| 1. |
- Di Legge, A., et al.
(författare)
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Lesion size affects diagnostic performance of IOTA logistic regression models, IOTA simple rules and risk of malignancy index in discriminating between benign and malignant adnexal masses
- 2012
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Ingår i: Ultrasound in Obstetrics & Gynecology. - : Wiley. - 1469-0705 .- 0960-7692. ; 40:3, s. 345-354
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Tidskriftsartikel (refereegranskat)abstract
- Objectives To estimate the ability to discriminate between benign and malignant adnexal masses of different size using: subjective assessment, two International Ovarian Tumor Analysis (IOTA) logistic regression models (LR1 and LR2), the IOTA simple rules and the risk of malignancy index (RMI). Methods We used a multicenter IOTA database of 2445 patients with at least one adnexal mass, i.e. the database previously used to prospectively validate the diagnostic performance of LR1 and LR2. The masses were categorized into three subgroups according to their largest diameter: small tumors (diameter < 4 cm; n = 396), medium-sized tumors (diameter, 49.9 cm; n = 1457) and large tumors (diameter = 10 cm, n = 592). Subjective assessment, LR1 and LR2, IOTA simple rules and the RMI were applied to each of the three groups. Sensitivity, specificity, positive and negative likelihood ratio (LR+, LR-), diagnostic odds ratio (DOR) and area under the receiveroperating characteristics curve (AUC) were used to describe diagnostic performance. A moving window technique was applied to estimate the effect of tumor size as a continuous variable on the AUC. The reference standard was the histological diagnosis of the surgically removed adnexal mass. Results The frequency of invasive malignancy was 10% in small tumors, 19% in medium-sized tumors and 40% in large tumors; 11% of the large tumors were borderline tumors vs 3% and 4%, respectively, of the small and medium-sized tumors. The type of benign histology also differed among the three subgroups. For all methods, sensitivity with regard to malignancy was lowest in small tumors (5684% vs 6793% in medium-sized tumors and 7495% in large tumors) while specificity was lowest in large tumors (6087%vs 8395% in medium-sized tumors and 8396% in small tumors ). The DOR and the AUC value were highest in medium-sized tumors and the AUC was largest in tumors with a largest diameter of 711 cm. Conclusion Tumor size affects the performance of subjective assessment, LR1 and LR2, the IOTA simple rules and the RMI in discriminating correctly between benign and malignant adnexal masses. The likely explanation, at least in part, is the difference in histology among tumors of different size. Copyright (C) 2012 ISUOG. Published by John Wiley & Sons, Ltd.
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| 2. |
- Dierickx, I., et al.
(författare)
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Imaging in gynecological disease (7): clinical and ultrasound features of Brenner tumors of the ovary
- 2012
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Ingår i: Ultrasound in Obstetrics & Gynecology. - : Wiley. - 1469-0705 .- 0960-7692. ; 40:6, s. 706-713
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Tidskriftsartikel (refereegranskat)abstract
- Objectives To describe clinical and ultrasound features of Brenner tumors of the ovary. Methods In this retrospective study, the databases of the International Ovarian Tumor Analysis (IOTA) studies and one tertiary center were searched to identify patients who had undergone an ultrasound scan before surgery for an adnexal mass that proved to be a Brenner tumor. Twenty-eight patients with 29 Brenner tumors were included, most of which had been collected within the framework of the IOTA studies. An experienced ultrasound examiner reviewed available ultrasound images (available for 14 tumors), searching for a pattern specific to Brenner tumors. Results Most patients were postmenopausal and asymptomatic. Twenty-four (83%) tumors were benign, two (7%) were borderline and three (10%) were malignant. Most benign tumors (17/24, 71%) contained solid components and manifested no or minimal blood flow on Doppler examination (19/24, 79%). Information about calcifications was available for 15 benign tumors, and in 13 (87%) calcifications were present. The five borderline and invasively malignant tumors contained solid components less often than did the benign ones (3/5, 60%) and were more richly vascularized on Doppler examination. Information about calcifications was available for four borderline or invasively malignant tumors, and in three (75%) calcifications were present. Conclusion We failed to demonstrate ultrasound features specific to Brenner tumors. A prospective study is needed to determine if ultrasound features of calcifications can discriminate between Brenner tumors and other types of ovarian tumor. Copyright (c) 2012 ISUOG. Published by John Wiley & Sons, Ltd.
