18F-FDG PET/CT- and MRI-Based Locally Advanced Cervical Cancer Early-Response Assessment after Concurrent Chemo- and Radiotherapy-Impact on Patient Outcomes and Survival Prediction.

With one third of patients with locally advanced cervical cancer (LACC) expected to develop cancer recurrence in the first two years after therapy, accurate assessment of the response and timely detection of cancer recurrence after concurrent chemo- and radiotherapy (CCRT) treatment is of great importance. Although there is neither definite consensus about the preferred imaging modality, nor the time interval until the first diagnostic examination after CCRT, the National Comprehensive Cancer Network (NCCN) recommends the use of MRI and 18F-FDG PET/CT as a post-treatment LACC response-assessment imaging tools. In this study, we tried to appraise the early therapy response in LACC patients by both 18F-FDG PET/CT and MRI in regard to the follow-up imaging results and their mutual interrelationship, and to ascertain if the post-treatment 18F-FDG PET/CT and MRI results were related to the progression-free and overall survival rate in women with LACC after CCRT. We also aimed to estimate the early and follow-up diagnostic imaging impact on further therapy management. Based on our results, we concluded that 18F-FDG PET/CT did surpass MRI in the early assessment of therapeutic response in LACC patients after CCRT. Both modalities provided information that may serve as predictive biomarkers of outcome and LACC patients' survival.

A Rare Case of Invasive Thyroid Aspergillosis Revealed on 18F-FDG-PET/CT.

Invasive aspergillosis (IA) represents a common form of fungal infection caused by various species of Aspergillus that most frequently affect immunocompromised patients. Typically, this disease occurs preferentially in high-risk groups including patients infected with the human immunodeficiency virus (HIV), patients with leukemia, patients with autoimmune diseases, and organ transplant patients undergoing medical immunosuppression. Considered the second most common cause of opportunistic fungal infection in humans after Candida albicans, this pathogen predominantly affects the lungs, but it may also spread by a hematogenous route to various organs and have a heterogeneous presentation. Owing to its high iodine levels, high perfusion, and enclosed capsule, the thyroid gland is considered to have a lower susceptibility to microbial invasion, and it is fairly uncommon to find associated infectious nodules. In metabolic imaging, 18F-FDG-PET/CT has become increasingly useful for detecting a wide range of infectious and inflammatory diseases and is already the gold standard for certain indications. According to the literature, no studies of hypermetabolic nodular thyroid aspergillosis on 18F-FDG-PET/CT confirmed on histology have yet been reported. Here, we report the first case of a patient with a heterogeneous presentation of IA and the presence of a hypermetabolic nodule in the thyroid with a surprising result.

Prognostic Value of the 18F-FDG PET/CT and Haematological Parameters in Head and Neck Cancer.

INTRODUCTION: Fluorine 18-fluoro-glucose positron emission tomography/computed tomography (18F-FDG PET/CT) is commonly used for the staging of head and neck cancer. This study aimed to evaluate the correlation between 18F-FDG PET/CT, haematological parameters and prognosis in patients with advanced head and neck cancer. METHODS: This was a single-institutional retrospective study of 83 patients with advanced head and neck squamous cell carcinoma (HNSCC) who underwent 18F-FDG PET/CT imaging before initial treatment between 2014 and 2018. 18F-FDG PET/CT after treatment was performed in 57 patients. The prognostic parameters of the pre- and post-treatment maximum standardised uptake value (SUVmax), metabolic tumour volume (MTV), total lesion glycolysis (TLG) of primary tumours and haematological parameters were analysed to evaluate the association between overall survival (OS) and progression-free survival (PFS). RESULTS: Pre-MTV, pre-TLG and post-SUVmax were significantly associated with poor OS and PFS (p < 0.05). Haematological parameters, including pretreatment neutrophil/lymphocyte ratio and C-reactive protein/albumin ratio, were associated with 18F-FDG PET/CT parameters. In multivariate analysis, post-SUVmax was an independent prognostic factor for OS and PFS. CONCLUSION: A correlation between PET/CT metabolic and haematological parameters was observed. The volume and intensity of 18F-FDG uptake region, in addition to haematological parameters, are feasible markers for predicting the progression of HNSCC in daily practice. Further, post-SUVmax could be an independent parameter for predicting poor survival.

The clinical and predictive value of 18F-FDG PET/CT metabolic patterns in a clinical Chinese cohort with autoimmune encephalitis.

