Correlation of 18F-sodium fluoride uptake and radiodensity in extraosseous metastases of medullary thyroid carcinoma

ABSTRACT Objective: Although 18F-sodium fluoride (18F-NaF) uptake is frequently observed in extraosseous metastases of medullary thyroid carcinoma (MTC) with calcification, it can also occur in metastatic sites without visible calcium deposition, leading to the hypothesis that visually undetectable calcium accumulation may be responsible for this uptake. The aim of this study was to indirectly support this hypothesis by analyzing the correlation between the degree of 18F-NaF uptake and radiodensity in extraosseous MTC metastases, since calcium deposition can increase attenuation even when not visually detectable. Subjects and methods: Extraosseous metastatic lesions of 15 patients with MTC were evaluated using 18F-NaF positron-emission tomography (PET)/computed tomography (CT) and segmented by levels of standardized uptake value (SUV). The correlation between mean SUV and mean Hounsfield unit (HU) values was assessed for the entire group of segments and for two subgroups with different mean HU values. Results: Very high correlations were observed between mean SUV and mean HU values for both the entire group of segments and the subgroup with a mean HU value greater than 130 (p = 0.92 and p = 0.95, respectively; p < 0.01). High correlation (p = 0.71) was also observed in the subgroup with mean HU values ranging from 20 to 130 (p < 0.01). Conclusion: The findings of the present study suggest that there is an association between 18F-NaF uptake and calcium deposition in extraosseous metastases of MTC, supporting the hypothesis that visually undetectable calcium accumulation may be responsible for 18F-NaF uptake in regions without visible calcium deposition.

Progress in diagnosis and treatment of hepatic alveolar echinococcosis / 器官移植

Hepatic echinococcosis is a chronic parasitic disease, which is caused by the larvae of Echinococcus multilocularis. It has a high risk of disability and mortality, which is also known as "parasite cancer". In clinical practice, hepatic echinococcosis can be divided into hepatic alveolar echinococcosis and hepatic cystic echinococcosis. Hepatic echinococcosis is widely prevalent worldwide. It mainly occurs in the populations residing agricultural and pastoral areas in western China, posing significant threats to the quality of life of local residents. At present, surgery is the main treatment for hepatic echinococcosis in clinical settings. With rapid development of surgical diagnosis and treatment technology and deepening understanding of hepatic echinococcosis, diagnosis and treatment regimens have also been constantly improved. In this article, research progresses on the diagnosis and treatment of hepatic alveolar echinococcosis were reviewed, aiming to provide reference for clinicians, deliver early diagnosis and treatment, mitigate adverse effects of this disease upon patients and improve clinical prognosis.

Impacto del PET/CT en el diagnóstico de insulinoma / Impact of PET/CT in the Diagnosis of Insulinoma

Introducción: La tomografía de emisión de positrones es una técnica diagnóstica no invasiva que permite tomar imágenes del organismo que muestra el metabolismo de los órganos del cuerpo. Objetivo: Destacar el valor de la PET/CT en el diagnóstico imagenológico prequirúrgico del enfermo. Presentación de caso: Se presentó un paciente masculino de 39 años sin antecedentes de importancia, con un cuadro de hipoglucemias severas de 5 años de evolución, a pesar de los múltiples estudios imagenológicos se incluyó la ecoendoscopía digestiva, lo que no fue posible evidenciar la lesión tumoral. Se le realiza PET/CT cuyo resultado fue crucial para localizar el tumor, se le dio al paciente la oportunidad de un tratamiento quirúrgico y la demostración anatomopatológica de insulinoma. Conclusiones: Los insulinomas son tumores pancreáticos poco frecuentes que provocan hiperinsulinismo endógeno y son difíciles de visualizar debido a su tamaño por las técnicas de imágenes convencionales, por lo que el PET/CT es un estudio bastante efectivo para localizar la lesión tumoral, y así realizar un procedimiento quirúrgico(AU)

