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Dive into the research topics where Alfons G. H. Kessels is active.

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Featured researches published by Alfons G. H. Kessels.


Radiotherapy and Oncology | 2010

Comparison of the effectiveness of radiotherapy with photons, protons and carbon-ions for non-small cell lung cancer: A meta-analysis

Jp Grutters; Alfons G. H. Kessels; Madelon Pijls-Johannesma; Dirk De Ruysscher; Manuela A. Joore; Philippe Lambin

PURPOSE To provide a comparison between radiotherapy with photons, protons and carbon-ions in the treatment of Non-Small-Cell Lung Cancer (NSCLC), performing a meta-analysis of observational studies. METHODS Eligible studies on conventional radiotherapy (CRT), stereotactic radiotherapy (SBRT), concurrent chemoradiation (CCR), proton therapy and carbon-ion therapy were searched through a systematic review. To obtain pooled estimates of 2- and 5-year disease-specific and overall survival and the occurrence of severe adverse events for each treatment modality, a random effects meta-analysis was carried out. Pooled estimates were corrected for effect modifiers. RESULTS Corrected pooled estimates for 2-year overall survival in stage I inoperable NSCLC ranged from 53% for CRT to 74% for carbon-ion therapy. Five-year overall survival for CRT (20%) was statistically significantly lower than that for SBRT (42%), proton therapy (40%) and carbon-ion therapy (42%). However, caution is warranted due to the limited number of patients and limited length of follow-up of the particle studies. CONCLUSION Survival rates for particle therapy were higher than those for CRT, but similar to SBRT in stage I inoperable NSCLC. Particle therapy may be more beneficial in stage III NSCLC, especially in reducing adverse events.


BMJ | 2014

A GRADE Working Group approach for rating the quality of treatment effect estimates from network meta-analysis

Milo A. Puhan; Holger J. Schünemann; Mohammad Hassan Murad; Tianjing Li; Romina Brignardello-Petersen; Jasvinder A. Singh; Alfons G. H. Kessels; Gordon H. Guyatt

Network meta-analysis (NMA), combining direct and indirect comparisons, is increasingly being used to examine the comparative effectiveness of medical interventions. Minimal guidance exists on how to rate the quality of evidence supporting treatment effect estimates obtained from NMA. We present a four-step approach to rate the quality of evidence in each of the direct, indirect, and NMA estimates based on methods developed by the GRADE working group. Using an example of a published NMA, we show that the quality of evidence supporting NMA estimates varies from high to very low across comparisons, and that quality ratings given to a whole network are uninformative and likely to mislead.


Anesthesiology | 2005

Pulsed and continous radiofrequency current adjacent to the cervical dorsal root ganglion of the rat induces late cellular activity in the dorsal horn

Jan Van Zundert; Anton de Louw; Elbert A. Joosten; Alfons G. H. Kessels; Wiel Honig; Pieter J. Dederen; Jan G. Veening; Johan S.H. Vles; Maarten van Kleef

Background: Pulsed radiofrequency treatment has recently been described as a non-neurodestructive or minimally neurodestructive alternative to radiofrequency heat lesions. In clinical practice long-lasting results of pulsed radiofrequency treatment adjacent to the cervical dorsal root ganglion for the management of chronic radicular spinal pain have been reported without neurologic complications. However, the mode of action is unclear. An early (3 h) effect of pulsed radiofrequency as measured by an increase of c-Fos in the pain-processing neurons of the dorsal horn of rats has been described in the literature. This effect was not mediated by tissue heating. The authors investigated a possible late or long-term effect of three different radiofrequency modalities. Methods: Cervical laminectomy was performed in 19 male Wistar rats. The cervical dorsal root ganglion was randomly exposed to one of the four interventions: sham, continuous radiofrequency current at 67 centigrades, or pulsed radiofrequency current for 120 s or 8 min. The animals were sacrificed and the spinal cord was prepared for c-Fos labeling 7 days after the intervention. Results: The number of c-Fos immunoreactive cells in the dorsal horn was significantly increased in the three different radiofrequency modalities as compared with sham. No significant difference was demonstrated between the three active intervention groups. Conclusions: The authors demonstrated a late neuronal activity in the dorsal horn after exposure of the cervical dorsal root ganglion to different radiofrequency modalities, which was not temperature dependent.


Pain | 2007

High prevalence of pain in patients with cancer in a large population-based study in The Netherlands.

