Utility of a Second 99mTc-MIBI Scintigraphy Before Reoperation for Patients With Persistent Sporadic Primary Hyperparathyroidism: Results of a Retrospective Multicenter Study.

ABSTRACT

BACKGROUND: Persistent primary hyperparathyroidism (PHPT) occurs in 2.5% to 15% of cases after parathyroidectomy. Few studies have evaluated the best pre-reoperative imaging approaches for persistent sporadic PHPT. This retrospective multicenter study aimed to evaluate the benefit of a second pre-reoperative 99mTc-methoxy-isobutyl-isonitrile (MIBI) scintigraphy for patients with persistent PHPT who had a 99mTc-MIBI before their initial surgery. METHODS: The study enrolled 50 patients with persistent sporadic PHPT who had reoperation between 2006 and 2016 in three French University Hospitals (Angers, Nantes, and La Pitié Salpêtrière-Paris). Preoperative 99mTc-MIBI scan was performed before each operation. RESULTS: After the reoperation, 42 patients (84%) were cured. By the second 99mTc-MIBI, 31 patients (62%) had a removed gland identified. A new pathologic gland was identified by a second 99mTc-MIBI in 25 patients (50%), and this imaging permitted correction of an initial surgical error in six patients (12%). A second 99mTc-MIBI showed a sensitivity of 63%, a specificity of 89%, a positive predictive value (PPV) of 78%, and a negative predictive value (NPV) of 80%. A concordant second 99mTc-MIBI and ultrasonography (17 patients) showed a sensitivity of 70%, a specificity of 81%, a PPV of 70%, and an NPV of 81%. CONCLUSIONS: Performing a second 99mTc-MIBI scan permitted 62% of the persistent PHPT patients to be cured, allowing identification of new pathologic glands in 50% of the cases and correction of an initial surgical error in 12% of the cases, with high specificity and PPV. These results reinforce the fact that a second 99mTc-MIBI scan should be performed at first intention before reoperation of patients with persistent PHPT, regardless of the result from the initial 99mTc-MIBI scan.