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Dive into the research topics where Helena M. Dekker is active.

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Featured researches published by Helena M. Dekker.


Gastroenterology | 2009

Lanreotide Reduces the Volume of Polycystic Liver: A Randomized, Double-Blind, Placebo-Controlled Trial

Loes van Keimpema; Frederik Nevens; Ragna Vanslembrouck; Martijn G. van Oijen; Aswin L. Hoffmann; Helena M. Dekker; Robert A. de Man; Joost P. H. Drenth

BACKGROUND & AIMS Therapy for polycystic liver is invasive, expensive, and has disappointing long-term results. Treatment with somatostatin analogues slowed kidney growth in patients with polycystic kidney disease (PKD) and reduced liver and kidney volume in a PKD rodent model. We evaluated the effects of lanreotide, a somatostatin analogue, in patients with polycystic liver because of autosomal-dominant (AD) PKD or autosomal-dominant polycystic liver disease (PCLD). METHODS We performed a randomized, double-blind, placebo-controlled trial in 2 tertiary referral centers. Patients with polycystic liver (n = 54) were randomly assigned to groups given lanreotide (120 mg) or placebo, administered every 28 days for 24 weeks. The primary end point was the difference in total liver volume, measured by computerized tomography at weeks 0 and 24. Analyses were performed on an intention-to-treat basis. RESULTS Baseline characteristics were comparable for both groups, except that more patients with ADPKD were assigned to the placebo group (P = .03). The mean liver volume decreased 2.9%, from 4606 mL (95% confidence interval (CI): 547-8665) to 4471 mL (95% CI: 542-8401 mL), in patients given lanreotide. In the placebo group, the mean liver volume increased 1.6%, from 4689 mL (95% CI: 613-8765 mL) to 4895 mL (95% CI: 739-9053 mL) (P < .01). Post hoc stratification for patients with ADPKD or PCLD revealed similar changes in liver volume, with statistically significant differences in patients given lanreotide (P < .01 for both diseases). CONCLUSIONS In patients with polycystic liver, 6 months of treatment with lanreotide reduces liver volume.


The Journal of Nuclear Medicine | 2009

Improved Selection of Patients for Hepatic Surgery of Colorectal Liver Metastases with 18 F-FDG PET: A Randomized Study

T. Ruers; Bastiaan Wiering; Joost R.M. van der Sijp; R. Roumen; Koert P. de Jong; Emile F.I. Comans; Jan Pruim; Helena M. Dekker; Paul F. M. Krabbe; Wim J.G. Oyen

With the increasing possibilities for surgical treatment of colorectal liver metastases, careful selection of patients who may benefit from surgical treatment becomes critical. The addition of PET to 18F-FDG may significantly improve conventional staging by CT. Up to now, definitive evidence that the addition of 18F-FDG PET to conventional staging leads to superior clinical results and improved clinical management in these patients has been lacking. In this randomized controlled trial in patients with colorectal liver metastases, we investigated whether the addition of 18F-FDG PET is beneficial and reduces the number of futile laparotomies. Methods: A total of 150 patients with colorectal liver metastases selected for surgical treatment by imaging with CT were randomly assigned to CT only (n = 75) or CT plus 18F-FDG PET (n = 75). Patients were followed up for at least 3 y. The primary outcome measure was futile laparotomy, defined as any laparotomy that did not result in complete tumor treatment, that revealed benign disease, or that did not result in a disease-free survival period longer than 6 mo. Results: Patient and tumor characteristics were similar for both groups. The number of futile laparotomies was 34 (45%) in the control arm without 18F-FDG PET and 21 (28%) in the experimental arm with 18F-FDG PET; the relative risk reduction was 38% (95% confidence interval, 4%−60%, P = 0.042). Conclusion: The number of futile laparotomies was reduced from 45% to 28%; thus, the addition of 18F-FDG PET to the work-up for surgical resection of colorectal liver metastases prevents unnecessary surgery in 1 of 6 patients.


Radiology | 2010

Minor Head Injury: CT-based Strategies for Management—A Cost-effectiveness Analysis

Marion Smits; Diederik W.J. Dippel; Paul J. Nederkoorn; Helena M. Dekker; Pieter E. Vos; Digna R. Kool; Daphne A. van Rijssel; Paul A. M. Hofman; Albert Twijnstra; Hervé L. J. Tanghe; M. G. Myriam Hunink

