umu.sePublications
Change search
Refine search result
1 - 17 of 17
CiteExportLink to result list
Permanent link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
Rows per page
  • 5
  • 10
  • 20
  • 50
  • 100
  • 250
Sort
  • Standard (Relevance)
  • Author A-Ö
  • Author Ö-A
  • Title A-Ö
  • Title Ö-A
  • Publication type A-Ö
  • Publication type Ö-A
  • Issued (Oldest first)
  • Issued (Newest first)
  • Created (Oldest first)
  • Created (Newest first)
  • Last updated (Oldest first)
  • Last updated (Newest first)
  • Disputation date (earliest first)
  • Disputation date (latest first)
  • Standard (Relevance)
  • Author A-Ö
  • Author Ö-A
  • Title A-Ö
  • Title Ö-A
  • Publication type A-Ö
  • Publication type Ö-A
  • Issued (Oldest first)
  • Issued (Newest first)
  • Created (Oldest first)
  • Created (Newest first)
  • Last updated (Oldest first)
  • Last updated (Newest first)
  • Disputation date (earliest first)
  • Disputation date (latest first)
Select
The maximal number of hits you can export is 250. When you want to export more records please use the Create feeds function.
  • 1.
    Adjeiwaah, Mary
    et al.
    Umeå University, Faculty of Medicine, Department of Radiation Sciences.
    Bylund, Mikael
    Umeå University, Faculty of Medicine, Department of Radiation Sciences.
    Lundman, Josef A.
    Umeå University, Faculty of Medicine, Department of Radiation Sciences.
    Söderström, Karin
    Umeå University, Faculty of Medicine, Department of Radiation Sciences.
    Zackrisson, Björn
    Umeå University, Faculty of Medicine, Department of Radiation Sciences.
    Jonsson, Joakim H.
    Umeå University, Faculty of Medicine, Department of Radiation Sciences.
    Garpebring, Anders
    Umeå University, Faculty of Medicine, Department of Radiation Sciences.
    Nyholm, Tufve
    Umeå University, Faculty of Medicine, Department of Radiation Sciences.
    Dosimetric Impact of MRI Distortions: A Study on Head and Neck Cancers2019In: International Journal of Radiation Oncology, Biology, Physics, ISSN 0360-3016, E-ISSN 1879-355X, Vol. 103, no 4, p. 994-1003Article in journal (Refereed)
    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.

  • 2.
    Adjeiwaah, Mary
    et al.
    Umeå University, Faculty of Medicine, Department of Radiation Sciences.
    Bylund, Mikael
    Umeå University, Faculty of Medicine, Department of Radiation Sciences.
    Lundman, Josef A.
    Umeå University, Faculty of Medicine, Department of Radiation Sciences.
    Thellenberg Karlsson, Camilla
    Umeå University, Faculty of Medicine, Department of Radiation Sciences.
    Jonsson, Joakim H.
    Umeå University, Faculty of Medicine, Department of Radiation Sciences.
    Nyholm, Tufve
    Umeå University, Faculty of Medicine, Department of Radiation Sciences. Medical Radiation Physics, Department of Immunology, Genetics and Pathology, Uppsala University, Uppsala, Sweden.
    Quantifying the effect of 3T MRI residual system and patient-induced susceptibility distortions on radiotherapy treatment planning for prostate cancer2018In: International Journal of Radiation Oncology, Biology, Physics, ISSN 0360-3016, E-ISSN 1879-355X, Vol. 100, no 2, p. 317-324Article in journal (Refereed)
    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%.