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| 3. |
- Sokalska, A., et al.
(författare)
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Diagnostic accuracy of transvaginal ultrasound examination for assigning a specific diagnosis to adnexal masses
- 2009
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Ingår i: Ultrasound in Obstetrics & Gynecology. - : Wiley. - 1469-0705 .- 0960-7692. ; 34:4, s. 462-470
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Tidskriftsartikel (refereegranskat)abstract
- Objectives To determine the sensitivity and specificity of subjective evaluation of gray-scale and Doppler ultrasound findings (here called pattern recognition) when used by experienced ultrasound examiners with regard to making a specific diagnosis of adnexal masses. Methods Within the framework of a European multi-center study, the International Ovarian Tumor Analysis study, comprising nine ultrasound centers, women with at least one adnexal mass were examined with gray-scale and color Doppler ultrasonography by experienced ultrasound examiners. A standardized examination technique, and standardized terms and definitions were used. Using pattern recognition the examiners classified each mass as benign or malignant and suggested a specific diagnosis (e.g. dermoid cyst or endometrioma). The reference standard was the histology of the surgically removed adnexal tumors. Results A total of 1066 women were included, of whom 800 bad a benign mass and 266 a malignant mass. A specific diagnosis based on ultrasound findings was suggested in 899 (84%) tumors. The specificity was high for all diagnoses (range, 94-100%). The sensitivity was highest for benign teratoma/dermoid cysts (86%, 100/116), hydrosalpinges (86%, 18/21), peritoneal pseudocysts (80%, 4/5) and endometriomas (77%, 1531199), and lowest for functional cysts (17%, 4124), paraovarian/parasalpingeal cysts (14%, 3121), benign rare tumors (11%, 119), adenofibromas (8%, 3/39), simple cysts (6%, 1/18) and struma ovarii (0%, 0/5). The positive and negative likelihood ratios of pattern recognition with regard to dermoid cysts, hydrosalpinges and endometriomas were 68.2 and 0.14, 38.9 and 0.15, and 33.3 and 0.24, respectively. Dermoid cysts, hydrosalpinges, functional cysts, paraovarian cysts, peritoneal pseudocysts, fibromas/fibrothecomas and simple cysts were never misdiagnosed as malignancies by the ultrasound examiner, whereas more than 10% of inflammatory processes, adenofibromas and rare benign tumors including struma ovarii were misdiagnosed as malignancies. Conclusions Using subjective evaluation of gray-scale and Doppler ultrasound findings it is possible to make an almost conclusive diagnosis of a dermoid cyst, endometrioma and hydrosalpinx. Many other adnexal pathologies can be recognized but not confidently confirmed or excluded. Copyright (C) 2009 ISUOG. Published by John Wiley & Sons, Ltd.
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| 4. |
- Timmerman, D., et al.
(författare)
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Ovarian cancer prediction in adnexal masses using ultrasound-based logistic regression models: a temporal and external validation study by the IOTA group
- 2010
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Ingår i: Ultrasound in Obstetrics & Gynecology. - : Wiley. - 1469-0705 .- 0960-7692. ; 36:2, s. 226-234
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Tidskriftsartikel (refereegranskat)abstract
- Objectives The aims of the study were to temporally and externally validate the diagnostic performance of two logistic regression models containing clinical and ultrasound variables in order to estimate the risk of malignancy in adnexal masses, and to compare the results with the subjective interpretation of ultrasound findings carried out by an experienced ultrasound examiner ('subjective assessment'). Methods Patients with adnexal masses, who were put forward by the 19 centers participating in the study, underwent a standardized transvaginal ultrasound examination by a gynecologist or a radiologist specialized in ultrasonography. The examiner prospectively collected information on clinical and ultrasound variables, and classified each mass as benign or malignant on the basis of subjective evaluation of ultrasound findings. The gold standard was the histology of the mass with local clinicians deciding whether to operate on the basis of ultrasound results and the clinical picture. The models' ability to discriminate between malignant and benign masses was assessed, together with the accuracy of the risk estimates. Results Of the 1938 patients included in the study, 1396 had benign, 373 had primary invasive, 111 had borderline malignant and 58 had metastatic tumors. On external validation (997 patients from 12 centers), the area under the receiver operating characteristics curve (AUC) for a model containing 12 predictors (LR1) was 0.956, for a reduced model with six predictors (LR2) was 0.949 and for subjective assessment was 0.949. Subjective assessment gave a positive likelihood ratio of 11.0 and a negative likelihood ratio of 0.14. The corresponding likelihood ratios for a previously derived probability threshold (0.1) were 6.84 and 0.09 for LR1, and 6.36 and 0.10 for LR2. On temporal validation (941 patients from seven centers), the AUCs were 0.945 (LR1), 0.918 (LR2) and 0.959 (subjective assessment). Conclusions Both models provide excellent discrimination between benign and malignant masses. Because the models provide an objective and reasonably accurate risk estimation, they may improve the management of women with suspected ovarian pathology. Copyright (C) 2010 ISUOG. Published by John Wiley & Sons, Ltd.