PURPOSE To compare the cost-effectiveness of using selective computed tomographic (CT) strategies with that of performing CT in all patients with minor head injury (MHI). MATERIALS AND METHODS The internal review board approved the study; written informed consent was obtained from all interviewed patients. Five strategies were evaluated, with CT performed in all patients with MHI; selectively according to the New Orleans criteria (NOC), Canadian CT head rule (CCHR), or CT in head injury patients (CHIP) rule; or in no patients. A decision tree was used to analyze short-term costs and effectiveness, and a Markov model was used to analyze long-term costs and effectiveness. n-Way and probabilistic sensitivity analyses and value-of-information (VOI) analysis were performed. Data from the multicenter CHIP Study involving 3181 patients with MHI were used. Outcome measures were first-year and lifetime costs, quality-adjusted life-years, and incremental cost-effectiveness ratios. RESULTS Study results showed that performing CT selectively according to the CCHR or the CHIP rule could lead to substantial U.S. cost savings (


Radiology | 2008

Arm Raising at Exposure-controlled Multidetector Trauma CT of Thoracoabdominal Region: Higher Image Quality, Lower Radiation Dose

Monique Brink; Frank de Lange; Luuk J. Oostveen; Helena M. Dekker; Digna R. Kool; Jaap Deunk; Michael J. R. Edwards; Cornelis van Kuijk; Richard L. Kamman; Johan G. Blickman

120 million and


Annals of Surgery | 2010

Predictors for the selection of patients for abdominal CT after blunt trauma: a proposal for a diagnostic algorithm.

Jaap Deunk; Monique Brink; Helena M. Dekker; Digna R. Kool; Johan G. Blickman; Arie B. van Vugt; Michael J. Edwards

71 million, respectively), and the CCHR was the most cost-effective at reference-case analysis. When the prediction rule had lower than 97% sensitivity for the identification of patients who required neurosurgery, performing CT in all patients was cost-effective. The CHIP rule was most likely to be cost-effective. At VOI analysis, the expected value of perfect information was


Alimentary Pharmacology & Therapeutics | 2012

The long-term outcome of patients with polycystic liver disease treated with lanreotide

Melissa Chrispijn; Frederik Nevens; Tom J. G. Gevers; Ragna Vanslembrouck; M.G.H. van Oijen; Walter Coudyzer; Aswin L. Hoffmann; Helena M. Dekker; R.A. de Man; L. van Keimpema; Joost P. H. Drenth

7 billion, mainly because of uncertainty about long-term functional outcomes. CONCLUSION Selecting patients with MHI for CT renders cost savings and may be cost-effective, provided the sensitivity for the identification of patients who require neurosurgery is extremely high. Uncertainty regarding long-term functional outcomes after MHI justifies the routine use of CT in all patients with these injuries.


American Journal of Neuroradiology | 2008

Outcome after Complicated Minor Head Injury

Marion Smits; M. G. Myriam Hunink; D.A. van Rijssel; Helena M. Dekker; Pieter E. Vos; Digna R. Kool; Paul J. Nederkoorn; Paul A. M. Hofman; Albert Twijnstra; Hervé L. J. Tanghe; Diederik W.J. Dippel

PURPOSE To evaluate the effect of arm position on image quality and effective radiation dose in an automatic exposure-controlled (AEC) multidetector thoracoabdominal computed tomography (CT) protocol in trauma patients. MATERIALS AND METHODS This retrospective study of the data of 177 trauma patients (117 male; median age, 39 years) was approved by the institutional ethics board, with informed patient consent waived. Patients underwent scanning by using an AEC 16-detector thoracoabdominal CT protocol in which both arms were raised above the shoulder region (standard-position group, 132 patients), one arm was raised and the other was down (one-arm group, 27 patients), or both arms were down (two-arm group, 18 patients). Objective and subjective image quality was assessed. Individual effective radiation dose was calculated from the effective tube current-time product per exposed section. For this purpose, section location-dependent conversion factors were derived by using a CT dosimetry calculator. The effect of arm position on effective dose was quantified by using linear regression analysis with correction for patient volume and attenuation. RESULTS Compared with the image quality in the standard-position group, the image quality in the one- and two-arm groups was decreased but within acceptable diagnostic limits. The median corrected effective dose in the standard-position group was 18.6 mSv; the dose in the one-arm group was 18% (95% confidence interval: 11%, 25%) higher than this, and that in the two-arm group was 45% (95% confidence interval: 34%, 57%) higher. CONCLUSION Omitting arm raising results in lower but acceptable image quality and a substantially higher effective radiation dose. Hence, effort should be made to position the arms above the shoulder when scanning trauma patients. Clinical trial registration no. NCT00228111.


