.

Evidence acquisition: A systematic PubMed/Medline search was conducted in December 2015. Studies included were imaging studies of post-RP patients focusing on local and/or regional recurrence where sensitivity and specificity of MRI or PET were the primary end points. Only studies using biopsy, other histological analysis, and/or treatment follow-up as reference standard were included. Quality Assessment of Diagnostic Accuracy Studies-2 was used to score the study quality. Twenty-five articles were deemed of sufficient quality and included in the review.

Evidence synthesis: [11C]Acetate had the highest pooled sensitivity (92%), while [11C]choline and [18F]choline had pooled sensitivities of 71% and 84%, respectively. The PET tracer with highest pooled specificity was [11C]choline (86%). Regarding MRI, MR spectroscopy combined with dynamic contrast enhanced (DCE) MRI showed the highest pooled sensitivity (89%). High pooled sensitivities were also seen using multiparametric MRI (84%), diffusion-weighted MRI combined with T2-weigthed (T2w) imaging (82%), and DCE MRI combined with T2w imaging (82%). These also showed high pooled specificities (85%, 89%, and 92%, respectively).

Conclusions: Both MRI and PET have adequate sensitivity and specificity for the detection of prostate cancer recurrences post-RP. Multiparametric MRI, using diffusion-weighted and/or DCE imaging, and the choline-labeled tracers showed high pooled sensitivity and specificity, although their ranges were broad.

Patient summary: After reviewing imaging studies of recurrent prostate cancer after prostatectomy, we concluded that choline positron emission tomography and diffusion-weighted magnetic resonance imaging can be proposed as the current standard, with high sensitivity and specificity.

Place, publisher, year, edition, pages
Elsevier, 2017
Keywords
Magnetic resonance imaging, Positron emission tomography, Prostate cancer, Recurrence, Salvage radiotherapy
National Category
Urology and Nephrology Medical Image Processing
Identifiers
urn:nbn:se:umu:diva-142318 (URN)10.1016/j.euf.2017.11.001 (DOI)29133278 (PubMedID)2-s2.0-85033577338 (Scopus ID)
Available from: 2017-11-27 Created: 2017-11-27 Last updated: 2019-02-22
Persson, E., Gustafsson, C., Nordström, F., Sohlin, M., Gunnlaugsson, A., Petruson, K., . . . Jonsson, J. (2017). MR-OPERA: a multicenter/multivendor validation of magnetic resonance imaging–only prostate treatment planning using synthetic computed tomography images. International Journal of Radiation Oncology, Biology, Physics, 99(3), 692-700
Open this publication in new window or tab >>MR-OPERA: a multicenter/multivendor validation of magnetic resonance imaging–only prostate treatment planning using synthetic computed tomography images
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2017 (English)In: International Journal of Radiation Oncology, Biology, Physics, ISSN 0360-3016, E-ISSN 1879-355X, Vol. 99, no 3, p. 692-700Article in journal (Refereed) Published
Abstract [en]

Purpose: To validate the dosimetric accuracy and clinical robustness of a commercially available software for magnetic resonance (MR) to synthetic computed tomography (sCT) conversion, in an MR imaging–only workflow for 170 prostate cancer patients.

Methods and Materials: The 4 participating centers had MriPlanner (Spectronic Medical), an atlas-based sCT generation software, installed as a cloud-based service. A T2-weighted MR sequence, covering the body contour, was added to the clinical protocol. The MR images were sent from the MR scanner workstation to the MriPlanner platform. The sCT was automatically returned to the treatment planning system. Four MR scanners and 2 magnetic field strengths were included in the study. For each patient, a CT-treatment plan was created and approved according to clinical practice. The sCT was rigidly registered to the CT, and the clinical treatment plan was recalculated on the sCT. The dose distributions from the CT plan and the sCT plan were compared according to a set of dose-volume histogram parameters and gamma evaluation. Treatment techniques included volumetric modulated arc therapy, intensity modulated radiation therapy, and conventional treatment using 2 treatment planning systems and different dose calculation algorithms.

Results: The overall (multicenter/multivendor) mean dose differences between sCT and CT dose distributions were below 0.3% for all evaluated organs and targets. Gamma evaluation showed a mean pass rate of 99.12% (0.63%, 1 SD) in the complete body volume and 99.97% (0.13%, 1 SD) in the planning target volume using a 2%/2-mm global gamma criteria.

Conclusions: Results of the study show that the sCT conversion method can be used clinically, with minimal differences between sCT and CT dose distributions for target and relevant organs at risk. The small differences seen are consistent between centers, indicating that an MR imaging–only workflow using MriPlanner is robust for a variety of field strengths, vendors, and treatment techniques.

Place, publisher, year, edition, pages
Elsevier, 2017
National Category
Radiology, Nuclear Medicine and Medical Imaging
Identifiers
urn:nbn:se:umu:diva-140632 (URN)10.1016/j.ijrobp.2017.06.006 (DOI)000411225300032 ()
Available from: 2017-10-18 Created: 2017-10-18 Last updated: 2018-06-09Bibliographically approved
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