NUCLEAR MEDICINE REVIEW最新文献

A cold vertebral defect is an uncommon finding, especially in Gallium-67-citrate ([67Ga]Ga-citrate) - and [18F]fluorodeoxyglucose ([18F]FDG) - avid lymphomas, representing a diagnostic challenge. Here, we present the case of a patient with non-Hodgkin lymphoma (NHL), in whom the [67Ga]Ga-citrate and [18F]FDG scans showed a diffuse skeletal uptake pattern with concomitant appearance of a cold vertebral defect. Awareness of the different causes of such uptake patterns and accurate clinical information is important to avoid misinterpretation of nuclear studies in oncologic patients.

Background: A challenge for modern medicine is the development of clinical protocols for precise diagnosis and therapy. This study aimed to propose a simple method for modification of 2-[18F]FDG used routinely in hospitals in a way, appropriate for patients' personalized radiopharmaceuticals approach.

Material and methods: For the purposes of the presented study chemo selective method for indirect radiofluorination was applauded to custom synthesized aminooxy- and hydrazine-functionalized tetrazines for 18F-glycolation via oxime or hydrazone formation. 2-[18F]FDG produced with medical baby cyclotron in Nuclear Medicine Clinic at the University Hospital St. Marina-Varna, was used. Thin layer chromatography (TLC) and radio TLC were used to follow the progress of synthesis and to determine radio chemical yield (RCY).

Results: The 2-[18F]FDG was modified with two bifunctional tetrazines aminooxy-acetic acid-6-(2-aminooxy-acetoxy)-[1,2,4,5] tetrazin-3-yl ester (Tz1) and {3-[4-(6-phenyl-[1,2,4,5]tetrazin-3-yl)-phenoxy]-propyl}-hydrazine (Tz2) via oxime and hydrazone formation. The radiolabeling was carried out as one-pot reaction with following parameters: temperature 70-75°C; catalyst p- diaminobenzene (Cat.); pH = 4.2; time 30 minutes; RCY = 70-99%. The radiolabeled tetrazines are appropriate for further bioorthogonal (pretargeting) strategy by click reactions with trans-cyclooctene conjugated bioactive molecules. The methodology is applicable to standard clinical conditions.

We present the first 99mTc-Vitamin C single-photon emission computed tomography/computed tomography (SPECT/CT) images obtained in patients with SARS-CoV-2 (COVID-19) infection. The CT portion of SPECT/CT images showed mostly peripheral patchy and ground-glass opacities in both lungs, which are consistent with a diagnosis of SARS-CoV-2-associated pneumonia in both patients. 99mTc-Vitamin C SPECT images showed increased tracer uptake corresponding to abnormal lung findings seen on CT in patient 1 who was newly diagnosed and treatment naïve. However, no abnormal uptake corresponding to lung CT findings was seen in patient 2 who received anti-SARS-CoV-2 treatment.

Background: This diagnostic study aimed to assess degree of agreement between dacryoscintigraphy and dacryocystography as supporting examinations in patients with primary acquired nasolacrimal duct obstruction (PANDO). Patients with PANDO who complained of epiphora and visited our outpatient clinic were subsequently sent for dacryoscintigraphy and dacryocystography examinations. Side effects and convenience of both examinations were assessed by observation and questionnaire.

Material and methods: Through irrigation and probing, there were 47 out of 62 eyes were found with PANDO. As much as 87.1% subjects were female, with mostly (74.2%) aged > 40 years old. With dacryoscintigraphy, time needed to reach sac was 0 minutes, 5 minutes (duct), and 12.5 minutes (nasal cavity).

Results: Degree of agreement between both examinations was 83.8% to determine obstruction and 70.9% to locate obstruction. There were 22 subjects complained about pain in dacryocystography examination while none with dacryoscintigraphy (p < 0.005). Sixteen subjects feel dacryoscintigraphy examination was more convenient, eleven subjects feel dacryocystohraphy was more convenient, while 4 subjects feel the two examinations were similar.

Conclusions: Even though dacryocystography examination was considered more painful than dacryoscintigraphy, both examinations had high convenience level for patients. Dacryoscintigraphy and dacryocystography also had a good agreement in detecting and locating obstruction in PANDO.

Prostate-specific membrane antigen (PSMA) - based radiopharmaceuticals are promising for the evaluation of PSMA-positive non-prostate cancers. In this case study, 18F-BF3-Cy3-ACUPA and 68Ga-PSMA positron emission tomography/magnetic resonance imaging (PET/MRI) were compared in a patient with metastatic colon cancer. Both 18F-BF3-Cy3-ACUPA and 68Ga-PSMA PET/MRI showed biopsy-proven metastatic left external iliac adenopathy, highlighting the feasibility of PSMA uptake in PET/MRI of metastatic nodal disease from colon cancer. Along with imaging evaluation, PSMA-based radiopharmaceuticals may also be used as a surrogate imaging tracer for potential theranostic applications using alpha or beta emitters in the context of PSMA-directed radiopharmaceutical therapy in advanced and progressive colorectal cancer.

SPECT/CT imaging is transitioning from solely qualitative applications to quantitative analysis. Quantitative SPECT/CT systems require proper calibration, optimization and quality control. Various types of modern SPECT/CT scanners have different software for calibration and quality control (QC). There is still no standardization in this regard for quantitative SPECT/CT. This issue hinders the exchange of obtained results across centers and stunts the development of repeatable and reproducible measurements. The unification and standardization of calibration and quality control techniques for quantitative SPECT/CT systems is currently a pressing need for nuclear medicine departments. The present study presents three selected physical quantities characterizing the quality of quantitative SPECT/CT system and seven quantities, currently used in the literature, to assess the quality of quantitative SPECT/CT images. The measurement of these parameters requires the use of standard gamma camera software for QC, external programs for quantitative analysis of recorded data and clinical software. The authors hope this will help physicists who are willing to perform quantitative SPECT/CT in their departments.