American Journal of Roentgenology | 2008

Added Value of Routine Chest MDCT After Blunt Trauma: Evaluation of Additional Findings and Impact on Patient Management

Monique Brink; Jaap Deunk; Helena M. Dekker; Digna R. Kool; Michael J. R. Edwards; Arie B. van Vugt; Johan G. Blickman

Objective:To select parameters that can predict which patients should receive abdominal computed tomography (CT) after high-energy blunt trauma. Summary Background Data:Abdominal CT accurately detects injuries of the abdomen, pelvis, and lumbar spine, but has important disadvantages. More evidence for an appropriate patient selection for CT is required. Methods:A prospective observational study was performed on consecutive adult high-energy blunt trauma patients. All patients received primary and secondary surveys according to the advanced trauma life support, sonography (focused assessment with sonography for trauma [FAST]), conventional radiography (CR) of the chest, pelvis, and spine and routine abdominal CT. Parameters from prehospital information, physical examination, laboratory investigations, FAST, and CR were prospectively recorded for all patients. Independent predictors for the presence of ≥1 injuries on abdominal CT were determined using a multivariate logistic regression analysis. Results:A total of 1040 patients were included, 309 had injuries on abdominal CT. Nine parameters were independent predictors for injuries on CT: abnormal CR of the pelvis (odds ratio [OR], 46.8), lumbar spine (OR, 16.2), and chest (OR, 2.37), abnormal FAST (OR, 26.7), abnormalities in physical examination of the abdomen/pelvis (OR, 2.41) or lumbar spine (OR 2.53), base excess <−3 (OR, 2.39), systolic blood pressure <90 mm Hg (OR, 3.81), and long bone fractures (OR, 1.61). The prediction model based on these predictors resulted in a R2 of 0.60, a sensitivity of 97%, and a specificity of 33%. A diagnostic algorithm was subsequently proposed, which could reduce CT usage with 22% as compared with a routine use. Conclusions:Based on parameters from physical examination, laboratory, FAST, and CR, we created a prediction model with a high sensitivity to select patients for abdominal CT after blunt trauma. A diagnostic algorithm was proposed.


Journal of Trauma-injury Infection and Critical Care | 2009

Routine Versus Selective Computed Tomography of the Abdomen, Pelvis, and Lumbar Spine in Blunt Trauma : A Prospective Evaluation

Jaap Deunk; Monique Brink; Helena M. Dekker; Digna R. Kool; Cees van Kuijk; Johan G. Blickman; Arie B. van Vugt; Michael J. R. Edwards

Aliment Pharmacol Ther 2012; 35: 266–274


Gut | 2009

Using CT colonography as a triage technique after a positive faecal occult blood test in colorectal cancer screening

Marjolein H. Liedenbaum; A. F. van Rijn; A. H. de Vries; Helena M. Dekker; Maarten Thomeer; C J van Marrewijk; Lieke Hol; M G W Dijkgraaf; P. Fockens; Patrick M. Bossuyt; Evelien Dekker; Jaap Stoker

BACKGROUND AND PURPOSE: Functional outcome in patients with minor head injury with neurocranial traumatic findings on CT is largely unknown. We hypothesized that certain CT findings may be predictive of poor functional outcome. Materials and METHODS: All patients from the CT in Head Injury Patients (CHIP) study with neurocranial traumatic CT findings were included. The CHIP study is a prospective, multicenter study of consecutive patients, ≥16 years of age, presenting within 24 hours of blunt head injury, with a Glasgow Coma Scale (GCS) score of 13–14 or a GCS score of 15 and a risk factor. Primary outcome was functional outcome according to the Glasgow Outcome Scale (GOS). Other outcome measures were the modified Rankin Scale (mRS), the Barthel Index (BI), and number and severity of postconcussive symptoms. The association between CT findings and outcome was assessed by using univariable and multivariable regression analysis. RESULTS: GOS was assessed in 237/312 patients (76%) at an average of 15 months after injury. There was full recovery in 150 patients (63%), moderate disability in 70 (30%), severe disability in 7 (3.0%), and death in 10 (4.2%). Outcome according to the mRS and BI was also favorable in most patients, but 82% of patients had postconcussive symptoms. Evidence of parenchymal damage was the only independent predictor of poor functional outcome (odds ratio = 1.89, P = .022). CONCLUSION: Patients with neurocranial complications after minor head injury generally make a good functional recovery, but postconcussive symptoms may persist. Evidence of parenchymal damage on CT was predictive of poor functional outcome.

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Digna R. Kool

Radboud University Nijmegen Medical Centre

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Monique Brink

Radboud University Nijmegen Medical Centre

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Jaap Deunk

Radboud University Nijmegen Medical Centre

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Bastiaan Wiering

Radboud University Nijmegen Medical Centre

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Michael J. R. Edwards

Radboud University Nijmegen Medical Centre

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Paul F. M. Krabbe

University Medical Center Groningen

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Jan Pruim

Stellenbosch University

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T. Ruers

Radboud University Nijmegen

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