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

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 Tc-methoxy-isobutyl-isonitrile (MIBI) scintigraphy for patients with persistent PHPT who had a Tc-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 Tc-MIBI scan was performed before each operation.

RESULTS

After the reoperation, 42 patients (84%) were cured. By the second Tc-MIBI, 31 patients (62%) had a removed gland identified. A new pathologic gland was identified by a second Tc-MIBI in 25 patients (50%), and this imaging permitted correction of an initial surgical error in six patients (12%). A second Tc-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 Tc-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 Tc-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 Tc-MIBI scan should be performed at first intention before reoperation of patients with persistent PHPT, regardless of the result from the initial Tc-MIBI scan.