Nuclear Medicine Communications最新文献

Purpose: To evaluate the predictive value of 18F-fluorodeoxyglucose (18F-FDG) PET/computed tomography (CT) imaging features - including standardized uptake value (SUV), tumor-to-background ratio (TBR), metabolic tumor volume (MTV), and others - for overall survival (OS) in patients with glioma, and to clarify their clinical significance as independent prognostic factors.

Methods: This prospective cohort study enrolled 121 patients with pathologically confirmed glioma between January 2012 and December 2022. All patients underwent 18F-FDG PET/CT within 1 month before surgery. Metabolic parameters, including maximum/mean/minimum SUV (SUVmax, SUVmean, and SUVmin), TBRmax, MTV, and total lesion glycolysis (TLG), were extracted. Kaplan-Meier survival curves were generated, and differences in OS between parameter-stratified groups (high vs. low levels) were compared using log-rank tests. Univariate and multivariate Cox proportional hazards regression models were employed to identify independent prognostic factors for OS.

Results: Survival analysis revealed that high SUVmax, SUVmean, TBRmax, and TLG were significantly associated with reduced OS (log-rank P < 0.05). Multivariate Cox regression demonstrated that WHO grade III [adjusted hazard ratio = 8.99, 95% confidence interval (CI): 3.80-21.06], WHO grade IV (adjusted hazard ratio = 12.97, 95% CI: 5.81-42.00), isocitrate dehydrogenase (IDH) wild-type status (adjusted hazard ratio = 2.03, 95% CI: 1.18-3.51, P = 0.011), high SUVmax (adjusted hazard ratio = 2.66, 95% CI: 1.50-3.76, P = 0.021), and high TBRmax (adjusted hazard ratio = 2.11, 95% CI: 1.24-3.74) were independent risk factors for OS.

Conclusion: SUVmax and TBRmax derived from 18F-FDG PET/CT serve as independent predictors of OS in patients with glioma. When integrated with conventional prognostic markers (e.g. WHO grade and IDH mutation status), these metabolic parameters provide critical insights for risk stratification and personalized therapeutic decision-making.

Objective: To investigate the influence of different feature aggregation and selection methods on the predictive performance of fluorine-18 fluorodeoxyglucose (18F-FDG) PET radiomics in assessing survival outcomes in patients with lymphoma.

Methods: This retrospective analysis included 80 patients with histologically confirmed lymphoma, each presenting with at least three lesions on baseline 18F-FDG PET images. Metabolic tumor volumes were segmented using a standardized uptake value threshold of 4.0. From each lesion, 107 radiomic features were extracted. Of these, 30 features were preselected based on their robustness to variations in tracer uptake time, image reconstruction parameters, and respiratory motion. Six distinct feature aggregation approaches were evaluated in combination with six feature selection methods. Multivariable Cox proportional hazards regression was used to assess the predictive performance of each aggregation-selection strategy for progression-free survival (PFS) and overall survival (OS).

Results: All combinations of feature aggregation and selection methods produced statistically significant prognostic models for PFS and OS, with Harrell's concordance indices (C-index) ranging from 0.582 to 0.668 for PFS and from 0.597 to 0.721 for OS. The best predictive performance was achieved using median value aggregation across all individual lesions combined with feature selection via the least absolute shrinkage and selection operator. Integrating clinical variables with radiomic features further improved predictive performance.

Conclusion: The prognostic value of 18F-FDG PET radiomics remained consistent across different feature aggregation and selection strategies. The establishment of standardized analysis workflows is essential to facilitate its clinical implementation in personalized treatment planning for patients with lymphoma.

Objective: To evaluate the therapeutic efficacy and safety of intrathoracic administration of 90Y-labeled anti-podoplanin antibody NZ-16 in a pleural mesothelioma murine model, in comparison with conventional intravenous administration.

Materials and methods: An intrathoracic mesothelioma model was established using H226-Luc cells in nude mice. Biodistribution and dosimetry were assessed using 111In-labeled NZ-16. Mice received either intravenous or intrathoracic administration of 90Y-labeled NZ-16 (3.7 or 7.4 MBq). Tumor growth, survival duration, hematologic toxicity, and histological changes were evaluated.

