GRAPPATINI T2 Mapping to Predict Dopamine Agonist Resistance in Prolactinomas: A Pilot study

Motivation: Managing dopamine agonist (DA) resistance in prolactinoma is challenging, with no reliable imaging markers for prediction. Goal(s): This study used accelerated quantitative T2 mapping (GRAPPATINI) to evaluate DA sensitivity in prolactinoma patients. Approach: This cross-sectional study analyzed the diagnostic performance of T2 values with multiple echo times (TEs) and signal intensity (SI) ratios to predict drug sensitivity between drug-resistant and sensitive groups. Results: The study elucidated significantly reduced T2 values in patients with DA-resistant prolactinoma, reaching an area under the curve (AUC) of 0.850 for accurately distinguishing DA sensitivity, with pronounced differences observed at TE38ms. Conversely, T2 SI ratios showed no statistical significance. Impact: This pilot study was novel in using GRAPPATINI in prolactinoma. Quantitative T2 values of tumors were lower in patients with DA-resistant prolactinoma. Hence, T2 values may be a promising predictive imaging biomarker for DA sensitivity.