Introduction: Positron emission tomography is a non-invasive diagnostic technique, allowing images of the body to be taken that show the metabolism of the body's organs. Objective: To highlight the value of PET/CT in the pre-surgical imaging diagnosis of the patient. Case presentation: We report the case of a 39-year-old male patient with no significant medical history, but a 5-year history of severe hypoglycemia. Despite multiple imaging studies, digestive ultrasound endoscopy was included, which was not possible to demonstrate the tumor lesion. PET/CT was performed, the result of which was crucial in locating the tumor. The patient was given the opportunity for surgical treatment and the pathological demonstration of insulinoma. Conclusions: Insulinomas are rare pancreatic tumors that cause endogenous hyperinsulinism and are difficult to visualize due to their size using conventional imaging techniques, therefore PET/CT is a fairly effective study to locate the tumor lesion, and thus perform a surgical procedure(AU)

Prognostic role of metabolic 18F?FDG PET/CT parameters and hematological prognostic indicators in patients with colorectal cancer

Background: The aim of this study is to evaluate the role of preoperative 18F?fluorodeoxyglucose (FDG) positron emission tomography朿omputed tomography (PET/CT) parameters, including maximum standardized uptake value (SUVmax), metabolic tumor volume (MTV), and total lesion glycolysis (TLG), hematologic prognostic indicators in patients with colorectal cancer (CRC) in terms of predicting prognosis. Methods: One hundred and one patients who had undergone 18F?FDG PET/CT for initial staging were evaluated retrospectively. Patient data including pathologic stage at presentation, histology, tumor location, and overall survival (OS) were analyzed. Neutrophil to lymphocyte ratio (NLR), platelet to lymphocyte ratio (PLR), serum carcinoembryonic antigen (CEA) (ng/mL), CA?125 (cancer antigen 125) (U/mL), and CA19?9 (U/mL) levels, which were obtained within 2 weeks of the PET/CT examination, were used for hematological data. Results: The TNM Classification of Malignant Tumors stage and PET/CT parameters, including SUVmax, MTV, and TLG, were found to be correlated with survival rate in univariate analysis (P < 0.05). All hematological markers excluding PLR were also significantly associated with survival time. Receiver operating characteristics (ROC) analysis revealed that the optimal SUVmax cutoff value for predicting survival time in patients with CRC was >17.9 (Area under curve (AUC) = 0.625; P < 0.05). The calculated sensitivity and specificity values for this cutoff were 60% and 65.7%, respectively. To predict the survival time in these patients, the optimal MTV cutoff value was >34.29 (AUC = 0.775; P < 0.001; sensitivity = 85%; specificity = 62.3%). The optimal TLG cutoff value for predicting survival time was >270.4 (AUC = 0.790; P < 0.001; sensitivity = 77.5%; specificity = 68.9%). Conclusions: FDG PET/CT metabolical parameters are useful for predicting the prognosis in patients with CRC. High preoperative NLR and high tumor markers were also shown to be negative independent prognostic factors in these patients

Evaluation of 18FDG PET-CT-positive mediastinal-hilar lymph nodes in extrathoracic malignancies by EBUS-TBNA; correlation of SUVmax, and short-axis diameter with the final diagnosis

Introduction: Intrathoracic lymph node metastasis from extrathoracic neoplasms are rare. Primary malignancies that metastasize to mediastinal-hilar lymph nodes are head and neck , carcinoma breast ,and genitourinary. Endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA)/endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) is currently the preferred modality for mediastinal lymph node sampling. Methods: Fifty seven patients with extrathoracic malignancies with maximum standardized uptake value (SUVmax) of mediastinal-hilar lymph nodes greater than or equal to 2.5 were taken up for EBUS-TBNA. The histo-cytopathological results obtained from EBUS-TBNA were compared with SUVmax value and short-axis diameter of a lymph node as noted on EBUS. Results: Out of 74 sampled nodes, 49 (66.2%) were benign and 25 (33.8%) were malignant. The SUVmax range of benign nodes was 2.8� as compared to 3� of malignant nodes. The size range of malignant and benign nodes were 8� mm and 8� mm, respectively. The mean size of abnormal nodes (metastatic + granulomatous) was 17.5 (8� mm) and the mean SUVmax was 9.1 (3.4�), and it was a statistically significant difference when compared to reactive (normal) nodes. At SUVmax cut-off 7.5, sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV) were 78.5%, 81.2%, 84.6%, and 74.2%, respectively for detecting abnormal nodes. At 13 mm size cut-off, sensitivity, specificity, PPV, NPV were 75.5%, 65%, 75%, and 72%, respectively, for detecting abnormal nodes. Conclusion: The majority of mediastinal-hilar nodes with increased metabolic activity are benign in nature. Size and SUVmax are poor predictors of metastasis in tuberculosis endemic region. There should be a restrictive attitude toward invasive diagnostic testing for mediastinal-hilar nodes in extrathoracic malignancies.

