Nuclear Medicine Communications最新文献

Purpose: This study demonstrates the feasibility and benefits of using a deep learning-based approach for attenuation correction in [ 68 Ga]Ga-PSMA PET scans.

Methods: A dataset of 700 prostate cancer patients (mean age: 67.6 ± 5.9 years, range: 45-85 years) who underwent [ 68 Ga]Ga-PSMA PET/computed tomography was collected. A deep learning model was trained to perform attenuation correction on these images. Quantitative accuracy was assessed using clinical data from 92 patients, comparing the deep learning-based attenuation correction (DLAC) to computed tomography-based PET attenuation correction (PET-CTAC) using mean error, mean absolute error, and root mean square error based on standard uptake value. Clinical evaluation was conducted by three specialists who performed a blinded assessment of lesion detectability and overall image quality in a subset of 50 subjects, comparing DLAC and PET-CTAC images.

Results: The DLAC model yielded mean error, mean absolute error, and root mean square error values of -0.007 ± 0.032, 0.08 ± 0.033, and 0.252 ± 125 standard uptake value, respectively. Regarding lesion detection and image quality, DLAC showed superior performance in 16 of the 50 cases, while in 56% of the cases, the images generated by DLAC and PET-CTAC were found to have closely comparable quality and lesion detectability.

Conclusion: This study highlights significant improvements in image quality and lesion detection capabilities through the integration of DLAC in [ 68 Ga]Ga-PSMA PET imaging. This innovative approach not only addresses challenges such as bladder radioactivity but also represents a promising method to minimize patient radiation exposure by integrating low-dose computed tomography and DLAC, ultimately improving diagnostic accuracy and patient outcomes.

Objective: Evaluating the predictive models (PM) for a major adverse cardiac event (MACE) only in women with abnormal summed difference score (SDS ≥ 1), borderline myocardial ischemia (borderline-MIsch: SDS = 1), MIsch (SDS ≥ 2), mild-MIsch (SDS = 2-4), and moderate-severe MIsch (ms-MIsch: SDS ≥ 5).

Methods: Between January 2000 and January 2018, of 25 943 consecutive patients who underwent gated single-photon emission computed tomography myocardial perfusion imaging (gSPECT-MPI) for coronary risk stratification; 717 women (age 68.37 ± 3.4 years) with an abnormal SDS ≥ 1 were included. During the follow-up (mean 4 ± 2.9 years) post-gSPECT-MPI, MACE (unstable angina, nonfatal myocardial infarction, coronary revascularization, cardiac death) was assessed.

Results: In the global women cohort with abnormal SDS (n = 717), the PM was angina [hazard ratio (HR): 1.65, P = 0.016], diabetes (HR: 1.72, P = 0.004), beta-blockers (HR: 1.61, P = 0.009), pharmacological stress (HR: 1.74, P = 0.007), ↓ segment (ST) mm ≥ 1 (HR: 1.54, P = 0.039), and moderate-to-severe abnormal summed stress score (ms-SSS) (HR: 2.92, P = 0.001). In borderline-MIsch group (n = 208), the PM was previous myocardial infarction (HR: 3.8, P = 0.001), nitrates (HR: 2.13, P = 0.047), pharmacological stress (HR: 4.81, P < 0.001), and ↓ST mm ≥ 1 (HR: 3.07, P = 0.014). In MIsch group (n = 509), the PM model was ms-SSS (HR: 2.25, P = 0.001), diabetes (HR: 1.73, P = 0.011), angina (HR: 1.68, P = 0.029), beta-blockers (HR: 1.59, P = 0.026), and ms-MIsch (HR: 1.62, P = 0.044). In mild-MIsch group (n = 399), the PM was ms-SSS (HR: 2.55, P = 0.003), diabetes (HR: 2.17, P = 0.004), angina (HR: 1.89, P = 0.037), and beta-blockers (HR: 2.01, P = 0.011). In ms-MIsch group (n = 110), the predictive variable for MACE was ms-SSS (HR: 2.27, P = 0.016). The ms-SSS significantly increases the prognostic value of the ms-MIsch (P = 0.001).

Conclusion: Women with different degrees of abnormal SDS have different PMs of MACE. The ms-SSS stands out as the most significant predictive variable.

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

Methods: Seventy-five patients with suspected cardiac amyloidosis who underwent 99mTc-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 99mTc-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 99mTc-HMDP than AL group (n = 3) (P = 0.003). ATTR group (n = 15) had significantly higher myocardial SUVmax/SUVpeak of 99mTc-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 99mTc-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.

Aim: This article aimed to study the frequency and characteristics of ectopic/intrathyroidal parathyroid adenomas in patients referred for 18F-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.

Objective: The objective of this study was to characterize exclusive costal lesions detected by 68Gallium-labelled prostate-specific membrane antigen ([68Ga]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 [68Ga]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 [68Ga]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.

Objective: To evaluate the effect of prostate-specific membrane antigen (PSMA) PET/computed tomography (CT) on clinical decision-making of radical prostatectomy (RP) and pelvic lymph node dissection (PLND) after its utilization in daily clinical practice at an European high-volume cancer center.

