SPECT/CT With 99mTc-MIBI as an Early Indicator of the Success of Radiofrequency Ablation of Parathyroid Adenomas.

A 55-year-old man with hypercalcemic primary hyperparathyroidism underwent preprocedural localization with 99mTc-MIBI SPECT/CT, demonstrating a right inferior parathyroid adenoma. As the patient refused surgery, radiofrequency ablation was performed. Calcium normalized progressively, while parathyroid hormone (PTH) levels remained mildly elevated at 6 months. Follow-up 99mTc-MIBI SPECT/CT showed no residual adenomatous uptake, correctly predicting delayed biochemical cure, with subsequent normalization of PTH at 1 year. This case highlights the potential value of 99mTc-MIBI SPECT/CT as an early imaging biomarker of therapeutic success after radiofrequency ablation in patients with persistent mild PTH elevation.