The FDA recommends Blinded Independent Central Review (BICR) with double reads for imaging in clinical trials, but inter-reader variability raises concerns. Our study examined this variability in lung clinical trials using RECIST. We analyzed 5 phase III trials with 7 readers forming 11 teams, covering 1,017 patients. The study focused on Discrepancy Rate (DR), bias, endorsement rate, and the impact of adjudication on Progression-Free Survival (PFS). Results showed significant bias among readers, affecting double readings but no correlation between bias and DR. Additionally, adjudication significantly affects PFS. These outcomes highlight the need to improve monitoring in clinical trials.