The Relationship of Negative Imaging Result and Surgical Success Rate in Primary Hyperparathyroidism

OBJECTIVES: In present, the effect of pre-operative negative imaging results on surgical outcomes of primary hyperparathyroidism (pHPT) is still controversial. In this study, we aimed to evaluate the effect of pre-operative imaging on surgical outcomes. METHODS: The data of pHPT patients who were operated between 2009 and 2018 were evaluated retrospectively. Patients were divided three groups according to scintigraphy and/or ultrasonography results: Group 1; both imaging positive, Group 2; single imaging positive, and Group 3; patients in whom both imaging modalities are negative. Pre-operative biochemical characteristics, parathyroid pathologies, diameter and volume of the pathological gland, surgery rates, persistence, and recurrent disease rates of the groups were compared. RESULTS: Of 311 patients (258F, 53M) with a mean follow-up period of 24.7±18 months and a mean age of 54.1±12.9 years; 161 were in Group 1, 111 were in Group 2, and 39 were in Group 3. The diameter of pathological gland (2.1±0.8, 1.6±0.9, 1.5±0.7 cm; p<0.001; in Group 1,2,3 respectively) and the volume of pathological gland (2±3.2, 1.4±2.9, 1.1±2.2 cm(3); p<0.001; in Group 1,2,3, respectively) in Group 1; the rate of multi gland disease (5.7%, 11%, 21%; p=0.024; in Group 1, 2, 3, respectively) in Group 3 were significantly higher. In the 1, 2, 3 group; bilateral exploration rates were 93.2%, 48.6%, and 5.1%, and focused surgery or unilateral exploration rates were 6.8%, 51.4%, and 94.9%, respectively, with a significant difference (p<0.001). After the first surgery, the cure rate was 91.3%, 93.7%, and 89.7%, and the persistent patient rate was 7.5%, 3.6%, and 10.3% in Groups 1,2,3, respectively, and there was no significant difference. At the end of the follow-up period after secondary intervention applied in persistent and recurrent patients, the overall cure rate was 97.4%, 96.4%, and 97.4%, persistent disease rate 1.3%, 1.8%, and 2.6%, recurrent disease rate 1.3%, 1.8%, and 0%, respectively. CONCLUSION: In imaging-negative patients with pHPT, the possibility of multi gland disease and smaller pathological glands should be considered at the time of surgery. Surgery in imaging-negative patients can be performed with a similar and acceptable cure rate to imaging-positive patients.