摘要:The aim of the present study was to evaluate the predictive value of 25-hydroxyvitamin D, calcium and parathormone level, co-existence of thyroid nodule, thyroidectomy history and adenoma volume on the success of neck ultrasound (US) and technetium-99m sestamibi (MIBI) scan in primary hyperparathyroidism (PHP) patients. This study included 256 patients with PHP who underwent parathyroidectomy. 169 (%66) patients had vitamin D deficiency and 56 (%22) of patients had insufficiency. The sensitivity of US and MIBI studies showed no difference between vitamin D deficiency, insufficiency and replete groups (%80.5, %82 and %71 (p > 0.05) and %81, %84 and %71 respectively (p > 0.05)). Vitamin D level was not found to be an independent predictor of localization on either US or MIBI scan after adjusting for different variables (p > 0.05). Calcium level was found to be an independent predictor for US sensitivity (r 2 :0,033, p:0,032) and parathormone level for MIBI sensitivity (r 2 :0,05, p:0,025). The co-existence of nodular thyroid disease and history of thyroidectomy significantly decreased the sensitivity of US (%76 and %43). MIBI sensitivity was not impaired by nodular disease but the history of thyroidectomy also impaired the sensitivity of MIBI (%43). As a result vitamin D level does not affect the sensitivity of preoperative localization tests.