RESUMEN
PURPOSE: The small bowel is a main dose-limiting organ in pelvic radiotherapy in the patients with rectal cancer. Conventionally, pelvic radiotherapy of patients with rectal cancer is performed in the prone position. MATERIAL AND METHODS: Thirty-nine patients underwent CT planning scan in the treatment position (20 patients in prone position group and 19 patients in supine position group). After radiation treatment planning optimization, the volumes of the irradiated small intestines were investigated. RESULTS: The volume of irradiated small bowel was higher in the supine position (mean difference; 36,274 cm3). However, it was not statistically significant (P value=0.187) CONCLUSION: Supine position could be accepted for the patients undergoing preoperative rectal cancer chemo-radiation.
Asunto(s)
Intestino Delgado/efectos de la radiación , Órganos en Riesgo , Posicionamiento del Paciente/métodos , Posición Prona , Neoplasias del Recto/radioterapia , Posición Supina , Adulto , Anciano , Anciano de 80 o más Años , Femenino , Humanos , Masculino , Persona de Mediana Edad , Terapia Neoadyuvante , Pelvis/diagnóstico por imagen , Dosificación Radioterapéutica , Planificación de la Radioterapia Asistida por Computador , Tomografía Computarizada por Rayos XRESUMEN
PURPOSE: Historically, electron boost dose mainly was delivered by a direct field in adjuvant radiotherapy of breast cancer. In this prospective study, we investigated direct electron field, in terms of optimal coverage of tumour bed volume following localization using ultrasound and surgical clips. MATERIAL AND METHODS: First, for all 24 patients, a breast sonographer drew perimeter of tumour bed on the breast skin. Then an electron boost field was outlined on the demarcated territory, and a lead wire marker compatible with CT scan was placed on the field borders by a 2cm margin. After CT scan simulation, all patients underwent adjuvant whole breast irradiation with 3D-conformal radiotherapy to 50Gy in 25 fractions. Then for boost radiotherapy, lead wire in CT images was countoured as electron boost field. Also, the tumour bed was contoured based on surgical clips (true clinical target volume and true planning target volume). Electron treatment planning was done for electron boost field. Finally isodose coverages for true planning target volume investigated. RESULTS: On average, 16.68% of clips planning target volume (true planning target volume; range: 0.00 to 95%) received 90% oor more of the prescribed dose when the electron treatment plan was made. Isodose curves does not provide adequate coverage on the tumour bed (clips planning target volume) when electron boost treatment planning was generated for electron boost field (en face electron field). In fact, a part of target (planning target volume-c) is missed and more doses is absorbed in normal tissue. CONCLUSIONS: Electron boost treatment planning (an en face electron field) following tumour bed localization using ultrasonography does not provide an optimized coverage of tumour bed volume.
Asunto(s)
Neoplasias de la Mama/radioterapia , Dosificación Radioterapéutica , Radioterapia Conformacional/métodos , Adulto , Anciano , Femenino , Humanos , Imagenología Tridimensional , Persona de Mediana Edad , Estudios Prospectivos , Radioterapia Adyuvante , Radioterapia Guiada por ImagenRESUMEN
AIMS: Growth of the cancer incidence rate in Iran has been very high in recent years. Therefore, the Iranian health care system should be prepared for the treatment of a huge number of patients in the foreseeable future. One of the most important treatment options for cancer is radiation. However, there is no comprehensive information on infrastructure for radiation oncology in this country. MATERIALS AND METHODS: In 2015, a questionnaire was designed by the Iranian Society of Clinical Oncology (ISCO) and all radiation oncology centres in the country were visited to determine four important components of radiation oncology services, including facilities, equipment, personnel and patients. RESULTS: In 2015, 94 radiotherapy centres were identified in Iran. Sixty-one centres were fully operational, six centres were commissioning, 26 centres were under construction and one was inactive. Among the fully operational radiotherapy centres, 54 offered three-dimensional conformal radiotherapy and two-dimensional radiotherapy, eight offered brachytherapy, two intensity-modulated radiotherapy, two intraoperative radiotherapy, ostereotactic radiosurgery, two hyperthermia and 59 chemotherapy. Moreover, the survey identified 110 linear accelerators, 25 cobalt-60, one gamma knife, 21 remote brachytherapy afterloaders and six orthovoltage units. Treatment planning equipment included 15 graphy simulators, 19 dedicated computed tomography simulators, 22 multileaf collimator and 12 electronic portal imaging devices. Moreover, in 2015, 243 clinical oncologists participated in the treatment of 42 350 cancer patients in need of radiotherapy, which is about one radiation oncologist for 175 patients. During 2010-2015, number of cobalt-60 reduced 70%, from 25 units to 8 units. CONCLUSIONS: There is a significant gap between Iran's available facilities for radiation therapy and international standards. Moreover, during international economic sanctions against Iran this gap widened.