The role and importance of dynamic thyroid scintigraphy in clinical practice
No Thumbnail Available
Date
Authors
Journal Title
Journal ISSN
Volume Title
Publisher
Abstract
Aim: In this study, we aimed to determine the nodule activity in thyroid scintigraphy in patients with thyroid nodules, as well as to determine the contribution of dynamic radionuclide thyroid Scintigraphy (RTS) in distinguishing between benign and malignant nodules. Material and Methods: A total of 48 patients (30 women, 18 men) with hypo- and/or hyperactive thyroid nodules on thyroid scintigraphy larger than 1 cm were included in the study. Dynamic imaging was achieved in the thyroid region of the patients under a gamma camera and with an intravenous injection of 185 M beta q Tc99mpertechnetate. Retention rate (RR) was calculated using these curves and static anterior image counts. RR was found by drawing a total of 75 nodules of 48 patients. Power Doppler ultrasonography (PDUS) was performed on each patient at the same time and central peripheral resistive index (SRI) and peripheral resistive index (PRI) were measured. Nodule vascularization pattern was classified in PDUS. Results: The mean age of the patients was 54.12 +/- 13.41 years. While 40 patients had a fine needle aspiration biopsy (FNAB), 8 patients did not have an FNAB. Of the 64 nodules in 40 patients who underwent FNAB, 20 were identified as non-diagnostic, 38 as benign cytology (BC), and 6 as malignant cytology (MC). In the time activity curve obtained from RTA, it was determined that the probability of malignancy was high in nodules that were hyper-vascular and showed rapid clearance. While the average RR of nodules in BC was 0.41 +/- 0.70, it was calculated as 0.43 +/- 0.23 in MC. The average central RI in nodules in BC was 0.39 +/- 0.12, while in MC it was 0.30 +/- 0.63. The average peripheral RI value was calculated as 0.60 +/- 0.45 in BC and 0.62 +/- 0.29 in MC. Although our number of malignant cytology nodules was quite low, there was a statistically significant positive correlation between the malignant cytology RR value and the malignant cytology peripheral RI value (p = 0.003, r = 0.043). There was a significant positive correlation between the BC central RI value and the BC RR value (p = 0.012, r = 0.054). Discussion: We think that dynamic RTS, which is a method that will increase the sensitivity of classical thyroid scintigraphy, support the necessity of FNAB, and will not bring additional radiation dose or difficulty to the patient, can be used routinely and has diagnostic value in the benign-malignant discrimination of thyroid nodules.