Marieke H.J. van den Beuken-van Everdingen; Janneke M. de Rijke; Alfons G. H. Kessels; Harry C. Schouten; Maarten van Kleef; Jacob Patijn

Abstract At present, no definite conclusions can be drawn about the real extent of the pain suffered by cancer patients. A population‐based study was conducted to obtain reliable information about the prevalence and severity of pain in cancer patients (all phases) and about predictors of pain. A representative sample of cancer patients was recruited in the area from a cancer registry. Pain was assessed by the Brief Pain Inventory (BPI). Adequacy of pain treatment was assessed with the Pain Management Index (PMI). We found that 55% of the 1429 respondents had experienced pain past week; in 44% (n = 351), the pain was moderate to severe (BPI score ⩾4). Total prevalence of pain/moderate to severe pain was present in 49%/41% in patients with curative treatment ⩾6 months ago, 57%/43% in patients with current curative treatment or treatment <6 months ago, 56%/43% in patients with current palliative anti‐cancer treatment and in 75%/70% in patients for whom treatment was no longer feasible. Positive predictors of the prevalence of pain were lower education level, more advanced disease and haematological (excluding (non)‐Hodgkin lymphoma), gastro‐intestinal, lung, or breast malignancies. According to the PMI, analgesic treatment was inadequate in 42% of the patients. Negative predictors of adequate treatment were current curative anti‐cancer treatment and low education level. Conclusion: A substantial proportion of cancer patients does suffer from moderate to severe pain and does not receive adequate pain treatment.


Pain | 2007

Pulsed radiofrequency adjacent to the cervical dorsal root ganglion in chronic cervical radicular pain: A double blind sham controlled randomized clinical trial

Jan Van Zundert; Jacob Patijn; Alfons G. H. Kessels; I.E. Lame; Hans van Suijlekom; Maarten van Kleef

Abstract Cervical radicular pain affects approximately 1 on 1000 adults per year. Although many treatment modalities are described in the literature, the available evidence for efficacy is not sufficient to allow definitive conclusions on the optimal therapy to be made. The effect of pulsed radiofrequency treatment for this type of patients was evaluated in a prospective audit that showed satisfactory pain relief for a mean period of 9.2 months, justifying a randomized sham controlled trial. Twenty‐three patients, out of 256 screened, met the inclusion criteria and were randomly assigned in a double blind fashion to receive either pulsed radiofrequency or sham intervention. The evaluation was done by an independent observer. At 3 months the pulsed radiofrequency group showed a significantly better outcome with regard to the global perceived effect (>50% improvement) and visual analogue scale (20 point pain reduction). The quality of life scales also showed a positive trend in favor of the pulsed radiofrequency group, but significance was only reached in the SF‐36 domain vitality at 3 months. The need for pain medication was significantly reduced in the pulsed radiofrequency group after six months. No complications were observed during the study period. These study results are in agreement with the findings of our previous clinical audit that pulsed radiofrequency treatment of the cervical dorsal root ganglion may provide pain relief for a limited number of carefully selected patients with chronic cervical radicular pain as assessed by clinical and neurological examination.


Nephrology Dialysis Transplantation | 2010

Buttonhole needling of haemodialysis arteriovenous fistulae results in less complications and interventions compared to the rope-ladder technique

Magda van Loon; Tony Goovaerts; Alfons G. H. Kessels; Frank M. van der Sande; Jan H. M. Tordoir

BACKGROUND The rope-ladder puncture technique, with cannulation along the whole length of the vessel traject, has been very common in haemodialysis patients with autogenous arterio-venous fistula (AVF). Todays dialysis population with AVF may exhibit difficult cannulation, because of a short vein length or a complicated cannulation route. An alternative needling possibility is the buttonhole (BH) technique, which inserts needles at exactly the same location during every dialysis session. The present study was conducted to investigate the effect of both cannulation techniques on the incidence of vascular access (VA) complications. METHODS A total of 75 prevalent haemodialysis patients with autogenous AVF using the BH technique were compared with 70 patients using the rope-ladder technique. The following parameters were registered: haematoma occurrence, redness, swelling, aneurysm formation, the use of sharp or dull needles, miscannulations, and interventions. Needling pain and fear of puncture were assessed using a verbal rating scale (VRS). The duration of the follow-up was 9 months. RESULTS Patients in the BH group had more unsuccessful cannulations, compared with the rope-ladder method (P < 0.0001), but the frequency of haematoma (P < 0.0001) and aneurysm formation (P < 0.0001) was less. In addition, intervention such as angioplasty (P < 0.0001) was higher in patients using the rope-ladder technique. A negative outcome of the BH technique was the higher incidence of access infections compared to the rope-ladder method. CONCLUSION This study showed that the BH method is a valuable technique with few complications like haematoma, aneurysm formation and the need for interventions. However, the infections induced by the BH method should not be underestimated. This underlines the importance of an aseptic and correct technique of the buttonhole procedure.


Radiology | 2008

USPIO-enhanced MR Imaging for Nodal Staging in Patients with Primary Rectal Cancer: Predictive Criteria

Max J. Lahaye; Sanne M. E. Engelen; Alfons G. H. Kessels; Adriaan P. de Bruïne; Maarten F. von Meyenfeldt; Jos M. A. van Engelshoven; Cornelis J. H. van de Velde; Geerard L. Beets; Regina G. H. Beets-Tan