The role of MRI and 18F-FDG PET/CT with respect to evaluation of pathological response in the rectal cancer patients after neoadjuvant chemoradiotherapy

Background: We aimed to evaluate the role of magnetic resonance imaging (MRI) and 18F-fluorodeoxyglucose (FDG) positron emission tomography朿omputed tomography (PET-CT) in determining the correct stage and predicting the pathological response. Methods: Seventy one patients with pathologic proven rectal adenocarcinoma, clinical stage IIA-IVA, and neoadjuvant chemoradiotherapy (CRT) were evaluated retrospectively. Radiotherapy was delivered 45� Gy in 25 fractions with concomitant oral capecitabine. Pelvic MRI, colonoscopy, and 18F-FDG PET-CT were performed before the neoadjuvant treatment (NAT). After NAT, MRI and PET-CT were performed for re-evaluation. Results: The median follow-up time was 25 months (range: 3� months). Of the 71 patients who underwent NAT, 57 patients underwent surgery. Downstaging was recorded in 48 (84.2%) of 57 patients who underwent surgery. There was no statistically significant difference between both MRI and PET-CT with pathology results in terms of response evaluation. As a result of the comparison of MRI and PET-CT with pathological results; sensitivity and specificity were 91.6% (44/48) and 22.2% (2/9) for MRI, and 100% (47/47) and 12.5% (1/8) for PET-CT, respectively. Conclusion: PET-CT and MRI are effective in predicting response to NAT and predictive for the pathological response. A more accurate response can be judged when both PET-CT and MRI are executed together in restaging after NAT

Consenso colombo-peruano de cáncer de próstata. Lima, Perú, 14 y 15 de abril del 2023 / Colombian-Peruvian Consensus on Prostate Cancer. April 14 and 15, 2023, Lima, Peru

Entre el 14 y 15 de abril del 2023 se realizó la reunión académica organizada por la Sociedad Colombiana de Urología y la Sociedad Peruana de Urología en Lima (Perú), donde los panelistas expertos en cáncer de próstata en el área de urología oncológica, urología funcional, oncología clínica, radioterapia oncológica y medicina nuclear debatieron sobre la evidencia actual en los diferentes escenarios de la enfermedad, logrando el primer Consenso Colombo-Peruano de Cáncer de Próstata.

Between April 14 and 15, 2023, the academic meeting organized by the Colombian Society of Urology and the Peruvian Society of Urology was held in Lima (Peru), where expert panelists in prostate cancer in the area of oncological urology, functional urology, clinical oncology, oncological radiotherapy and nuclear medicine discussed the current evidence in the different scenarios of the disease, achieving the first Colombo-Peruvian Consensus on Prostate Cancer.

Arteritis de Takayasu como hallazgo incidental en un paciente con enfermedad celiaca: la importancia de la tomografía computarizada por emisión de positrones / Takayasu's arteritis as an incidental finding in a patient with celiac disease: the importance of positron emission computed tomography

