>>ARIA site vs IRC
Someone who I respect hypothesized that the difference between the central and the local review was because some small peripheral sarcomas (e.g. nerve sheath) are tricky to measure radiographically, and consequently the expert centers, who have seen a much greater volume of scans, detect progression earlier. She said she was not at all surprised by the discrepancy, and did not believe it indicated bias.
If this is correct, it suggests that although there was subtle progression in the discrepant scans, it was likely not clinically meaningful progression.
Peter