  • 3. Bosco, Cecilia
    et al.
    Garmo, Hans
    Adolfsson, Jan
    Stattin, Pär
    Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences, Urology and Andrology. Department of Surgical Sciences, Uppsala University, Uppsala, Sweden.
    Holmberg, Lars
    Nilsson, Per
    Gunnlaugsson, Adalsteinn
    Widmark, Anders
    Umeå University, Faculty of Medicine, Department of Radiation Sciences, Oncology.
    Van Hemelrijck, Mieke
    Prostate Cancer Radiation Therapy and Risk of Thromboembolic Events2017In: International Journal of Radiation Oncology, Biology, Physics, ISSN 0360-3016, E-ISSN 1879-355X, Vol. 97, no 5, p. 1026-1031Article in journal (Refereed)
    Abstract [en]

    Purpose: To investigate the risk of thromboembolic disease (TED) after radiation therapy (RT) with curative intent for prostate cancer (PCa). Patients and Methods: We identified all men who received RT as curative treatment (n=9410) and grouped according to external beam RT (EBRT) or brachytherapy (BT). By comparing with an age-and county-matched comparison cohort of PCa-free men (n = 46,826), we investigated risk of TED after RT using Cox proportional hazard regression models. The model was adjusted for tumor characteristics, demographics, comorbidities, PCa treatments, and known risk factors of TED, such as recent surgery and disease progression. Results: Between 2006 and 2013, 6232 men with PCa received EBRT, and 3178 underwent BT. A statistically significant association was found between EBRT and BT and risk of pulmonary embolism in the crude analysis. However, upon adjusting for known TED risk factors these associations disappeared. No significant associations were found between BT or EBRT and deep venous thrombosis. Conclusion: Curative RT for prostate cancer using contemporary methodologies was not associated with an increased risk of TED.

  • 4.
    Dasu, Alexandru
    et al.
    Umeå University, Faculty of Medicine, Department of Radiation Sciences, Radiation Physics.
    Toma-Daşu, Iuliana
    What is the Clinically Relevant Relative Biologic Effectiveness? A Warning for Fractionated Treatments With High Linear Energy Transfer Radiation2008In: International Journal of Radiation Oncology, Biology, Physics, ISSN 0360-3016, E-ISSN 1879-355X, Vol. 70, no 3, p. 867-874Article in journal (Refereed)
    Abstract [en]

    PURPOSE: To study the clinically relevant relative biologic effectiveness (RBE) of fractionated treatments with high linear energy transfer (LET) radiation and to identify the important factors that might influence the transfer of tolerance and curative levels from low LET radiation. These are important questions in the light of the growing interest for the therapeutic use of radiation with higher LET than electrons or photons.

    METHODS AND MATERIALS: The RBE of various fractionated schedules was analyzed with theoretical models for radiation effect, and the resulting predictions were compared with the published clinical and experimental data regarding fractionated irradiation with high LET radiation.

    RESULTS: The clinically relevant RBE increased for greater doses per fraction, in contrast to the predictions from single-dose experiments. Furthermore, the RBE for late-reacting tissues appeared to modify more quickly than that for early-reacting tissues. These aspects have quite important clinical implications, because the increased biologic effectiveness reported for this type of radiation would otherwise support the use of hypofractionation. Thus, the differential between acute and late-reacting tissues could put the late-reacting normal tissues at more risk from high LET irradiation; however, at the same time, it could increase the therapeutic window for slow-growing tumors.

    CONCLUSIONS: The modification of the RBE with the dose per fraction must be carefully taken into consideration when devising fractionated treatments with high LET radiation. Neglecting to do so might result in an avalanche of complications that could obscure the potential advantages of the therapeutic use of this type of radiation.

  • 5.
    Daşu, Alexandru
    et al.
    Umeå University, Faculty of Medicine, Department of Radiation Sciences, Radiation Physics.
    Toma-Daşu, Iuliana
    Franzén, Lars
    Umeå University, Faculty of Medicine, Department of Radiation Sciences, Oncology.
    Widmark, Anders
    Umeå University, Faculty of Medicine, Department of Radiation Sciences, Oncology.
    Nilsson, Per
    Umeå University, Faculty of Medicine, Department of Radiation Sciences, Radiation Physics.
    Secondary malignancies from prostate cancer radiation treatment: a risk analysis of the influence of target margins and fractionation patterns2011In: International Journal of Radiation Oncology, Biology, Physics, ISSN 0360-3016, E-ISSN 1879-355X, Vol. 79, no 3, p. 738-746Article in journal (Refereed)
    Abstract [en]

    The results have shown the complex interplay between the risk for secondary malignancies, the details of the treatment delivery, and the patient heterogeneity that may influence comparisons between the long-term effects of various treatment techniques. Nevertheless, absolute risk levels seem very small and comparable to mortality risks from surgical interventions, thus supporting the robustness of radiation therapy as a successful treatment modality for prostate carcinomas.

