Low-dose-rate induces more severe cognitive impairment than high-dose-rate in rats exposed to chronic low-dose γ-radiation.

Background: Owing to the long penetration depth of gamma (γ)-rays, individuals working in ionizing radiation environments are chronically exposed to low-dose γ-radiation, resulting in cognitive changes. Dose rate significantly affects radiation-induced biological effects; however, its role in chronic low-dose γ-irradiation-induced cognitive impairment remains unclear. We aimed to investigate whether chronic low-dose γ-irradiation at low-dose-rate (LDR) could induce cognitive impairment and to compare the cognitive alteration caused by chronic low-dose γ-irradiation at LDR and high-dose-rate (HDR). Methods: The rats were exposed to γ-irradiation at a LDR of 6 mGy/h and a HDR of 20 mGy/h for 30 days (5 h/day). Functional imaging was performed to assess the brain inflammation and blood-brain barrier (BBB) destruction of rats. Histological and immunofluorescence analyses were used to reveal the neuron damage and the activation of microglia and astrocytes in the hippocampus. RNA sequencing was conducted to investigate changes in gene expression in hippocampus. Results: The rats in the LDR group exhibited more persistent cognitive impairment than those in the HDR group. Furthermore, irradiated rats showed brain inflammation and a compromised BBB. Histologically, the number of hippocampal neurons were comparable in the LDR group but were markedly decreased in the HDR. Additionally, activated M1-like microglia and A1-like astrocytes were observed in the hippocampus of rats in the LDR group; however, only M1-like microglia were activated in the HDR group. Mechanistically, the PI3K-Akt signaling pathway contributed to the different cognitive function change between the LDR group and HDR group. Conclusion: Compared with chronic low-dose γ-irradiation at HDR, LDR induced more severe cognitive impairment which might involve PI3K/Akt signaling pathway.

Diffuse Intense 18 F-PSMA-1007 Uptake of the Breasts in a Woman With TFE3-Rearranged Renal Cell Carcinoma.

ABSTRACT: A 23-year-old woman presenting with gross hematuria was found to have a left renal mass suspicious for renal cell carcinoma on abdominal contrast-enhanced CT. An 18 F-PSMA-1007 PET/CT scan was performed for evaluating the renal mass. 18 F-PSMA-1007 PET/CT showed focal activity of the renal mass, which was a transcription factor E3-rearranged renal cell carcinoma proved after nephrectomy. Surprisingly, diffuse heterogeneous intense activity of the bilateral breasts and moderate activity of the right accessory breast was observed. There was no morphological abnormality of the bilateral breasts and right accessory breast on CT images, indicating physiological PSMA uptake.

One-day examination of triple nuclear medicine imaging and application in evaluating transarterial embolization.

A diagnosis based on multiple nuclear medicine imaging (NMI) was more comprehensive in approaching the nature of pathological changes. In this research, a method to realize triple NMIs within one day was developed based on the reasonable arrangements of 68Ga-RGD PET/CT specialized on neovascularization, 99mTc-HL-91 SPECT/CT specialized on hypoxia and 18F-FDG PET/CT specialized on tumor metabolism. Feasibility was verified in evaluating the therapeutic effects of transarterial embolization (TAE) performed on rabbit models with VX2 tumor. Radiation dosimetry was carried out to record the radiation exposure from multiple injections of radiopharmaceuticals. In results, the one-day examination of triple NMIs manifested the diversity of the postoperative histological changes, including the local neovascularization induced by embolization, hypoxic state of embolized tissues, and suppression of tumor metabolism. More importantly, radiation dosage from radiopharmaceuticals was limited below 5.70 ± 0.90 mSv. In conclusion, the strong timeliness and complementarity of one-day examination of triple nuclear medicine imaging made it clinically operative and worthy of popularizing. There was flexibility in combining distinct NMIs according to the clinical demands, so as to provide comprehensive information for diagnosis.

Intense FDG Uptake in Well-Differentiated Inflammatory Liposarcoma of the Retroperitoneum.

