RESUMO
A frameless method for stereotactic multiple arc radiotherapy (SMART) is described. Three short gold wires are implanted in the scalp approximately 100 mm apart. These are localized in a computed tomographic or angiographic study along with the target. Subsequently the gold markers are localized on beam films and the target position calculated using a computer program ISOLOC. This program provides the couch movements required to move the target to the isocentre and a micropositioner attached to the couch is used to make the adjustment. Beam films are repeated until the movements required are less than 1 mm in any direction. It is shown that the simple procedures of implanting the markers subcutaneously do not provide a stable reference system in about 25% of patients and the markers are now screwed into the cranium. The precision of the method is evaluated by phantom studies and measurements taken during several hundred treatments.
Assuntos
Radioterapia Assistida por Computador/métodos , Técnicas Estereotáxicas , Encefalopatias/radioterapia , Estudos de Avaliação como Assunto , Ouro , Humanos , Modelos Estruturais , Dosagem Radioterapêutica , Planejamento da Radioterapia Assistida por ComputadorRESUMO
A case of locally extensive perianal Paget's disease is presented. Initial wide local excision, guided by frozen sections, was inadequate. Multiple punch biopsies subsequently revealed extensive circumferential involvement of the anoderm by Paget's disease, making wide local excision difficult. Therefore, the patient was treated with combined chemoradiotherapy (5000 cGy, 5-fluorouracil, and mitomycin C). Fourteen months after treatment, the patient had a complete response.
