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  • 1. Jäderling, Fredrik
    et al.
    Akre, Olof
    Aly, Markus
    Björklund, Johan
    Olsson, Mats
    Adding, Christofer
    Öberg, Michael
    Blomqvist, Lennart
    Umeå University, Faculty of Medicine, Department of Radiation Sciences. Department of Molecular Medicine and Surgery, Karolinska Institutet, Stockholm, Sweden Department of Urology, Karolinska University Hospital, Solna, Sweden.
    Nyberg, Tommy
    Wiklund, Peter
    Carlsson, Stefan
    Preoperative staging using magnetic resonance imaging and risk of positive surgical margins after prostate-cancer surgery2019In: Prostate Cancer and Prostatic Diseases, ISSN 1365-7852, E-ISSN 1476-5608, Vol. 22, no 3, p. 391-398Article in journal (Refereed)
    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.

  • 2. Jäderling, Fredrik
    et al.
    Nyberg, Tommy
    Öberg, Michael
    Carlsson, Stefan
    Skorpil, Mikael
    Umeå University, Faculty of Medicine, Department of Radiation Sciences. Department of Radiology, Uppsala University Hospital, Uppsala, Sweden.
    Blomqvist, Lennart
    Umeå University, Faculty of Medicine, Department of Radiation Sciences. Department of Radiology, Karolinska University Hospital, Solna, Sweden; Department of Molecular Medicine and Surgery, Karolinska Institutet, Stockholm, Sweden.
    Accuracy in local staging of prostate cancer by adding a three-dimensional T2-weighted sequence with radial reconstructions in magnetic resonance imaging2018In: Acta radiologica open, E-ISSN 2058-4601, Vol. 7, no 2Article in journal (Refereed)
    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.

  • 3.
    Nyholm, Tufve
    et al.
    Umeå University, Faculty of Medicine, Department of Radiation Sciences.
    Svensson, Stina
    Andersson, Sebastian
    Jonsson, Joakim
    Umeå University, Faculty of Medicine, Department of Radiation Sciences.
    Sohlin, Maja
    Gustafsson, Christian
    Kjellén, Elisabeth
    Söderström, Karin
    Umeå University, Faculty of Medicine, Department of Radiation Sciences.
    Albertsson, Per
    Blomqvist, Lennart
    Umeå University, Faculty of Medicine, Department of Radiation Sciences. Department of Molecular Medicine and Surgery, Karolinska Institutet, Stockholm, Sweden.
    Zackrisson, Björn
    Umeå University, Faculty of Medicine, Department of Radiation Sciences.
    Olsson, Lars E.
    Gunnlaugsson, Adalsteinn
    MR and CT data with multiobserver delineations of organs in the pelvic area: Part of the Gold Atlas project2018In: Medical physics (Lancaster), ISSN 0094-2405, Vol. 45, no 3, p. 1295-1300Article in journal (Refereed)
    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.

  • 4. Persson, Emilia
    et al.
    Gustafsson, Christian
    Nordström, Fredrik
    Sohlin, Maja
    Gunnlaugsson, Adalsteinn
    Petruson, Karin
    Rintelä, Niina
    Hed, Kristoffer
    Blomqvist, Lennart
    Umeå University, Faculty of Medicine, Department of Radiation Sciences.
    Zackrisson, Björn
    Umeå University, Faculty of Medicine, Department of Radiation Sciences.
    Nyholm, Tufve
    Umeå University, Faculty of Medicine, Department of Radiation Sciences.
    Olsson, Lars E.
    Siversson, Carl
    Jonsson, Joakim
    Umeå University, Faculty of Medicine, Department of Radiation Sciences.
    MR-OPERA: a multicenter/multivendor validation of magnetic resonance imaging–only prostate treatment planning using synthetic computed tomography images2017In: International Journal of Radiation Oncology, Biology, Physics, ISSN 0360-3016, E-ISSN 1879-355X, Vol. 99, no 3, p. 692-700Article in journal (Refereed)
    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.

