Hellenic journal of nuclear medicine最新文献

Objective: In this study, we compared myocardial blood flow single photon emission computed tomography (SPECT) using technetium-99m (^99mTc) and thalium-201 (²⁰¹Tl) preparations.

Materials and methods: An the EMIT phantom was used to confirm that the ^99mTc formulation met the criteria of the "myocardial blood flow SPECT standardization guidelines", and ²⁰¹Tl formulation was imaging performed under the same conditions.

Results: In the physical evaluation, no significant differences were found in differential homogeneity and % counts. However, in the evaluation using the RH-2 phantom, increasing the ²⁰¹Tl concentration from 2% to 4% decreased the difference from the ^99mTc preparation in the bull's eye display.

Conclusion: The lack of differences in physical and visual evaluations despite different collection energies and doses may be because the number of gates and matrix size remained constant. These results suggest that imaging conditions that meet the criteria for ^99mTc formulations can be applied to ²⁰¹Tl formulations.

Objective: Prognosis evaluation in cervical cancer is crucial for treatment decisions. This study aims to develop and validate a combined model using positron emission tomography (PET)-derived intratumoral and peritumoral radiomic parameters to predict cervical cancer prognosis based on the Shapley additive explanations (SHAP) method.

Subjects and methods: A retrospective cohort of 114 patients with cervical cancer from two institutions was used, with one institution's data designated for training and the other for testing. Semi-automatic segmentation of fluorine-18-fluorodeoxyglucose (¹⁸F-FDG) PET images was performed to delineate the primary intratumoral and peritumoral regions, defined by expanding the tumor boundary by 2mm, 4mm, 6mm, and 8mm. Radiomic features were extracted from each region. Six machine learning algorithms were employed to construct intratumoral and peritumoral radiomic models, with the optimal model selected based on performance evaluated through receiver operating characteristic (ROC) and calibration curves. Area under the curve (AUC) values were compared using the DeLong test. The SHAP method was used to identify the key features influencing prognosis.

Results: Among the intratumoral and peritumoral radiomic models, the Gradient Boosting Machine (GBM) algorithm showed superior performance. The 4mm peritumoral model exhibited the best performance among the four peritumoral models, with a testing AUC of 0.762 (95% CI: 0.582-0.944). The integrated model combining the intratumoral and 4mm peritumoral regions emerged as the optimal radiomic model for predicting cervical cancer prognosis, achieving the highest AUC of 0.954 (95% CI: 0.882-1.000) in the testing set. At the patient level, SHAP force plots provided valuable insights into the combined model's predictive ability for prognosis.

Conclusion: The integrated radiomic model, particularly for the 4mm peritumoral region, was validated as the optimal approach for predicting overall survival in cervical cancer. The application of the SHAP method enhanced interpretability, allowing for the identification of key features influencing prognosis and offering transparent insights for guiding personalized treatment strategies.

Objective: Diabetic polyneuropathy (DPN) is a common and disabling complication of type 2 diabetes mellitus (T2DM). Vitamin D deficiency has been implicated as a potential modifiable risk factor. This study aimed to investigate the relationship between serum 25-hydroxyvitamin D [25(OH)D] levels and DPN using the radioimmunoassay (RIA) method.

Subjects and methods: One hundred twenty T2DM patients (80 with DPN and 40 without neuropathy) have been enrolled, while 40 healthy volunteers served as group control. Neuropathy diagnosis was based on clinical assessment (through Michigan neuropathy screening instrument (MNSI) - both questionnaire and examination) and nerve conduction studies. Serum 25(OH)D levels were quantified using RIA.

Results: Vitamin D levels were significantly lower in DPN patients (mean 13.2ng/mL) compared to diabetic (18.3ng/mL) and healthy controls (31.2ng/mL, P<0.001). Vitamin D deficiency (<10ng/mL) was found in 72.5% of DPN patients. Apart from severe neuropathy, other factors (age, body mass index -BMI- and HbA1c) have all been mildly inversely correlated to Vitamin D levels.

Conclusion: Vitamin D deficiency is significantly associated with the presence and severity of DPN. These findings support the clinical value of assessing and potentially improving vitamin D status in diabetic patients, particularly in those with severe neuropathy.