Results: Intrathoracic administration resulted in 1.3-fold higher tumor uptake and reduced accumulation in normal organs compared with intravenous administration. Dosimetric analysis showed lower absorbed doses in bone marrow and lungs with intrathoracic delivery. At 3.7 MBq, intrathoracic administration significantly improved tumor regression and survival compared with the intravenous route. Histological analysis revealed enhanced fibrosis in intrathoracic-treated tumors. Hematologic toxicity was milder with intrathoracic administration.

Conclusion: Intrathoracic administration of 90Y-labeled NZ-16 may offer improved therapeutic efficacy and reduced systemic toxicity compared with intravenous administration in pleural mesothelioma. These findings suggest that intrathoracic delivery could be a promising approach for enhancing treatment outcomes in patients with unresectable disease.

Aims: To determine the diagnostic performance and clinical usefulness of 18F-fluorodeoxyglucose (18F-FDG) PET computerised tomography (CT) in detecting cardiac inflammation in patients with suspected cardiac sarcoidosis; and to explore the role of interval and correlative imaging.

Material and methods: A 10-year (2015-2024) retrospective observational study was conducted at our teaching hospital. 397 18F-FDG PET-CT scans performed in 296 patients with suspected or known cardiac sarcoidosis were reviewed. Assessment of diagnostic quality, patterns of myocardial and extracardiac FDG uptake, concordance with other modalities [cardiac MRI (CMR) and myocardial perfusion imaging (MPI)] were assessed. Separate subgroup analysis of patients undergoing repeat 18F-FDG PET-CT scans was conducted.

Results: Images of excellent diagnostic quality 18F-FDG PET-CT were obtained in 365/397 studies (91.9%). Cardiac inflammation was identified in 226 and scans were normal in 139 patients. Extracardiac sarcoidosis was present in 230 (63%) patients. MPI was abnormal in 50/98 patients (51%) and CMR was abnormal in 88/126 patients (70%). PET and MPI findings showed concordance in 53% patients but not considered significant (P = 0.78). High concordance with CMR was noted in 85.7% patients (P < 0.001). For treatment monitoring, follow-up 18F-FDG PET-CT scans accurately assessed disease status in 66/70 patients (94.2%).

Conclusion: We obtained excellent diagnostic quality of images in a high proportion of our patients (92%). Because of a high degree of concordance between 18F-FDG PET-CT and CMR, we propose that either test can be used initially and the other test can be used in cases of clinical discordance. Interval 18F-FDG PET-CT scans are immensely useful for treatment response monitoring.

Purpose: 177Lu-DOTATATE-targeted radionuclide therapy (TRT) is effective for patients with somatostatin receptor (SSTR)-positive neuroendocrine tumors; however, radiation safety regulations often necessitate hospitalization, particularly in countries with stringent discharge criteria. This study aimed to identify pretreatment factors predicting outpatient eligibility.

Methods: We retrospectively analyzed 26 patients who underwent their first cycle of 177Lu-DOTATATE TRT with complete data for analysis. The external dose rate at 1 m (EDR-1 m) was measured 6 h after administration. Patients were divided into two groups: EDR-1 m greater than or equal to 18 μSv/h and less than 18 μSv/h. Characteristics, including age, sex, BMI, body surface area, estimated glomerular filtration rate, administered dose, and tumor site, were compared. In addition, the whole-body washout rate from pretreatment SSTR imaging was evaluated as a potential predictor. Logistic regression and receiver operating characteristic (ROC) analyses were conducted.

Results: Fourteen of the 26 (53.8%) patients met the discharge criterion at 6 h. No significant differences were observed in demographic or clinical characteristics between groups. The median washout rate was significantly higher in those meeting the criterion (57.6 vs. 35.0%; P < 0.001). The area under the ROC curve for the washout rate was 0.929, indicating excellent predictive ability. An optimal cut-off value of 53.5% predicted same-day discharge with a sensitivity of 92.9% and specificity of 91.7%.

Conclusion: The whole-body washout rate derived from pretreatment SSTR imaging is a strong, practical predictor for outpatient eligibility following 177Lu-DOTATATE TRT. Incorporating this simple, noninvasive marker into clinical workflow could support individualized discharge planning and improve patient access under strict radiation safety regulations.

Objective: The aim of this retrospective study is to evaluate the diagnostic accuracy of [68Ga]Ga-Trivehexin PET/CT compared with [18F]fluorodeoxyglucose (FDG) PET/computed tomography (CT) for nodal staging in various solid tumors.