Resumen Introducción: La arteritis de Takayasu es una vasculitis de grandes vasos que afecta a las arterias elásticas de gran calibre, fundamentalmente la aorta y sus ramas principales. Ocurre frecuentemente en mujeres entre los 20-30 años, por lo que es muy infrecuente en la edad pediátrica. Caso clínico: Se presenta el caso de una paciente de 15 años en seguimiento desde los 9 años por enfermedad celiaca. A los 13 años se detectó anemia de trastornos crónicos, elevación de proteína C reactiva y velocidad de sedimentación globular. La paciente permaneció en todo momento asintomática. Tras descartar otros procesos, se solicitó tomografía computarizada por emisión de positrones (PET-TC), donde se detectaron lesiones compatibles con vasculitis de grandes vasos. La valoración por Cardiología evidenció un aneurisma en coronaria derecha. Se realizó angio-TC, que sugirió arteritis de Takayasu tipo III. Conclusiones: Es frecuente un retraso en el diagnóstico de la arteritis de Takayasu en los pacientes pediátricos. En este caso se encontraron lesiones de la fase II sin la presencia de síntomas correspondientes a la fase I. El PET-TC permitió el diagnóstico de vasculitis, clave para el diagnóstico de la paciente.

Abstract Background: Takayasu arteritis is a large-vessel vasculitis which affects large-caliber elastic arteries, primarily the aorta and its main branches. It mainly affects women between 20-30 years, so it is rare in children. Case report: We describe the case of a 15-year-old female who was followed up since she was 9 years old due to celiac disease. At the age of 13, anaemia of chronic disorders associated to elevated C-reactive protein and erythrocyte sedimentation were detected. The patient remained asymptomatic. After excluding other diseases, we requested a positron emission computed tomography (PET-CT); lesions compatible with large-vessel vasculitis were detected. Cardiology evaluation showed an aneurysm in the right coronary artery. Angio-CT suggested Takayasu type III arteritis. Conclusions: The delay in the diagnosis of Takayasu arteritis in pediatric patients is quite common. In this case, we have found phase II lesions, with no previous phase I symptoms. However, PET-CT allowed the diagnosis of vasculitis, key to the diagnosis of the patient.

Evaluation of patients via colonoscopy who underwent positron emission tomography/computerized tomography due to colon involvement

SUMMARY OBJECTIVE: Fluorodeoxyglucose is not a tumor-specific agent and it can also be involved in benign conditions, which may cause diagnostic confusion. This research aims to elucidate the colonoscopic findings of patients who underwent colonoscopy due to colon involvement in positron emission tomography/computerized tomography. METHODS: A total of 71 patients who underwent colonoscopy due to colonic involvement in positron emission tomography/computerized tomography at SBU Keçiören Training and Research Hospital Gastroenterology Clinic Endoscopy Unit have been analyzed retrospectively. Demographic characteristics of the patients, areas of involvement in positron emission tomography/computerized tomography, and severity have been obtained from the hospital database. RESULTS: The gastrointestinal involvement area of 22.5% (n=16) of the patients was ascending colon, 15.5% (n=11) was sigmoid, 15.5% (n=11) was rectum, 12.7% (n=9) was stomach, 11.3% (n=8) was transverse colon, 8.5% (n=6) was anal canal, 5.6% (n=4) was esophagus, and 5.6% (n=4) was descending colon. The endoscopic findings of 19.7% (n=14) patients were normal, whereas 29.6% (n=21) had polyps, 9.9% (n=7) had cancer, 2.8% (n=2) had an ulcer, 15.5% (n=11) had gastritis, 14.1% (n=10) had hemorrhoids, and 7% (n=5) had colitis. CONCLUSION: Fluorodeoxyglucose-positron emission tomography can detect unexpected distant metastases with high sensitivity because it allows whole-body imaging. Curative resection significantly contributes to the choice of treatment modality in the pre-operative period of colorectal cancer patients with planned surgery.

