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- Abdul Qadhr, Göran, et al.
(author)
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Whole-body diffusion-weighted imaging compared with FDG-PET/CT in staging of lymphoma patients
- 2011
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In: Acta Radiologica. - : SAGE Publications. - 0284-1851 .- 1600-0455. ; 52:2, s. 173-180
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Journal article (peer-reviewed)abstract
- Background:Diffusion-weighted imaging (DWI) has become increasingly valuable in lymph node imaging, yet the clinical utility of this technique in the staging of lymphoma has not been established.Purpose:To compare whole-body DWI with FDG-PET/CT in the staging of lymphoma patients.Material and Methods:Thirty-one patients, eight with Hodgkin lymphoma (HL) and 23 with non-Hodgkin's lymphoma (18 aggressive and five indolent) underwent both whole-body DWI, whole-body MRI (T1W and T2W-STIR) and FDG-PET/CT. Lesions on whole-body DWI were only considered positive if they correlated with lesions on T1W and T2W-STIR images. The staging given by each technique was compared, according to the Ann Arbor staging system. Differences in staging were solved using biopsy results, and clinical and CT follow-ups as standard of reference.Results: The staging was the same for DWI and FDG-PET/CT in 28 (90.3%) patients and different in three (9.7%). Of the 28 patients with the same staging, 11 had stage IV in both techniques and 17 had stages 0-III. No HL or aggressive non-Hodgkin's lymphoma patients had different staging. Three indolent small lymphocytic lymphoma/chronic lymphocytic leukemia (SLL/CLL) lymphoma had higher staging with DWI when compared with FDG-PET/CT. One small subcutaneous breast lymphoma was not seen but all other extranodal sites were detected by both techniques.Conclusion:Whole-body DWI is a promising technique for staging of both (aggressive and indolent) non-Hodgkin's lymphoma and HL.
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| 2. |
- Lyrdal, David, 1965, et al.
(author)
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Evaluation of sorafenib treatment in metastatic renal cell carcinoma with 2-fluoro-2-deoxyglucose positron emission tomography and computed tomography.
- 2009
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In: Nuclear medicine communications. - 1473-5628. ; 30:7, s. 519-24
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Journal article (peer-reviewed)abstract
- OBJECTIVE: New potent tyrosine kinase inhibitors such as sorafenib are the most effective treatment for metastatic renal cell carcinoma (MRCC) today. In this study, we used [18F]-2-fluoro-2-deoxyglucose (FDG) with positron emission tomography (PET) combined with computed tomography (CT) to evaluate early effects of sorafenib in patients with MRCC. METHODS: Ten patients, eight males and two females, with a mean age of 61 years (49-72 years), with MRCC were enrolled. A total of 52 lesions, two to nine lesions/patient, out of which 39 were soft lesions, were evaluated. The [18F]FDG-PET/CT was performed before treatment and after 1-2 months. A region of interest (ROI) was identified including the lesions where the glucose uptake was measured, calculating the average value within the ROI and using the cerebellum as the reference. The same ROI was measured in the subsequent FDG-PET. The sum of the diameters was measured in CT according to the Response Evaluation Criteria in Solid Tumors (RECIST). Sorafenib was given 400 mg twice daily orally. RESULTS: After 1-2 months, the mean glucose uptake in all lesions decreased to 75% (32-105%) of initial values of ROI as measured by FDG-PET. The mean glucose uptake in soft lesions decreased to 71% (32-108%) and in skeletal lesions to 82% (53-101%). The sum of the diameters measured by CT decreased to 80% (57-94%) of the initial value in soft lesions according to the RECIST. CONCLUSION: An early decrease in the mean glucose uptake was found in both soft and skeletal lesions after treatment with sorafenib. FDG-PET thus seems to be advantageous, compared with RECIST evaluation, which is limited to soft lesions.
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| 4. |
- Sadik, May, 1970, et al.