ABSTRACT: Inflammatory variant of well-differentiated liposarcoma is a rare subtype of liposarcoma, and its imaging features have been rarely reported. We describe FDG PET/CT findings in a case of well-differentiated inflammatory liposarcoma. The tumor showed no detectable fat and intense FDG uptake and caused diffuse FDG uptake of the bone marrow due to paraneoplastic leukemoid reaction. Microscopically, there were extensive inflammatory infiltrates in the tumor, which may contribute to the intense FDG uptake. This case indicates that although well-differentiated liposarcoma usually shows low-grade FDG uptake, inflammatory variant of well-differentiated liposarcoma can show intense FDG uptake mimicking high-grade liposarcoma.

Preoperative nomogram for predicting spread through air spaces in clinical-stage IA non-small cell lung cancer using 18F-fluorodeoxyglucose positron emission tomography/computed tomography.

PURPOSE: This study aims to assess the predictive value of 18F-fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDG PET/CT) radiological features and the maximum standardized uptake value (SUVmax) in determining the presence of spread through air spaces (STAS) in clinical-stage IA non-small cell lung cancer (NSCLC). METHODS: A retrospective analysis was conducted on 180 cases of NSCLC with postoperative pathological assessment of STAS status, spanning from September 2019 to September 2023. Of these, 116 cases from hospital one comprised the training set, while 64 cases from hospital two formed the testing set. The clinical information, tumor SUVmax, and 13 related CT features were analyzed. Subgroup analysis was carried out based on tumor density type. In the training set, univariable and multivariable logistic regression analyses were employed to identify the most significant variables. A multivariable logistic regression model was constructed and the corresponding nomogram was developed to predict STAS in NSCLC, and its diagnostic efficacy was evaluated in the testing set. RESULTS: SUVmax, consolidation-to-tumor ratio (CTR), and lobulation sign emerged as the best combination of variables for predicting STAS in NSCLC. Among these, SUVmax and CTR were identified as independent predictors for STAS prediction. The constructed prediction model demonstrated area under the curve (AUC) values of 0.796 and 0.821 in the training and testing sets, respectively. Subgroup analysis revealed a 2.69 times higher STAS-positive rate in solid nodules compared to part-solid nodules. SUVmax was an independent predictor for predicting STAS in solid nodular NSCLC, while CTR and an emphysema background were independent predictors for STAS in part-solid nodular NSCLC. CONCLUSION: Our nomogram based on preoperative 18F-FDG PET/CT radiological features and SUVmax effectively predicts STAS status in clinical-stage IA NSCLC. Furthermore, our study highlights that metabolic parameters and CT variables associated with STAS differ between solid and part-solid nodular NSCLC.

Intense PSMA Uptake in Solitary Fibrous Tumor of the Seminal Vesicle.

ABSTRACT: Solitary fibrous tumor arising from the seminal vesicle is very rare. We describe 18 F-PSMA-1007 PET/CT findings in a case of prostate adenocarcinoma with a solitary fibrous tumor of the left seminal vesicle. The solitary fibrous tumor showed intense 18 F-PSMA-1007 uptake mimicking metastatic prostate adenocarcinoma. This case indicates that solitary fibrous tumor may cause false-positive result when using PSMA PET in staging of prostate cancer.

68 Ga-FAPI-04 PET/CT for the Evaluation of Cholangiocarcinoma : Comparison With 18 F-FDG PET/CT and Abdominal 68 Ga-FAPI-04 PET/MR.