  • 6. Degerfält, J. E.
    et al.
    Sjöstedt, S.
    Fransson, Per
    Umeå University, Faculty of Medicine, Department of Nursing.
    Kjellén, E.
    Werner, M. U.
    E-learning programs in oncology: a nationwide experience from 2005 to 20142016In: International Journal of Radiation Oncology, Biology, Physics, ISSN 0360-3016, E-ISSN 1879-355X, Vol. 96, no 2, p. E413-E414Article in journal (Refereed)
  • 7.
    Fransson, Per
    et al.
    Umeå University, Faculty of Medicine, Department of Radiation Sciences, Oncology.
    Bergström, Per
    Umeå University, Faculty of Medicine, Department of Radiation Sciences, Oncology.
    Löfroth, Per-Olov
    Umeå University, Faculty of Medicine, Department of Radiation Sciences, Radiation Physics.
    Widmark, Anders
    Umeå University, Faculty of Medicine, Department of Radiation Sciences, Oncology.
    Five-year prospective patient evaluation of bladder and bowel symptoms after dose-escalated radiotherapy for prostate cancer with the Beamcath (R) technique2006In: International Journal of Radiation Oncology, Biology, Physics, ISSN 0360-3016, E-ISSN 1879-355X, Vol. 66, no 2, p. 430-438Article in journal (Refereed)
    Abstract [en]

    Purpose: Late side effects were prospectively evaluated up to 5 years after dose-escalated external beam radiotherapy (EBRT) and were compared with a previously treated series with conventional conformal technique.

    Methods and Materials: Bladder and bowel symptoms were prospectively evaluated with the Prostate Cancer Symptom Scale (PCSS) questionnaire up to 5 years posttreatment. In all, 257 patients completed the questionnaire 5 years posttreatment. A total of 168 patients were treated with the conformal technique at doses <71 Gy, and 195 were treated with the dose-escalated stereotactic BeamCath® technique comprising three dose levels: 74 Gy (n = 68), 76 Gy (n = 74), and 78 Gy (n = 53).

    Results: For all dose groups analyzed together, 5 years after treatment, urinary starting problems decreased and urinary incontinence increased in comparison to baseline values. No increase in other bladder symptoms or frequency was detected. When comparing dose groups after 5 years, both the 74-Gy and 78-Gy groups reported increased urinary starting problems compared with patients given the conventional dose (<71 Gy). No increased incontinence was seen in the 76-Gy or the 78-Gy groups. Bowel symptoms were slightly increased during the follow-up period in comparison to baseline. Dose escalation with stereotactic EBRT (74–78 Gy) did not increase gastrointestinal late side effects after 5 years in comparison to doses <71 Gy.

    Conclusion: Dose-escalated EBRT with the BeamCath® technique with doses up to 78 Gy is tolerable, and the toxicity profile is similar to that observed with conventional doses <71 Gy.

