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Featured researches published by Paul Knegt.


International Journal of Radiation Oncology Biology Physics | 1998

The Value of Ultrasound With Ultrasound-Guided Fine-Needle Aspiration Biopsy Compared to Computed Tomography in the Detection of Regional Metastases in the Clinically Negative Neck

Robert P. Takes; Paul D. Righi; C.A. Meeuwis; J.J. Manni; Paul Knegt; H.A.M. Marres

PURPOSE Head and neck oncologists have not reached consensus regarding the role of contemporary imaging techniques in the evaluation of the clinically negative neck in patients with head and neck squamous cell carcinoma (HNSCC). The purpose of the present study was to compare the accuracy of ultrasound with guided fine-needle aspiration biopsy (UGFNAB) and computed tomography (CT) in detecting lymph node metastasis in the clinically negative neck. METHODS AND MATERIALS Sixty-four neck sides of patients with HNSCC were examined preoperatively by ultrasound/UGFNAB and CT at one of five participating tertiary care medical centers. The findings were correlated with the results of histopathologic examination of the neck specimen. RESULTS Ultrasound with guided fine-needle aspiration biopsy was characterized by a sensitivity of 48%, specificity of 100%, and overall accuracy of 79%. Three cases had nondiagnostic aspirations using UGFNAB and were excluded. CT demonstrated a sensitivity of 54%, specificity of 92%, and overall accuracy of 77%. UGFNAB detected two additional metastases not visualized on CT, whereas CT detected no metastases not seen on UGFNAB. The results of UGFNAB were similar between the participating centers. CONCLUSIONS Approximately one half of the clinically occult nodal metastases in our patient group were identified by both CT and UGFNAB. Overall, UGFNAB and CT demonstrated comparable accuracy. The sensitivity of CT was slightly better than UGFNAB, but the latter remained characterized by a superior specificity. The results of CT and UGFNAB did not appear to be supplementary. The choice of imaging modality for staging of the clinically negative neck depends on tumor site, T-stage, and experience and preference of the head and neck oncologist. If CT is required for staging of the primary tumor, additional staging of the neck by UGFNAB does not provide significant additional value.


European Journal of Cancer | 2001

The costs of head and neck oncology: primary tumours, recurrent tumours and long-term follow-up.

M van Agthoven; B.M. van Ineveld; M. de Boer; Charles R. Leemans; Paul Knegt; G.B Snow; Ca Uyl-de Groot

We retrospectively calculated the costs of head and neck oncology for reimbursement purposes. This analysis was based on 854 head and neck cancer patients treated between 1994 and 1996 in two major Dutch university hospitals. To anticipate future care costs, costs of required improvements in the quality of care were added. Costs of diagnosis, treatment and 2 years of follow-up of patients with a primary tumour were (euro) 21 858. For patients with a recurrent tumour, this amount was (euro) 27 629. The costs of 10 years of follow-up were (euro) 423 after discounting and correction for survival. In total, average costs per new patient were (euro) 31 829, which covered discounted costs of treating the primary tumour, costs of treating recurrent tumours in 40% of all patients and the costs of 10 years of follow-up. Costs of improving the quality of care were estimated to be (euro) 1598 per new patient.


Head and Neck-journal for The Sciences and Specialties of The Head and Neck | 2001

CO2-laser treatment of recurrent glottic carcinoma

Henriëtte H. W. de Gier; Paul Knegt; Maarten F. de Boer; Cees A. Meeuwis; Lilly-Ann van der Velden; Jeroen D. F. Kerrebijn

Evaluation of the results of CO2 laser treatment of recurrent glottic carcinoma after radiotherapy.


Patient Education and Counseling | 1997

Continuity of information in cancer care: evaluation of a logbook

A. van Wersch; M.F. de Boer; E. van der Does; P. de Jong; Paul Knegt; C.A. Meeuwis; P. Stringer; Jean F. A. Pruyn

A logbook, or patient-dossier, was developed, to improve continuity of information in the treatment and care of head-and-neck cancer patients. It contained information modules on different aspects of care, as well as forms to facilitate communication both between patient and care-professional and between the various care-professionals. The logbooks effectiveness was evaluated in two hospitals in Rotterdam, by comparing outcomes for trial and comparison groups of, respectively, 71 and 54 patients and 59 and 35 care-professionals. Trial patients proved to be better informed, to receive more support and to experience fewer psychosocial problems. Professionals who used the logbook were better informed about their patients, and about the care-activities of fellow-professionals than those who did not. They recognised an improvement in their contact with colleagues and in the harmonisation of their respective care-activities.


International Journal of Radiation Oncology Biology Physics | 1989

Evaluation of treatment results of squamous cell carcinoma of the buccal mucosa

L.A.M. Pop; W.M.H. Eijukenboom; M.F.de Boer; P.C.de Jong; Paul Knegt; Peter C. Levendag; C.A. Meeuwis; B.A. Reichgelt; W.L.J. van Putten

Of the 49 patients with squamous cell carcinoma of the buccal mucosa referred to the Rotterdam Radio-Therapeutic Institute (RRTI) and Universital Hospital Dijkzigt Rotterdam (AZD) during 1970-1984, 31 patients had an advanced stage of disease, 21 patients had clinical evidence of lymph node metastasis. Forty patients were treated with curative intention. Treatment modalities were: radiation therapy, preoperative radiation followed by surgery, and primary surgery. Eighteen of the 40 patients (45%) developed a local tumor recurrence; nearly all recurrences occurred within 2 years. The incidence was equal in all treatment groups. Of the 22 patients with initial clinically negative neck, regional relapse occurred in 3 of the 14 patients, of whom the neck was not treated electively by radiation therapy; all three in combination with a local recurrence. None of the 8 patients with electively irradiated necks developed a regional relapse. Eight of the 18 patients with initial clinically enlarged lymph nodes treated either by radiotherapy or surgery, developed a regional relapse, 5 in combination with a local recurrence. Treatment of the clinically positive neck by neck dissection was superior to radiotherapy. Local recurrence carried a poor prognosis. Almost 70% died of their disease. The overall and corrected 5-year survival was 38% and 52% respectively.


