Annals of Nuclear Medicine最新文献

Objective

At present, most of the targeted imaging based on insulin-like growth factor 1 receptor (IGF-1R) is for tumor research, and there is no IGF-1R-targeted imaging for Graves’ ophthalmopathy(GO). This study aims to develop a peptide probe, ^99mTc-Z_IGF1R:4551-GGGC, targeting the IGF-1R, and to achieve specific imaging in Graves’ disease (GD) animal models exhibiting GO.

Methods

99mTc-ZIGF1R:4551-GGGC probe was synthesized using a direct labeling method and its labeling efficiency assessed via instant thin-layer chromatography (ITLC). Western blot analysis confirmed the overexpression of IGF-1R in malignant melanoma B16F10 cells. Subsequent SPECT/CT whole-body imaging of B16F10 tumor-bearing mice evaluated the probe’s targeting accuracy. In addition, a GO model was established using an electroporation immunoassay, followed by serological and histopathological examinations. The GO models then underwent 99mTc-ZIGF1R:4551-GGGC SPECT/CT imaging to assess eye-targeted imaging capabilities.

Results

The peptide probe exhibited a labeling efficiency exceeding 90%. Both GD and GO models were effectively created via electroporation immunoassay. Imaging results indicated significant accumulation and retention of the peptide probes in the tumors of B16F10 tumor-bearing mice. In the GO models, probe uptake was predominantly observed in retrobulbar tissues, contrasting with primary accumulation in the lungs and gastrointestinal tract in normal mice, where only minimal tracer was observed in retrobulbar tissues. Notably, GO mice demonstrated higher probe uptake and prolonged retention.

Conclusion

This study successfully established GD and GO models, reducing the duration of the immune cycle. Moreover, a peptide probe targeting IGF-1R was synthesized, enabling specific imaging of retrobulbar tissues in GO models.

The Japanese Society of Nuclear Medicine (JSNM) celebrates its 60th anniversary this year. JSNM has been contributing a lot to the development of nuclear medicine, leading a number of international activities. New procedures both in diagnosis and treatment have been continuously developed. JSNM will work hard for the better management of patients.

Dynamic positron emission tomography (PET) can be used to non-invasively estimate the blood flow of different organs via compartmental modeling. Out of different PET tracers, water labeled with the radioactive (^{15})O isotope of oxygen (half-life of 2.04 min) is freely diffusable, and therefore, very well-suited for blood flow quantification. While the earlier (^{15})O-water PET research has primarily focused on cerebral or myocardial blood flow quantification, the recent emergence of total-body PET scanners has enabled greater application possibilities for both PET imaging in general and also (^{15})O-water PET based blood flow quantification in particular. However, to validate new methods, it is necessary to compare them to earlier research. To help in this process, we systematically review 53 articles quantifying blood flow via compartmental modeling. We introduce the articles organized within subcategories of cerebral, myocardial, renal, pulmonary, pancreatic, hepatic, muscle, and tumor blood flow and summarize their results so that they can easily be evaluated in terms of population characteristics of the patients such as age or sex ratio and their potential diagnoses. We compare how both the compartment model used and the potential corrections for arterial blood volume, non-perfusable tissue, spill-over from the heart cavities, and time delay caused while the tracer travels between different areas of interest are generally implemented in the articles. We also analyze the differences in the data pre-processing techniques. According to our results, the estimates of cerebral and tumor blood flow vary considerably more between the articles than those of myocardial blood flow. This might be caused by differences in the model approaches or the study populations. We also note that the choice of the unit for these estimates is quite inconsistent as certain researchers seem to prefer mL/min/g over mL/min/mL even if no weight or density parameter is present in the modeling. We encourage more research on sex- and age-based differences in blood flow estimates and organ-specific blood flow quantification studies for kidneys, lungs, liver, and other important organs besides brain and heart.

Objective

To compare the acute (within 30 days of treatment) laboratory toxicities of Yttrium-90 (Y-90) resin and glass microspheres.

Methods

Selective intra-arterial radionuclide therapies (SIRTs) with Y-90 resin and glass microspheres were retrospectively reviewed. Liver-hematological data were collected at baseline and at 1 week and 1 month follow-up. The percentage change of laboratory data and the albumin–bilirubin (ALBI) score were calculated.

Results

A total of 219 SIRTs (n: 110 resin, n: 109 glass) from 177 patients were included. There was no difference in age, liver pathologies, extrahepatic disease, baseline liver function tests, and total blood counts between the two microsphere groups. Administered activity was higher in treatments with Y-90 glass microspheres (p < 0.001). An increase in serum liver enzymes was observed after treatment with both microspheres. The difference between the treatment groups was the higher percentage increase of AST and ALT at the first week following Y-90 glass treatment (p < 0.001). However, this situation was not observed after 1 month. No difference in the percentage change of other laboratory parameters was found between two groups. The number of patients with an increase [resin n: 24 (24.7%) vs glass n: 26 (27.1%), p: 0.711) and decrease [resin n: 13 (13.4%) vs glass n: 8 (8.3%), p: 0.258] in the ALBI grade after SIRT was similar among groups.

Conclusions

An increase in liver enzymes was observed in the early period after SIRT with both microspheres. No significant difference in liver and hematological data was detected during early follow-up between the two groups, except that the percentage increase of AST and ALT were higher at the first week in the Y-90 glass group, possibly due to higher administered activity.

The purpose of this systematic review was to evaluate the role of PSMA PET/CT in intermediate-risk prostate cancer (PCa) patients, to determine whether it could help improve treatment strategy and prognostic stratification. A systematic literature search up to May 2024 was conducted in the PubMed, Embase and Scopus databases. Articles with mixed risk patient populations, review articles, editorials, letters, comments, or case reports were excluded. The quality of the papers was assessed by using the CASP criteria. The literature search returned 1111 studies; however, 1105 articles were excluded, and therefore 6 full-text papers were retrieved for the final analysis. Three out of six papers focused on the utility of SUVmax in identifying high ISUP grade in patients with intermediate-risk PCa. The latest three papers discussed the controversial role of PSMA PET/CT in predicting the lymph node involvement, mainly in the case of favorable subset. PSMA PET has completely changed the management of patients with PCa; indeed its role is still undefined in patients with intermediate-risk disease. Future perspective is to investigate larger cohorts of intermediate-risk PCa patients, to fully recognize the added value offered by PSMA PET in this category of subjects.