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| 5. |
- Van Holsbeke, C., et al.
(författare)
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Endometriomas: their ultrasound characteristics
- 2010
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Ingår i: Ultrasound in Obstetrics & Gynecology. - : Wiley. - 1469-0705 .- 0960-7692. ; 35:6, s. 730-740
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Tidskriftsartikel (refereegranskat)abstract
- Objectives To describe the ultrasound characteristics of endometriomas in pre- and postmenopausal patients and to develop rules that characterize endometriomas. Methods All patients included in the International Ovarian Tumor Analysis (IOTA) studies were used in our analysis. Patients with an adnexal mass were scanned by experienced sonologists using a standardized research protocol. The gold standard was the histology of the surgically removed adnexal mass. The gray-scale and Doppler ultrasound characteristics of the endometriomas were compared with those of other benign and malignant masses. Based on decision-tree analysis, the existing literature and clinical experience, ultrasound rules for the detection of endometriomas were created and evaluated. Results Of all 3511 patients included in the IOTA studies, 713 (20%) had endometriomas. Fifty-one per cent of the endometriomas were unilocular cysts with ground glass echogenicity of the cyst fluid. These characteristics were found less often among other benign tumors or malignancies, or among the small set of endometriomas (4%) that were found in postmenopausal patients. Based on the decision-tree analysis, the optimal rule to detect endometriomas was an adnexal mass in a premenopausal patient with ground glass echogenicity of the cyst fluid, one to four locules and no papillations with detectable blood flow'. Based on clinical considerations, the following rule: 'premenopausal status, ground glass echogenicity of the cyst fluid, one to four locules and no solid parts' seems preferable. Conclusions Several rules had a good ability to characterize endometriomas. The ultrasound characteristics of endometriomas differ between pre- and postmenopausal patients. Masses in postmenopausal women whose cystic contents have a ground glass appearance have a high risk of malignancy. Copyright (C) 2010 ISUOG. Published by John Wiley & Sons, Ltd.
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| 6. |
- Ameye, L., et al.
