1：Experimental Design and Method Selection:

A THz time-domain reflection imaging system with photoconductive antennas and a fast optical delay line was used. The setup included off-axis parabolic mirrors to focus THz waves, with an incident angle of 15 degrees and a focused diameter of

2：7 mm at 5 THz. A quartz window served as the imaging plate to provide a flat reflection surface. Sample Selection and Data Sources:

Four fresh keratinizing SCC tissue specimens were surgically resected from patients, with normal and cancerous tissues obtained. Specimens were sliced to 1 mm thickness and handled minimally to prevent denaturation.

3：List of Experimental Equipment and Materials:

Equipment included a THz time-domain reflection imaging system, photoconductive antennas, fast optical delay line (operating frequency 20 Hz, time window 37 ps), off-axis parabolic mirrors, quartz imaging plate, double-sided tape, polyethylene tape, cotton swabs, and epoxy for attaching reference pots. Materials included water and metal for reference signals.

4：Experimental Procedures and Operational Workflow:

Specimens were placed on the quartz plate, covered to prevent moisture evaporation, and scanned with a 250 μm resolution over a 50 mm × 25 mm area. THz signals were acquired, normalized using water reference, and parameters like peak-to-peak values were extracted. Histopathological examination with H&E staining was performed post-experiment.

5：Data Analysis Methods:

THz images were generated using normalized peak-to-peak values from reflection signals. Refractive indices and absorption coefficients were calculated from averaged time-domain signals. Statistical analysis included mean and standard deviation calculations from multiple points within regions of interest.