  • 8.
    Jonsson, Joakim H
    et al.
    Umeå University, Faculty of Medicine, Department of Radiation Sciences, Radiation Physics.
    Garpebring, Anders
    Umeå University, Faculty of Medicine, Department of Radiation Sciences, Radiation Physics.
    Karlsson, Magnus G
    Umeå University, Faculty of Medicine, Department of Radiation Sciences, Radiation Physics.
    Nyholm, Tufve
    Umeå University, Faculty of Medicine, Department of Radiation Sciences, Radiation Physics.
    Internal fiducial markers and susceptibility effects in MRI: simulation and measurement of spatial accuracy2012In: International Journal of Radiation Oncology, Biology, Physics, ISSN 0360-3016, E-ISSN 1879-355X, Vol. 82, no 5, p. 1612-1618Article in journal (Refereed)
    Abstract [en]

    BACKGROUND: It is well-known that magnetic resonance imaging (MRI) is preferable to computed tomography (CT) in radiotherapy target delineation. To benefit from this, there are two options available: transferring the MRI delineated target volume to the planning CT or performing the treatment planning directly on the MRI study. A precondition for excluding the CT study is the possibility to define internal structures visible on both the planning MRI and on the images used to position the patient at treatment. In prostate cancer radiotherapy, internal gold markers are commonly used, and they are visible on CT, MRI, x-ray, and portal images. The depiction of the markers in MRI are, however, dependent on their shape and orientation relative the main magnetic field because of susceptibility effects. In the present work, these effects are investigated and quantified using both simulations and phantom measurements.

    METHODS AND MATERIALS: Software that simulated the magnetic field distortions around user defined geometries of variable susceptibilities was constructed. These magnetic field perturbation maps were then reconstructed to images that were evaluated. The simulation software was validated through phantom measurements of four commercially available gold markers of different shapes and one in-house gold marker.

    RESULTS: Both simulations and phantom measurements revealed small position deviations of the imaged marker positions relative the actual marker positions (<1 mm).

    CONCLUSION: Cylindrical gold markers can be used as internal fiducial markers in MRI.

  • 9. Lassen, P.
    et al.
    Lacas, B.
    Pignon, J. P.
    Trotti, A.
    Zackrisson, Björn
    Umeå University, Faculty of Medicine, Department of Radiation Sciences, Oncology.
    Zhang, Q.
    Overgaard, J.
    Blanchard, P.
    Prognostic Impact of HPV-Associated p16 Expression and Smoking Status on Outcomes Following Radiation Therapy for Oropharyngeal Cancer: the MARCH-HPV Project2018In: International Journal of Radiation Oncology, Biology, Physics, ISSN 0360-3016, E-ISSN 1879-355X, Vol. 100, no 5, p. 1332-1332Article in journal (Other academic)
  • 10.
    Lindvall, Peter
    et al.
    Umeå University, Faculty of Medicine, Department of Pharmacology and Clinical Neuroscience, Neurosurgery.
    Bergström, Per
    Umeå University, Faculty of Medicine, Department of Radiation Sciences, Oncology.
    Löfroth, Per-Olov
    Umeå University, Faculty of Medicine, Department of Radiation Sciences, Radiation Physics.
    Henriksson, Roger
    Umeå University, Faculty of Medicine, Department of Radiation Sciences, Oncology.
    Bergenheim, A Tommy
    Umeå University, Faculty of Medicine, Department of Pharmacology and Clinical Neuroscience, Neurosurgery.
    Hypofractionated conformal stereotactic radiotherapy alone or in combination with whole-brain radiotherapy in patients with cerebral metastases2005In: International Journal of Radiation Oncology, Biology, Physics, ISSN 0360-3016, E-ISSN 1879-355X, Vol. 61, no 5, p. 1460-1466Article in journal (Refereed)
  • 11. 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.

  • 12. Pixberg, Caroline
    et al.
    Koch, Raphael
    Eich, Hans Theodor
    Martinsson, Ulla
    Kristensen, Ingrid
    Matuschek, Christiane
    Kortmann, Rolf-Dieter
    Pohl, Fabian
    Elsayad, Khaled
    Christiansen, Hans
    Willich, Normann
    Lindh, Jack
    Umeå University, Faculty of Medicine, Department of Radiation Sciences.
    Steinmann, Diana
    Acute Toxicity Grade 3 and 4 After Irradiation in Children and Adolescents: Results From the IPPARCA Collaboration2016In: International Journal of Radiation Oncology, Biology, Physics, ISSN 0360-3016, E-ISSN 1879-355X, Vol. 94, no 4, p. 792-799Article in journal (Refereed)
    Abstract [en]

    Purpose: In the context of oncologic therapy for children, radiation therapy is frequently indicated. This study identified the frequency of and reasons for the development of high-grade acute toxicity and possible sequelae.

