Level 2: blind & randomization expert scoring
Ten out of the 20 testing patients were randomly selected by Fisher-Yates shuffle for Level-2 evaluation. For CTV evaluation, five patients were randomly selected, and for each patient five CT slices were selected to display GT contours (CTV-GT: 5 × 5 = 25), and it went likewise with the rest 5 patients to generate CT slices with DL contours (CTV-DL: 5 × 5 = 25 slices in one folder). Similarly, five MRI slices for five randomly selected patients were randomly extracted to display GT GTV contours (GTV-GT: 5 × 5 = 25) and five MRI slices for the rest 5 patients to display DL GTV contours (GTV-DL: 5 × 5 = 25 slices in another folder). The DICOM-RT slices were exported as non-compressed TIFF images. In total, two folders of 50 images for CTV (GT = 25, DL = 25) and GTV (GT = 25, DL = 25) evaluation were prepared. The images in each folder were reshuffled (in Python) and anonymized by ordering numbers each time before we sent them to an external expert for independent scoring.The rubric for scoring was in grade (Table 
Rubric for expert scoring