Frédéric Beaulieu

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This study examines the area of eye movement dysfunctions as an indicator of vulnerability to schizophrenia. Eye movement performance was investigated with three different paradigms: Smooth Pursuit Eye Movements (SPEM); Visually Guided Saccades (VGS); and Antisaccades (AS) in 21 clinically stable patients with schizophrenia, 21 of their healthy, biological(More)
Inverse planning in external beam radiotherapy often requires a scalar objective function that incorporates importance factors to mimic the planner's preferences between conflicting objectives. Defining those importance factors is not straightforward, and frequently leads to an iterative process in which the importance factors become variables of the(More)
Clinical studies show that schizophrenic and depressive subjects have problems with daily life activities, and neuropsychological studies tend to explain these problems in terms of a dysexecutive syndrome. Verbal fluency and sentence arrangement are tasks considered to focus on two aspects of the dysexecutive syndrome known as initiation and supervision(More)
PURPOSE To verify the potential of aperture-based intensity-modulated radiotherapy (AB-IMRT) to realize dose escalation plans for non-preselected non-small-cell lung cancer (NSCLC) patients, using photon beam energy optimization. METHODS AND MATERIALS Seven cases of NSCLC were retrospectively studied. Clinical reference plans were made at 60 Gy by an(More)
Optimal choice of beam energy in radiation therapy is easy in many well-documented cases, but less obvious in some others. Low-energy beams may provide better conformity around the target than their high-energy counterparts due to reduced lateral scatter, but they also contribute to overdosage of peripheral normal tissue. Beam energy was added as an(More)
We have developed an algorithm to automatically generate anatomy-based MLC fields. For each beam, a first field is adjusted to the projection of the target in a beam's eye view, allowing subsequent fields to be derived from this conformal field by removing the overlapping surface of each organ at risk, respectively. The projections are based on a surface(More)
PURPOSE To assess disease control and acute and chronic toxicity with aperture-based intensity-modulated radiotherapy (AB-IMRT) for postoperative pelvic irradiation of endometrial cancer. METHODS AND MATERIALS Between January and July 2005, after hysterectomy for endometrial cancer, 15 patients received 45 Gy to the pelvis using AB-IMRT. The AB-IMRT plans(More)
PURPOSE To implement SPECT-based optimization in an anatomy-based aperture inverse planning system for the functional avoidance of lung in thoracic irradiation. MATERIAL AND METHODS SPECT information has been introduced as a voxel-by-voxel modulation of lung importance factors proportionally to the local perfusion count. Fifteen cases of lung cancer have(More)
Examen peu contraignant sinon par sa durée d’enregistrement, la scintigraphie gastrique au sulfocolloide technetié a pris place dans l’exploration des reflux gastro-œsophagiens et de leurs complications. Son caractère physiologique, son irradiation modérée quel que soit le nombre d’images, sa grande sensibilité permettant des clichés tardifs et les(More)
PURPOSE To evaluate dosimetric and treatment delivery advantages of aperture-based intensity-modulated radiotherapy (AB-IMRT) for the treatment of patients receiving whole pelvic radiotherapy for gynecologic malignancies. METHODS AND MATERIALS Nineteen patients undergoing pelvic radiotherapy after resection of endometrial cancers were selected. A 45-Gy(More)