AIMS: To investigate the diagnostic and predictive role of 18F-FDG PET/CT in patients with autoimmune encephalitis (AE) as a whole group. METHODS: Thrty-five patients (20 females and 15 males) with AE were recruited. A voxel-to-voxel semi-quantitative analysis based on SPM12 was used to analyze 18F-FDG PET/CT imaging data compared to healthy controls. Further comparison was made in different prognostic groups categorized by modified Rankin Scale (mRS). RESULTS: In total, 24 patients (68.6%) were tested positive neuronal antibodies in serum and/or CSF. Psychiatric symptoms and seizure attacks were major clinical symptoms. In the acute stage, 13 patients (37.1%) demonstrated abnormal brain MRI results, while 33 (94.3%) presented abnormal metabolism patterns. 18F-FDG PET/CT was more sensitive than MRI (p < 0.05). Patients with AE mainly presented mixed metabolism patterns compared to the matched controls, demonstrating hypermetabolism mainly in the cerebellum, BG, MTL, brainstem, insula, middle frontal gyrus, and relatively hypometabolism in the frontal cortex, occipital cortex, temporal gyrus, right parietal gyrus, left cingulate gyrus (p < 0.05, FWE corrected). After a median follow-up of 26 months, the multivariable analysis identified a decreased level of consciousness as an independent risk factor associated with poor outcome of AE (HR = 3.591, p = 0.016). Meanwhile, decreased metabolism of right superior frontal gyrus along with increased metabolism of the middle and upper brainstem was more evident in patients with poor outcome (p < 0.001, uncorrected). CONCLUSION: 18F-FDG PET/CT was more sensitive than MRI to detect neuroimaging abnormalities of AE. A mixed metabolic pattern, characterized by large areas of cortical hypometabolism with focal hypermetabolism was a general metabolic pattern. Decreased metabolism of right superior frontal gyrus with increased metabolism of the middle and upper brainstem may predict poor long-term prognosis of AE.

Comparison of the Performance of [18F]-FDG PET/CT and [18F]-FDG PET/MRI for Lymph Node Metastasis in Breast Cancer: A Systematic Review and Meta- Analysis.

OBJECTIVE: The primary objective of this study was to conduct a comparative analysis of the diagnostic efficacy of [18F]-FDG PET/CT and [18F]-FDG PET/MRI in the detection of breast cancer lymph node metastasis. METHODS: We conducted a comprehensive search on PubMed, Embase, and Web of Science databases, encompassing eligible articles until March 2023. The pooled sensitivity and specificity for [18F]-FDG PET/CT and [18F]-FDG PET/MRI have been reported as estimates with 95% Confidence Intervals (CIs) using a bivariate random-effect model. Utilizing the I square (I2) statistic, heterogeneity among pooled studies was evaluated. The quality assessment of the included studies was conducted using the Quality Assessment of Diagnostic Accuracy Studies-2 (QUADAS-2) methodology. RESULTS: We included 18 studies (2057 patients). The sensitivity, specificity, and AUC (Area Under the Curve) values of [18F]-FDG PET/CT for overall lymph node metastasis in breast cancer have been found to be 0.58 (0.39 - 0.75), 0.83 (0.69-0.92), and 0.79 (0.75-0.82), respectively. Correspondingly, the values for [18F]-FDG PET/MRI were found to be 0.76 (0.60-0.88), 0.85 (0.77-0.91), and 0.89 (0.86-0.91), respectively. The sensitivity, specificity, and AUC values of [18F]-FDG PET/CT for axillary lymph node metastasis in breast cancer were 0.52 (0.37-0.67), 0.84 (0.68-0.92), and 0.73 (0.69-0.76), respectively. Correspondingly, the values for [18F]-FDG PET/MRI were 0.84 (0.76-0.89), 0.87 (0.75-0.94), and 0.86 (0.83-0.89), respectively. CONCLUSION: This study has suggested [18F]-FDG PET/MRI to have greater diagnostic power than [18F]-FDG PET/CT in detecting lymph node metastasis in breast cancer. However, the [18F]-FDG PET/MRI results have been obtained from a small sample size study, and more and larger prospective studies are needed for further confirmation on this issue.

18F-FDG PET/CT Radiomics-Based Multimodality Fusion Model for Preoperative Individualized Noninvasive Prediction of Peritoneal Metastasis in Advanced Gastric Cancer.

PURPOSE: This study was designed to develop and validate a machine learning-based, multimodality fusion (MMF) model using 18F-fluorodeoxyglucose (FDG) PET/CT radiomics and kernelled support tensor machine (KSTM), integrated with clinical factors and nuclear medicine experts' diagnoses to individually predict peritoneal metastasis (PM) in advanced gastric cancer (AGC). METHODS: A total of 167 patients receiving preoperative PET/CT and subsequent surgery were included between November 2006 and September 2020 and were divided into a training and testing cohort. The PM status was confirmed via laparoscopic exploration and postoperative pathology. The PET/CT signatures were constructed by classic radiomic, handcrafted-feature-based model and KSTM self-learning-based model. The clinical nomogram was constructed by independent risk factors for PM. Lastly, the PET/CT signatures, clinical nomogram, and experts' diagnoses were fused using evidential reasoning to establish the MMF model. RESULTS: The MMF model showed excellent performance in both cohorts (area under the curve [AUC] 94.16% and 90.84% in training and testing), and demonstrated better prediction accuracy than clinical nomogram or experts' diagnoses (net reclassification improvement p < 0.05). The MMF model also had satisfactory generalization ability, even in mucinous adenocarcinoma and signet ring cell carcinoma which have poor uptake of 18F-FDG (AUC 97.98% and 89.71% in training and testing). CONCLUSIONS: The 18F-FDG PET/CT radiomics-based MMF model may have significant clinical implications in predicting PM in AGC, revealing that it is necessary to combine the information from different modalities for comprehensive prediction of PM.