PURPOSE: In this study, we evaluated and compared the diagnostic performances of 68 Ga-FAPI-04 PET/CT and 18 F-FDG PET/CT for primary and metastatic cholangiocarcinoma (CCA) lesions. We also investigated the performance of PET/MR for visualizing and characterizing CCA and liver metastasis lesions. PATIENTS AND METHODS: Forty-four patients with suspected CCA were recruited and underwent 68 Ga-FAPI-04 and 18 F-FDG PET/CT within 1 week, including 30 patients who underwent simultaneous abdominal 68 Ga-FAPI-04 PET/MR scanning. The findings were confirmed by histopathology or radiographic follow-up. RESULTS: Compared with 18 F-FDG PET/CT, 68 Ga-FAPI-04 PET/CT showed higher sensitivity (94.3% vs 88.6%) and the same accuracy (86.4% vs 86.4%) in evaluating primary tumors. However, its specificity was lower (55.6% vs 77.8%). 68 Ga-FAPI-04 PET was superior to 18 F-FDG PET in both patient-based and lesion-based evaluations except for metastatic lesions in the liver and bone. For intrahepatic CCA, 68 Ga-FAPI-04 PET/CT and 18 F-FDG PET/CT (100% vs 100%) had similar detection rates, with similar uptake levels between tracers ( P > 0.05). However, for extrahepatic CCA, 68 Ga-FAPI-04 PET/CT had a higher detection rate (89.5% vs 78.9%), and 68 Ga-FAPI-04 had a higher uptake ( P < 0.05). PET/MR was more effective than PET/CT in terms of lesion conspicuity and diagnostic confidence for primary tumors and liver metastases. In addition, multisequence MRI identified more liver metastases than 68 Ga-FAPI-04 PET/CT and 18 F-FDG PET/CT. CONCLUSIONS: Compared with 18 F-FDG PET/CT, 68 Ga-FAPI-04 PET/CT showed a higher sensitivity in detecting primary CCA tumors, involved lymph nodes, and peritoneal metastases. Compared with 68 Ga-FAPI-04 PET/CT, PET/MR detected primary and liver metastatic lesions more accurately. For extrahepatic CCA, the combination of 68 Ga-FAPI-04 PET/CT and abdominal PET/MRI may replace 18 F-FDG PET/CT.

Molecular imaging reveals the heterogeneous progression of tumor cells and tumor stroma: a practice of FDG PET and FAPI PET in diagnosing PSMA-negative bone metastases of progressive prostate cancer.

Tumors are often with complex and heterogeneous biological processes, such as glycometabolism and fibrosis, which are the main biochemical pathways that determine therapeutic effects. Specifically, this study aims to assess the diagnosing performance of 18F-FDG and 68Ga-FAPI-04 PET for different stages of progressive bone metastases with PSMA-negative pathology. Bone metastatic mouse model of prostate cancer was constructed via intra-bone injection of PSMA-negative prostate cancer PC3 cells. Cellular uptakes of 18F-FDG and 68Ga-FAPI-04 were separately performed on PC3, NIH-3T3 (FAP-positive) and a mixture. 68Ga-PSMA-11, 18F-FDG and 68Ga-FAPI-04 PET/CT imaging were performed at 2, 4 weeks after tumor cell transplantation. Furthermore, PSMA and FAP expression in bone metastases were assessed by immunohistochemistry, and then compared with the imageological findings. On the cellular level, the independent tracer uptake on the basis of glycometabolism and fibrosis was observed. For animal imaging, 68Ga-PSMA-11 imaging showed weak or absent tracer uptake in PSMA-negative bone metastatic lesions. In contrast, 68Ga-FAPI-04 PET of bone metastases had a higher uptake and tumor-to-muscle (T/M) ratio than 18F-FDG PET that was relative steady during the observation, but T/M ratio of fibrosis gradually decreased with increasing tumor growth, which ranged from 5.11 ± 1.26 at 2 weeks to 3.54 ± 0.23 at 4 weeks, revealing the delayed formation of tumor stroma in rapid proliferation. In addition, PET imaging results were corroborated by immunohistochemical assessment. In conclusion, molecular imaging approach revealed the heterogeneous progression of tumor cells and tumor stroma of bone metastasis of prostate cancer, and further confirming the necessity of multi-molecular imaging in cancer imaging.

Semisupervised 3D segmentation of pancreatic tumors in positron emission tomography/computed tomography images using a mutual information minimization and cross-fusion strategy.

