Development Of An Improved Wood’S Alloy End-Frame Casting Unit For Electron Field Shaping In Radiotherapy

Abstract

As the second leading cause of death, cancer is a harsh reality. Skin cancer is one of the most prevalent cancers in South Africa and is commonly treated using electron radiation in radiotherapy. The applied radiation field needs to be shaped to the size of the cancer-affected area on the patient. This can be achieved through end-frames that fit into applicators that attach to the treatment unit. The end-frames are produced by casting Wood’s alloy into commercially available jigs. However, producing these end-frames presents various shortcomings such as lack of dimensional accuracy, the inconsistent density of the castings and the high cost of the jigs. The aim of this study was to develop a Wood’s alloy casting unit that can be made available to local oncology departments to produce endframes that are superior to what can be produced through commercial jigs. This paper describes the development and manufacturing of the new casting equipment and experiments performed to evaluate end-frames produced. Results showed that end-frames cast in the newly developed casting equipment are dimensionally more accurate, have consistent high density, and can be produced in a shorter time.