Progress in heavy ion cancer therapy at IMP and future development

Basic research on heavy ion cancer therapy such as radiobiology, medicalphysics, and therapeutic technique has been conducted at the Institute ofModern Physics (IMP), Chinese Academy of Sciences since 1995. Based on theachievements acquired in the basic research and the requirements for a heavyion accelerator for radiotherapy purposes, a dedicated heavy ion therapy facilitynamed Heavy Ion Medical Machine (HIMM) was designed at IMP andconstructed in Wuwei, China. The HIMM facility consists of two electroncyclotron resonance ion sources, one cyclotron as the injector and onesynchrotron as the main accelerator, and four different treatment roomsequipped with passive or active beam delivery systems, and accelerates carbonions up to 400 MeV/u. After the performance inspection of HIMM organized bythe National Medical Device Inspection Center, preclinical tests like cell andanimal radiobiological experiments and dosimetric verification using anthropomorphicphantoms for elucidating the biophysical properties of the carbon ionbeams provided by HIMM were carried out. According to the Chinese medicaldevice regulations, a clinical trial in which 46 tumor patients were recruited andtwo hospitals participated was conducted in the HIMM facility, aiming atevaluating the treatment safety and short-term efficacy of the medical device.The success of the clinical trial helped the HIMM facility be authorized by theChinese government as a class III medical device. In this paper, all the aspectsmentioned above are introduced and discussed, and implications for futureimprovements are also given.