Nuclear Medicine Communications最新文献

Objective: The objective of this study was to characterize exclusive costal lesions detected by 68 Gallium-labelled prostate-specific membrane antigen ([ 68 Ga]Ga-PSMA-11) PET/computed tomography (CT) at initial staging or biochemical recurrence (BCR) in prostate cancer (PCa) patients, and to identify clinical and/or PET/CT criteria associated with benign and malignant lesions.

Methods: We retrospectively identified 54 patients with PCa who underwent [ 68 Ga]Ga-PSMA-11 PET/CT for initial staging ( N  = 39) or BCR ( N  = 15) and whose reports described rib lesions, at the exclusion of any other lesions, whether doubtful, suspicious, or established. Posttherapy prostate-specific antigen (PSA) levels were used to determine whether those lesions were benign or malignant. Each patient's prostate-specific membrane antigen PET/CT report was classified as true positive, true negative, false positive, or false negative based on the posttherapy PSA level. We then assessed whether any clinical and/or PET/CT criteria could help differentiate benign from malignant lesions, and if any criteria were misleading.

Results: Among the 54 patients, 46 (85.2%) had 64 benign costal lesions, and eight (14.8%) had 10 malignant lesions. PET/CT reports indicated rib lesions as benign/equivocal in 38/54 (55.6%) patients and malignant in 16/54 (29.6%). Benign features on CT were the only parameter significantly associated with the final diagnosis. Factors such as patient age, maximum standardized uptake value of lesions, lesion dispersion, and malignant features described on CT were found to be misleading when deciding the malignant or benign status.

Conclusion: Most exclusive costal lesions detected by [ 68 Ga]Ga-PSMA-11 PET/CT are benign. Apart from specific benign CT features, no clinical or PET/CT criteria reliably differentiate benign from malignant costal lesions.

Purpose: This study aims to investigate the diagnostic value of baseline F18 fluorodeoxyglucose (FDG) PET/computed tomography (CT) parameters and peripheral blood inflammatory markers in aggressive lymphoma of non-Hodgkin lymphoma (NHL) and the correlation between peripheral blood inflammatory markers and maximum standardized uptake value (SUV max ).

Patients and methods: We conducted a retrospective analysis including 121 patients with NHL. Patients were divided into aggressive lymphoma group and indolent lymphoma group. Mann-Whitney U test, chi-square test and multivariate stepwise logistic regression were used to analyse. Subsequently, receiver operating characteristic (ROC) curve analysis was conducted to evaluate the diagnostic performance. Additionally, Spearman correlation analysis was utilized to explore the correlation between peripheral blood inflammatory markers and SUV max .

Results: Leptin mass criterion uptake value (SUL) max , SUV max , SUV avg , SUV peak , focal SUV max /liver SUV max , focal SUV max / mediastinal SUV max , SUL avg , SUL peak , systemic immune-inflammation (SII), neutrophil ratio, total lesion glycolysis (TLG), neutrophils versus lymphocyte ratio (NLR), plateletto-lymphocyte ratio (PLR), lactate dehydrogenase (LDH) and lymphocyle ratio between two groups were statistically significant ( P  < 0.05). SUV max was an independent influencing factor, and the area under the ROC curve was 0.862. There was a positive correlation between the PLR and SUV max ( r  = 0.239; P  = 0.008).

Conclusion: PET/CT parameters and peripheral blood inflammatory markers have certain value in the diagnosis of aggressive lymphoma in NHL, among which SUV max is an independent influencing marker and is positively correlated with PLR.

Objective: This study aimed to evaluate the diagnostic performance of 99m Tc-hydroxymethylene diphosphonate ( 99m Tc-HMDP) imaging for cardiac amyloidosis and to demonstrate changes in cardiac uptake of 99m Tc-HMDP after tafamidis treatment.

Methods: Seventy-five patients with suspected cardiac amyloidosis who underwent 99m Tc-HMDP imaging were included. We compared visual Perugini grades and semiquantitative heart-to-contralateral (H/CL) area ratios, myocardial maximum standardized uptake value (SUVmax), and peak of SUV (SUVpeak) between cardiac transthyretin amyloidosis (ATTR) and amyloid light-chain amyloidosis (AL). Comparison of interobserver reproducibility between H/CL ratios and myocardial SUVmax/SUVpeak was performed. H/CL ratio of 99m Tc-HMDP and myocardial SUVmax/SUVpeak were compared before and after tafamidis administration for cardiac wild-type ATTR.

