Introduction:The treatment for differentiated thyroid cancers (DTCs) has always been radioactive iodine 131I therapy after definitive surgical management. Clinicians are faced with therapeutic challenges when dealing with patients having thyroglobulin-elevated negative iodine scintigraphy (TENIS) syndrome (elevated serum thyroglobulin [Tg] levels but negative whole-body scans [WBSs]).Objective:The aim of the study was to determine the prevalence of TENIS syndrome in our local setting and to evaluate the use of 18-fluoro-2-deoxyglucose (18F-FDG) positron emission tomography-computed tomography (PET-CT) in the management.Methodology:The data from DTC patients treated in the Department of Nuclear Medicine, Hospital Pulau Pinang from December 1, 2010, to November 30, 2016, with negative WBS and elevated Tg were reviewed. These patients should have undergone 18F-FDG PET-CT to be included in the study.Results:Only forty (10.4%) out of a total of 386 patients treated in Hospital Pulau Pinang during the study fulfilled the inclusion criteria. There were 28 women (70%) with median age of 59 years old. Thirty-four patients (85%) had papillary thyroid cancer (PTC) and six patients had follicular thyroid cancer. The use of 18F-FDG PET-CT revealed 23 patients (57.5%) with 18F-FDG avid metastases suggesting dedifferentiation of thyroid cancers. Based on this study, the probability of detecting FDG-avid disease is higher (P = 0.03) if 18F-FDG PET-CT was performed when Tg ≥15 ng/mL.Conclusion:TENIS syndrome constitutes a significant number of cases in our setting. Our data suggest a cutoff Tg ≥15 ng/mL for performing 18F-FDG PET-CT for these patients would be more beneficial than the currently American Thyroid Association recommended cutoff of 10 ng/mL.

Radioiodine (131I) therapy is the mainstay of treatment for patients who had undergone total thyroidectomy for well differentiated thyroid carcinoma. Increased fluid intake has always been encouraged to minimize the risk of non-target organ exposure to I-131radiation. This study aimed to determine the minimum amount of fluids needed for patients to have the fastest time to achieve permissible level for release after high dose I-131therapy. Methodology: All the patients who were treated with high dose I-131from 18th January 2016 till 31st December 2016 in Hospital Pulau Pinang, Malaysia were recruited. The data from 126 patients on thyroxine hormone withdrawal (THW) group and 18 patients on recombinant human thyroid stimulating hormone (rhTSH) group were analysed. There is no change in patient management in terms of preparation, dose or post therapy whole-body scan. Fluid intake of patients were monitored strictly and whole-body retention of I-131are measured using ionizing chamber meter immediately after ingestion of I-131then at 1 hour, 24 hours, 48 hours, 72 hours and 96 hours. Results: The median time to achieve permissible release limit (50 μSV/hr at 1 meter) was 21.6 hours and 22.1 hours post-ingestion of I-131in the THW and rhTSH group respectively. The minimum amount of fluid needed to reach permissible release limit in the fastest time was 2,103 ml and 2,148ml for the THW and TSH respectively. Conclusion: Clinicians would be able to evidently advise their patient on the amount of fluid to consume and utilize their isolation wards faster to treat more patients.

Tenofovir, used in the treatment of chronic hepatitis B and HIV, is known for its side effects on the kidneys and bones. We share interesting images of a patient with tenofovir-induced osteomalacia on Technetium-99 m hydroxymethyelene (Tc-99 m HDP) bone scintigraphy. Pattern recognition of this bone scintigraphy and correlation with the clinical history is essential to avoid misdiagnosis.

No abstract