OPN1MW and neoplasm: Statistical analysis in both the CBD and CBD + RT groups showed significant differences in CBD levels between plasma and neoplasia (p = 0.003, 95% CI = 60.4–227, paired t-test) and between plasma and intact brain (p = 0.0007, 95% CI = 94.6–250.9, paired t-test), but no significant difference between neoplasia and non-diseased brain tissue (p = 0.439, 95% CI = −110.3–52.2, paired t-test).