  • 5.
    Rutegård, Miriam
    et al.
    Umeå University, Faculty of Medicine, Department of Radiation Sciences, Diagnostic Radiology.
    Båtsman, Malin
    Umeå University, Faculty of Medicine, Department of Medical Biosciences, Pathology.
    Axelsson, Jan
    Umeå University, Faculty of Medicine, Department of Radiation Sciences, Diagnostic Radiology.
    Brynolfsson, Patrik
    Umeå University, Faculty of Medicine, Department of Radiation Sciences, Diagnostic Radiology.
    Brännström, Fredrik
    Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences, Surgery.
    Rutegård, Jörgen
    Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences, Surgery.
    Ljuslinder, Ingrid
    Umeå University, Faculty of Medicine, Department of Radiation Sciences, Oncology.
    Blomqvist, Lennart
    Umeå University, Faculty of Medicine, Department of Radiation Sciences, Diagnostic Radiology.
    Palmqvist, Richard
    Umeå University, Faculty of Medicine, Department of Medical Biosciences, Pathology.
    Rutegård, Martin
    Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences, Surgery.
    Riklund, Katrine
    Umeå University, Faculty of Medicine, Department of Radiation Sciences, Diagnostic Radiology.
    PET/MRI and PET/CT hybrid imaging of rectal cancer - description and initial observations from the RECTOPET (REctal Cancer trial on PET/MRI/CT) study2019In: Cancer Imaging, ISSN 1740-5025, E-ISSN 1470-7330, Vol. 19, article id 52Article in journal (Refereed)
    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.

  • 6.
    Sandgren, Kristina
    et al.
    Umeå University, Faculty of Medicine, Department of Radiation Sciences.
    Jonsson, Joakim
    Umeå University, Faculty of Medicine, Department of Radiation Sciences.
    Nyholm, Tufve
    Umeå University, Faculty of Medicine, Department of Radiation Sciences.
    Strandberg, Sara
    Umeå University, Faculty of Medicine, Department of Radiation Sciences.
    Ögren, M.
    Umeå University, Faculty of Medicine, Department of Radiation Sciences.
    Axelsson, Jan
    Umeå University, Faculty of Medicine, Department of Radiation Sciences.
    Blomqvist, Lennart
    Umeå University, Faculty of Medicine, Department of Radiation Sciences.
    Friedrich, Bengt
    Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences, Urology and Andrology.
    Bergh, Anders
    Umeå University, Faculty of Medicine, Department of Medical Biosciences.
    Ahlström Riklund, Katrine
    Umeå University, Faculty of Medicine, Department of Radiation Sciences.
    Windmark, Anders
    Umeå University, Faculty of Medicine, Department of Radiation Sciences.
    Histology correlation of in vivo [68Ga]PSMA-PET/MRI data of the prostate2018In: Radiotherapy and Oncology, ISSN 0167-8140, E-ISSN 1879-0887, Vol. 127, p. S541-S541Article in journal (Other academic)
  • 7.
    Sandgren, Kristina
    et al.
    Umeå University, Faculty of Medicine, Department of Radiation Sciences.
    Westerlinck, Philippe
    Jonsson, Joakim H
    Umeå University, Faculty of Medicine, Department of Radiation Sciences.
    Blomqvist, Lennart
    Umeå University, Faculty of Medicine, Department of Radiation Sciences. Department of Molecular Medicine and Surgery, Karolinska Institutet, Stockholm, Sweden.
    Thellenberg Karlsson, Camilla
    Umeå University, Faculty of Medicine, Department of Radiation Sciences.
    Nyholm, Tufve
    Umeå University, Faculty of Medicine, Department of Radiation Sciences. Department of Immunology, Genetics, and Pathology, Medical Radiation Science, Uppsala University, Uppsala, Sweden.
    Dirix, Piet
    Imaging for the Detection of Locoregional Recurrences in Biochemical Progression After Radical Prostatectomy: A Systematic Review2017In: European Urology Focus, ISSN 2405-4569Article, review/survey (Refereed)
    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.

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