Effect of different input functions of whole-body dynamic 18F-FDG PET/CT imaging reconstruction on quantitative parameters of lung cancer / 中华放射医学与防护杂志

Objective:To investigate the effect of using two different input functions to reconstruct 18F-FDG PET/CT Patlak multi-parameter images on the quantitative parameters of lung cancer lesions. Methods:The original whole-body dynamic 18F-FDG PET/CT scan data of lung cancer patients in the Department of Nuclear Medicine, First Affiliated Hospital of Anhui Medical University were retrospectively analyzed. The total scan time was 75 min. Two input functions were used for Patlak multi-parameter reconstruction: ① Image-derived input function(IDIF)using the Time-activity curve(TAC)of descending aorta from 0 min to 75 min. ② Population-based input function (PBIF) developed by Yale University. Metabolic rate of FDG (MR FDG) and Distribution volume (DV) images were obtained by Patlak multi-parameter analysis software using the above input functions. The region of interest (ROI) method was used to delineate the lesions to obtain multi-parameter quantitative information, including the max, peak and mean value of MR FDG and DV. Paired t-test was used for statistical analysis. Results:The original data of 27 lung cancer patients who received whole-body dynamic 18F-FDG PET/CT imaging were reconstructed by Patlak with two different input functions. The max, peak and mean values of MR FDG-IDIF and MR FDG-PBIF in lung cancer lesions were as follows: (0.26 ± 0.15), (0.19 ± 0.12), (0.14 ± 0.08)μmol·min -1·ml -1 and (0.26 ± 0.15), ( 0.20 ± 0.13), (0.15 ± 0.09)μmol·min -1·ml -1, with no statistically significant difference between two functions( P > 0.05). The max, peak and mean values of DV IDIF and DV PBIF were (165.56 ± 99.89)%, (117.66 ± 72.24)%, (62.16 ± 33.65)% and(170.04 ± 103.93)%, (121.91 ± 73.71)%, (65.05 ± 37.17)%, with no statistically significant difference between two functions ( P > 0.05). Conclusions:The population-based input function may be an alternative for patients who could not lie supine for long time during whole-body dynamic 18F-FDG PET/CT Patlak multi-parameter imaging.

Adjunctive role of dual time point imaging in evaluating bone lesions with increased 18F-PSMA-1007 uptake

Background@#Non-specific focal uptake in the skeleton is a diagnostic pitfall on 18F-PSMA-1007 PET/CT, but adjunctive measures to aid interpretation of these lesions are currently lacking. We present two cases where dual time point imaging provided additional information. @*Case Presentation@#The first patient had a PI-RADS 3 lesion on MRI. No PSMA-avid abnormality was seen on PET, save for focal uptake in the right pubis with no anatomic correlate. Additional imaging showed a decrease in lesion SUV, and this was interpreted as benign. Another patient, diagnosed with prostate cancer, had multiple PSMA-avid pelvic foci. Two suspiciously malignant bone lesions had increasing SUV trend after dual time point imaging despite only faint sclerosis on CT. In contrast, one faint PSMA-avid lesion with no anatomic abnormality was read as benign after a decrease in SUV. A decrease in lesion SUV may point to a benign etiology, while an increase would heighten suspicion for malignancy. One possible molecular explanation is that a true PSMA-overexpressing lesion would bind to the tracer for a longer period than a false positive.@*Conclusion@#Dual time point imaging provides additional information that may be useful in the interpretation of non-specificskeletal lesions with increased 18F-PSMA-1007 uptake.

Relationship between myocardial viability and early application of intra-aortic balloon pump after coronary artery bypass grafting / 中国胸心血管外科临床杂志

