Background: A cross-sectional prospective study has been conducted on differentiated thyroid cancer (DTC) patients using negative 131Iodine (131I) whole body scans and elevated thyroglobulin (Tg) levels. The main objective of this research was to determine the prevalence of the conversion of differentiated to dedifferentiated thyroid cancer patients during follow up at the Hospital Kuala Lumpur. It has been demonstrated that fluorodeoxyglucose (FDG) uptake is inversely proportional to the iodine concentration and to differentiation of the cells. Methodology: Thirty-five patients with histologically proven DTC that have undergone total or near total thyroidectomy, and post 131I radioactive iodine ablation therapy, were selected and prospectively analysed. The patients also had to show at least one negative whole body scan and Tg levels of 10 μg/L and above. The results of the FDG-Positron Emission Tomography/Computed Tomography (PET/CT) were then studied to determine the association and the predictors influencing the outcome by using univariable and multivariable analyses. Results: Out of the thirty-five patients, 60% of them (twenty-one) showed positive results and 40% (fourteen) showed negative. Age, gender, and type of histopathology (HPE) showed significant associations with the positive results of the FDG-PET/CT. The results also showed no correlations observed between the Tg levels and standardised uptake value (SUV)max in the DTC patients with positive disease findings in the FDG-PET/CT. The predictor for this study was age. Conclusion: The prevalence of the conversion of differentiated to dedifferentiated thyroid cancer among patients with negative 131I and elevated Tg was 60%, with age as the predictor. DTC patients aged 45 year-old and older were seven times more likely to have positive results of FDG-PET/CT imaging.

Neuroendocrine tumours (NETs) are a category of neoplasm that is characterised by its phenotypic and heterogeneity. The occurrence of this type of neoplasm in the nasal cavity and paranasal sinuses is extremely rare accounting for only 0.2-0.8% of all cancers. NET tends to expresses somatostatin receptors (SSTR) and owning to this unique characteristic, molecular imaging has been able to detect these tumours using radiolabelled somatostatin analogue agent. Gallium-68 (Ga-68) DOTATATE PET/CT is an example of SSTR imaging and has been shown to be of importance in the assessment and staging of NET. We present a case of a rare sphenoid sinus NET in a 45-year-old gentleman whom initially presented with persistent left eye pain which led to visual loss. We described the utilization of Ga-68 DOTATATE PET/CT in the diagnosis and staging of this patient which in turn dictated treatment approach.

The aim is to evaluate the usefulness of technetium pertechnetate (99mTc) thyroid uptake (TcTU) obtained from thyroid scintigraphy using quantitative Single Photon Emission Computed Tomography / Computed Tomography (SPECT/CT) in determining personalised dose of 131I radioactive iodine (RAI) therapy for hyperthyroidism. A study of 131 participants with hyperthyroidism referred for RAI therapy was performed. 66 participants were enrolled into the prospective (calculated dose) group whereas 65 participants were from retrospective control (fixed dose) group. Quantitative thyroid SPECT/CT was performed for the prospective group prior to receiving RAI. TcTU and thyroid gland volume obtained from the Quantitative thyroid SPECT/CT were incorporated into modified Marinelli formula for RAI dose. Outcome of RAI was determined at the end of 6 months follow-up. Descriptive analysis of demographics and regression analyses of variables were performed. Mean calculated RAI dose was 17.74 mCi (SD 6.27) with mean dose for successful RAI at 6 months was 16.42 mCi (SD 5.87). Success rate was 80.3 % in the calculated group, versus 60.0 % in the fixed dose group (p-value 0.013). Regression analysis showed thyroid gland volume as an independent factor in determining successful outcome (adjusted OR = 0.963 CI: 0.942, 0.985) with volume of <77.2 ml more likely to produce successful outcome; sensitivity and specificity of 69 % and 83 % respectively. Quantitative SPECT/CT is useful in determining personalised dose of 131I RAI therapy. It significantly improves treatment outcome for hyperthyroidism as compared to the conventional fixed dose method.
Hyperthyroidism