(författare)
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Clinically oriented three-step strategy for assessment of adnexal pathology
- 2012
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Ingår i: Ultrasound in Obstetrics & Gynecology. - : Wiley. - 1469-0705 .- 0960-7692. ; 40:5, s. 582-591
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Tidskriftsartikel (refereegranskat)abstract
- Objective To determine the diagnostic performance of ultrasound-based simple rules, risk of malignancy index (RMI), two logistic regression models (LR1 and LR2) and real-time subjective assessment by experienced ultrasound examiners following the exclusion of masses likely to be judged as easy and 'instant' to diagnose by an ultrasound examiner, and to develop a new strategy for the assessment of adnexal pathology based on this. Methods 3511 patients with at least one persistent adnexal mass preoperatively underwent transvaginal ultrasonography to assess tumor morphology and vascularity. They were included in two consecutive prospective studies by the International Ovarian Tumor Analysis (IOTA) group: Phase 1 (1999-2005), development of the simple rules and logistic regression models LR1 and LR2, and Phase 2, a validation study (2005-2007). Results Almost half of the cases (43%) were identified as 'instant' to diagnose on the basis of descriptors applied to the database. To assess diagnostic performance in the more difficult 'non-instant' masses, we used only Phase 2 data (n = 1036). The sensitivity of LR2 was 88%, of RMI it was 41% and of subjective assessment it was 87%. The specificity of LR2 was 67%, of RMI it was 90% and of subjective assessment it was 86%. The simple rules yielded a conclusive result in almost 2/3 of the masses, where they resulted in sensitivity and specificity similar to those of real-time subjective assessment by experienced ultrasound examiners: sensitivity 89 vs 89% (P = 0.76), specificity 91 vs 91% (P = 0.65). When a three-step strategy was appliedwith easy 'instant' diagnoses as Step 1, simple rules where conclusive as Step 2 and subjective assessment by an experienced ultrasound examiner in the remaining masses as Step 3, we obtained a sensitivity of 92% and specificity of 92% compared with sensitivity 90% (P = 0.03) and specificity 93% (P = 0.44) when using real-time subjective assessment by experts in all tumors. Conclusion A diagnostic strategy using simple descriptors and ultrasound rules when applied to the variables contained in the IOTA database obtains results that are at least as good as those obtained by subjective assessment of a mass by an expert. Copyright. (C) 2012 ISUOG. Published by John Wiley & Sons, Ltd.
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| 7. |
- Perkmann, M., et al.
(författare)
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Academic engagement and commercialisation: A review of the literature on university-industry relations
- 2013
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Ingår i: Research Policy. - : Elsevier BV. - 0048-7333 .- 1873-7625. ; 42:2, s. 423-442
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Tidskriftsartikel (refereegranskat)abstract
- A considerable body of work highlights the relevance of collaborative research, contract research, consulting and informal relationships for university–industry knowledge transfer. We present a systematic review of research on academic scientists’ involvement in these activities to which we refer as ‘academic engagement’. Apart from extracting findings that are generalisable across studies, we ask how academic engagement differs from commercialisation, defined as intellectual property creation and academic entrepreneurship. We identify the individual, organisational and institutional antecedents and consequences of academic engagement, and then compare these findings with the antecedents and consequences of commercialisation. Apart from being more widely practiced, academic engagement is distinct from commercialisation in that it is closely aligned with traditional academic research activities, and pursued by academics to access resources supporting their research agendas. We conclude by identifying future research needs, opportunities for methodological improvement and policy interventions.
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| 8. |
- Valentin, Lil, et al.
(författare)
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Adnexal masses difficult to classify as benign or malignant using subjective assessment of gray scale and Doppler ultrasound findings: logistic regression models do not help.
- 2011
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Ingår i: Ultrasound in obstetrics & gynecology : the official journal of the International Society of Ultrasound in Obstetrics and Gynecology. - : Wiley. - 1469-0705. ; 38:4, s. 456-465
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Tidskriftsartikel (refereegranskat)abstract
