NIRS, Chiba-shi
Construction of new treatment facility as an extension of the existing HIMAC facility, in which all treatment room will be equipped with a 3D pencil beam scanning system, is in progress at NIRS. The challenge of this project is to realize treatment of a moving target by scanning irradiation, because pencil beam scanning is more sensitive to organ motions compared with the conventional broad-beam irradiation. To accomplish practical moving target irradiation, a prototype of the scanning irradiation system was constructed and installed into existing HIMAC physics experiment course. One of the most important features of the system to be tested is fast scanning toward moving target irradiation with a relatively large number of rescannings within an acceptable irradiation time. Commissioning of the prototype is successfully in progress cooperating with highly stabilized beam provided by the HIMAC accelerator complex. We will report the design of the system and the status of the beam study.
NIRS, Chiba-shi
AEC, Chiba
Based on more than ten years of experience of the carbon cancer therapy with HIMAC, we have proposed a new treatment facility for the further development of the therapy with HIMAC. This facility will consist of three treatment rooms: two rooms equipped with horizontal and vertical beam-delivery systems and one room with a rotating gantry. For the beam-delivery system of the new treatment facility, a 3D hybrid raster-scanning method with gated irradiation with patient's respiration has been proposed. A R&D study has been carried out toward the practical use of the proposed method. In the R&D study, we have improved the beam control of the size, the position and the time structure for the proposed scanning method with the irradiation gated with patient's respiration. Further, owing to the intensity upgrade of the HIMAC synchrotron, we can successfully extend the flattop duration, which can complete one fractional irradiation with one operation period. The building construction of the new treatment facility will be completed at March 2010 and treatment of 1st patient is scheduled at March 2011. We will report the recent progress on the new treatment facility project at HIMAC.
NIRS, Chiba-shi
The development of the screen monitor system (SCN) at the Heavy Ion Medical Accelerator in Chiba (HIMAC) comprises the surveillance of the carbon beam. In the three-dimensional scanning system for the carbon therapy, the beam qualities, i.e., position, size and intensity of the beam, play a significant role for the patient's treatment. Therefore, we designed a semi-nondestructive monitoring system located on the the high-energy beam transport line to monitor the beam qualities by using a thin fluorescent screen and a high-speed charge-coupled device. The beam position and profile were obtained from the light emitting distribution of the screen. The SCN was checked on the prototype scanning system at HIMAC and succeeded to monitor the beam real-time in steps of about 10 msec, corresponding to a 100 Hz sampling rate. The developments steps will focus toward a operation at HIMAC's new therapy facility extension, recently. In the conference, we would like to report on details of the automatic beam tuning before starting the treatment and the interlock system during therapy using the SCN.