This overview covers the effects of radiation on living organisms, including risks and legal requirements. It defines basic radiation terms, such as ionization, activity, energy dose, or equivalent dose, and explains direct and indirect radiation effects. It also lists foods that should be avoided after a reactor accident, including the topic of iodine prophylaxis.

Objective: This study aimed to identify factors influencing salivary gland uptake in fluorine-18-fluorodeoxyglucose (¹⁸F-FDG) positron emission tomography/computed tomography (PET/CT).

Subjects and methods: We retrospectively reviewed patients aged 20-95 years diagnosed with T1N0M0 or T2N0M0 glottic carcinoma between July 2019 and March 2025, who underwent PET/CT for initial staging and radiotherapy planning. Maximum standardized uptake value (SUVmax) and total lesion glycolysis (TLG) were measured and compared based on gender, smoking history, hypertension, diabetes mellitus, dyslipidemia, stage, and primary tumor site.

Results: A total of 61 patients were included (mean age, 68.3±12.4 years; 57 male, 4 female). The cohort included 41 patients with T1N0M0 and 20 with T2N0M0 disease. Hypertension status was negative in 32, positive in 28, and unknown in 1; diabetes status was negative in 54, positive in 6, and unknown in 1; dyslipidemia status was negative in 51, positive in 9, and unknown in 1. Smoking history was negative in 7, positive in 53, and unknown in 1. Primary tumor accumulation was observed in 44 patients, while 17 showed no uptake at the primary site. The mean SUVmax of the right submandibular gland was 3.16±0.70 on the left, it was 3.05±0.76. In the right gland, median SUVmax was significantly higher in patients without hypertension 3.350 than in those with hypertension 2.725; P<0.01). In the left gland, median SUVmax was significantly higher in patients without hypertension 3.18 than in those with hypertension 2.56; P<0.01.

Conclusion: In T1N0M0-T2N0M0 glottic carcinoma, ¹⁸F-FDG uptake in the submandibular glands is reduced in patients with hypertension.

Objective: Using radiolabeled prostate-specific membrane antigen (PSMA) ligands for the treatment of metastatic prostate cancer is a promising therapeutic approach. This systematic review and meta-analysis aims to assess the efficacy and safety of actinium-225 (²²⁵Ac)-PSMA radioligand therapy (RLT) for prostate cancer.

Materials and methods: The systematic review and meta-analysis adheres to the preferred reporting items for systematic reviews and meta-analyses (PRISMA). Searches were conducted in databases including PubMed, Web of Science, Medline, CNKI, and VIP, for studies related to ²²⁵Ac-PSMA RLT for prostate cancer from inception until April 2024. The primary endpoint was the therapeutic effect as measured by post-treatment biochemical response evaluation criteria, while secondary endpoints included evaluating overall survival (OS), progression-free survival (PFS), molecular responses.

Results: A total of 17 studies involving 1042 patients were included. The pooled proportion of patients with PSA reduction was 85% (95% confidence interval [CI]: 80%-91%), and the pooled rate of PSA reduction >50% was 66% (95% CI: 58%-75%). The combined values for OS and PFS were 13.79 months (95% CI: 11.11-16.48 months) and 9.67 months (95% CI: 6.99-12.35 months), respectively. The molecular response rate was 71% (95% CI: 56-87%). The most common side effect of ²²⁵Ac-PSMA RLT was xerostomia, accounting for 63.5%. Anemia, leukopenia, thrombocytopenia, and renal toxicity were observed in 54.3%, 30.4%, 31.8%, 32.0%, respectively.

Conclusion: Actinium-225 -PSMA RLT is an effective and safe treatment for metastatic castration-resistant prostate cancer (mCRPC) patients, with a low incidence of treatment-related adverse reactions. Additionally, a history of lutetium-177 (¹⁷⁷Lu) treatment may have an impact on PSA reduction in mCRPC patients.

Objective: To analyze and compare the diagnostic value of fluorine-18-fluorodeoxyglucose (¹⁸F-FDG) positron emission tomography/computed tomography (PET/CT) imaging and integrated PET/magnetic resonance imaging (MR) in pediatric tumors.