(author)
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A new computer-based decision-support system for the interpretation of bone scans
- 2006
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In: Nucl Med Commun. - 0143-3636. ; 27:5, s. 417-423
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Journal article (peer-reviewed)abstract
- OBJECTIVE: To develop a completely automated method, based on image processing techniques and artificial neural networks, for the interpretation of bone scans regarding the presence or absence of metastases. METHODS: A total of 200 patients, all of whom had the diagnosis of breast or prostate cancer and had undergone bone scintigraphy, were studied retrospectively. Whole-body images, anterior and posterior, were obtained after injection of 99mTc-methylene diphosphonate. The study material was randomly divided into a training group and a test group, with 100 patients in each group. The training group was used in the process of developing the image analysis techniques and to train the artificial neural networks. The test group was used to evaluate the automated method. The image processing techniques included algorithms for segmentation of the head, chest, spine, pelvis and bladder, automatic thresholding and detection of hot spots. Fourteen features from each examination were used as input to artificial neural networks trained to classify the images. The interpretations by an experienced physician were used as the 'gold standard'. RESULTS: The automated method correctly identified 28 of the 31 patients with metastases in the test group, i.e., a sensitivity of 90%. A false positive classification of metastases was made in 18 of the 69 patients not classified as having metastases by the experienced physician, resulting in a specificity of 74%. CONCLUSION: A completely automated method can be used to detect metastases in bone scans. Future developments in this field may lead to clinically valuable decision-support tools.
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| 6. |
- Sadik, May, 1970, et al.
(author)
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Improved Classifications of Planar Whole-Body Bone Scans Using a Computer-Assisted Diagnosis System: A Multicenter, Multiple-Reader, Multiple-Case Study
- 2009
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In: Journal of nuclear medicine. - : Society of Nuclear Medicine. - 0161-5505 .- 2159-662X. ; 50:3, s. 368-375
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Journal article (peer-reviewed)abstract
- The aim of this multicenter study was to investigate whether a computer-assisted diagnosis (CAD) system could improve performance and reduce interobserver variation in bone-scan interpretations of the presence or absence of bone metastases. Methods: The whole-body bone scans (anterior and posterior views) of 59 patients with breast or prostate cancer who had undergone scintigraphy for suspected bone metastatic disease were studied. The patients were selected to reflect the spectrum of pathology found in everyday clinical work. Thirty-five physicians working at 18 of the 30 nuclear medicine departments in Sweden agreed to participate. The physicians were asked to classify each case for the presence or absence of bone metastasis, without (baseline) and with the aid of the CAD system (1 y later), using a 4-point scale. The final clinical assessments, based on follow-up scans and other clinical data including the results of laboratory tests and available diagnostic images (such as MRI, CT, and radiographs from a mean follow-up period of 4.8 y), were used as the gold standard. Each physician's classification was pairwise compared with the classifications made by all the other physicians, resulting in 595 pairs of comparisons, both at baseline and after using the CAD system. Results: The physicians increased their sensitivity from 78% without to 88% with the aid of the CAD system (P < 0.001). The specificity did not change significantly with CAD. Percentage agreement and κ-values between paired physicians on average increased from 64% to 70% and from 0.48 to 0.55, respectively, with the CAD system. Conclusion: A CAD system improved physicians' sensitivity in detecting metastases and reduced interobserver variation in planar whole-body bone scans. The CAD system appears to have significant potential in assisting physicians in their clinical routine.
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| 7. |
- Sadik, May, et al.
(author)
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Quality of planar whole-body bone scan interpretations - a nationwide survey
- 2008
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In: European Journal of Nuclear Medicine and Molecular Imaging. - : Springer Science and Business Media LLC. - 1619-7070 .- 1619-7089. ; 35:8, s. 1464-1472
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Journal article (peer-reviewed)abstract
- Purpose The purpose of this study was to investigate, in a nationwide study, the inter-observer variation and performance in interpretations of bone scans regarding the presence or absence of bone metastases. Methods Bone scan images from 59 patients with breast or prostate cancer, who had undergone scintigraphy due to suspected bone metastatic disease, were studied. The patients were selected to reflect the spectrum of pathology found in everyday clinical work. Whole body images, anterior and posterior views, were sent to all 30 hospitals in Sweden that perform bone scans. Thirty-seven observers from 18 hospitals agreed to participate in the study. They were asked to classify each of the patient studies regarding the presence of bone metastasis, using a four-point scale. Each observer's classifications were pairwise compared with the classifications made by all the other observers, resulting in 666 pairs of comparisons. The interpretations of the 37 observers were also compared with the final clinical assessment, which was based on follow-up scans and other clinical data. Results On average, two observers agreed on 64% of the bone scan classifications. Kappa values ranged between 0.16 and 0.82, with a mean of 0.48. Sensitivity and specificity for the observers compared with the final clinical assessment were 77% and 96%, respectively, for detecting bone metastases in planar whole-body bone scanning. Conclusions Moderate inter-observer agreement was found when observers were compared pairwise. False-negative errors seem to be the major problem in the interpretations of bone scan images, whilst the specificities for the observers were high.
