The findings and outcome of surgery in 193 patients with a unilateral uptake on -sestamibi/¹²³I scintigraphy. TP: true positive scintigraphy finding; that is, a pathological parathyroid gland was found at the scan-guided site at surgery. FP: false positive scintigraphy finding; that is, no pathological gland was found at the scan-guided site at surgery. FN: false negative scintigraphy finding; that is, a pathological gland was identified at surgery despite no positive preoperative imaging finding at this site, or a patient was not cured despite the removal of a gland identified by preoperative imaging.