Evaluation of Radiation Shielding Requirements and Self-shielding Characteristics for a Novel Radiosurgery System.

In order to provide safe operating conditions for radiation workers and the public at large, the radiation shielding for radiotherapy treatment rooms will have to be determined by an expert physicist according to the applicable radiation control regulations. A new radiosurgery system with integrated self-shielding, called the Zap-X, obviates the need for costly and complex radiation bunkers. Radiation levels in the vicinity of the ZAP-X radiosurgery system were acquired for a number of different operating conditions, and a 3D radiation dose distribution was measured for better visualization of hot spots and the general dose distribution. The radiation shielding requirements were evaluated according to the International and Chinese standards, respectively. While the integral self-shielding of the Zap-X was designed in accordance with international standards, it was found to be insufficient for Chinese standards. In order to meet the needs of the growing new generation of radiotherapy equipment, several suggestions for improvement of Chinese standards are proposed.