Accelerators Development for Intraoperative Radiation Therapy

The "Intra Operative Radiation Therapy" (IORT) consists in delivering a single high dose on a tumour bed soon after surgery resection. The "IORT Project", funded by the Italian Ministry of Research (MURST), was started in 1998 from ENEA (Italian National Agency for New Technologies, Energy and the Environment) and is aimed to design and construct two innovative IORT systems (named IORT-1 and IORT-2) equipped with advanced treatment planning and real time dosimetry. These developments will improve the present IORTNOVAC7 system, jointly developed in the latest years from ENEA and the Italian Hitesys Company. In the paper the advance status of the project is described and IORT-1 experimental results are presented with particular attention to innovative technical aspects of these new generation IORT accelerators. 1 INTRA-OPERATIVE RADIOTHERAPY The "Intra Operative Radiation Therapy" (IORT) [1] represents a very effective and emerging oncological treatment. The main advantage of IORT technique, in addition to the possibility to avoid additional radiotreatments after surgery intervention, is to be referred to the improved tumor local control [2]: as a matter of fact the technique allows the hitting with an high single dose focused only on diseased tissue, avoiding to irradiate healthy tissues and preventing tumor recurrence in surrounding area. The IORT last generation equipment, that is represented by a very compact, light and mobile EB-machine located in the same operating room, overcomes, moreover, the previously foreseen patients transfer to the hospital radiotherapy shielded department just after the resection (patient’s additional stress and anaesthesia, difficulties to preserve a sterile path during conveyance, etc.). The first world equipment of such type was conceived by ENEA and the Italian Co. HITESYS, since early ‘90s, and named as NOVAC7 [3], and at present more than ten models of such equipment are actively operating by Italian and European hospitals with some hundreds successful treatments carried out. The experience carried out on such system showed that, although it is one of the most advanced IORT equipments worldwide, some technical modifications can allow a meaningful improvement of present performances. At this aim in 1998 ENEA launched the “IORT Project”[4], funded by the Italian Ministry of Research