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| 8. |
- Stierner, Ulrika, 1952, et al.
(author)
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UVB-induced melanocyte proliferation and 5-S-cysteinyldopa excretion in dysplastic nevus syndrome.
- 1988
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In: Photo-dermatology. - 0108-9684. ; 5:5, s. 218-23
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Journal article (peer-reviewed)abstract
- This is the first in vivo study of the effects of UV on the epidermal melanocytes in dysplastic nevus syndrome (DNS). Eleven DNS patients and 22 healthy subjects were given total body UVB irradiation 8 times during 17 days and the melanocyte population was estimated in biopsies from shielded and irradiated skin. There was a doubling of the melanocyte counts in irradiated skin and a less pronounced but significant increase in the shielded skin area. The urinary excretion of 5-S-cysteinyldopa (5-S-CD) was measured before, during and after the irradiation period. The 5-S-CD excretion reached a maximum after 2 weeks of irradiation and returned towards the basal value after the irradiation period. We were not able to document any abnormal melanocytic UV response in DNS patients before, during or after the irradiation.
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| 9. |
- Ulmert, David, et al.
(author)
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A novel automated platform for quantifying the extent of skeletal tumour involvement in prostate cancer patients using the bone scan index
- 2012
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In: European Urology. - : Elsevier BV. - 0302-2838 .- 1873-7560. ; 62:1, s. 78-84
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Journal article (peer-reviewed)abstract
- Background: There is little consensus on a standard approach to analysing bone scan images. The Bone Scan Index (BSI) is predictive of survival in patients with progressive prostate cancer (PCa), but the popularity of this metric is hampered by the tedium of the manual calculation. Objective: Develop a fully automated method of quantifying the BSI and determining the clinical value of automated BSI measurements beyond conventional clinical and pathologic features. Design, setting, and participants: We conditioned a computer-assisted diagnosis system identifying metastatic lesions on a bone scan to automatically compute BSI measurements. A training group of 795 bone scans was used in the conditioning process. Independent validation of the method used bone scans obtained ≤3 mo from diagnosis of 384 PCa cases in two large population-based cohorts. An experienced analyser (blinded to case identity, prior BSI, and outcome) scored the BSI measurements twice. We measured prediction of outcome using pretreatment Gleason score, clinical stage, and prostate-specific antigen with models that also incorporated either manual or automated BSI measurements. Measurements: The agreement between methods was evaluated using Pearson's correlation coefficient. Discrimination between prognostic models was assessed using the concordance index (C-index). Results and limitations: Manual and automated BSI measurements were strongly correlated (ρ = 0.80), correlated more closely (ρ = 0.93) when excluding cases with BSI scores ≥10 (1.8%), and were independently associated with PCa death (p < 0.0001 for each) when added to the prediction model. Predictive accuracy of the base model (C-index: 0.768; 95% confidence interval [CI], 0.702-0.837) increased to 0.794 (95% CI, 0.727-0.860) by adding manual BSI scoring, and increased to 0.825 (95% CI, 0.754-0.881) by adding automated BSI scoring to the base model. Conclusions: Automated BSI scoring, with its 100% reproducibility, reduces turnaround time, eliminates operator-dependent subjectivity, and provides important clinical information comparable to that of manual BSI scoring. © 2012 European Association of Urology.
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