Year: 2017
Type: dissertation
Study design: Observational Study
Abstract: Results:The study included 362 patients who met the inclusion criteria with median age 65 years (range 19-96), and median follow-up of 24 months (range 1-103).Lymphoid, lung and colorectal malignancy were the most common indications for staging.The median overall survival was 20 months (IQR 9.5-39).The majority of deaths was due to the primary malignancy (92.2%).One patient (0.6%) died from incidental medullary thyroid cancer.FDG-avidity in primary malignancy, advanced stage and clinician decision to not investigate FDG-avid TI were all predictors of mortality with hazard ratios of 8.5 (95%CI 4.6-15.8),3.0 (95%CI 2.3-3.9) and 3.3 (95%CI 2.0-5.0)respectively (P<0.001).Receiver operator curve (ROC) analysis demonstrated on optimal SUV-max threshold of 5.33.Sensitivity and specificity of thyroid cancer detected incidentally on PET/CT on ROC analysis was 73.47 and 46.94 respectively, with a broad area under the ROC curve of 0.66 (p = 0.005).Five nodules (20%) necessitated revision of diagnosis on correlative histopathologic-imaging review.Two presumed malignant FDG-avid TI found on imaging were correlated to non-malignant Hürthle cell adenomas on pathology, indicating misclassification by location. Conclusion:The overall survival with FDG-avid TI was poor due to the prognosis associated with underlying malignancy which must be considered prior to investigation of FDG-avid TI.Active surveillance should be considered in this group of patients.SUV-max is not a safe tool to discriminate benign from malignant TI and should remain a theoretical adjunctive tool for predicting thyroid cancer.Benign and malignant oncocytic lesions are a common cause of FDG-avid TI.The incidence of FDG-avid malignancy may be overestimated without careful imaging and histopathologic correlation.First and foremost, I would like to acknowledge and thank my supervisor and mentor, Miss
Author: Michael Bozin
Language: English
Subfield: Endocrinology, Diabetes and Metabolism
Field: Medicine
Domain: Health Sciences
Open Access status: green
OpenAlex ID: W2774144288