PURPOSE To prospectively determine diagnostic performance of predictive criteria for nodal staging with ultrasmall superparamagnetic iron oxide (USPIO)-enhanced magnetic resonance (MR) imaging in primary rectal cancer patients, with histopathologic findings as reference standard. MATERIALS AND METHODS Institutional review board approval and informed consent were obtained. Twenty-eight rectal cancer patients (18 men, 10 women; mean age, 68 years) underwent USPIO-enhanced MR. Two observers with different experience evaluated each node on three-dimensional T2*-weighted images for border irregularity, short- and long-axis diameter, and estimated percentage (<30%, 30%-50%, or >50%) of white region within the node. Ratio of measured surface area of white region within the node to measured surface area of total node (ratio(A)) was calculated. Signal intensity (SI) of gluteus muscle (SI(GM)), total node (SI(TN)), and white (SI(WR)) and dark (SI(DR)) regions within the node were used to calculate SI(TN)/SI(GM) and SI(WR)/SI(DR) ratios. Lesion-by-lesion, receiver operating characteristic curve, and interobserver agreement analyses were performed. The most accurate and practical criterion was evaluated by observer 3. RESULTS In 28 patients, 236 lymph nodes were examined. Area under the receiver operating characteristic curve (AUC) of estimated percentage of white region and ratio(A) were 0.96 and 0.99 (observer 1) and 0.95 and 0.97 (observer 2), respectively. AUC of estimated percentage criterion for observer 3 was 0.96. AUC of border, short- and long-axis diameter, and SI(TN)/SI(GM) and SI(WR)/SI(DR) ratios were 0.65, 0.75, 0.79, 0.85, and 0.75 (observer 1) and 0.58, 0.75, 0.79, 0.89, and 0.79 (observer 2), respectively. Interobserver agreement (kappa value) for estimated white region between observers 1 and 2, 1 and 3, and 2 and 3 were 0.77, 0.79, and 0.84, respectively. For observers 1 and 2, kappa value for border was 0.28. For observers 1 and 2, intraclass correlation coefficient for short- and long-axis diameters, ratio(A), and SI(TN)/SI(GM) and SI(WR)/SI(DR) ratios were 0.91, 0.96, 0.91, 0.72, and 0.92, respectively. CONCLUSION Estimated percentage of white region and measured ratio(A) are the most accurate criteria for predicting malignant nodes with USPIO-enhanced MR imaging; the first criterion is the most practical.


Hypertension | 2007

Self-measurement of blood pressure at home reduces the need for antihypertensive drugs: a randomized, controlled trial.

Willem J. Verberk; Abraham A. Kroon; Jacques W. M. Lenders; Alfons G. H. Kessels; Gert A. van Montfrans; Andries J. Smit; Paul-Hugo M. van der Kuy; Patricia J. Nelemans; Roger J. M. W. Rennenberg; Diederick E. Grobbee; Frank W. Beltman; Manuela A. Joore; Daniëlle E.M. Brunenberg; Carmen D. Dirksen; Theo Thien; Peter W. de Leeuw

It is still uncertain whether one can safely base treatment decisions on self-measurement of blood pressure. In the present study, we investigated whether antihypertensive treatment based on self-measurement of blood pressure leads to the use of less medication without the loss of blood pressure control. We randomly assigned 430 hypertensive patients to receive treatment either on the basis of self-measured pressures (n=216) or office pressures (OPs; n=214). During 1-year follow-up, blood pressure was measured by office measurement (10 visits), ambulatory monitoring (start and end), and self-measurement (8 times, self-pressure group only). In addition, drug use, associated costs, and degree of target organ damage (echocardiography and microalbuminuria) were assessed. The self-pressure group used less medication than the OP group (1.47 versus 2.48 drug steps; P<0.001) with lower costs (


Radiology | 2009

Locally advanced rectal cancer: MR imaging for restaging after neoadjuvant radiation therapy with concomitant chemotherapy. Part I. Are we able to predict tumor confined to the rectal wall?

Raphaëla C. Dresen; Geerard L. Beets; Harm Rutten; Sanne M. E. Engelen; Max J. Lahaye; Roy F. A. Vliegen; Adriaan P. de Bruïne; Alfons G. H. Kessels; Guido Lammering; Regina G. H. Beets-Tan

3222 versus


European Urology | 2012

Efficacy and Adverse Events of Antimuscarinics for Treating Overactive Bladder: Network Meta-analyses

Nora Buser; Sandra Ivic; Thomas M. Kessler; Alfons G. H. Kessels; Lucas M. Bachmann

4420 per 100 patients per month; P<0.001) but without significant differences in systolic and diastolic OP values (1.6/1.0 mm Hg; P=0.25/0.20), in changes in left ventricular mass index (-6.5 g/m(2) versus -5.6 g/m(2); P=0.72), or in median urinary microalbumin concentration (-1.7 versus -1.5 mg per 24 hours; P=0.87). Nevertheless, 24-hour ambulatory blood pressure values at the end of the trial were higher in the self-pressure than in the OP group: 125.9 versus 123.8 mm Hg (P<0.05) for systolic and 77.2 versus 76.1 mm Hg (P<0.05) for diastolic blood pressure. These data show that self-measurement leads to less medication use than office blood pressure measurement without leading to significant differences in OP values or target organ damage. Ambulatory values, however, remain slightly elevated for the self-pressure group.

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Geerard L. Beets

Netherlands Cancer Institute

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Carmen D. Dirksen

Maastricht University Medical Centre

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