EP78 – The impact of dual-isotope parathyroid scintigraphy in thyroid cancer detection

      Koutsikos, Ioannis1; Velidaki, Antigoni2 1 Department of Nuclear Medicine,  Army Share Fund Hospital, Athens, Greece 2 Department of Nuclear Medicine, Laiko General Hospital of Athens, Athens, Greece   Background/ Purpose: Parathyroid scintigraphy with Tc-99m Sestamibi (MIBI) is recommended in patients with primary hyperparathyroidism. Several protocols are currently in use. Subtraction planar scintigraphy with dual-isotope, seems to be more accurate and reliable; however, methods with single isotope and with early and delayed images are also in use. MIBI has been reported as highly sensitive for thyroid neoplasia; however, it is not currently performed for routine clinical application. The aim of our study was to determine, in the same patients with primary hyperparathyroidism, the impact of MIBI–Tc-99m pertechnetate scintigraphy in identifying thyroid cancer. Methods: We studied prospectively the database of 485 patients who underwent parathyroid scintigraphy in our departments. We identified patients who were operated for PHPT and underwent simultaneous thyroidectomy. Results: A total of 80 patients underwent both thyroidectomy and parathyroidectomy. Papillary carcinoma was detected in 2 patients (2.5%), both with multifocal tumors. MIBI early-delayed imaging was positive in 62 patients; in 18 patients no area of increased MIBI uptake was revealed. On Tc-99m pertechnetate scintigraphy, 8/62 MIBI (+)ve patients had also increased radiopharmaceutical uptake, while 4 patients had “cold” nodules; 2 in accordance with MIBI (+)ve site and in 2/18 MIBI (-)ve patients. The 2 MIBI (+)ve/ Tc-99m pertechnetate cold were the patients with the papillary carcinoma. In the 2 MIBI (-)ve/ Tc-99m pertechnetate cold patients, neither malignancy, nor parathyroid abnormality was identified. Discussion & Conclusion: The dual-isotope parathyroid scintigraphy is superior to other scintigraphic techniques in detecting thyroid cancer. We should be aware of a MIBI (+)ve/ Tc-99m pertechnetate cold pattern.   References:
    1. Emirikçi S, Özç?nar B, Öner G, Omarov N, A?cao?lu O, Soyta? Y, et al. Thyroid cancer incidence in simultaneous thyroidectomy with parathyroid surgery. Ulus Cerrahi Derg. 2015 Aug 18;31(4):214-7.
    2. Onkendi EO, Richards ML, Thompson GB, Farley DR, Peller PJ, Grant CS. Thyroid cancer detection with dual-isotope parathyroid scintigraphy in primary hyperparathyroidism. Ann Surg Oncol. 2012 May;19(5):1446-52.
    3. Riazi A, Kalantarhormozi M, Nabipour I, Eghbali SS, Farzaneh M, Javadi H, et al. Technetium-99m methoxyisobutylisonitrile scintigraphy in the assessment of cold thyroid nodules: is it time to change the approach to the management of cold thyroid nodules? Nucl Med Commun. 2014 Jan;35(1):51-7.
    4. Rubello D, Toniato A, Pelizzo MR, Casara D. Papillary thyroid carcinoma associated with parathyroid adenoma detected by pertechnetate-MIBI subtraction scintigraphy. Clin Nucl Med. 2000 Nov;25(11):898-900.
    5. Ryhänen EM, Schildt J, Heiskanen I, Väisänen M, Ahonen A, Löyttyniemi E, et al. (99m)Technetium Sestamibi-(123)Iodine Scintigraphy Is More Accurate Than (99m)Technetium Sestamibi Alone before Surgery for Primary Hyperparathyroidism. Int J Mol Imaging. 2015;2015:391625.
    6. Wale A, Miles KA, Young B, Zammit C, Williams A, Quin J, et al. Combined (99m)Tc-methoxyisobutylisonitrile scintigraphy and fine-needle aspiration cytology offers an accurate and potentially cost-effective investigative strategy for the assessment of solitary or dominant thyroid nodules. Eur J Nucl Med Mol Imaging. 2014 Jan;41(1):105-15.


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