Materials and methods: Patients who had unfavorable intermediate- and high-risk prostate cancer between 2017 and 2021 were included retrospectively and divided into two groups; those who staged using PSMA PET/CT (group 1) and those who staged using conventional modalities (group 2). Clinical decision-making of RP over nonsurgical treatments and f PLND were primary endpoints and evaluated using regression models.

Results: PSMA PET/CT claimed significantly more N1 (24.2% vs. 11.3%; P = 0.01; OR, 1.97; 95% CI, 1.18-3.28) but insignificantly more M1 disease (9.9% vs. 5.7%; P = 0.42; OR, 1.91; 95% CI, 0.39-9.23), compared with the conventional imaging modalities. miN0 stage was related to more RP decisions compared with cN0 stage (P < 0.001; OR, 1.91; 95% CI, 1.48-2.46). PLND decision-making was significantly driven by positive cmiN stage findings, which were more reliable when it was reported after a PSMA PET/CT examination (P < 0.001; OR, 35.55; 95% CI, 6.74-187.45 for conventional imaging modalities vs. P < 0.001; OR, 91.72; 95% CI, 11.25-747.56 for PSMA PET/CT).

Conclusions: Patients with no suspicion of lymph node invasion on molecular imaging (PSMA PET/CT) tended to be referred to RP more compared to radiological imaging. Also, the PLND decision was strongly driven by staging findings. Compared with conventional imaging, PSMA PET/CT findings were more reliable during PLND decision-making.

Introduction: The use of in-house developed software as a medical device (IHD-SaMD) is core to many nuclear medicine (NM) services in the UK, including applications in nonimaging studies and image processing. Expected regulatory changes in 2025 could have significant implications due to a lack of resources and expertise in the implementation and maintenance of software Quality Management Systems (QMS) and associated standards. This survey investigated the national use of IHD-SaMD and the readiness of services to adapt to the upcoming regulatory changes.

Method: An online survey was used to investigate the current national usage of IHD-SaMD. Representatives of 64 UK NM physics services were invited to participate, with 43 responding.

Results: It was found that 98% of respondents use IHD-SaMD clinically. About 65% use IHD-SaMD that respondents felt was under-supported (e.g. legacy software). Approximately 60% of respondents use or support two or more pieces of IHD-SaMD. Around 66% of respondents use a QMS in their department, with about 48% using a software-specific QMS. Most respondents indicate understaffing, particularly with regard to IT/software skillsets. Almost all respondents indicate without an increase in the preparedness and understanding of the requirements, all dependent clinical services would be severely impacted or indeed stopped.

Conclusion: This national survey shows that pending regulatory changes could significantly impact NM services, up to and including stopping clinical services. Additional resources would be required to support in-house software management under an appropriate QMS or move to European conformity marking (CE)-marked software where available. This must be urgently considered and addressed by all NM stakeholders.

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.

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 (SUVmax).

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 SUVmax.

Results: Leptin mass criterion uptake value (SUL)max, SUVmax, SUVavg, SUVpeak, focal SUVmax/liver SUVmax, focal SUVmax/ mediastinal SUVmax, SULavg, SULpeak, systemic immune-inflammation, neutrophil ratio, total lesion glycolysis, neutrophils versus lymphocyte ratio, platelet-to-lymphocyte ratio, hemoglobin-to-white blood cell ratio, lactate dehydrogenase and lymphocyte ratio between two groups were statistically significant (P < 0.05). SUVmax was an independent influencing factor, and the area under the ROC curve was 0.862. There was a positive correlation between the platelet-to-lymphocyte ratio and SUVmax (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 SUVmax is an independent influencing marker and is positively correlated with PLR.

Objectives: White blood cells, neutrophils, lymphocytes, and neutrophil-to-lymphocyte ratio (NLR) distribution patterns in patients with anatomic coronary disease have previously been associated with cardiac events such as myocardial infarct size, complications, and prognosis. However, it remains unknown whether myocardial perfusion mass defect percentage (MDP) obtained from gated myocardial perfusion imaging (G-MPI) correlates with these hematological parameters. Therefore, our research aimed to investigate the application of MDP in the evaluation of acute coronary syndrome (ACS).

Methods: Thirty-six patients with ACS underwent single-photon emission computed tomography/computed tomography using retrospective electrocardiography gating during the resting state. The primary outcome was the percentage of left ventricular mass with abnormal myocardial perfusion (i.e. MDP) in G-MPI. Furthermore, the correlation between myocardial perfusion MDP and lymphocyte count, neutrophil count, white blood cell count, and NLR was calculated. In addition, we explored the relationship of myocardial perfusion MDP with other cardiac function parameters obtained from G-MPI, such as summed rest score, left ventricular ejection fraction, end-systolic volume, and end-diastolic volume.

Results: Myocardial perfusion MDP significantly correlated with white blood cell count, neutrophil count, and NLR (P < 0.01). Furthermore, these hematological parameters were significantly different between low and high MDP groups. Additionally, myocardial perfusion MDP negatively correlated with end-systolic volume (r = -0.615) and left ventricular ejection fraction (r = -0.657).

Conclusion: Myocardial perfusion MDP has a high correlation with inflammatory cell counts and cardiac function parameters obtained from G-MPI in ACS; this may be of help in the evaluation and treatment of these patients.