Role of TC-99M thyroid scintigraphy in investigating thyroid swelling: is it of any help for surgeons

Abstract

Objective: To assess the role of thyroid scintigraphy with technetium 99m pertechnetate in patient undergoing thyroid surgery for thyroid swelling and whether this investigation helps in decision making for surgeons regarding management strategy. Study Design: A prospective quasi-experimental study. Place & Duration of Study: This is a multicentric study conducted at the department of ENT, Head & Neck Surgery, Civil Hospital Karachi, Jinnah Medical College Hospital, Hamdard University Hospital, and PNS Shifa, over a period of three and half years from August 2006 to February 2010. Patients & Methods: A total number of 110 patients were included in this study undergoing thyroid surgery for any thyroid swelling where thyroid scintigraphy with Tc-99m pertechnetate was done in all the cases with FNAC, thyroid sonography, thyroid function tests and post-operative histopathology. Data collected was analyzed for sensitivity, specificity, accuracy, positive predictive value and negative predictive value of thyroid scintigraphy for malignancy. Results: In this study, on thyroid scintigraphy 50.9% of the cases were multinodular goiter, 48.2% were cold nodules and 0.9% was hot nodule. On post-operative histopathology 94 cases (85.4%) were benign swellings and 16 cases (14.6%) were malignant. Sensitivity, specificity, accuracy, positive predictive value and negative predictive value of thyroid scintigraphy were found to be 68.7%, 55.3%, 57.2%, 20.7% and 91.2% respectively. Conclusion: In our view thyroid scintigraphy should not be ordered in every case of thyroid swelling because of its low predictive value for malignancy