Background: Accurate segmentation of pancreatic cancer tumors using positron emission tomography/computed tomography (PET/CT) multimodal images is crucial for clinical diagnosis and prognosis evaluation. However, deep learning methods for automated medical image segmentation require a substantial amount of manually labeled data, making it time-consuming and labor-intensive. Moreover, addition or simple stitching of multimodal images leads to redundant information, failing to fully exploit the complementary information of multimodal images. Therefore, we developed a semisupervised multimodal network that leverages limited labeled samples and introduces a cross-fusion and mutual information minimization (MIM) strategy for PET/CT 3D segmentation of pancreatic tumors. Methods: Our approach combined a cross multimodal fusion (CMF) module with a cross-attention mechanism. The complementary multimodal features were fused to form a multifeature set to enhance the effectiveness of feature extraction while preserving specific features of each modal image. In addition, we designed an MIM module to mitigate redundant high-level modal information and compute the latent loss of PET and CT. Finally, our method employed the uncertainty-aware mean teacher semi-supervised framework to segment regions of interest from PET/CT images using a small amount of labeled data and a large amount of unlabeled data. Results: We evaluated our combined MIM and CMF semisupervised segmentation network (MIM-CMFNet) on a private dataset of pancreatic cancer, yielding an average Dice coefficient of 73.14%, an average Jaccard index score of 60.56%, and an average 95% Hausdorff distance (95HD) of 6.30 mm. In addition, to verify the broad applicability of our method, we used a public dataset of head and neck cancer, yielding an average Dice coefficient of 68.71%, an average Jaccard index score of 57.72%, and an average 95HD of 7.88 mm. Conclusions: The experimental results demonstrate the superiority of our MIM-CMFNet over existing semisupervised techniques. Our approach can achieve a performance similar to that of fully supervised segmentation methods while significantly reducing the data annotation cost by 80%, suggesting it is highly practicable for clinical application.

Autophagy inhibition improves the targeted radionuclide therapy efficacy of 131I-FAP-2286 in pancreatic cancer xenografts.

PURPOSES: Radiotherapy can induce tumor cell autophagy, which might impair the antitumoral effect. This study aims to investigate the effect of autophagy inhibition on the targeted radionuclide therapy (TRT) efficacy of 131I-FAP-2286 in pancreatic cancer. METHODS: Human pancreatic cancer PANC-1 cells were exposed to 131I-FAP-2286 radiotherapy alone or with the autophagy inhibitor 3-MA. The autophagy level and proliferative activity of PANC-1 cells were analyzed. The pancreatic cancer xenograft-bearing nude mice were established by the co-injection of PANC-1 cells and pancreatic cancer-associated fibroblasts (CAFs), and then were randomly divided into four groups and treated with saline (control group), 3-MA, 131I-FAP-2286 and 131I-FAP-2286 + 3-MA, respectively. SPECT/CT imaging was performed to evaluate the bio-distribution of 131I-FAP-2286 in pancreatic cancer-bearing mice. The therapeutic effect of tumor was evaluated by 18F-FDG PET/CT imaging, tumor volume measurements, and the hematoxylin and eosin (H&E) staining, and immunohistochemical staining assay of tumor tissues. RESULTS: 131I-FAP-2286 inhibited proliferation and increased the autophagy level of PANC-1 cells in a dose-dependent manner. 3-MA promoted 131I-FAP-2286-induced apoptosis of PANC-1 cells via suppressing autophagy. SPECT/CT imaging of pancreatic cancer xenograft-bearing nude mice showed that 131I-FAP-2286 can target the tumor effectively. According to 18F-FDG PET/CT imaging, the tumor growth curves and immunohistochemical analysis, 131I-FAP-2286 TRT was capable of suppressing the growth of pancreatic tumor accompanying with autophagy induction, but the addition of 3-MA enabled 131I-FAP-2286 to achieve a better therapeutic effect along with the autophagy inhibition. In addition, 3-MA alone did not inhibit tumor growth. CONCLUSIONS: 131I-FAP-2286 exposure induces the protective autophagy of pancreatic cancer cells, and the application of autophagy inhibitor is capable of enhancing the TRT therapeutic effect.

Hemangioma of the Ilium Simulating Bone Metastasis on 18 F-PSMA-1007 PET/CT.

ABSTRACT: A 64-year-old man was referred for 18 F-PSMA-1007 PET/CT scan for initial staging of biopsy-proved prostate adenocarcinoma. 18 F-PSMA-1007 PET/CT showed focal intense 18 F-PSMA-1007 of the prostate adenocarcinoma and a focal intense activity with SUV max of 10.5 in the left ilium. The 18 F-PSMA-1007-avid iliac bone lesion corresponded to a hemangioma, which was initially detected on pelvic MRI 13 months ago and remained stable in size. This case indicates that hemangioma should be included in the differential diagnosis of PSMA-avid iliac bone lesions.

Elevated splenic 18F-fluorodeoxyglucose positron emission tomography/computed tomography activity is associated with 5-year risk of recurrence in non-metastatic invasive ductal carcinoma of the breast.

OBJECTIVE: To construct prediction models including baseline 18F-fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDG PET/CT) metabolic parameters of tumoural lesions and non-tumour lymphoid tissue for recurrence-free survival within 5 years (5y-RFS) after imaging examination in patients with invasive ductal carcinomas (IDCs) of the breast. METHODS: The study included 101 consecutive female patients. Univariable and multivariable Cox regression were used to identify clinicopathological and metabolic parameters associated with risk of recurrence. Four prediction models based on the results of multivariable analysis were constructed and visualized as nomograms. Performance of each nomogram was evaluated using the concordance index (C-index), integrated discrimination improvement, decision curve analysis (DCA), and calibration curve. RESULTS: N3 status, total metabolic tumour volume, the maximum standardized uptake value of spleen, and spleen-to-liver ratio were significant predictors of 5y-RFS. The nomogram including all significant predictors demonstrated superior predictive performance for 5y-RFS, with a C-index of 0.907 (95% CI, 0.833-0.981), greatest net benefit on DCA, good accuracy on calibration curves, and excellent risk stratification on Kaplan-Meier curves. CONCLUSIONS: The model that included metabolic parameters of the spleen had the best performance for predicting 5y-RFS in patients with IDCs of the breast. This model may guide personalized treatment decisions and inform patients and clinicians about prognosis. ADVANCES IN KNOWLEDGE: This research identifies 18F-FDG PET/CT metabolic parameters of non-tumour lymphoid tissue as predictors of recurrence in breast cancer.

Hemochromatosis Affects the Distribution of 68 Ga-DOTATATE in the Liver and Spleen.

ABSTRACT: Hemosiderosis is a chronic condition characterized by abnormal iron accumulation in tissues. In a PET scan of a 37-year-old woman, we observed an irregular distribution of 68 Ga-DOTATATE in the liver and spleen. Specifically, 68 Ga-DOTATATE appeared to be concentrated primarily in the peripheral regions of these organs, creating a distinctive "shell-like" appearance. This peculiar pattern may be attributed to the substantial accumulation of hemosiderin in the liver and spleen.

Intense 18 F-PSMA-1007 Uptake of Splenic Hemangioma.

ABSTRACT: A 77-year-old man was referred for 18 F-PSMA-1007 PET/CT scan for initial staging of biopsy-proved prostate adenocarcinoma. 18 F-PSMA-1007 PET/CT showed focal intense 18 F-PSMA-1007 of the prostate adenocarcinoma and a focal intense activity (SUV max , 27) in the spleen. The 18 F-PSMA-1007-avid splenic lesion corresponded to a splenic hemangioma, which was initially detected on contrast-enhanced CT 7 months ago and unchanged in size and enhancement pattern on follow-up contrast-enhanced CT. This case indicates that splenic hemangioma should be included in the differential diagnosis of PSMA-avid splenic lesions.

Deep learning-based whole-body characterization of prostate cancer lesions on [68Ga]Ga-PSMA-11 PET/CT in patients with post-prostatectomy recurrence.

PURPOSE: The automatic segmentation and detection of prostate cancer (PC) lesions throughout the body are extremely challenging due to the lesions' complexity and variability in appearance, shape, and location. In this study, we investigated the performance of a three-dimensional (3D) convolutional neural network (CNN) to automatically characterize metastatic lesions throughout the body in a dataset of PC patients with recurrence after radical prostatectomy. METHODS: We retrospectively collected [68 Ga]Ga-PSMA-11 PET/CT images from 116 patients with metastatic PC at two centers: center 1 provided the data for fivefold cross validation (n = 78) and internal testing (n = 19), and center 2 provided the data for external testing (n = 19). PET and CT data were jointly input into a 3D U-Net to achieve whole-body segmentation and detection of PC lesions. The performance in both the segmentation and the detection of lesions throughout the body was evaluated using established metrics, including the Dice similarity coefficient (DSC) for segmentation and the recall, precision, and F1-score for detection. The correlation and consistency between tumor burdens (PSMA-TV and TL-PSMA) calculated from automatic segmentation and artificial ground truth were assessed by linear regression and Bland‒Altman plots. RESULTS: On the internal test set, the DSC, precision, recall, and F1-score values were 0.631, 0.961, 0.721, and 0.824, respectively. On the external test set, the corresponding values were 0.596, 0.888, 0.792, and 0.837, respectively. Our approach outperformed previous studies in segmenting and detecting metastatic lesions throughout the body. Tumor burden indicators derived from deep learning and ground truth showed strong correlation (R2 ≥ 0.991, all P < 0.05) and consistency. CONCLUSION: Our 3D CNN accurately characterizes whole-body tumors in relapsed PC patients; its results are highly consistent with those of manual contouring. This automatic method is expected to improve work efficiency and to aid in the assessment of tumor burden.

Alpha-Emitter Radium-223 Induces STING-Dependent Pyroptosis to Trigger Robust Antitumor Immunity.

Radium-223 (223 Ra) is the first-in-class alpha-emitter to mediate tumor eradication, which is commonly thought to kill tumor cells by directly cleaving double-strand DNA. However, the immunogenic characteristics and cell death modalities triggered by 223 Ra remain unclear. Here, it is reported that the 223 Ra irradiation induces the pro-inflammatory damage-associated molecular patterns including calreticulin, HMGB1, and HSP70, hallmarks of tumor immunogenicity. Moreover, therapeutic 223 Ra retards tumor progression by triggering pyroptosis, an immunogenic cell death. Mechanically, 223 Ra-induced DNA damage leads to the activation of stimulator of interferon genes (STING)-mediated DNA sensing pathway, which is critical for NLRP3 inflammasome-dependent pyroptosis and subsequent DCs maturation as well as T cell activation. These findings establish an essential role of STING in mediating alpha-emitter 223 Ra-induced antitumor immunity, which provides the basis for the development of novel cancer therapeutic strategies and combinatory therapy.

Inhibition of a novel Dickkopf-1-LDL receptor-related proteins 5 and 6 axis prevents diabetic cardiomyopathy in mice.

BACKGROUND AND AIMS: Anti-hypertensive agents are one of the most frequently used drugs worldwide. However, no blood pressure-lowering strategy is superior to placebo with respect to survival in diabetic hypertensive patients. Previous findings show that Wnt co-receptors LDL receptor-related proteins 5 and 6 (LRP5/6) can directly bind to several G protein-coupled receptors (GPCRs). Because angiotensin II type 1 receptor (AT1R) is the most important GPCR in regulating hypertension, this study examines the possible mechanistic association between LRP5/6 and their binding protein Dickkopf-1 (DKK1) and activation of the AT1R and further hypothesizes that the LRP5/6-GPCR interaction may affect hypertension and potentiate cardiac impairment in the setting of diabetes. METHODS: The roles of serum DKK1 and DKK1-LRP5/6 signalling in diabetic injuries were investigated in human and diabetic mice. RESULTS: Blood pressure up-regulation positively correlated with serum DKK1 elevations in humans. Notably, LRP5/6 physically and functionally interacted with AT1R. The loss of membrane LRP5/6 caused by injection of a recombinant DKK1 protein or conditional LRP5/6 deletions resulted in AT1R activation and hypertension, as well as ß-arrestin1 activation and cardiac impairment, possibly because of multiple GPCR alterations. Importantly, unlike commonly used anti-hypertensive agents, administration of the anti-DKK1 neutralizing antibody effectively prevented diabetic cardiac impairment in mice. CONCLUSIONS: These findings establish a novel DKK1-LRP5/6-GPCR pathway in inducing diabetic injuries and may resolve the long-standing conundrum as to why elevated blood DKK1 has deleterious effects. Thus, monitoring and therapeutic elimination of blood DKK1 may be a promising strategy to attenuate diabetic injuries.

Elevated 68 Ga-FAPI-04 Activity Due to Staphylococcus aureus Intracranial Infection.

ABSTRACT: A 37-year-old man was admitted to our hospital after experiencing syncope. An MRI of his head revealed multiple foci of abnormal signal, which could potentially be metastases. The patient then underwent a 68 Ga-FAPI-04 PET/MRI examination, which revealed multiple FAPI-avid foci in the brain. Upon analyzing the cerebrospinal fluid, it was found that the patient had a Staphylococcus aureus infection. The results suggest that 68 Ga-FAPI-04 PET has the potential to be a valuable tool in the visualization of intracranial infectious lesions.

Head-to-head comparison of prostate-specific membrane antigen PET and multiparametric MRI in the diagnosis of pretreatment patients with prostate cancer: a meta-analysis.

OBJECTIVES: To compare prostate-specific membrane antigen (PSMA) PET with multiparametric MRI (mpMRI) in the diagnosis of pretreatment prostate cancer (PCa). METHODS: Pubmed, Embase, Medline, Web of Science, and Cochrane Library were searched for eligible studies published before June 22, 2022. We assessed risk of bias and applicability by using QUADAS-2 tool. Data synthesis was performed with Stata 17.0 software, using the "midas" and "meqrlogit" packages. RESULTS: We included 29 articles focusing on primary cancer detection, 18 articles about primary staging, and two articles containing them both. For PSMA PET versus mpMRI in primary PCa detection, sensitivities and specificities in the per-patient analysis were 0.90 and 0.84 (p<0.0001), and 0.66 and 0.60 (p <0.0001), and in the per-lesion analysis they were 0.79 and 0.78 (p <0.0001), and 0.84 and 0.82 (p <0.0001). For the per-patient analysis of PSMA PET versus mpMRI in primary staging, sensitivities and specificities in extracapsular extension detection were 0.59 and 0.66 (p =0.005), and 0.79 and 0.76 (p =0.0074), and in seminal vesicle infiltration (SVI) detection they were 0.51 and 0.60 (p =0.0008), and 0.93 and 0.96 (p =0.0092). For PSMA PET versus mpMRI in lymph node metastasis (LNM) detection, sensitivities and specificities in the per-patient analysis were 0.68 and 0.46 (p <0.0001), and 0.91 and 0.90 (p =0.81), and in the per-lesion analysis they were 0.67 and 0.36 (p <0.0001), and 0.99 and 0.99 (p =0.18). CONCLUSION: PSMA PET has higher diagnostic value than mpMRI in the detection of primary PCa. Regarding the primary staging, mpMRI has potential advantages in SVI detection, while PSMA PET has relative advantages in LNM detection. CLINICAL RELEVANCE STATEMENT: The integration of prostate-specific membrane antigen (PSMA) PET into the diagnostic pathway may be helpful for improving the accuracy of prostate cancer detection. However, further studies are needed to address the cost implications and evaluate its utility in specific patient populations or clinical scenarios. Moreover, we recommend the combination of PSMA PET and mpMRI for cancer staging. KEY POINTS: • Prostate-specific membrane antigen PET has higher sensitivity and specificity for primary tumor detection in prostate cancer compared to multiparametric MRI. • Prostate-specific membrane antigen PET also has significantly better sensitivity and specificity for lymph node metastases of prostate cancer compared to multiparametric MRI. • Multiparametric MRI has better accuracy for extracapsular extension and seminal vesicle infiltration compared to ate-specific membrane antigen PET.

Fusing Positive and Negative CT Contrast Nanoagent for the Sensitive Detection of Hepatoma.

Positive computed tomography (CT) contrast nanoagent has significant applications in diagnosing tumors. However, the sensitive differentiation between hepatoma and normal liver tissue remains challenging. This challenge arises primarily because both normal liver and hepatoma tissues capture the nanoagent, resulting in similar positive CT contrasts. Here, a strategy for fusing positive and negative CT contrast nanoagent is proposed to detect hepatoma. A nanoagent Hf-MOF@AB@PVP initially generates a positive CT contrast signal of 120.3 HU in the liver. Subsequently, it can specifically respond to the acidic microenvironment of hepatoma to generate H2 , further achieving a negative contrast of -96.0 HU. More importantly, the relative position between the negative and positive signals area is helpful to determine the location of hepatoma and normal liver tissues. The distinct contrast difference of 216.3 HU and relative orientation between normal liver and tumor tissues are meaningful to sensitively distinguish hepatoma from normal liver tissue utilizing CT imaging.