Results: Among 75 patients, 20 patients (26.7%) were visually positive based on Perugini grade. Fifteen and three patients were pathologically identified as cardiac ATTR and AL, respectively. ATTR group ( n  = 15) had significantly higher H/CL ratios of 99m Tc-HMDP than AL group ( n  = 3) ( P  = 0.003). ATTR group ( n  = 15) had significantly higher myocardial SUVmax/SUVpeak of 99m Tc-HMDP than AL group ( n  = 2) ( P  = 0.015). Myocardial SUVmax/SUVpeak had better interobserver reproducibility than H/CL ratios. After tafamidis treatment for cardiac wild-type ATTR, the decrease in myocardial SUVpeak was significant but not in H/CL ratios and myocardial SUVmax.

Conclusion: H/CL ratio and SUVmax/SUVpeak in 99m Tc-HMDP imaging were useful for diagnosing cardiac ATTR. Myocardial SUVpeak may be useful for monitoring changes in cardiac uptake after tafamidis treatment for cardiac ATTR.

Objective: This study aimed to evaluate the diagnostic accuracy of 18 F-fibroblast activation protein inhibitor (FAPI) PET/computed tomography (CT) in identifying primary tumors and mediastinal lymph node metastases in nonsmall cell lung cancer (NSCLC), with histopathological findings serving as the reference standard.

Methods: Nineteen patients underwent preoperative 18 F-FAPI PET/CT and subsequent surgery; of these, 13 also underwent 18 F-fluorodeoxyglucose (FDG) PET/CT within 1 week. The diagnostic accuracy of primary tumors and lymph node metastases was evaluated for both modalities. Semiquantitative parameters, including maximum standardized uptake values (SUV max ) and target-to-background ratios (TBRs), for both primary tumors and lymph node metastases were assessed for both modalities.

Results: For primary tumors, 18 of 19 (94.7%) showed positive results on 18 F-FAPI PET/CT scans. In 13 patients who also underwent 18 F-FDG PET/CT, 18 F-FAPI PET/CT demonstrated a higher detection rate compared with 18 F-FDG PET/CT (100% vs. 69.1%). The overall accuracy of lymph node assessment with 18 F-FAPI PET/CT (95.9-97.1%) was significantly higher compared to 18 F-FDG PET/CT (51.0%). Malignant lymph nodes exhibited significantly higher SUV max and TBR on 18 F-FAPI scans (SUV max : 7.0 vs. 0.9, P  < 0.001; TBR muscle : 5.0 vs. 0.8, P  < 0.001) than on 18 F-FDG scans (SUV max : 3.9 vs. 1.8, P  = 0.01), except for the liver TBR on 18 F-FDG scans (TBR liver : 1.8 vs. 1.0, P  = 0.055).

Conclusion: 18 F-FAPI could be utilized in the preoperative staging of NSCLC to mitigate the incidence of false positives associated with 18 F-FDG, due to its higher accuracy in identifying mediastinal lymph node metastasis.

Aim: This article aimed to study the frequency and characteristics of ectopic/intrathyroidal parathyroid adenomas in patients referred for 18 F-fluorocholine PET/computed tomography (CT).

Patients and methods: From 11 June 2015 to 15 January 2024, 729 patients were studied. Recorded patient variables included hyperparathyroidism type, sex, age, presence of symptoms, renal involvement, bone involvement, parathyroid hormone (PTH), and serum calcium, phosphate, and vitamin D as well as 24-h urine calcium excretion. PET/CT results were also collected. In case of parathyroidectomy, the weight of the adenomas was recorded. Continuous variables were expressed as mean ± SD. Differences were evaluated with Mann-Whitney U -tests or two-sample t -tests, when appropriate. P -values ≤0.05 were considered statistically significant.

