Fast regional readout CMOS Image Sensor for dynamic MLC tracking

17th International Conference on the Use of Computers in Radiation Therapy

物理学;计算机科学

Zin, H.^1,2 ; Harris, E.^2 ; Osmond, J.^2 ; Evans, P.^2,3

Advanced Medical and Dental Institute, Universiti Sains Malaysia, 13200, Kepala Batas, Penang, Malaysia^1

Joint Department of Physics, Institute of Cancer Research, Royal Marsden NHS Foundation Trust, Downs Road, Sutton, Surrey, SM2 5PT, United Kingdom^2

Centre for Vision, Speech and Signal Processing, University of Surrey, Guildford, Surrey, GU2 7XH, United Kingdom^3

关键词: Complementary metal oxide semiconductor image sensor;    Dynamic MLC tracking;    Electronic portal imaging devices;    Frames per seconds;    High energy radiation;    Multileaf collimators;    Verification tools;    Volumetric modulated arc therapy;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/489/1/012085/pdf
DOI  :  10.1088/1742-6596/489/1/012085

学科分类：计算机科学（综合）

来源: IOP

【 摘 要 】

Advanced radiotherapy techniques such as volumetric modulated arc therapy (VMAT) require verification of the complex beam delivery including tracking of multileaf collimators (MLC) and monitoring the dose rate. This work explores the feasibility of a prototype Complementary metal-oxide semiconductor Image Sensor (CIS) for tracking these complex treatments by utilising fast, region of interest (ROI) read out functionality. An automatic edge tracking algorithm was used to locate the MLC leaves edges moving at various speeds (from a moving triangle field shape) and imaged with various sensor frame rates. The CIS demonstrates successful edge detection of the dynamic MLC motion within accuracy of 1.0 mm. This demonstrates the feasibility of the sensor to verify treatment delivery involving dynamic MLC up to ∼400 frames per second (equivalent to the linac pulse rate), which is superior to any current techniques such as using electronic portal imaging devices (EPID). CIS provides the basis to an essential real-time verification tool, useful in accessing accurate delivery of complex high energy radiation to the tumour and ultimately to achieve better cure rates for cancer patients.