Accuracy in dosimetry of diagnostic agents: impact of the number of source tissues used in whole organ S value-based calculations.

Background: Dosimetry for diagnostic agents is performed to assess the risk of radiation detriment (e.g., cancer) associated with the imaging agent and the risk is assessed by computing the effective dose coefficient, e.

Comparison of the Variability of SUV Normalized by Skeletal Volume with the Variability of SUV Normalized by Body Weight in F-Fluoride PET/CT.

Our objective was to test the hypothesis that variability in SUV normalized by skeletal volume (SV) in F-fluoride (F-NaF) PET/CT studies is lower than variability in SUV normalized by body weight (BW). The mean SUV (SUV) was obtained for whole skeletal volume of interest (wsVOI) in 163 selected F-NaF PET/CT studies. These studies were performed to investigate bone metastases and were considered to have normal results.

Brain Metastasis of Medullary Thyroid Carcinoma Without Macroscopic Calcification Detected First on 68Ga-Dotatate and Then on 18F-Fluoride PET/CT.

We report a case of a medullary thyroid carcinoma noncalcified brain metastasis characterized on Ga-dotatate PET/CT but not on an F-fluoride PET/CT performed 1 month later. Subsequent F-fluoride PET/CT studies performed 7 and 19 months after the Ga-dotatate PET/CT study demonstrated focal uptake in the metastasis. The CT images of the last PET/CT study also depicted a small focus of calcification beginning in the metastatic site.

Iodine/FDG "Flip-Flop" Phenomenon Inside a Large Metastatic Thyroid Cancer Lesion Better Characterized on SPECT/CT and PET/CT Studies.

Iodine/FDG "flip-flop" phenomenon inside large metastatic thyroid cancer lesions has been rarely described. We present a case of this phenomenon better characterized using SPECT/CT and PET/CT studies.

Comparative Dosimetry for Ga-DOTATATE: Impact of Using Updated ICRP Phantoms, S Values, and Tissue-Weighting Factors.

The data that have been used in almost all calculations of MIRD S value absorbed dose and effective dose are based on stylized anatomic computational phantoms and tissue-weighting factors adopted by the International Commission on Radiological Protection (ICRP) in its publication 60. The more anatomically realistic phantoms that have recently become available are likely to provide more accurate effective doses for diagnostic agents. Ga-DOTATATE is a radiolabeled somatostatin analog that binds with high affinity to somatostatin receptors, which are overexpressed in neuroendocrine tumors and can be used for diagnostic PET/CT-based imaging.

Could the treatment of differentiated thyroid carcinoma with 3.7 and 5.55 GBq of (131I)NaI, on an outpatient basis, be safe?

Objectives: The first objective of this study was to evaluate the radiological impact on relatives and the environment because of outpatient treatment of differentiated thyroid carcinoma with 3.7 and 5.55 GBq of (131I)NaI.