Appropriateness of ultrasound imaging for thyroid pathology, the standard of radiology reporting on thyroid nodules and the detection rates of thyroid malignancy: a tertiary centre retrospective audit

Abstract

Background: The incidence of thyroid cancer is increasing worldwide without a simultaneous rise in mortality. It is thought that the incidence of non-clinically significant thyroid cancers are on the rise as a result of more sensitive diagnostic imaging. Aim: To determine the number of inappropriate requests for thyroid ultrasound (US), the quality of radiology reporting for thyroid nodules based on accepted guidelines and the resultant number of thyroid cancers identified because of these investigations. Methods: Electronic medical records of patients who underwent thyroid US imaging and thereafter referred to the Endocrine Department at Gold Coast University Hospital, Queensland, between July 2014 and July 2017 were reviewed. Data for 251 patients who had thyroid US were analysed and the final 201 patients who were found to have thyroid nodules were evaluated using descriptive statistics. Indications for thyroid US imaging among referring clinicians were assessed and we compared both clinical management and radiology reporting practices of thyroid nodules to the published 2009 and 2015 American Thyroid Association (ATA) guidelines. Results: There were 50.2% of patients with initial thyroid US imaging deemed outside of expert recommendations where 42% of these patients required further surveillance imaging and 25.4% required fine needle aspiration of their thyroid nodules. A definite recommendation whether to evaluate thyroid nodules further was provided in 44.8% of radiology reports. There were no radiology reports that described thyroid nodules findings based on patterns as recommended by the 2015 ATA guidelines. Two cases of thyroid cancer were detected including one patient with prior history of thyroid cancer and a second patient with hypothyroidism. Conclusion: Routine use of US thyroid imaging outside expert recommendation is common. There is lack of standardised reporting when assessing thyroid nodules on US. Limiting the initial use of US in cases of palpable neck lumps and the use of systematic reporting according to the 2017 guidelines published by the American College of Radiology Thyroid Imaging Reporting and Data System may reduce unnecessary investigations for thyroid nodules in the future.