Activity

ndications than those currently approved.

Somatostatin is an endocrine peptide hormone that regulates neurotransmission and cell proliferation by interacting with G protein-coupled somatostatin receptors (SSTRs). SSTRs are specific molecular targets of several radiotracers for neuroendocrine tumor (NET) imaging. Gallium-68 (

Ga)-DOTA-TATE is widely used for positron emission tomography/computed tomography (PET/CT) imaging of SSTRs and has shown a higher affinity for SSTR2, the most common SSTR subtype found in NETs. We aimed to analyze the distribution pattern of

Ga-DOTA-TATE in normal subjects.

A total of 617 consecutive

Ga-DOTA-TATE PET/CT whole-body scans performed in our department from May 2015 through April 2020 with known or suspected neuroendocrine malignancies, mostly to evaluate adrenal adenomas, were retrospectively analyzed by 2 nuclear medicine physicians. One hundred eighteen subjects without a diagnosis of NET, with no tracer avid lesion of NET on

Ga-DOTA-TATE PET/CT, and followed up for at least 6 months (average 2-3 years) without any biochemical, clinical, or imaging findings suggestive of NET were included in this study.

The highest uptake of

Ga-DOTA-TATE was noted in the spleen followed by the kidneys, adrenal glands, liver, stomach, small intestine, prostate gland, pancreas head, pancreas body, thyroid gland, and uterus, in descending order. Minimal to mild uptake was detected in the submandibular glands, parotid glands, thymus, muscles, bones, breast, lungs, and mediastinum.

Our study shows the biodistribution pattern of

Ga-DOTA-TATE in normal subjects and the ranges of the maximum standard uptake value (SUV

) and SUV

values of 68Ga-DOTA-TATE obtained in several tissues for reliably identifying malignancy in

Ga-DOTA-TATE PET/CT studies.

Our study shows the biodistribution pattern of 68Ga-DOTA-TATE in normal subjects and the ranges of the maximum standard uptake value (SUVmax) and SUVmean values of 68Ga-DOTA-TATE obtained in several tissues for reliably identifying malignancy in 68Ga-DOTA-TATE PET/CT studies.

Germanium-68/gallium-68 (

Ge/

Ga) generator eluate contains a number of metal cations that can compete with

GaCl

, reducing specific radioactivity. The first step in peptide labeling with

GaCl

is to remove

Ge and several other metals with a long half-life. In this purification step, the elution residue that is passed through the cartridge is collected in glass waste bottles. Waste management is included in good production practices, and in particular, the activity of long half-life

Ge (270.95 days) and other toxic metal levels need to be examined. Our objective in this study is to determine the

Ge activity in liquid waste produced by the generation of

Ga and heavy metal concentrations from the generator column materials and to assess whether it can be disposed of as normal waste.

Liquid wastes produced by passing the

Ge/

Ga generator eluate of 2 different identities via PSH+ cartridge have been analyzed with the inductively coupled plasma mass spectrometry device in the advanced technoheir own certificates. Metallic contamination in the postmarking waste of 68Ge/68Ga generators can be different. It would be a safe method to keep these wastes in place until they are dumped into the sewage systems, given their half-lives in terms of long half-life radioactive metallic contamination.

Chronic thromboembolic pulmonary hypertension (CTEPH) is a type of pulmonary hypertension with persistent pulmonary vascular obstruction and exercise intolerance, which may benefit from pulmonary endarterectomy (PEA). Ventilation/perfusion (V/Q) scan is the preferred screening test of CTEPH, which can be used to assess the anatomical extent of the disease. This study aimed to analyze the correlation between the extent of mismatched Q defects in V/Q single photon emission computed tomography/computed tomography (SPECT/CT) with preoperative clinical and hemodynamic parameters in patients with CTEPH.

A total of 102 patients with CTEPH prior to PEA having V/Q SPECT/CT scans were retrospectively reviewed. Age, gender, New York Heart Association classification, intraoperative right-sided heart catheterization (mPAP and PVR), and 6-minute walk test (6MWT) findings were obtained from clinical records of patients.

Linear regression analysis showed a significant but weak correlation between the preoperative mPAP and PVR with the extent of mismatched Q defects in V/Q SPECT/CT (rs=0.09474 with p=0.0016 and rs=0.045 with p=0.045, respectively). No significant correlation was found between 6MWT and extent of mismatched Q defects in V/Q SPECT/CT (p>0.05).

A quantitative assessment of Q defects on V/Q SPECT/CT might provide information about hemodynamic parameters in patients with CTEPH.

A quantitative assessment of Q defects on V/Q SPECT/CT might provide information about hemodynamic parameters in patients with CTEPH.

The aim of the study was to evaluate the utility of

fluorine-fluorodeoxyglucose (

F-FDG) positron emission tomography/computed tomography (PET/CT) in the diagnosis, staging, restaging, and treatment response of childhood malignancies.

This study included 52 patients (32 boys, 20 girls) who were referred to our clinic between November 2008 and December 2018 with the diagnosis of malignancy. The patients were evaluated retrospectively. Median age of the patients was 13 years (range 2-17).

F-FDG was given to the patients intravenously, and time of flight with PET/16 slice CT was performed 1 hour thereafter. The lowest dose was 2 mCi (74 MBq) and the highest dose was 10 mCi (370 MBq). learn more Fasting blood sugars of all patients were found below 200 mg/dL (11.1 mmol/L).

F-FDG PET/CT was performed to evaluate the response to treatment in 38 of 52 children, staging in 11 patients (staging and evaluation of the response to treatment in nine of them), restaging in 2 patients, restaging, and evaluation of the response to treatment in 1 patient.

F-FDG PET/CT examination was reported as normal in 13 patients (5 girls, 8 boys). The pathological

F-FDG uptake was detected in 39 patients (14 girls, 25 boys), which indicated metastasis and/or recurrence of the primary disease. Total number of deaths was 30 (13 girls, 17 boys).

F-FDG PET/CT has a significant role for staging, restaging, treatment response, and detection of metastatic disease but it is limited for the early diagnosis of childhood cancers.

18F-FDG PET/CT has a significant role for staging, restaging, treatment response, and detection of metastatic disease but it is limited for the early diagnosis of childhood cancers.