The development of a new technology in the late 1990s has made it possible to deliver 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 targeted intra-operative radiotherapy (TARGIT IORT), accurately targeted to the tissues that are at highest risk of local recurrence, from within the breast. 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 over 300 renowned centers in 35 countries around the globe. INTRABEAM is also used to irradiate brain tumors, spinal metastasis, tumors of the gastrointestinal tract and skin cancer, with the greatest experience in breast TARGIT IORT.
The TARGIT-A and TARGIT-B trials TARGIT IORT | Intrabeam are a collaborative international effort to scientifically test in randomised clinical trials, the hypothesis that the strategy of delivering TARGIT IORT in patients breast cancer.
The TARGIT-A randomised trial closed to recruitment in 2012 and results, published in high-impact journals TARGIT IORT | Intrabeam Results , show that firstly, it achieves breast cancer control similar to traditional radiotherapy that is given daily over 3-6 weeks; importantly, it also, reduces deaths from causes other than breast cancer such as heart attacks and deaths from other cancers.
The very low recurrence rates after giving a TARGIT-IORT Intrabeam tumour bed boost (in addition to whole breast radiotherapy) in the first 300 cases treated since 1998 and the tumour inhibitory effect of TARGIT IORT on surgical wound fluids led to the TARGIT-B randomised trial, which is currently testing whether for patients who are younger than 45 years or at high risk of local recurrence, will have an improved breast cancer control if a TARGIT IORT Intrabeam boost is given during surgery.
Funding for the TARGIT-A and TARGIT-B trials come from the UK department of health's HTA programme.