Results: PET/CT showed no adenoma in 163 (22%), adenoma in 451 (62%), hyperplasia/multiglandular disease in 32 (4%), and equivocal results in 83 (11%) patients. A total of 6/729 (1%) adenomas were located intrathyroidally and 16/729 (2%) had an ectopic location. Patients with ectopic/intrathyroidal adenoma showed significantly higher serum PTH levels than patients with no visualization of adenoma on PET. The mean mass of the adenoma was 1 ± 2.3 g in patients with orthotopic adenomas versus 2.7 ± 3.3 g in patients with ectopic/intrathyroidal adenomas; however, this was not significantly different ( P  = 0.09).

Conclusion: In the presented cohort, the frequency of ectopic/intrathyroidal parathyroid adenomas was 3%. No significant difference in weight was found between orthotopic and ectopic/intrathyroidal parathyroid adenomas.

Introduction: Voiding cystourethrography (VCUG) is the standard method for diagnosing vesicoureteral reflux (VUR) but has been criticized for radiation exposure. Direct radionuclide cystography (DRC) was developed to reduce this risk. We aimed to assess DRC's efficacy as a screening tool and compare its radiation burden to VCUG.

Materials and methods: We retrospectively analyzed patient records encompassing children who underwent VCUG or DRC to diagnose VUR from 2011 to 2020 at our hospital.

Results: A total of 156 children were included (median age: 0.75 years, 53.8% females). Indications included urinary tract infection in 71.2% of patients and antenatal hydronephrosis in 26.9%. DRC was performed on 122 patients (78.2%) and VCUG on 96 patients (61.5%), with solitary use in 38.5 and 21.8% of cases, respectively, and combined application in 39.7%. DRC detected VUR in 35.3% (43/122) and VCUG in 61.5% (59/96) of patients. Bladder-filling rates differed significantly between DRC (37%) and VCUG (67%) ( P  < 0.0001). Median radiation doses were lower in VCUG (0.023 mSv) than in DRC (0.073 mSv). For patients requiring complementary VCUG after DRC, the median radiation dose for DRC was 0.063 mSv ( P  < 0.0001), resulting in a total median dose of 0.098 mSv. Cost analysis revealed VCUG as more cost-effective, with an additional expenditure of approximately 345 euros per patient undergoing DRC in our cohort.

Conclusion: DRC imposed a higher radiation burden on patients than VCUG and often necessitated follow-up VCUG for positive cases. This challenges the utility of DRC as a low-radiation alternative in VUR screening.

Level of evidence: Level 4: cohort study without a control group.

Dementia with Lewy bodies (DLB) and Parkinson's disease dementia (PDD) are closely related neurodegenerative conditions within the Lewy body spectrum. The relationship between DLB and PDD remains debated, with ongoing discussion about whether they are distinct diseases or different manifestations of the same disorder. This study aimed to identify differences in cerebral perfusion patterns between DLB and PDD patients. Single-photon emission computed tomography ethyl cysteinate dimer imaging was performed on each patient, and relative tracer uptake levels across 47 regions of interest and 240 subregions were analyzed. A two-sided Welch's t-test was employed to evaluate mean perfusion differences, with results further confirmed through a voxel-wise t-test mapping. The greatest difference in perfusion was in the visual cortices, with lower mean perfusion observed in PDD patients than those with DLB. However, no comparisons remained significant at the 0.05 significance level after adjusting for multiple comparisons with the Benjamini-Hochberg procedure.

Objective: Diagnosis of early onset dementia is critical for initiating management. Although structural MRI is an established procedure for dementia evaluation, early cases may be missed. Neurodegenerative diseases lead to reductions in glucose consumption and grey matter volume loss. Our primary aim was to establish whether metabolic changes precede perfusion abnormalities in early cases of dementia especially, frontotemporal dementia (FTD). Secondly to study if cerebral atrophy using Pasquier visual rating scales can be used reliably to correlate with hypometabolism in this group of patients.

Materials and methods: A total of 56 patients (M:F = 39:17) with memory loss as per the DSM-5 diagnostic criteria were clinically and neurologically examined and referred for 18F-fluorodeoxyglucose (FDG) PET brain imaging. A few patients who had a prior (recent, <1 week) MR brain underwent brain 18F-FDG PET-CT, and all others were considered for simultaneous 18F-FDG PETMR imaging of brain. T2-weighted images were used to report Pasquier rating scales in all our patients as per recommendation.