Materials and methods: Between 2024 and 2025, a total of 15 patients with histopathologically confirmed primary or recurrent cancer were enrolled in the study. All participants underwent both [18F]FDG and [68Ga]Ga-Trivehexin PET/CT imaging for oncologic staging. Imaging findings were compared with histopathological results and clinical/radiological follow-up. Primary tumors, lymph nodes, and metastases were visually assessed, and maximum standardized uptake values were calculated.

Results: The median age of the patients was 62 years. Diagnoses included colorectal, breast, pancreatic, lung, bladder, thyroid, and endometrial cancers. Both [18F]FDG and [68Ga]Ga-Trivehexin PET/CT demonstrated uptake in all primary tumors. While [18F]FDG PET/CT showed uptake in all lymph nodes, [68Ga]Ga-Trivehexin PET/CT demonstrated positive uptake only in metastatic lymph nodes. The positive predictive value of [68Ga]Ga-Trivehexin PET/CT was calculated as 100%. In contrast, [18F]FDG PET/CT exhibited lower specificity, with a positive predictive value of 26.3%.

Conclusion: This study demonstrates that [68Ga]Ga-Trivehexin PET/CT offers higher specificity than [18F]FDG PET/CT, particularly in benign lymph node lesions, and is effective in accurately identifying metastatic lymph nodes. Compared to [18F]FDG PET/CT, 68Ga-Trivehexin PET/CT provides lower false-positive rates and higher diagnostic accuracy, potentially reducing the need for unnecessary invasive procedures.

Objectives: To investigate the differences fluorodeoxyglucose (FDG) dynamics between clear cell renal cell carcinoma (ccRCC) and non-ccRCC as a potential diagnostic clue, using dynamic whole-body (D-WB) and dual-time-point (DTP) FDG-PET/computed tomography (CT) imaging.

Patients and methods: D-WB and DTP FDG-PET/CT scans were performed for 26 RCC patients. We obtained Pearson's correlation coefficients between the static [maximum standardized uptake value (SUVmax) and tumor size] and dynamic [metabolic rate (MRFDG) and distribution volume of FDG (DVFDG)] parameters. We compared MRFDG and DVFDG by tumor type and performed receiver operating characteristic (ROC) analyses for each parameter.

Results: Nineteen ccRCC and nine non-ccRCC lesions including molecularly defined carcinomas were analyzed. Compared with the ccRCC (r = 0.55-0.81), the MRFDG in the non-ccRCC was more strongly correlated with the early (SUVe) and delayed (SUVd) SUVmax and tumor size (r = 0.72-0.97). The DVFDG in the non-ccRCC was more strongly correlated with SUVe and SUVd (r = 0.93, 0.84) vs. the ccRCC (r = 0.55, 0.66). SUVe and SUVd were significantly higher in the non-ccRCC vs. ccRCC (analyses for all or T3/4 RCC, both P < 0.05). MRFDG was significantly higher in the T3/4 non-ccRCC vs. the T3/4 ccRCC (P = 0.04). In the ROC analysis for differentiating ccRCC and non-ccRCC, SUVd showed the highest area under the curve (0.92-0.93 for all and T3/4 RCC) than other parameters (0.70-0.84).

Conclusion: D-WB FDG-PET/CT imaging clearly demonstrated different FDG dynamics between ccRCC and non-ccRCC. Non-ccRCC showed higher MRFDG values than ccRCC, but dynamic images have a limited role in differentiating these lesions. SUVd could be the most suitable parameter for differentiating ccRCC and non-ccRCC.

Background: Nuclear medicine's lung perfusion scintigraphy is a valuable imaging technique for assessing many health conditions. Various methods have been described in the literature for segmenting and quantifying the lung perfusion in single-photon emission computed tomography/computed tomography (SPECT/CT) images, but they rely on commercially available software, require manual definition of regions/volumes of interest, or both.

Objective: This study proposes a never reported approach to segment and quantify SPECT (and SPECT/CT) lung perfusion images by developing a fully automated algorithm utilizing only free software.

Methods: Python programming language was used to write a completely automated algorithm for 3D Slicer to segment and quantify SPECT and SPECT/CT images. The algorithm was tested in 37 lung perfusion images, collected retrospectively from a public hospital database.

Results: The algorithm was able to perform fully automated lobar perfusion quantification. The mean relative perfusion found were: LUL - 23.5%, LLL - 22.3%, RUL - 24.6%, RML - 7.9%, and RLL - 21.7%. The algorithm also segmented and quantified the relative perfusion of the left (L) and right (R) lungs without the aid of CT: L - 44.6% and R - 55.3%; and found no statistical difference in the results obtained with or without CT (P-value = 0.38 and 0.44, respectively).

Conclusion: The algorithm created required no user interaction, presented good agreement with previously reported works, and was on average 10 times faster than the fastest algorithm reported on the literature, thus making it a free, efficient, and reliable tool for assisting diagnosis.

Purpose: To evaluate the relationships between anatomical, functional, and metabolic parameters and distant metastasis in the primary staging of rectal adenocarcinoma.

Methods: Seventy-three patients with rectal adenocarcinoma, who underwent pelvic MRI and whole-body 18F-FDG PET/MRI for staging, were included. Anatomical [T and N stages, extramural venous invasion (EMVI) and circumferential resection margin (CRM) statuses] and functional parameters [apparent diffusion coefficient (ADC)mean (mm²/sn × 10-6)] of primary tumor were recorded from pelvic MRI, and metabolic data (maximum standard uptake value (SUVmax), mean SUV (SUVmean ), metabolic tumor volume (MTV), total lesion glycolysis (TLG), and total lesion quotient (TLQ) were recorded from 18F-FDG PET/MRI. Quantitative parameters combining functional and metabolic data (SUVmax/ADCmean, SUVmean/ADCmean, MTV/ADCmean, TLG/ADCmean, TLQ/ADCmean) were calculated. Distant metastases were recorded via 18F-FDG PET/MRI. To detect lung nodules, supplementary 18F-FDG PET/CT scans of the thorax were utilized. Relationship between these parameters and distant metastasis, and their ability to predict for distant metastatic disease, were statistically evaluated.

Results: In the univariate logistic regression analysis, the SUVmax (1.04; 1.0-1.08; P = 0.031), TLG (1.0; 1.0-1.005; P = 0.044), TLG/ADCmean (8.12; 1.04-63.78; P = 0.046), and presence of EMVI (4.13; 1.31-12.98; P = 0.015) (OR; CI; P) were found to predict distant metastasis. In multivariate regression analysis, SUVmax (1.05; 1.0-1.1; P = 0.023) and the presence of EMVI (6.82; 1.64-28.48; P = 0.008) were identified as independent predictors for distant metastatic disease (OR; CI; P). Significant associations were detected between distant lymph node metastasis and T stage and the presence of EMVI, whereas significant associations were detected between the size of distant lymph node metastases and the SUVmax, SUVmean, SUVmax/ADCmean, and SUVmean/ADCmean (P < 0.05). Patients with lung and other organ metastases had significantly greater TLG and TLG/ADCmean values (P < 0.05).

Conclusion: 18F-FDG PET/MRI allows obtaining anatomical, functional, and metabolic parameters related to the primary tumor in a single session and has the potential to predict information regarding tumor behavior, including distant metastatic spread.

Objective: In 2002 a UK audit was performed by the Nuclear Medicine Software Quality Group of filtered back projection (FBP) software, designed to evaluate the quantitative characteristics of single-photon emission computed tomography (SPECT). Subsequently, the use of FBP has reduced in common practice, with most guidelines now recommending and using iterative reconstruction. This study aimed to audit ordered-subset expectation-maximisation (OSEM) algorithms in clinical use, acting on the same input data.

Methods: A computational phantom was devised to evaluate the effect of sphere diameter, position and activity concentration along with an assessment of uniformity and resolution. Additional sections were implemented to evaluate the recovery in photopoenic areas and of small lesions adjacent to active structures. SPECT projections were created from the phantom and placed in the Digital Imaging and Communications in Medicine structures of acquired data from three SPECT camera manufacturers. Resultant projections were reconstructed via six commercial reconstruction platforms and quantitative measures from the above sections compared.

Results: Across all measures it was found that there was excellent agreement among platforms offering similar reconstruction methods. One platform was found to not offer the ability to perform a true 'pencil-beam' OSEM reconstruction and results varied with different manufacturer data supplied.

Conclusion: While there are differences in how reconstruction platforms process data from different manufacturers, these differences were generally small, with results from the one wide-beam reconstruction method having the largest variation. It would be advisable that users implementing sensitivity-based quantitative SPECT should derive factors for the various combinations of acquisition and reconstruction platforms at their disposal.