The recent development of a new technology has made possible the delivery of radiation directly to the tissues at the site of the primary tumour. The INTRABEAM® manufactured by Carl Zeiss, is a simple but ingenious device, in essence a miniature electron beam-driven X-ray source, which provides a point source of low energy X-rays (50kV max) at the tip of a 3.2mm diameter tube. The radiation source can be inserted into the area of interest immediately after excision of the tumour and switched on for 25-30 minutes to provide intra-operative radiotherapy (IORT), accurately targeted to the tissues that are at highest risk of local recurrence. The physics, dosimetry and clinical applications of this soft x-ray device have been well studied.
Today INTRABEAM is in-use for routine therapy and within the framework of clinical studies in a number of renowned centers around the globe. INTRABEAM is used to irradiate brain tumors, tumors of the gastrointestinal tract and skin cancer, with the greatest experience in breast IORT. The TARGIT trial is a collaborative international effort to test the hypothesis that the strategy of delivering IORT in patients with low risk early stage breast cancer is equivalent in local recurrence rate to a 6 week course of whole breast radiotherapy.