European Archives of Oto-rhino-laryngology | 1997

The effects of alcohol and smoking upon the age, anatomic sites and stage in the development of cancer of the oral cavity and oropharynx in females in the south west Netherlands.

M. F. de Boer; R.J. Sanderson; R.A.M. Damhuis; C.A. Meeuwis; Paul Knegt

A retrospective review of 303 women, aged 40 or over, with squamous cell carcinomas of the oral cavity or oropharynx was conducted in the south-west Netherlands to study the effects of smoking and alcohol upon the age of onset, site and stage of disease. It was noted that patients presenting with oropharyngeal cancers were younger and had a higher incidence of smoking and history of heavy drinking. Age at presentation was also affected by the amount of alcohol and tobacco consumed with non-users presenting with tumors approximately 15 years later. A specific finding was that heavy drinkers and smokers tended to present with late-stage-disease.


Operations Research Letters | 1995

First results with the Blom-Singer® adjustable tracheostoma valve

Wilko Grolman; Paul F. Schouwenburg; M.F. de Boer; Paul Knegt; H. A. A. Spoelstra; C.A. Meeuwis

The Blom-Singer adjustable tracheostoma valve (ATV) is a new tracheostoma valve, introduced in 1992 to improve voice rehabilitation after total laryngectomy. Little research has been done to evaluate the benefits of this valve. Our study evaluates the advantages and disadvantages of using this device. Eighteen laryngectomized patients with a low-resistance Provox voice prosthesis received an ATV, using minimal selection criteria. The patients are evaluated according to a specific protocol. The effectiveness of the humidifilter, valve and fixation method and the benefits are evaluated. Approximately 66% of the 18 patients are still using the ATV. We report the differences between the current users and the dropout group. Patient factors are discussed that seem to have an impact on the effective use of the valve, such as age and mucus production. We consider the ATV to be a valuable device for fingerless speech in the laryngectomized patient.


European Archives of Oto-rhino-laryngology | 1995

Cervical metastasis from the unknown primary tumor

A. L. Oen; M. F. de Boer; Paul Knegt; Wim C. J. Hop

A retrospective study was performed to examine the results of treatment for cervical lymph node metastases f rom an unknown primary between 1978 and 1988. We reviewed 66 patients treated with either surgery and/or radiotherapy (n = 41), radiation therapy and chemotherapy (n = 11), combined modality treatment with surgery (n = 8) or with management delayed to proven disease (n = 6). The male-to-female ratio was 5.6 to 1, and the median age was 64 years (range, 15–89 years). Intercurrent death-corrected 5-year survival was 50%. The most important prognostic factors were M category and involvement of supraclavicular nodes. Primary tumor was eventually discovered in 12 patients during follow-up, 6 of whom received treatment with curative intent. The most common site of primary tumor was found to be the lung (n = 5).


Operations Research Letters | 1993

Ultrasound Characteristics of Thyroglossal Duct Anomalies

Robert J. Baatenburg de Jong; Robert J. Rongen; Johan S. Laméris; Paul Knegt; Carel D. A. Verwoerd

The purpose of this study was to determine the value of ultrasound examination in the diagnosis of thyroglossal duct anomalies. The ultrasound and palpation findings in 24 patients with a thyroglossal duct anomaly were reviewed. Cysts, tracts and ectopic thyroid tissue appeared to produce a characteristic ultrasound pattern in most cases. This study includes 5 patients with non-symptomatic lesions which were detected at ultrasound examination. The necessity of performing a radionuclide scan prior to surgery for a thyroglossal duct anomaly is reconsidered in view of the diagnostic power of ultrasound in thyroid disease.


Otolaryngology-Head and Neck Surgery | 2006

Repetitive Endoscopic Sinus Surgery Failure: A Role for Radical Surgery?

W. J. M. Videler; Volkert B. Wreesmann; Freerk W. van der Meulen; Paul Knegt; Wytske J. Fokkens

OBJECTIVES: Endoscopic sinus surgery (ESS) is considered to be the golden standard for surgery in patients with chronic rhinosinusitis and nasal polyposis. However, there is still a small group of patients unresponsive despite repetitive surgery. Radical surgery aimed at reduction of the inflammatory burden and optimization of drainage of the sinuses has been suggested as a last resort for these patients. STUDY DESIGN: A prospective, questionnaire-based study was conducted in a group of 23 patients who underwent Denkers procedure for refractory chronic rhinosinusitis. Symptoms were evaluated before Denkers procedure and 12 months and 2 years after surgery. RESULTS: Patients reported improvement of feelings of congestion in 74%, rhinorrhea in 70%, and nasal obstruction in 60% of the cases. The following postoperative improvements were statistically significant: rhinorrhea (P = 0.001), feelings of congestion (P = 0.02), and nasal obstruction (P = 0.03). Reduced olfactory perception and asthma did not improve. CONCLUSION: Radical surgery may be a viable treatment option in case of recurrent ESS failure.

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C.A. Meeuwis

Erasmus University Rotterdam

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Maarten F. de Boer

Erasmus University Rotterdam

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M.F. De Boer

Erasmus University Rotterdam

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Bing Tan

Netherlands Cancer Institute

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Cees A. Meeuwis

Erasmus University Medical Center

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H.A.M. Marres

Radboud University Nijmegen Medical Centre

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