RESUMEN
Advanced radiotherapy techniques, such as intensity-modulated radiotherapy (IMRT), may significantly benefit cervical cancer patients, in terms of reducing late toxicity and potentiating dose escalation. Given the steep dose gradients around the planning target volume (PTV) with IMRT planning, internal movement of organs during treatment may cause geographical miss of the target and unnecessary organs at risk (OAR) inclusion into high dose regions. It is therefore important to consider the extent and patterns of organ motion and to investigate potential image-guided radiotherapy (IGRT) solutions before implementing IMRT for cervical cancer. A systematic literature search was carried out using Medline, Embase, Cochrane Library, Web of Science, Cinahl and Pubmed. Database-appropriate search strategies were developed based upon terms for uterine neoplasms, IGRT, organ motion and target volume. In total, 448 studies were identified and screened to find 39 relevant studies, 12 of which were abstracts. These studies show that within the target volume for cervical cancer radiotherapy, uterine motion is greater than cervical. Uterine motion is predominantly influenced by bladder filling, cervical motion by rectal filling. Organ motion patterns are patient specific, with some having very little (5 mm) and others having much larger shifts (40 mm) of the target volume. Population-based clinical target volume (CTV)-PTV margins would be large (up to 4 cm around the uterus), resulting in unnecessary OAR inclusion within the PTV, reducing the benefits of IMRT. Potential solutions include anisotropic margins with increased margins in the anteroposterior and superoinferior directions, or greater PTV margins around the uterine fundus than the cervix. As pelvic organ motion seems to be patient specific, individualised PTV margins and adaptive IGRT strategies have also been recommended to ensure target volume coverage while increasing OAR sparing. Although these strategies are promising, they need significant validation before they can be adopted into clinical practice.
Asunto(s)
Planificación de la Radioterapia Asistida por Computador/métodos , Neoplasias del Cuello Uterino/radioterapia , Femenino , Humanos , Movimiento/fisiología , Radioterapia Guiada por Imagen/métodos , Resultado del TratamientoRESUMEN
OBJECTIVE: To explore the treatment preferences of clinical oncologists for managing early prostate cancer and to compare the results with the preferences of urologists. METHODS: A postal questionnaire survey was conducted of consultant clinical oncologists in the UK. RESULTS: Consultant clinical oncologists favour radical radiotherapy in most men aged < 70 years, whereas a previous study showed that consultant urologists had a greater preference for radical surgery. CONCLUSION: There is little consensus about which treatment should be used for managing early prostate cancer. There is an urgent need for results from randomized clinical trials to determine the optimum treatment.
Asunto(s)
Oncología Médica , Neoplasias de la Próstata/radioterapia , Anciano , Braquiterapia/métodos , Terapia Combinada/métodos , Toma de Decisiones , Encuestas Epidemiológicas , Humanos , Masculino , Persona de Mediana Edad , Satisfacción del Paciente , Pautas de la Práctica en Medicina , Prostatectomía/métodos , Neoplasias de la Próstata/patología , Neoplasias de la Próstata/cirugíaRESUMEN
We report the results of a prospective study to quantify inaccuracies in patient set-up during routine radiotherapy for tumours of the brain and bladder, which took place as part of our departmental development. Knowledge of these inaccuracies is required to put into practice the ICRU 50 recommendations regarding clinical target volume and planning target volume. We measured inaccuracies in two dimensions by comparing portal beam films with the simulator check film. Our method used manual measurements, proved to be a very laborious technique, and demonstrated the need for portal imaging. Ninety-five brain and 97 bladder portal films from 30 brain and 30 bladder patients were examined. Displacements greater than 0.5 cm were seen in 13% of brain treatments in the supero-inferior direction and 1% in the anteroposterior direction. With bladder treatments, displacements greater than 0.75 cm were seen in 12% in the supero-inferior direction and 5% in the lateral direction. These results are consistent with other previous studies. We identified a very small systematic error in the department, which was not [corrected] considered to be clinically significant. These results are discussed with reference to other similar studies and the ICRU 50 recommendations.
Asunto(s)
Astrocitoma/radioterapia , Neoplasias Encefálicas/radioterapia , Carcinoma de Células Transicionales/radioterapia , Postura , Neoplasias de la Vejiga Urinaria/radioterapia , Adolescente , Adulto , Anciano , Niño , Femenino , Humanos , Masculino , Errores Médicos , Persona de Mediana Edad , Estudios ProspectivosRESUMEN
We have conducted a retrospective study of high-dose folinic acid and 5-fluorouracil in 96 patients with advanced colorectal cancer. Patients received 200 mg m-2 (maximum 300-350 mg) folinic acid by infusion over 2 h followed by an i.v. bolus of 5-fluorouracil 400 mg m-2 then an infusion of 5-fluorouracil 600 mg m-2 over 22 h. This was repeated over the next 24 h. The schedule was given every 2 weeks for four cycles; thereafter patients with objective response continued to a maximum of eight cycles. The overall response rate was 10.6% in 85 evaluable patients. The median duration of response was 11 months. The median survival was 6 months. Toxicity was low, only one patient experiencing toxicity greater than WHO grade II (grade IV platelet toxicity). Diarrhoea, nausea, vomiting and mucositis also occurred but were mild and infrequent. Our low response rate may be related to factors such as patient characteristics or duration of treatment.