This retrospective study included rolactinoma patients treated with dopamine agonists (DAs) at Songklanagarind Hospital over a 19-year period (2005–2024). Patients aged ≥15 years with complete baseline and 1-year follow-up MRI were included, excluding those with incomplete imaging, poor compliance, or prior pituitary surgery.

Pituitary MRI findings were analyzed for tumor dimensions, cystic/hemorrhagic components, and invasive features (e.g., cavernous sinus and optic chiasm invasion). Statistical methods, including logistic regression and Fisher’s exact test, identified key predictors of treatment response, defined as ≥50% tumor size reduction and prolactin normalization. Notably, cystic reduction and optic chiasm invasion correlated strongly with better prolactin normalization, while cavernous sinus invasion predicted poor outcomes. A p-value < 0.05 confirmed statistical significance.

Inter-observer reliability between neuroradiologists was excellent, with Cohen’s Kappa values of 0.82–1.00 for categorical variables and ICC values of 0.983–0.996 for continuous measurements. This highlights the consistency of MRI interpretations.