Endocrine Abstracts

Pre-operative localization of parathyroid adenoma using parathyroid imaging remains a controversial issue. However, with the advent of minimally invasive parathyroid surgery and the use of more sensitive radionuclide (Technetium Seastamibi and recently Technetium tetrofosmin); the belief in the usefulness of parathyroid imaging is increasing.Our objectives were a) to compare the sensitivities of three parathyroid imaging modalities (Thallium Substraction, Low Dose and High Dose Technetium SestaMibi) in the preoperative localization of parathyroid adenomas in patients with primary hyperparathyroidism and b) to find out if combining parathyroid Ultrasound Scan (USS) to the above three parathyroid imaging would increase sensitivity of picking up PT adenomas.Retrospectively we looked into 35 patients (28 female & 7 males) with Primary Hyperparathyroidism who underwent parathyroidectomy between 1990 and 2002 in Princess Royal Hospital, Telford. All patients had PT Nuclear Medicine Scintigraphy (NM) combined with USS for pre-operative localisation. Initially Thallium Substraction was the standard NM used then later replaced by Technetium SestaMibi. In the latter two doses were used; Low Dose and later on upgraded to High Dose. We correlate the findings of each NM and USS separately and combined against the surgical findings. All patients had parathyroid surgery utilizing standard neck exploration.15 patients had Thallium substraction, 12 had Low dose Technetium SestaMibi and 8 had high Dose Technetium SestaMibi (total 35).All patients had parathyroid USS. The Sensitivities were as follows: Thallium substraction [alone (60%), combined with USS (80%)], Low Dose Tech SestaMibi [alone (50%), combined with USS (58%)], High Dose Tech SestaMibi [alone (90%) combined with USS (100%)] and USS alone (50%).We concluded that USS and NM provide complementary roles in the pre-operative localization of PT adenoma and High Dose Tech sestaMibi combined with USS is the best modality to inform surgical treatment.