Subjects and methods: A retrospective analysis was conducted on the clinical data of 61 pediatric patients with malignant tumors admitted to our hospital from September 2022 to December 2023. All patients underwent pathological examinations as well as ¹⁸F-FDG PET/CT and integrated PET/MR imaging. The pathological diagnosis results were used as the gold standard. Pearson correlation analysis, Bland-Altman analysis, and t-tests were used to compare the maximum standardized uptake value (SUVmax), signal-to-noise ratio (SNR), and target-to-background ratio (T/B) between the two methods. Chi-square tests were employed to compare the diagnostic efficacy differences of each index.

Results: Among the 61 pediatric malignant tumor patients, a total of 417 lesions were detected, of which 363 lesions showed high uptake on both PET/MR and PET/CT. Among the remaining 54 PET-negative lesions, 9 were CT-positive but MR-negative, including 6 in the lungs and 3 in the vertebrae, while 12 lesions were MR-positive but CT-negative, including 5 in the liver, 4 in the brain, and 3 in the breasts. No statistically significant difference was found in the PET positivity rate or diagnostic results between the two devices (P<0.05). Bland-Altman analysis showed that the background uptake of PET/MR images was lower than that of PET/CT, and the SNR was higher (P<0.05); the SUVmax of the lesions on PET/MR was higher than that on PET/CT (P<0.05); the T/B value of PET/MR images was higher than that of PET/CT (P<0.05). In terms of correlation, the SUVmax, SNR, and T/B values between PET/MR and PET/CT were positively correlated (r=0.919, 0.507, 0.698, P<0.05).

Conclusion: In the diagnosis of pediatric malignant tumors, PET/MR and PET/CT have relatively consistent lesion detection rates. PET/MR images have a higher SNR and better resolution, making them more advantageous than PET/CT for evaluating lesions in the liver, brain, and other soft tissue organs, thus warranting clinical application.

Objective: To evaluate whether pre-treatment salivary gland scintigraphy (SGS) with technetium-99m pertechnetate (^99mTcO₄^-) can predict the risk of moderate to severe salivary gland dysfunction and xerostomia in differentiated thyroid cancer (DTC) patients following their first radioiodine-131 (¹³¹I) therapy.

Subjects and methods: We retrospectively enrolled 149 DTC patients (107 females, 42 males; mean age 46.6±12.7 years) who underwent total thyroidectomy between October 2022 and March 2024. All subjects received pre-treatment SGS to measure the uptake index (UI) and excretion fraction (EF) of bilateral parotid and submandibular glands. Patients then underwent ¹³¹I therapy (1.85-5.55GBq) and repeat SGS 6-12 months later under identical conditions. Xerostomia severity was assessed using the xerostomia inventory (XI) score, categorizing patients into no/mild (XI 11-23) versus moderate-extreme xerostomia (XI 24-55).

Results: Post-therapy, all glands exhibited significant declines in UI (parotid and submandibular glands, P<0.001) and EF (P≤0.004). There was no significant correlation between administered ¹³¹I dose and percentage changes in UI (ΔUI%) or EF (ΔEF). However, higher ¹³¹I doses were associated with increased rates of moderate-severe xerostomia (P=0.015) and higher mean XI scores (P=0.008). Receiver operating characteristic (ROC) analysis demonstrated that pre-treatment UI reliably predicted moderate to severe functional decline (ΔUI% >20%) with areas under the curve (AUC) of 0.866 for the right parotid, 0.793 for the left parotid, 0.769 for the right submandibular, and 0.816 for the left submandibular glands (all P<0.001). Additionally, ΔUI% in both submandibular glands differed significantly between patients with no/mild and moderate-extreme xerostomia (right: P=0.004; left: P=0.012).

Conclusion: Pretreatment ^99mTcO₄^- SGS uptake index is a dependable predictor of moderate to severe salivary gland dysfunction and xerostomia following ¹³¹I therapy in DTC patients, enabling early identification of individuals at high risk and guiding tailored preventive strategies.

Clear iodine-131 (¹⁸I)-6-β-iodomethyl- norcholesterol aldosterinoma finding, proven on biopsy, without prior discontinuation of spironolactone (due to high blood pressure) reveals no changes on scintigraphic sensitivity.