    Materials and Methods: Irradiated children have been prospectively documented since 2001 in the Registry for the Evaluation of Side Effects After Radiation in Childhood and Adolescence (RiSK) database in Germany and since 2008 in the registry for radiation therapy toxicity (RADTOX) in Sweden. Data were collected using standardized, published forms. Toxicity classification was based on Radiation Therapy Oncology Group/European Organization for Research and Treatment of Cancer criteria.

    Results: As of June 2013, 1500 children have been recruited into the RiSK database and 485 into the RADTOX registry leading to an analysis population of 1359 patients (age range 0-18). A total of 18.9% (n=257) of all investigated patients developed high-grade acute toxicity (grades 3/4). High-grade toxicity of the bone marrow was documented for 63.8% (n=201) of those patients, oral mucositis for 7.6% (n=24), and dermatitis for 7.6% (n=24). Patients with high-grade acute toxicity received concomitant chemotherapy more frequently (56%) than patients with no or lower acute toxicity (31.5%). In multivariate analyses, concomitant chemotherapy, diagnosis of Ewing sarcoma, and total radiation dose showed a statistically noticeable effect (P <=.05) on acute toxicity, whereas age, concomitant chemotherapy, Hodgkin lymphoma, Ewing sarcoma, total radiation dose, and acute toxicity influenced the time until maximal late toxicity.

    Conclusions: Generally, high-grade acute toxicity after irradiation in children and adolescence occurs in a moderate proportion of patients (18.9%). As anticipated, the probability of acute toxicity appeared to depend on the prescribed dose as well as concomitant chemotherapy. The occurrence of chronic toxicity correlates with the prior acute toxicity grade. Age seems to influence the time until maximal late toxicity but not the development of acute toxicity.

  • 13. Reidunsdatter, Randi J.
    et al.
    Lund, Jo-AÅmund
    Fransson, Per
    Umeå University, Faculty of Medicine, Department of Radiation Sciences, Oncology.
    Widmark, Anders
    Umeå University, Faculty of Medicine, Department of Radiation Sciences, Oncology.
    Fosså, Sophie D
    Kaasa, Stein
    Validation of the intestinal part of the prostate cancer questionnaire "QUFW94": psychometric properties, responsiveness, and content validity2010In: International Journal of Radiation Oncology, Biology, Physics, ISSN 0360-3016, E-ISSN 1879-355X, Vol. 77, no 3, p. 793-804Article in journal (Refereed)
    Abstract [en]

    PURPOSE: Several treatment options are available for patients with prostate cancer. Applicable and valid self-assessment instruments for assessing health-related quality of life (HRQOL) are of paramount importance. The aim of this study was to explore the validity and responsiveness of the intestinal part of the prostate cancer-specific questionnaire QUFW94. METHODS AND MATERIALS: The content of the intestinal part of QUFW94 was examined by evaluation of experienced clinicians and reviewing the literature. The psychometric properties and responsiveness were assessed by analyzing HRQOL data from the randomized study Scandinavian Prostate Cancer Group 7 (SPCG)/Swedish Association for Urological Oncology 3 (SFUO). Subscales were constructed by means of exploratory factor analyses. Internal consistency was assessed by Cronbach's alpha. Responsiveness was investigated by comparing baseline scores with the 4-year posttreatment follow-up. RESULTS: The content validity was found acceptable, but some amendments were proposed. The factor analyses revealed two symptom scales. The first scale comprised five items regarding general stool problems, frequency, incontinence, need to plan toilet visits, and daily activity. Cronbach's alpha at 0.83 indicated acceptable homogeneity. The second scale was less consistent with a Cronbach's alpha at 0.55. The overall responsiveness was found to be very satisfactory. CONCLUSION: Two scales were identified in the bowel dimension of the QUFW94; the first one had good internal consistency. The responsiveness was excellent, and some modifications are suggested to strengthen the content validity.

