RESUMEN
The pituitary gland is an uncommon site of tumor metastasis in the brain, comprising only 1% of all intracranial metastasis. Large cell neuroendocrine carcinoma (LCNEC) is similarly rare, accounting for only 3% of all lung malignancies in adults. We describe a case of LCNEC of lung origin that metastasized to the pituitary gland. The pituitary lesion was found during the workup for a metastatic LCNEC of lung origin in the ovary. Initially thought to be a pituitary adenoma, interval growth of the lesion during imaging follow-up raised clinical suspicion of a second metastatic site. The patient underwent endoscopic resection and pathological examination confirmed the pituitary lesion to be from the lung primary. Post-operatively, the patient developed signs and symptoms of diabetes insipidus that was adequately treated with DDAVP. The patient underwent postoperative radiotherapy one month after the surgery and a repeat MRI at the 12-month follow-up demonstrates no progression of the pituitary lesion.
RESUMEN
Total body irradiation (TBI) is used prior to bone marrow transplantation as part of the conditioning regimen in selected patients. A linear accelerator-based technique was used at our treatment centre between June, 2004 and August, 2015. Patients were treated supine with extended source-to-surface distance (SSD) lateral fields, and prescription dose was 12 Gy delivered in six fractions, two fractions per day. Dose was prescribed to midplane at the level of the umbilicus and monitor units were calculated manually based on measured beam data. Dose variation within 10% of the prescribed midplane dose is considered acceptable for TBI treatment. This was achieved in our clinic by using compensators to account for missing tissue in the head and neck and lower leg regions. Lung attenuators were routinely used to correct for internal inhomogeneity, which resulted from low density lung tissue. The purpose of this study was to determine whether dose variation was within acceptable limits for these patients as part of a quality assurance process. Following chart review, 129 patients who received six-fraction TBI from 2004 to 2015 were included in this study. Patients receiving single fraction treatment were excluded. Metal oxide semiconductor field effect transistors (MOSFET) dosimetry was used to measure surface dose at four or five locations during patients' first fraction of TBI. Dosimetry was repeated during the second fraction for any site with variation greater than 10%. Statistical analysis was carried out on patient data, diagnosis and dosimetry measurements. Of the 129 patients who met the inclusion criteria, 50 were diagnosed with acute myelogenous leukemia, 30 with acute lymphoblastic leukemia and 11 with chronic myelogenous leukemia. The rest of the patients were diagnosed with lymphoma or myelodysplastic syndromes. The mean percent variation in dosimetry measurements taken at the specific locations ranged between 3.5% and 8.3%. The highest variation was found in measurements performed on the cheek. A high percentage of all dosimetry readings (85.5%) was within the acceptable range of +10% from the expected value. The highest number of individual readings taken at a specific location that fell outside this range were found at the cheek. We conclude that the linear accelerator delivered TBI at our centre meets the acceptable limits of dose variation over an 11-year period.
RESUMEN
INTRODUCTION: Physicians entering independent practice often express apprehension in managing the non-clinical aspects of practice. This study examined the perceived preparedness of radiation oncology (RO) residents for independent practice, identified education gaps, and discussed how these deficiencies could be addressed. MATERIALS AND METHODS: Focus groups with senior RO residents, fellows, new-to-practice radiation oncologists (ROs), and residency program directors were conducted. Data were coded using the Canadian Medical Education Directives for Specialists (CanMEDS) competencies using thematic analysis. RESULTS: Commonly reported gaps in the transition to practice (TtP) for ROs were lack of experience with: practice management, understanding the structure and function of the health care system and how it varies by jurisdiction, financial planning, effective communication and collaboration with other health care team members, creation of accurate and timely documentation, and radiotherapy problem-solving related to treatment planning and evaluation. Suggestions to address these challenges included use of mentorship, educational resources, courses, simulation-based medical education, improved graded responsibility, resident longitudinal clinics, and formal curricula in radiation therapy planning and evaluation. CONCLUSION: There are gaps in TtP education for RO trainees with opportunities for enrichment through the forthcoming implementation of a competency-based medical education framework in 2019. The gap in perceived competency in physician-related radiotherapy tasks may be caused by the complex interaction of clinical workflow processes, people and technology that has led to ineffective integration of trainees. The data are informative to medical education leaders for the development of comprehensive TtP curricula.