@#Objective    To explore the relationship between myocardial viability in patients with coronary artery disease who underwent elective coronary artery bypass grafting (CABG) and early application of intra-aortic balloon pump (IABP) after coronary revascularization, and to provide relevant clinical reference for the pre-implantation of 16G single-lumen catheter in the femoral artery of high-risk patients to facilitate the addition of IABP after operation. Methods    This retrospective study included 521 patients (414 males and 107 females, aged 62.50±8.82 years) who underwent positron emission tomography (PET)-computed tomography (CT) perfusion-metabolism imaging prior to CABG surgery in our institution from December 2015 to August 2020. The myocardial viability information and left ventricular functional parameters were measured, including the proportion of non-viable myocardium (perfusion-metabolic imaging match), hibernating myocardium (perfusion-metabolic imaging mismatch) and dysfunctional myocardium (non-viable+viable myocardium), left ventricular ejection fraction, left ventricular end-diastolic volume and left ventricular end-systolic volume (LVESV). The patients were divided into an IABP group and a non-IABP group  according to whether they received IABP treatment after revascularization. The clinical data were reviewed and compared to explore significant impact factors between the two groups. And the multivariate logistic regression analysis was performed to investigate the correlation between preoperative myocardial viability and early use of IABP after CABG. Results    In multivariate logistic regression analysis, the amount of non-viable, dysfunctional myocardium and LVESV value were identified as the independent predictors for the probability of IABP use in the initial postoperative period. Receiver operating characteristic analysis showed that 9.5% non-viable myocardium, 19.5% dysfunctional myocardium, and LVESV of 114.5 mL were the optimal cutoff for predicting early IABP implantation during CABG. Conclusion    The myocardial survival status displayed by preoperative PET-CT myocardial perfusion-metabolism imaging can predict the possibility of applying IABP in CABG perioperative period. In addition to routine pre-anesthesia assessment, anesthesiologists can conduct risk stratification assessment for patients with CABG according to the results of preoperative myocardial viability imaging, which is of great significance to ensure the perioperative safety of high-risk patients with CABG.

18F-FDG PET/CT Prognostic Role in Diffuse Large B-cell Lymphoma Following Chemotherapy / 中山大学学报(医学科学版)

ObjectiveTo assess the prognostic value of 18F-FDG PET/CT parameters for predicting therapeutic response in diffuse large B-cell lymphoma （DLBCL）. MethodsWe retrospectively analyzed the clinical data and 18F-FDG PET/CT radiomics features of 81 DLBCL patients enrolled between June 2015 and October 2020. Multivariate logistic regression analysis was used to identify the predictive factors for therapeutic response of DLBCL， based on which a predictive model was developed accordingly. The performance of the model was evaluated by receiver operating characteristic （ROC） curves and calibration plots. ResultsDuring the two years after first chemotherapy， 23 patients （28.3%） developed relapse and 58 patients （71.7%） had progression-free survival （PFS）. The analysis for the predictive capability of the binary logistic regression model incorporating the PET/CT features revealed that the imaging features of 18F-FDG PET/CT after chemotherapy were independent prognostic factors for PFS. Among them， SUVTHR-mean2 was the most important factor for predicting therapeutic response in DLBCL patients after chemotherapy， with a cutoff value of 2.00 （AUC=0.81）. Conclusions18F-FDG PET/CT showed a valuable prognostic performance for PFS in DLBCL patients after chemotherapy， with the imaging feature after chemotherapy SUVTLR-mean2 being the optimal independent predictor. Our predictive model of imaging features might have an important prognostic value in assessing the risk of disease progression， guiding the treatment and follow-up protocol， improving therapeutic efficiency and cutting down the medical cost.

How much exposure dose does a patient receive in PET/CT examination? / 中国辐射卫生

@#Positron emission tomography/computed tomography (PET/CT) scanner is an irreplaceable instrument in clinical diagnosis. The exposure dose that a patient receives is the sum of the doses caused by PET and CT examination. This study discussed the exposure dose level that a patient received during PET/CT examination according to the research data. Like other radiological diagnostic methods, PET/CT examination brings benefits outweighing its radiation risk. It is not advisable to exaggerate or ignore the exposure dose. The patient’s exposure dose caused by PET/CT examination should be controlled as much as possible under the premise of meeting clinical needs.

Progress in application of positron emission tomography/computed tomography (PET/CT) imaging in tumor screening / 中国辐射卫生

@#Worldwide, the incidence of cancer is greatest in China. Tumor screening is effective to achieve early diagnosis, improve prognosis, increase the quality of life, and reduce mortality among cancer patients. Positron emission tomography/computed tomography (PET/CT) imaging provides metabolic data to support initial staging, treatment planning, and response evaluation in tumor screening, as well as tumor follow-up. The progressive integration of PET/CT imaging in radiotherapy has its basic principle in the biological heterogeneity of inter- and intra-tumor malignant lesions, and the radiation dose is required to be adjusted to achieve effective local tumor control among cancer patients. In addition, PET/CT imaging provides data on the biological features of tumor lesions, such as metabolism, hypoxia, and proliferation, which is useful to identify radiation-resistant regions and optimize treatment plans. These data are effective to reduce the uncertainty and variability in the anatomic description of tumor sites. This review summarizes the application of PET/CT imaging in common tumors.

