1：Experimental Design and Method Selection:

A CCD camera and an LED light source were combined to fabricate a compact optical CT scanner. The collimated beam emitted by the LED passed through aquarium, gel phantom, and telecentric lens, and an image was collected by the CCD camera and reconstructed using MATLAB.

2：Sample Selection and Data Sources:

A polymer gel dosimeter was used for the therapeutic radiation dose evaluation.

3：List of Experimental Equipment and Materials:

LED (FELL3030, FELLIS, KOREA), CCD camera (model#:BM-500GE, JAI, Japan), telecentric lens (part#1-17820, Navitar, USA), stepping motor (RKD514H-C, Korea Oriental motor), LabVIEW (National InstrumentsTM, 2011), MATLABTM (The Math Works, Inc, USA).

4：Experimental Procedures and Operational Workflow:

The gel dosimeter was rotated at every 0.72o using a stepping motor and LabVIEW, and the time for collecting 500 slice images per a revolution was within 20 min.

5：72o using a stepping motor and LabVIEW, and the time for collecting 500 slice images per a revolution was within 20 min. Data Analysis Methods:

5. Data Analysis Methods: The image was reconstructed using MATLAB, and the modulation transfer function (MTF) and linear correlation coefficient were calculated.