NUCLEAR MEDICINE REVIEW最新文献

Prostate-specific membrane antigen (PSMA) is a membrane protein originally discovered in prostate cancer cells. It is widely used at all stages of prostate cancer diagnosis. Several studies have highlighted its possible wide application in other cancers. This review discusses the potential use of positron emission tomography with labelled PSMA for the diagnosis or differentiation of intracranial lesions. Given the numerous reports on the usefulness of PSMA in the diagnosis of brain tumours of glial origin, the focus is on lesions of a different aetiology.

Fluorine-18-deoxyglucose positron emission tomography/computed tomography ([18F]FDG PET/CT) has been shown to be superior to other conventional imaging modalities in the detection of extra-nodal lymphomatous localizations. Especially in neurolymphomatosis which is rarely encountered in high-grade lymphomas. We report a case of a woman diagnosed with non-Hodgkin lymphoma, whose initial staging with [18F]FDG PET/CT showed increased [18F]FDG uptake along the brachial and sacral plexuses. [18F]FDG PET/CT remains the most appropriate diagnostic tool in these cases, whose prognosis is often poor.

We report a 31-year-old male with a history of left forearm neuroma surgically removed, consulting for a supraclavicular bultoma congruent with the supradiaphragmatic lymphoproliferative syndrome in computed tomography (CT) scan. [18F]FDG PET/CT images helped to establish the most diagnostic yield lesion for the biopsy, and allowed an accurate staging of the neurofibromatosis (NF) disease, leading to the most appropriate therapeutic option for the patient.

Background: Our aim is to determine the accuracy of [68Ga]Ga-PSMA PET/CT in showing PSMA expression in primary prostate cancer and to investigate the relationship between SUVmax and immunohistochemical PSMA expression, Gleason score, and PSA value.

Material and methods: We retrospectively analyzed 66 male patients who were diagnosed with primary prostate adenocarcinoma, underwent pre-treatment [68Ga]Ga-PSMA PET/CT examination for staging, and performed radical prostatectomy between March 2018-August 2020. Immunohistochemical staining was applied to the radical prostatectomy specimens of all patients to detect PSMA expression. The results were evaluated as an immunoreactive score (IRS) and a modified IRS was obtained. Gleason score groups and prostate-specific antigen (PSA) serum values of the patients were obtained from the patient files.

Results: The high SUVmax of primary prostate tumors was significantly correlated with a high modified IRS score (score 2; 3), high PSA value, high Gleason score, and metastasis. In correlation analysis, a positive correlation was found between SUVmax and PSA value and modified IRS score (r = 0.69, p = 0.001; r = 0.39, p = 0.001). In addition, there was a statistically significant weak correlation between PSA serum concentration and modified IRS scores (r = 0.267; p = 0.03). In regression analysis, the percentage of positive cells had a statistically significant and increasing effect on SUVmax (p = 0.031; std beta = 0.268; 95% CI = 0.231-4.596).

Conclusions: In prostate adenocarcinoma, SUVmax of the primary tumor in [68Ga]Ga-PSMA PET/CT correlates with immunohistochemical PSMA expression. In addition, high SUVmax is associated with markers of poor prognoses, such as high PSMA expression, PSA value, and Gleason score.

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.

Neuroendocrine neoplasms (NENs) are a heterogeneous group of tumors originating from neuroendocrine cells spread throughout the body, forming the so-called diffuse endocrine system. The gold standard in treating unresectable or disseminated, progressive, and well-differentiated NENs is therapy with radiolabeled somatostatin analogs (peptide receptor radionuclide therapy - PRRT). PRRT is a method based on peptides combined with beta-emitting radionuclides. The study aimed to assess the early and long-term liver complications after administration of Lutetium-177 or Lutetium-177 combined with Yttrium-90. We enrolled 27 patients treated with [177Lu]Lu-DOTATATE with an activity of 7.4 GBq (200 mCi) and 9 patients received the tandem treatment [90Y]Y-DOTATATE + [177Lu]Lu-DOTATATE with an activity of 3.7 GBq (50 mCi + 50 mCi). In the assessment of early as well as long-term complications, no significant effect of the applied treatment on the parameters of liver injury was found. Regarding liver function PRRT was a safe treatment for patients with highly or moderately differentiated, unresectable, or diffuse NENs.

Amyloid transthyretin cardiomyopathy is a progressive disease that confers significant mortality. While it is relatively rare, the frequency of diagnoses has risen with the increased contribution of novel diagnostic approach over the last decade. Traditionally tissue biopsy was considered to be a gold standard for amyloidosis diagnosis. However, there are significant limitations in the wide application of this approach. A noninvasive imaging-based diagnostic algorithm has been substantially developed in recent years. Establishing radionuclide imaging standards may translate into a further enhancement of disease detection and improving prognosis in the group of patients. Therefore we present in the following document current evidence on the scintigraphic diagnosis of cardiac transthyretin amyloidosis. Moreover, we present standardized protocol for the acquisition and interpretation criteria in the scintigraphic evaluation of cardiac amyloidosis.