Ultrasmall, elementary and highly translational nanoparticle X-ray contrast media from amphiphilic iodinated statistical copolymers

To expand the single-dose duration over which noninvasive clinical and preclinical cancer imaging can be conducted with high sensitivity, and well-defined spatial and temporal resolutions, a facile strategy to prepare ultrasmall nanoparticulate X-ray contrast media (nano-XRCM) as dual-modality imaging agents for positron emission tomography (PET) and computed tomography (CT) has been established. Synthesized from controlled copolymerization of triiodobenzoyl ethyl acrylate and oligo(ethylene oxide) acrylate monomers, the amphiphilic statistical iodocopolymers (ICPs) could directly dissolve in water to afford thermodynamically stable solutions with high aqueous iodine concentrations (>140 mg iodine/mL water) and comparable viscosities to conventional small molecule XRCM. The formation of ultrasmall iodinated nanoparticles with hydrodynamic diameters of ca. 10 nm in water was confirmed by dynamic and static light scattering techniques. In a breast cancer mouse model, in vivo biodistribution studies revealed that the 64Cu-chelator-functionalized iodinated nano-XRCM exhibited extended blood residency and higher tumor accumulation compared to typical small molecule imaging agents. PET/CT imaging of tumor over 3 days showed good correlation between PET and CT signals, while CT imaging allowed continuous observation of tumor retention even after 10 days post-injection, enabling longitudinal monitoring of tumor retention for imaging or potentially therapeutic effect after a single administration of nano-XRCM.

Research hotspots of prostate cancer at the international conferences on urology in 2022 / 浙江大学学报·医学版

The American Urological Association (AUA), European Association of Urology (EUA) and International Urological Society (SIU) annual meetings were held in 2022. Studies on prostate cancer reported in the meetings mainly focus on the advances of diagnostic biomarkers (such as α-2, 3-1inked sialylation of terminal N-glycan on free PSA density, SelectMDx) and imaging techniques [such as multiparametric magnetic resonance imaging, prostate specific membrane antigen(PSMA)-PET/CT], the new method for prostate biopsy, the new treatments of prostate cancer including [177Lu] Ludotadipep and DROP-IN PSMA probe, and the prognosis assessment of prostate cancer (such as AR-V7). This article provides an overview on the research hotspots of three international academic meetings.

Causes of False-Positive Results in 68Ga-Labeled Fibroblast Activation Protein Inhibitor PET/CT Imaging / 中国医学科学院学报

Objective To investigate the causes of false-positive results in the 68Ga-labeled fibroblast activation protein inhibitor (68Ga-FAPI-04) PET/CT imaging. Methods The imaging data of 547 patients undergoing 68Ga-FAPI-04 PET/CT examination in the Department of Nuclear Medicine of the Affiliated Hospital of Southwest Medical University from September 2020 to May 2021 were retrospectively collected.Two experienced nuclear medicine diagnostic physicians analyzed the clinical data,relevant imaging examinations,laboratory examinations,pathological results and follow-up results of the patients with false-positive results. Results The 68Ga-FAPI-04 PET/CT imaging of 547 patients showed false-positive results in 99 (18.1%) patients,including 56 males and 43 females.The postoperative pathological examination confirmed false-positive results in 13 patients,including 1 patient of thyroiditis,2 patients of pulmonary tuberculosis,1 patient of bone tuberculosis,2 patients of pulmonary inflammatory pseudotumor,1 patient of pulmonary sarcoidosis,1 patient of pulmonary benign fibroma,1 patient of organic pneumonia,2 patients of renal angiomyolipoma,1 patient of mass pancreatitis,and 1 patient of pancreatic mucinous cystadenoma.The medical history,relevant imaging examination,and long-term follow-up confirmed false-positive results in 86 patients.Specifically,the false-positive uptake in the neck,chest,abdomen,bone joint,and skin occurred in 8 (9.3%),13 (15.1%),5 (5.8%),57 (66.3%),and 3 (3.5%) patients,respectively.Inflammation-related uptake appeared in 83 (83.8%) patients with false-positive imaging results,of which arthritis (23 patients) and osteophyte (29 patients) were the most common.Sixteen (16.2%) patients showed the false-positive uptake related to fibroblasts. Conclusion 68Ga-FAPI-04 PET/CT imaging will show non-malignant tumor false-positive results,which are mainly associated with inflammation and fibroblasts.