  • 14.
    Rojas, Ana Maria
    et al.
    Umeå University, Faculty of Medicine, Department of Radiation Sciences.
    Hirst, Victoria K
    Calvert, Angela
    Johns, Helen
    Carbogen and nicotinamide as radiosensitisers in a murine mammary carcinoma using conventional and accelerated radiotherapy1996In: International Journal of Radiation Oncology, Biology, Physics, ISSN 0360-3016, E-ISSN 1879-355X, Vol. 34, no 2, p. 357-365Article in journal (Refereed)
    Abstract [en]

    PURPOSE: To compare the radiosensitivity of mouse tumors treated in air with conventional and accelerated radiotherapy with that of tumors treated in carbogen alone or carbogen combined with nicotinamide. METHODS AND MATERIALS: CaNT mammary tumors were irradiated with either 30 x-ray fractions in 6 weeks or 40 fractions in 26 days in air, carbogen alone, or carbogen combined with 120 mg/kg of nicotinamide (NAM), the latter given intraperitonealy 30 min before each fraction. The response to treatment was assessed using local control, weight loss, and metastasis-free survival. RESULTS: Both carbogen and carbogen plus nicotinamide significantly increased tumor radiosensitivity; enhancement ratios (ERs) in the 6-week regimen were similar to those seen in the accelerated schedule. The majority of the effect was achieved by carbogen alone but the addition of NAM further enhanced tumor radiosensitization (ERs of 1.5 and 1.4 for carbogen in the conventional and accelerated schedule, respectively, were significantly lower than ERs of 1.7 and 1.6 obtained with carbogen plus nicotinamide; p < or = 0.005). Treatment protraction significantly increased radioresistance, especially when tumors were treated under air. An extra 1.5 Gy per day was required in air to counterbalance proliferation; in carbogen alone and carbogen plus nicotinamide a dose loss of 0.9 and 0.6 Gy per day was observed, respectively. Compared with treatments in air alone delivered in 6 weeks, acceleration of treatment combined with carbogen and nicotinamide gave the greatest increase in tumor radiosensitization (ER = 1.9). No toxic side effects and no detrimental changes in body weight were encountered when the sensitizers were administered 30 times (one fraction per day) or 40 times (two fractions per day). In both regimens, the incidence of metastases in mice treated with carbogen or carbogen plus nicotinamide was similar to that seen in animals treated in air. There was, however, a nonsignificant trend of a higher proportion of mice with metastasis in the accelerated schedule compared with the 6-week schedule. CONCLUSIONS: In both conventional and accelerated experimental radiotherapy, carbogen alone or combined with a small clinically relevant dose of NAM were well tolerated, achieved large and significant increases in radiosensitization, and did not affect the incidence of metastases. The sparing of damage, resulting from extending the overall treatment time, was less when the sensitizers were administered than when irradiations were performed in air. The study suggests that clinical radiotherapy regimens, which aim to reduce hypoxic and/or tumor clonogen proliferation, would benefit from the use of carbogen, especially if the gas is combined with nicotinamide and treatment acceleration.

