Early versus delayed post-therapy whole body scintigraphy for well-differentiated thyroid carcinoma: A meta-analysis

Introduction@#No clear consensus exists as to the optimal timing for conducting whole body scintigraphy (WBS) after radioactive iodine (RAI) therapy for differentiated thyroid carcinoma. @*Objective@#This study aimed to compare the utility of early versus delayed post-therapy WBS in identifying residual lesions and metastases.@*Methods@#A systematic review of existing literature was done, yielding 6 observational studies relevant to the subject. Meta-analyses were done comparing lesion detecting rates of early (3-4 days post-RAI) and delayed (7-11 days post-RAI) post-therapy WBS for thyroid remnants and metastases in the lymph nodes, lungs, and bone using a random-effects model with odds ratios (OR) and 95% confidence intervals (CIs). A subgroup analysis was also done relating to the type of collimator used in imaging.

Accuracy of Choline PET/CT vs. Tc 99m Sestamibi SPECT/CT parathyroid imaging in comparison to histopathology in the diagnosis of parathyroid adenoma : A meta-analysis

Introduction@#In the advent of the recently accepted use of Choline in parathyroid PET/CT, we aimed to assess its accuracy in diagnosing parathyroid adenomas in comparison to the Tc 99m Sestamibi SPECT/CT parathyroid imaging, with histopathology as the reference standard.@*Objective@#To determine the diagnostic accuracy of Choline PET/CT in comparison to Tc 99m Sestamibi parathyroid imaging in detecting parathyroid adenomas, with histopathology as the reference standard. @*Methods@#Cross-sectional studies from 2014 to 2019 were identified through MEDLINE, Pubmed, clinicaltrials.gov, and Google scholar. Our literature search yielded 13 articles, of which only 3 met the set inclusion and exclusion criteria.@*Results@#Three published cross-sectional studies were included with a total of population of 157 patients. Choline PET/CT was found to have a pooled sensitivity of 0.99 (0.96 - 1.00), pooled specificity of 0.45 (0.17 - 0.77), positive likelihood ratio of 1.79 (1.1 – 2.9), negative likelihood ratio of 0.03 (0.0 – 0.1), positive predictive value of 96.0% (93.4 - 97.7%) and negative predictive value of 83.3% (39.0 - 97.6%), estimated with 95% CI. Tc 99m Sestamibi SPECT/CT parathyroid imaging had a pooled sensitivity of 0.77 (0.70-0.84), pooled specificity of 0.45 (0.17 - 0.77), positive likelihood ratio of 1.43 (0.8–2.4), negative likelihood ratio of 0.49 (0.2–1.4), positive predictive value of 96.0% (93.4-97.7%) and negative predictive value of 83.3% (39.0-97.6%), estimated with 95% CI@*Conclusion@#Choline PET/CT showed superior sensitivity, negative predictive value and negative likelihood ratio over Tc 99m Sestamibi SPECT/CT parathyroid imaging. The measured specificities, positive predictive values and positive likelihood ratios of both modalities were found to be similar.

A systematic review and meta-analysis on the diagnostic accuracy of whole-body PET /CT for distant metastases in breast cancers

Background@#Breast cancer is the second most common malignancy globally. This study is a systematic review and meta-analysis assessing whole-body PET/CT using 18F-FDG in detecting breast carcinoma distant metastases as an update to the study of Xu et al.@*Objective@#To determine the diagnostic accuracy of whole-body PET/CT in distant metastasis detection among breast cancer patients.@*Methods@#The MEDLINE database was systematically searched for articles evaluating whole-body PET/CT in distant metastasis detection among breast cancer patients. Sensitivity, specificity, likelihood ratios and predictive values were derived by the three independent readers. Summary receiver operating characteristic curves were plotted.@*Results@#Fifteen studies (n=4175) were included with pooled sensitivities, specificities, positive and negative likelihood ratios, positive and negative predictive values (with 95% confidence intervals) of 0.98 (0.97-0.99), 0.98 (0.98-0.99), 86.6 (63.6-117.9), 0.01 (0.01-0.02), 0.94 (0.92-0.95) and 0.99 (0.995-0-.998), respectively. Pooled positive and negative predictive values with a prevalence of 13.6% are 0. 93 and 0.99, respectively.@*Conclusion@#Whole-body PET/CT with 18F-FDG provides excellent detection of distant metastases in breast cancer and is recommended in assessing patients in earlier stages of the disease, not only in the later stages, especially in more aggressive tumors.

HbA1c and Myocardial lschemia detected via Myocardial Perfusion Scintigraphy in type 2 Diabetes Mellitus

Background/Objective@#Coronary Artery Disease (CAD) is the leading cause of mortality among patients with type 2 diabetes mellitus. Several studies evaluated glycemic control and MPS resultswith good correlation. In the Philippines, data concerning this matter are few, hence this study.@*Methodology@#This is a cross-sectional study of selected Filipino patients with type 2 diabetes mellitus without previous cardiac events who underwent stress or pharmacologic stress MPS (TI-201 or Tc-99m sestamibi) over an 18-month period at the Philippine Heart Center. Electrocardiogram and 2D echocardiogram results were also noted. Patients were grouped into adequate glycemic control (HbA1c<7.0%) and inadequate glycemic control (HbA1c >7.0%). Binary logistic regression was computed to determine association of glycemic control to MPS defects. @*Results@#A total of 206 subjects (114 HBa1C <7.0%, 92 with HbA1c ? 7.0%), were included in the study; with male predominance. Mean HbA1c values showed direct correlation; the higher the HbA1c values, the more MPS defects. Inadequate glycemic control group had significanlty higher subjects with mild and moderate to severe degree of myocardial ischemia (p<0.001). the relative risk of having a significant CAD in the inadequate glycemic control group is 4.30 times more than their counterpart (p<0.001). Factoring the duration of inadequate glycemic control to > 10 years, relative risk increased to 7.63@*Conclusion@#The study shows that patients with type 2 diabetes mellitus with inadequate glycemic control have increased MPS defects and highter relative risk for having significant CAD. Diabetic patients with inadequate glycemic control for > 10 years have an even higher risk of having significant CAD.