Rubens Chojniak

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BACKGROUND Conformal external radiotherapy aims to improve tumor control by boosting tumor dose, reducing morbidity and sparing healthy tissues. To meet this objective careful visualization of the tumor and adjacent areas is required. However, one of the major issues to be solved in this context is the volumetric definition of the targets. This study(More)
BACKGROUND The use of computed tomography (CT)-guided biopsies facilitate the diagnosis and management in several medical settings. In this study, the authors analyzed how effective cutting and fine-needle biopsies are in pediatric oncology. METHODS Medical records of 75 patients were analyzed in retrospect allowing the study of 101 biopsy results. The(More)
Growth rate is a prognostic factor for pulmonary metastases treatment. We used computed tomography (CT) to quantify tumor doubling time (Tdt) variation of pulmonary metastases in the same patient, from different histologies and sizes. We prospectively evaluated chest CTs of patients with pulmonary metastases under no cancer treatment. Tdt of 408 pulmonary(More)
OBJECTIVES To evaluate the impact of the inclusion of computed tomographic colonography (CTC) involving faecal tagging and no laxatives on the computed tomography (CT) study routinely used in staging patients with colorectal cancer. METHODS CTC was performed on 25 patients who had a diagnosis of colorectal carcinoma, with pathological correlation.(More)
CONTEXT AND OBJECTIVE Computed tomography (CT) guided biopsy is widely accepted as effective and safe for diagnosis in many settings. Accuracy depends on target organ and needle type. Cutting needles present advantages over fine needles. This study presents experience from CT guided biopsies performed at an oncology center. DESIGN AND SETTING(More)
OBJECTIVE Anxiety disorders have been shown to undermine the quality of life of cancer patients. Unfortunately, medical professionals often neglect to screen for anxiety in their patients. The aim of the present study was to describe the prevalence of anxiety in patients awaiting diagnostic procedures in an oncology center waiting room, and to investigate(More)
OBJECTIVE To report oncological cases (excluding those related to breast cancer) for which radioguided surgery has been used in combination with the Radioguided Occult Lesion Localization technique. INTRODUCTION Radioguided surgery enables a surgeon to identify lesions or tissues that have been preoperatively marked with radioactive substances. The(More)
OBJECTIVE To verify the capacity of targeted ultrasound (US) to identify additional lesions detected on breast magnetic resonance imaging (MRI), but occult to initial mammography, US and clinical examinations. METHODS This prospective study included 68 additional relevant breast lesions identified on MRI of 49 patients. As an inclusion criterion, breast(More)
OBJECTIVE To evaluate the impact of adding 18F-fluorine-2-deoxy-d-glucose (FDG) positron emission tomography (PET) in the evaluation of suspicious breast lesions on magnetic resonance imaging (MRI). METHODS Sixty patients with suspicious breast lesions on MRI were selected to perform a PET-CT in prone position, dedicated to the evaluation of the breasts.(More)