  • 15. Saran, F.
    et al.
    Henriksson, Roger
    Umeå University, Faculty of Medicine, Department of Radiation Sciences, Oncology. Regional Cancer Center Stockholm and Umeå University, Stockholm/Umeå.
    Mason, W.
    Wick, W.
    Nishikawa, R.
    Cloughesy, T.
    Hilton, M.
    Kerloeguen, Y.
    Chinot, O. L.
    The Addition of Bevacizumab (BEV) to Temozolomide (TMZ) and Radiation Therapy (RT) in Newly Diagnosed Glioblastoma (GBM) Improves Progression-Free Survival (PFS) Without Adding to RT Toxicity2013In: International Journal of Radiation Oncology, Biology, Physics, ISSN 0360-3016, E-ISSN 1879-355X, Vol. 87, no 2, Supplement S, p. S16-S16Article in journal (Other academic)
  • 16. Sorbe, Bengt
    et al.
    Horvath, György
    Andersson, Håkan
    Boman, Karin
    Umeå University, Faculty of Medicine, Department of Radiation Sciences, Oncology.
    Lundgren, Caroline
    Pettersson, Birgitta
    External Pelvic and Vaginal Irradiation Versus Vaginal Irradiation Alone as Postoperative Therapy in Medium-risk Endometrial Carcinoma-A Prospective Randomized Study.2012In: International Journal of Radiation Oncology, Biology, Physics, ISSN 0360-3016, E-ISSN 1879-355X, Vol. 82, no 3, p. 1249-1255Article in journal (Refereed)
    Abstract [en]

    PURPOSE: To evaluate the value of adjuvant external beam pelvic radiotherapy as adjunct to vaginal brachytherapy (VBT) in medium-risk endometrial carcinoma, with regard to locoregional tumor control, recurrences, survival, and toxicity. METHODS AND MATERIALS: Consecutive series of 527 evaluable patients were included in this randomized trial. Median follow-up for patients alive was 62 months. The primary study endpoints were locoregional recurrences and overall survival. Secondary endpoints were recurrence-free survival, recurrence-free interval, cancer-specific survival, and toxicity. RESULTS: Five-year locoregional relapse rates were 1.5% after external beam radiotherapy (EBRT) plus VBT and 5% after vaginal irradiation alone (p = 0.013), and 5-year overall survival rates were 89% and 90%, respectively (p = 0.548). Endometrial cancer-related death rates were 3.8% after EBRT plus VBT and 6.8% after VBT (p = 0.118). Pelvic recurrences (exclusively vaginal recurrence) were reduced by 93% by the addition of EBRT to VBT. Deep myometrial infiltration was a significant prognostic factor in this medium-risk group of endometrioid carcinomas but not International Federation of Gynecology and Obstetrics grade or DNA ploidy. Combined radiotherapy was well tolerated, with serious (Grade 3) late side effects of less than 2%. However, there was a significant difference in favor of VBT alone. CONCLUSIONS: Despite a significant locoregional control benefit with combined radiotherapy, no survival improvement was recorded, but increased late toxicity was noted in the intestine, bladder, and vagina. Combined RT should probably be reserved for high-risk cases with two or more high-risk factors. VBT alone should be the adjuvant treatment option for purely medium-risk cases.

  • 17.
    Widmark, Anders
    et al.
    Umeå University, Faculty of Medicine, Department of Radiation Sciences, Oncology.
    Gunnlaugsson, A.
    Beckman, L.
    Thellenberg-Karlsson, Camilla
    Umeå University, Faculty of Medicine, Department of Radiation Sciences, Oncology.
    Hoyer, M.
    Lagerlund, M.
    Fransson, Per
    Umeå University, Faculty of Medicine, Department of Nursing.
    Kindblom, J.
    Ginman, C.
    Johansson, B.
    Seke, M.
    Björnlinger, K.
    Kjellén, E.
    Franzen, Lars
    Umeå University, Faculty of Medicine, Department of Radiation Sciences, Oncology.
    Nilsson, P.
    Extreme Hypofractionation versus Conventionally Fractionated Radiotherapy for Intermediate Risk Prostate Cancer: Early Toxicity Results from the Scandinavian Randomized Phase III Trial "HYPO-RT-PC"2016In: International Journal of Radiation Oncology, Biology, Physics, ISSN 0360-3016, E-ISSN 1879-355X, Vol. 96, no 5, p. 938-939Article in journal (Refereed)
1 - 17 of 17
CiteExportLink to result list
Permanent link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf