Nuclear Medicine Communications最新文献

Introduction: It is important to distinguish Waldenström macroglobulinemia from smoldering Waldenström macroglobulinemia (sWM), because only patients with Waldenström macroglobulinemia require treatment, however the distinction can be clinically complex. The aim of this study is to investigate whether [ 68 Ga]Ga-pentixafor PET/CT shows different characteristics in sWM and Waldenström macroglobulinemia patients and therefore can help to differentiate Waldenström macroglobulinemia and sWM.

Results: Thirty-seven patients with newly diagnosed Waldenström macroglobulinemia and 11 sWM patients were analyzed [35 men and 13 women; 64.3 ± 10.7 (range, 29-87) years old]. The SUV max of bone marrow disease, lymph nodes, and other extramedullary diseases on [ 68 Ga]Ga-pentixafor were significantly higher than those on 2-[ 18 F]FDG PET/CT ( P  < 0.05). On [ 68 Ga]Ga-pentixafor PET/CT, patients with Waldenström macroglobulinemia had more lymph node regions involved, significantly higher incidence of involvement in more than three lymph node regions, larger nodal disease, and higher incidence of other extramedullary disease when compared with sWM patients ( P  < 0.05). Waldenström macroglobulinemia patients showed significantly higher total lesions uptake, total lesion volume, and SUV max of extramedullary disease than sWM patients did ( P  < 0.05). None of the visual or semiquantitative indexes in 2-[ 18 F]FDG PET/CT showed significant difference between Waldenström macroglobulinemia and sWM patients.

Conclusion: [ 68 Ga]Ga-pentixafor PET/CT had better diagnostic performance than 2-[ 18 F]FDG PET/CT in Waldenström macroglobulinemia. Patients with Waldenström macroglobulinemia presented with more extensive extramedullary disease shown in [ 68 Ga]Ga-pentixafor PET/CT than sWM patients did.

Purpose: The aim of this study was to evaluate metabolism change in reference organs (liver and mediastinum) and lymphoid cell-rich organs (spleen and bone marrow) during programmed cell death-1 immunotherapy in relapsed or refractory lymphoma patients.

Methods: A total of 66 patients with baseline and serial monitoring fluorodeoxyglucose (FDG) PET/computed tomography scans were retrospectively enrolled. Mean standardized uptake value (SUV) and maximum SUV of evaluated organs were obtained by two reviewers, and their association with tumor burden and clinical response were evaluated. Immune-related adverse events detected by FDG PET/computed tomography were also recorded.

Results: The SUV values of reference organs and lymphoid cell-rich organs did not change significantly during the immunotherapy process. The intersubject variability of these values ranged from 13.0 to 28.5%. Meanwhile, metabolism of reference organs was affected by neither the tumor burden nor clinical response. SUV change of lymphoid cell-rich organs was associated with clinical response to immunotherapy. Responders showed decreased metabolism, while nonresponders showed a reverse trend (spleen SUV max : -0.30 ± 0.47 vs. 0.18 ± 0.39, P  = 0.001, spleen SUV mean : -0.24 ± 0.39 vs. 0.14 ± 0.31, P  = 0.001; and bone marrow SUV max : -0.14 ± 0.37 vs. 0.07 ± 0.46, P  = 0.042, respectively). The influence of immune-related adverse events on the SUV change in evaluated organs was not significant.

Conclusion: During programmed cell death-1 immunotherapy, metabolism change of reference organs is influenced neither by tumor burden nor by clinical response, while FDG uptake change of lymphoid cell-rich organs is significantly associated with clinical response.

Portal vein thrombosis, a relatively frequent complication associated with hepatocellular carcinoma (HCC) and liver cirrhosis, is recognized as a significant global health concern. This is mainly due to these conditions' high prevalence and potentially severe outcomes. The aim of our study was to conduct a comprehensive literature review to evaluate the efficacy, accuracy, and clinical implications of 18F-FDG PET-CT in diagnosing and managing portal vein tumor thrombosis (PVTT) in patients with HCC. HCC, which accounts for 80% of liver malignancies, ranks as the fourth most prevalent cancer globally and is a significant contributor to cancer-related mortality. The majority of HCC patients are diagnosed at an advanced stage, leading to a deterioration in patient outcomes. Involvement of the portal vein is also a significant negative factor. This review analyzes the application of 18F-FDG PET-CT in the detection and management of PVTT in patients with HCC, with an emphasis on the importance of the maximum standardized uptake value as an essential diagnostic and prognostic marker. 18F-FDG PET-CT is invaluable for detecting recurrence and guiding management strategies, particularly in patients with high-grade HCC, and plays a pivotal role in differentiating malignant portal vein thrombi from their benign counterparts.

Objectives: The objective of this study was to assess receptor expression in metastatic differentiated thyroid carcinoma patients with progressive elevated thyroglobulin and negative iodine scintigraphy, we used 68 Ga-DOTATATE [Gallium-68 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid (DOTA)-octreotate (DOTATATE)] (Krenning's score) and 68 Ga-PSMA-11 (Gallium-68 prostate-specific membrane antigen-11) PET-computed tomography (CT) [molecular imaging prostate-specific membrane antigen (miPSMA) score]. Patients with Krenning's score 3 and above and miPSMA score 2 and above were considered to determine the incidence of patients, who would qualify for treatment with 177 Lu-DOTATATE/PSMA [Lutetium-177 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid (DOTA)-octreotate (DOTATATE)/prostate-specific membrane antigen]-based therapy. In addition, we compared 68 Ga-DOTATATE and 68 Ga-PSMA-11 PET-CT with 2-deoxy-2-[F-18]fluoroglucose ( 18 F-FDG) PET-CT (using maximum standardized uptake value).

Materials and methods: A total of 74 patients with histopathologically proven metastatic differentiated thyroid carcinoma with thyroglobulin elevation and negative iodine scintigraphy syndrome were studied retrospectively. They all had 18 F-FDG, 68 Ga-DOTATATE, and 68 Ga-PSMA-11 PET-CT scans available for undertaking this analysis. The lesions detected by 68 Ga-DOTATATE and 68 Ga-PSMA-11 were evaluated using Krenning's and miPSMA scores. In addition, quantitative comparisons of maximum standardized uptake values for 68 Ga-DOTATATE and 68 Ga-PSMA-11, as well as with 18 F-FDG, were conducted.

Results: Patient-wise analysis revealed positivity rates of 40.5% for 68 Ga-DOTATATE, 41.89% for 68 Ga-PSMA-11, and 75.67% for 18 F-FDG. Among the 74 patients, 14 (18.91%) were deemed eligible for 177 Lu-DOTATATE/PSMA-617 therapy based on Krenning's score of 3 and above both/either miPSMA score of 2 and above on 68 Ga-DOTATATE or 68 Ga-PSMA-11 PET-CT. Within this subgroup, seven out of 74 patients (9.45%) were eligible for 177 Lu-DOTATATE therapy, and nine out of 74 patients (12.16%) were eligible for 177 Lu-PSMA-targeted therapy. Four patients were eligible for both therapies.

Conclusion: Among thyroglobulin elevation and negative iodine scintigraphy patient's subgroup, 9.45% could qualify for 177 Lu-DOTATATE and 12.16% for 177 Lu-PSMA-617. Four were eligible for both therapies. Given the lack of effective therapies, this subset of patients warrants consideration for radionuclide therapy exploration.

Background: In this substudy of the Value of Gated-SPECT MPI for Ischemia- Guided PCI of non-culprit vessels in STEMI Patients with Multi vessel Disease after primary PCI trial after primary PCI we aim to assess if infarct size affects conventional measures of dyssynchrony at rest. Additionally, we explore if there is an independent correlation of stress-inducible ischemia with dyssynchrony at rest.

Methods: The 48 patients with imaging at randomization were analyzed. Gated-single-photon emission computed tomography (SPECT) MPI with vasodilator stress and technetium-99m-labeled tracers was performed. The phase histogram bandwidth (HBW), phase SD, and entropy were obtained with the QGS software. Correlation between dyssynchrony at rest and infarct size and inducible ischemia was performed using the Spearman test.

Results: According to normal database limits dyssynchrony parameters at rest were abnormal for men. In women only HBW was abnormal. Correlation between the summed rest score with dyssynchrony was significant only for entropy ( P  = 0.035). No correlation was observed for dyssynchrony and stress-induced ischemia.

Conclusion: Entropy, as a measure of dyssynchrony, has potential in the assessment of patients with STEMI and multivessel disease after primary PCI. Smaller residual myocardial scars in PCI-reperfused patients with STEMI may contribute to the lack of correlation between dyssynchrony at rest and infarct size and stress-induced ischemia, respectively.

Aim: This study aimed to evaluate the potential role of 18F-fluorodeoxyglucose PET/computed tomography (18F-FDG PET/CT) in providing a targeted approach for diagnosing the etiology of Pyrexia of Unknown Origin (PUO).

Methods: A total of 573 PUO patients were included in this ambispective study, with a mean age of 39.40 ± 4.6 years. Patients underwent FDG PET/CT scans using dedicated hybrid scanners. PET/CT data were interpreted by experienced nuclear medicine physicians. The study analyzed the guidance provided by FDG PET/CT for appropriate biopsy sites and assessed concordance between PET/CT findings and histopathological examination.

Results: Out of the 573 patients, a final diagnosis was reached for 219 patients, including malignancy, infectious causes, noninfectious inflammatory causes (NIID), and precancerous conditions. FDG PET/CT played a crucial role in guiding clinicians to appropriate biopsy sites, contributing to a higher diagnostic yield. Concordance between PET/CT findings and histopathological examination emphasized the noninvasive diagnostic potential of PET/CT in identifying underlying causes of PUO. Overall, FDG PET/CT contributed to guiding the appropriate site of biopsy or concordance of the first differential diagnosis with the final diagnosis in 50.05% of cases.

Conclusion: This study highlights the valuable role of FDG PET/CT in providing a targeted approach for diagnosing PUO, showcasing its potential in guiding clinicians towards appropriate biopsy sites and improving the diagnostic yield. The findings underscore the importance of integrating FDG PET/CT into the diagnostic pathway for PUO, ultimately enhancing patient management and outcomes. Further prospective studies are necessary to validate these results and refine the integration of FDG PET/CT in the diagnosis of PUO.

Objective: We aimed to compare different segmentation methods used to calculate prognostically valuable volumetric parameters, somatostatin receptor expressing tumor volume (SRETV), and total lesion somatostatin receptor expression (TLSRE), measured by 68 Ga-DOTATATE PET/CT and to find the optimal segmentation method to predict prognosis.

Patients and methods: Images of 34 patients diagnosed with gastroenteropancreatic neuroendocrine tumor (GEPNET) who underwent 68 Ga-DOTATATE PET/CT imaging were reanalyzed. Four different threshold-based methods (fixed relative threshold method, normal liver background threshold method, fixed absolute standardized uptake value (SUV) threshold method, and adaptive threshold method) were used to calculate SRETV and TLSRE values. SRETV of all lesions of a patient was summarized as whole body SRETV (WB-SRETV) and TLSRE of all lesions of a patient was computed as whole body TLSRE (WB-TLSRE).

Results: WB-SRETVs calculated with all segmentation methods were statistically significantly associated with progression-free survival except WB-SRETV at which was calculated using adaptive threshold method. The fixed relative threshold methods calculated by using 45% (WB-SRETV 45% ) and 60% (WB-SRETV 60% ) of the SUV value as threshold respectively, were found to have statistically significant highest prognostic value (C-index = 0.704, CI = 0.622-0.786, P  = 0.007). Among WB-TLSRE parameters, WB-TLSRE 35% , WB-TLSRE 40% , and WB-TLSRE 50% had the highest prognostic value (C-index = 0.689, CI = 0.604-0.774, P  = 0.008).

Conclusion: The fixed relative threshold method was found to be the most effective and easily applicable method to measure SRETV on pretreatment 68 Ga-DOTATATE PET/CT to predict prognosis in GEPNET patients. WB-SRETV 45% (cutoff value of 11.8 cm 3 ) and WB-SRETV 60% (cutoff value of 6.3 cm 3 ) were found to be the strongest predictors of prognosis in GEPNET patients.

Altered copper metabolism in cancer has been linked to increased intracellular copper uptake mediated by human copper transporter 1, with [64Cu]Cu2+ as a potential biomarker for cancer theranostics. [64Cu]CuCl2 PET-CT though explored in various malignancies, a lack of standardized protocol exists, particularly regarding fasting status before imaging. This analysis aimed to evaluate the requirement of fasting for [64Cu]CuCl2 PET-CT along with temporal changes in physiological organ uptake in delayed scans. A total of 26 patients of prostate carcinoma who underwent [64Cu]CuCl2 PET-CT imaging were divided into two groups: (1) nonfasting (n = 12) and (2) fasting (n = 14). The nonfasting group received an average dose of 350 MBq, while the fasting group received 300 MBq of [64Cu]CuCl2, and PET-CT images acquired approximately 60-90 min (1 h image) and 3-3.5 h (delayed image) after intravenous injection of the tracer. An experienced nuclear medicine physician evaluated the images for qualitative assessment between the groups. Multiple spherical regions of interest were placed at sites of physiological organ uptake of the tracer and over the diseased lesions to measure the mean SUVmax. No significant difference was observed in the qualitative assessment of the images between the two groups (except for a slight predilection towards more hepatic tracer retention observed in the fasting group), including in the delayed images. The liver demonstrated the highest tracer uptake in all patients, with a mean SUVmax of 21.5 in the fasting group and 19.7 in the nonfasting group, showing no significant difference (P = 0.32). The kidneys, intestines, and salivary glands also showed similar trends of tracer uptake in both groups. The study illustrated that the fasting or nonfasting status did not affect image quality or semiquantitative measurements significantly in physiological organs and diseased lesions in patients with carcinoma prostate.

Purpose: Detection of osseous metastases by imaging can be challenging in patients with invasive lobular breast cancer (ILC). ILC may demonstrate low metabolic rate due to lower tumor cell density, decreased proliferation rate, diffuse infiltration of surrounding tissue, and low level of GLUT-1 expression. The aim of this study is to assess the diagnostic accuracy of 18F-FDG PET/CT in identifying bone metastases in ILC patients.

Material and methods: Out of 52 individuals diagnosed with lobular breast cancer and underwent 18F-FDG PET/CT for evaluation of metastases, 21 patients were included in our study population after applying inclusion and exclusion criteria. The radiological and clinical follow-up of at least 6 months served as the reference standard comparator.

Results: Bone metastases were confirmed in six patients. 18F-FDG PET/CT was true positive in two and false negative in four patients. The sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of 18F-FDG PET/CT were 33.33, 93.33, 66.67, 77.78, and 76.19%, respectively (95% confidence interval). The tendency of ILC osseous metastases to be more sclerotic explains the low diagnostic accuracy of 18F-FDG PET/CT in detection of bone metastases, making it a less suited method of evaluation.

Conclusion: The results of the present study indicate that 18F-FDG PET/CT has a low diagnostic accuracy in detecting bone metastases in lobular breast cancer and, by inference, new functional modalities can be explored in these patients. The findings contribute valuable insights to optimize the integration of molecular imaging into the diagnostic algorithm for this specific breast cancer subtype.

Purpose: The purpose of this study was to evaluate and quantify the prevalence of increased uptake in SPECT/CT in symptomatic and asymptomatic foot and ankle joints in patients with osteoarthritis.

Methods: In 63 patients with osteoarthritis (OA), the painful symptomatic foot (SF) and asymptomatic contralateral foot (AF) were imaged with bone SPECT/CT. Presence, localization, and maximum standardized uptake value (SUVmax) of the active joints were assessed for SF and AF. CT OA grade (grade 1: mild, grade 2: moderate, grade 3: severe) and presence of five morphological features of OA (joint space narrowing, subchondral sclerosis, subchondral cysts, irregular joint margins, and osteophytes) were evaluated.

Results: In total 32 (51%) patients showed additional uptake in the AF, whereas 31 (49%) patients showed it only in the SF. SF showed more active joints than AF (106 vs. 43). CT OA grades positively correlated with SUVmax (Kendall's tau b = 0.62, P < 0.001). SUVmax values (per foot) in SF were higher in patients with uptake in bilateral feet (SF+, AF+) [median (IQR): 17.9 (10.7-23.3)] as compared with patients with active sites only in the SF (SF+, AF-) [10.4 (6.4-19.1); P < 0.001]. Number of active OA joints in SF was higher in patients with bilateral uptake (P = 0.017).

Conclusion: In conclusion, half of the patients exhibited increased uptake in the contralateral asymptomatic foot. SUVmax showed a significant correlation to CT osteoarthritis grade, in the symptomatic and asymptomatic foot. Future follow-up studies will provide further insights into the prognostic and therapeutic value of these findings.