- AIM: To develop a logistic regression model that can discriminate between benign and malignant adnexal masses perceived to be difficult to classify by subjective evaluation of gray scale and Doppler ultrasound findings (subjective assessment) and to compare its diagnostic performance with that of subjective assessment, serum CA 125 and the risk of malignancy index (RMI). METHODS: We used the 3511 patients with an adnexal mass included in the International Ovarian Tumor Analysis (IOTA) studies. All patients had been examined with transvaginal gray scale and Doppler ultrasound following a standardized research protocol by an experienced ultrasound examiner using a high end ultrasound system. In addition to prospectively collecting information on > 40 clinical and ultrasound variables, the ultrasound examiner classified each mass as certainly or probably benign, unclassifiable, or certainly or probably malignant. A logistic regression model to discriminate between benignity and malignancy was developed for the unclassifiable masses (n = 244, i.e. 7% of all tumors) using a training set (160 tumors, 45 malignancies) and then tested on a test set (84 tumors, 28 malignancies). The gold standard was the histological diagnosis of the surgically removed adnexal mass. The area under the receiver operating characteristic curve (AUC), sensitivity, specificity, positive and negative likelihood ratio (LR+, LR-) were used to describe diagnostic performance and were compared between subjective assessment, CA 125, the RMI and the logistic regression model created. RESULTS: One variable was retained in the logistic regression model: the largest diameter (in mm) of the largest solid component of the tumor (OR 1.04, 95% CI 1.02 - 1.06). The model had an AUC of 0.68 (95% confidence interval, CI 0.59 to 0.78) on the training set and 0.65 (95%CI 0.53 to 0.78) on the test set. On the test set, a cutoff of 25% probability of malignancy (corresponding to largest diameter of largest solid component 23mm) resulted in sensitivity 64% (18/28), specificity 55% (31/56), LR+ 1.44 and LR- 0.65. The corresponding figures for subjective assessment were 68% (19/28), 59% (33/56), 1.65 and 0.55. On the test set of patients with available CA 125 results, the LR+ and LR- of the logistic regression model (cutoff 25% probability of malignancy) were 1.29 and 0.73, of subjective assessment 1.44 and 0.63, of CA 125 (cutoff 35 U/mL) 1.25 and 0.84 and of RMI (cutoff 200) 1.21 and 0.92. CONCLUSION: About 7% of adnexal masses that are considered appropriate to remove surgically cannot be classified as benign or malignant by experienced ultrasound examiners using subjective assessment. Logistic regression models to estimate the risk of malignancy, CA 125 measurements and the RMI are not helpful in these masses. Copyright © 2011 ISUOG. Published by John Wiley & Sons, Ltd.
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| 9. |
- Valentin, Lil, et al.
(författare)
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Unilocular adnexal cysts with papillary projections but no other solid components: is there a diagnostic method that can reliably classify them as benign or malignant before surgery?
- 2013
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Ingår i: Ultrasound in Obstetrics & Gynecology. - : Wiley. - 1469-0705 .- 0960-7692. ; 41:5, s. 570-581
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Tidskriftsartikel (refereegranskat)abstract
- Aim: To develop a logistic regression model for discrimination between benign and malignant unilocular solid cysts with papillary projections but no other solid components, and to compare its diagnostic performance with that of subjective evaluation of ultrasound findings (subjective assessment), CA 125 and the risk of malignancy index (RMI). Methods: Among the 3511 adnexal masses in the International Ovarian Tumor Analysis (IOTA) database there were 252 (7%) unilocular solid cysts with papillary projections but no other solid components ('unilocular cysts with papillations'). All had been examined with transvaginal ultrasound using the IOTA standardized research protocol. The ultrasound examiner also classified each mass as certainly or probably benign, unclassifiable, or certainly or probably malignant. A logistic regression model to discriminate between benignity and malignancy was developed for all unilocular cysts with papillations (175 tumors in training set, 77 in test set) and for unilocular cysts with papillations where the ultrasound examiner was not certain about benignity/malignancy (113 tumors in training set, 53 in test set). The gold standard was the histological diagnosis of the surgically removed adnexal mass. Results: A model containing six variables was developed for all unilocular cysts with papillations. The model had an area under the receiver operating characteristic curve (AUC) on the test set of 0.83 (95% CI, 0.74-0.93). The optimal risk cutoff as defined on the training set (0.35) resulted in sensitivity 69% (20/29), specificity 83% (40/48), LR+ 4.14 and LR- 0.37 on the test set. The corresponding values for subjective assessment when using the ultrasound examiner's dichotomous classification of the mass as benign or malignant were 97% (28/29), 79% (38/48), 4.63 and 0.04. A model containing four variables was developed for unilocular cysts with papillations where the ultrasound examiner was not certain about benignity/malignancy. The model had an AUC of 0.74 (95% CI, 0.60-0.88) on the test set. The optimal risk cutoff of the model as defined on the training set (0.30) resulted in sensitivity 62% (13/21), specificity 72% (23/32), LR+ 2.20 and LR- 0.53 on the test set. The corresponding values for subjective assessment were 95% (20/21), 78% (25/32), 4.35 and 0.06. CA125 and RMI had virtually no diagnostic ability. Conclusion: Even though logistic regression models to predict malignancy in unilocular cysts with papillations can be developed they have at most moderate performance and are not superior to subjective assessment for discrimination between benignity and malignancy. Copyright © 2012 ISUOG. Published by John Wiley & Sons, Ltd.
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