Simultaneous comparison of two independent dosimetry verification systems for VMAT irradiation in assessing 4D dose distribution

Abstract

Abstract Despite the rapid development of new technologies, 4D dose assessment related to the breathing movement of target organs during radiotherapy treatment is still a challenge. This study aimed to investigate the feasibility of polymer gel dosimeters to assess 4D dose distribution accuracy in VMAT radiotherapy treatment under dynamic conditions and to compare assessment results with the data obtained using a cylindrical water-equivalent phantom with a three-dimensional diode array (ArcCheck). For this purpose, several homemade polymer gels were filled in cylindrical containers and placed within the ArcCheck phantom. The entire system was mounted on rotating wheels and periodically moved by a connected robotic platform during irradiation. Generally, good agreement was found between measurement results of the 4D dose distribution obtained in the bulk of volume using homemade polymer gel dosimeters and diode detector system, indicating the potential to address the remaining small errors in further experiments. The latter implies the applicability of polymer gel dosimeters for the validation of high-dose stereotactic treatment plans under realistic 4D dose distribution conditions.