Frank R. Datema

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BACKGROUND In 2001, we presented a Cox regression model that is able to predict survival of the newly diagnosed patient with head and neck squamous cell carcinoma (HNSCC). This model is based on the TNM classification and other important clinical variables such as age at diagnosis, sex, primary tumor site, and prior malignancies. We aim to improve this(More)
BACKGROUND Basic patient and tumor characteristics impact overall survival of head and neck squamous cell carcinoma patients. Severe malnutrition, defined as weight loss > 10% in 6 months preceding primary tumor diagnosis, impacts overall survival as well. Little attention has been paid to the interaction between severe malnutrition and other relevant(More)
BACKGROUND Electronic patient files generate an enormous amount of medical data. These data can be used for research, such as prognostic modeling. Automatization of statistical prognostication processes allows automatic updating of models when new data is gathered. The increase of power behind an automated prognostic model makes its predictive capability(More)
Univariate analyses on malignant salivary gland tumors report a strong relation of histological subtypes and prognosis. However, multivariate analyses with sufficient patients and reflecting the broad spectrum of putative prognostic factors are rare. In order to study the prognostic value of cytology and histology in salivary carcinoma we performed(More)
BACKGROUND The purpose of this study was to update and external validation of a prognostic model that is able to predict the survival probability of newly diagnosed patients with head and neck cancer. METHODS Our original prognostic model is based on historical data of 1371 patients with primary head and neck cancer, diagnosed and treated in the Leiden(More)
An auricular pseudocyst is a benign cystic lesion of the auricular cartilage. When not recognized, it is a clinical presentation that can easily be misdiagnosed and subsequently be mistreated leading to unsatisfactory esthetical results or disease recurrence. A patient was presented with bilateral pseudocysts, which were surgically excised. The aim of the(More)
Overprojection of the nasal tip is a common problem in aesthetic Caucasian and Mediterranean rhinoplasty patients. In these patients, shortening of the conjoined medial crura frequently plays an important part in deprojection of the nasal tip. The combination of vertical incision maneuvers of the medial crura and tongue-in-groove (TIG) allows the surgeon to(More)
BACKGROUND The OM-6 survey is a validated and multinationally accepted instrument to measure the treatment effect of otitis media in children. Routine use of the OM-6 in a busy general practice is not always possible and can lead to incomplete returned surveys. A simplified method is favoured when the aim is a continuous process of complete(More)
BACKGROUND The use of alternative modeling techniques for predicting patient survival is complicated by the fact that some alternative techniques cannot readily deal with censoring, which is essential for analyzing survival data. In the current study, we aimed to demonstrate that pseudo values enable statistically appropriate analyses of survival outcomes(More)
OBJECTIVES/HYPOTHESIS Tongue-in-groove (TIG) is a conservative but powerful surgical suture technique to control shape, rotation, and projection of the nasal tip. In this study, statistical analyses were performed to determine the aesthetical and functional effectiveness of TIG rhinoplasty. STUDY DESIGN Prospective cohort study including 110 Caucasian or(More)