Diagnostic Efficacy of 18F-FDG PET/CT in Detecting Bone Marrow Infiltration in Patients with Newly Diagnosed Diffuse Large B-Cell Lymphoma / 生物医学与环境科学（英文）

OBJECTIVE@#Diffuse large B-cell lymphoma (DLBCL) is often associated with bone marrow infiltration, and 2-deoxy-2-(18F) fluorodeoxyglucose positron emission tomography/computed tomography ( 18F-FDG PET/CT) has potential diagnostic significance for bone marrow infiltration in DLBCL.@*METHODS@#A total of 102 patients diagnosed with DLBCL between September 2019 and August 2022 were included. Bone marrow biopsy and 18F-FDG PET/CT examinations were performed at the time of initial diagnosis. Kappa tests were used to evaluate the agreement of 18F-FDG PET/CT with the gold standard, and the imaging features of DLBCL bone marrow infiltration on PET/CT were described.@*RESULTS@#The total detection rate of bone marrow infiltration was not significantly different between PET/CT and primary bone marrow biopsy ( P = 0.302) or between the two bone marrow biopsies ( P = 0.826). The sensitivity, specificity, and Youden index of PET/CT for the diagnosis of DLBCL bone marrow infiltration were 0.923 (95% CI, 0.759-0.979), 0.934 (95% CI, 0.855-0.972), and 0.857, respectively.@*CONCLUSION@#18F-FDG PET/CT has a comparable efficiency in the diagnosis of DLBCL bone marrow infiltration. PET/CT-guided bone marrow biopsy can reduce the misdiagnosis of DLBCL bone marrow infiltration.

Diagnostic Efficacy of 68Ga-Labeled Prostate-Specific Membrane Antigen and 18F-Labeled Sodium Fluoride PET/CT in Prostate Cancer With Bone Metastasis / 中国医学科学院学报

Objective To compare the efficiency of 68Ga-labeled prostate-specific membrane antigen (68Ga-PSMA-11) and 18F-labeled sodium fluoride (18F-NaF) PET/CT in the diagnosis of bone metastasis in the patients with prostate cancer.Methods The prostate cancer patients suspected of bone metastasis who underwent 68Ga-PSMA-11 PET/CT and 18F-NaF PET/CT from January 2018 to January 2021 were included in this study.The number of lesions,maximum standardized uptake value (SUVmax),and tumor-to-background (T/B) ratio were compared between the two methods.Results 18F-NaF PET/CT detected more metastases than 68Ga-PSMA-11 PET/CT (310 vs.264,P<0.001).The median SUVmax[23.2 (16.4,33.4) vs.4.1 (2.5,5.6)] and median T/B ratio[7.0 (4.9,9.9) vs.6.7 (3.7,9.6)] of 18F-NaF PET/CT were higher than those of 68Ga-PSMA-11 PET/CT (all P<0.001).With the number of lesions as the indicator,the sensitivity,specificity,accuracy,positive predictive value,and negative predictive value of 18F-NaF PET/CT were 100.0%,92.0%,92.0%,98.7%,and 100.0% respectively,and those of 68Ga-PSMA-11 PET/CT were 85.2%,94.0%,79.2%,98.9%,and 50.5%,respectively.Conclusion 18F-NaF PET/CT is superior to 68Ga-PSMA-11 PET/CT in the detection of bone metastases of prostate cancer.