Results: Cognitive assessments were analysed along with neuroimaging findings. Highest diagnostic performance was obtained with 18F-FDG PET for identifying early FTD in our series of patients. Sensitivity, specificity and accuracy of FDG and arterial spin labeling (ASL) using simultaneous PETMR were found to be 96.34%/90.1%/89 : 53.57%/62.12%/78, respectively. Cerebral atrophy rated using Pasquier visual scales showed the lowest diagnostic performance. Our study showed that the earliest phase of cognitive decline was found to be associated with specific patterns of hypometabolism, even in the absence of atrophy, which are currently considered diagnostic biomarkers.

Conclusion: Metabolic derangements precede perfusion changes and cerebral atrophy in the setting of early dementia. Simultaneous FDG PETMR is being recommended as the investigation of choice for the evaluation of early FTD. This pilot study shows that FDG PET outperforms cognitive assessments and anatomical imaging modalities in early dementia evaluation. Although ASL can detect perfusion deficits in dementia, compared with FDG PET, its sensitivity and specificity for discerning early onset dementia from controls remain inferior to FDG PET. Pasquier scales, although easy to implement, cannot replace FDG PET metabolic findings, which start very early in the neuronal disease process.

Objective: This study aims to assess the role of 18F-fluorodeoxyglucose (FDG) PET/computed tomography (CT) in suspected recurrent ovarian carcinoma. Several clinical and PET parameters were assessed to evaluate disease burden and prognosis.

Methods: We did a single-center, retrospective study in patients with suspected recurrent ovarian carcinoma who underwent 18F-FDG PET/CT. The disease burden on the scan was evaluated. We calculated several semiquantitative markers, including standard uptake values (SUV), metabolic tumor volume (MTV), and total lesion glycolysis (TLG). Survival analysis was done with clinical parameters, CA-125 levels, disease distribution, and metabolic markers.

Results: Fifty-two patients were included in the study. Half of the patients had suspected recurrence within 12 months of primary diagnosis. PET/CT scan suggested disease in 35 (67.3%) patients. Multiple metastatic sites were noted in 21 (40.4%) patients. Extra-abdominal metastases were seen in 15 (28.8%) patients. Eight patients had 18F-FDG avid disease despite a low CA-125 level (<35 IU). Young patients (<50 years), extra-abdominal disease, multiple metastases, and higher restaging were associated with poor outcomes. Meanwhile, treatment history, CA-125 level, and post-PET/CT treatment had no significant effect on survival. MTV@40% SUV (>17.21) and TLG@40% SUV (>68.7) had the sensitivity of 87.5% and 75% for predicting disease outcome.

Conclusion: Recurrent ovarian carcinoma commonly presents with multiple metastasis and extra-abdominal metastases. 18F-FDG PET/CT-guided patterns of disease distribution were significant markers for poor prognosis. Disease burden on PET/CT-derived semiquantitative parameters was associated with poor outcomes.

Radiation treatments [radiotherapy and radionuclide treatments (RNTs)] are one of the main and effective treatment modalities of cancer. Globally, the number of cancer patients treated with radionuclides are much less as compared to number of radiotherapy cases but with the development of new radiotracers, most notably 177Lu and 225Ac-labeled prostate-specific membrane antigen ligands, and 223Ra-dichloride for prostate cancer and 177Lu-somatostatin analogs for neuroendocrine tumors, there is a significant rise in RNTs in the last decade. As therapeutic applications of nuclear medicine is on the rise, the aim of this review is to summarize biological responses to radiation treatments and molecular mechanisms of radiation-induced cell death (e.g. ionization, DNA damages such as double-strand breaks, DNA repair mechanisms, types of cell deaths such as apoptosis, necrosis, and immunogenic cell death), histopathological changes with radiation treatments, and role of PET imaging in RNTs as part of radionuclide theranostics for selecting and planning patients for RNTs, dosimetry, predicting and assessing response to RNTs, predicting toxicities, and other possible PET findings which may be seen after RNTs such as activation of immune system.