Misdiagnosis of a Drain-site Hernia Containing Fallopian Tube Fimbria on 18F-FDG PET/CT.

In a 55-year-old woman with sigmoid colon cancer, a subcutaneous mass in the left lower abdomen was incidentally found and gradually enlarged. For further diagnosis and staging, an 18F-fluorodeoxyglucose (FDG) positron emission tomography/computed tomography scan was performed, which revealed a subcutaneous mass in the left lower abdomen with mild uptake of 18F-FDG, suggesting the possibility of metastasis. However, post-surgery and pathological confirmation, this mass was diagnosed as a drain-site hernia containing fallopian tube fimbria, which is extremely rare but should be considered in the differential diagnosis of subcutaneous mass in the lower abdomen.

Jejunal Undifferentiated Spindle Cell Sarcoma with Intussusception Revealed by 18F-FDG PET/CT.

Spindle cell sarcoma is a malignant tumor with low incidence. They can occur in the soft tissue, bone, or viscera. The characteristics of morphology, density, and metabolism of spindle cell sarcoma are related to the location of the lesion. A 61-year-old woman presented with vomiting after eating for 2 weeks. Signs of peritoneal irritation were involved, but no response for symptomatic treatment included antiemetic and antispasmodic therapy. Abdominal computed tomography (CT) indicated a mass in the intestinal tract in the pelvic cavity. Then, 18F-fluorodeoxyglucose (18F-FDG) positron emission tomography/CT was performed, which interestingly detected a jejunal malignancy mass in the left upper abdomen with annular high uptake of 18F-FDG, which was complicated by intussusception and intestinal obstruction. Finally, the jejunal mass was pathologically clarified as an undifferentiated spindle cell sarcoma.

Isolated Diffuse Bone Marrow Metastases From Signet-ring Cell Gastric Carcinoma.

A 71-year-old female patient with a known history of signet-ring cell carcinoma presented with diffuse bone pain and anemic symptoms. An 18F-fluorodeoxyglucose (FDG) positron emission tomography/computed tomography study revealed diffuse heterogeneous hypermetabolic sclerotic lesions in the axial and proximal appendicular skeleton. No other 18F-FDG-avid lesions were detected. Subsequent bone marrow biopsy confirmed the diagnosis of metastatic carcinoma originating from the gastric primary site. Palliative treatment was initiated; however, the patient's condition deteriorated, and she succumbed to the disease two months later.

Infective endocarditis associated with left atrial appendage occlusion device: a contemporary systematic review.

BACKGROUND: Data are limited regarding infective endocarditis (IE) complicating left atrial appendage occlusion (LAAO) device procedures. This systematic review examines the etiology, diagnosis, and management of infective endocarditis (IE) following LAAO. METHODS: A comprehensive search of six databases was performed between 2007 and 2022. In selecting studies, articles were included if they provided information about IE complicating LAAO, with relevant clinical and imaging details. Articles were excluded if they were editorials, study protocols, letters, or abstracts. RESULTS: We identified seven cases of IE complicating LAAO published between 2007 and 2022, from the United States and Europe, highlighting the exceedingly rare reported incidence of the condition. Staphylococcus aureus is the predominant organism implicated in LAAO infections. Echocardiography is a key imaging modality for diagnosing LAAO IE. Both antibiotic therapy and surgical intervention in appropriate patients are important for managing LAAO device-related IE. CONCLUSIONS: The limited data in the current literature regarding LAAO IE underscores the need for prospective clinical trials to establish evidence-based guidelines for infection prophylaxis, diagnosis, and management. Our findings emphasize the importance of vigilance for device-related infections, especially as the use of LAAO devices continues to grow worldwide.

Prediction of Prognosis and Response to Androgen Deprivation Therapy in Intermediate to High-Risk Prostate Cancer Using 18F-FDG PET/CT Radiomics.

RATIONALE AND OBJECTIVES: This study aims to predict intermediate to high-risk prostate cancer (PCa) prognosis based on 18-fluoro-2-deoxyglucose (18F-FDG) positron emission tomography (PET)/computed tomography (CT) radiomics. Additionally, subgroup analysis will be performed on the androgen deprivation therapy (ADT) group and the metastatic PCa group. MATERIALS AND METHODS: In the retrospective analysis of 104 intermediate to high-risk PCa patients who underwent 18F-FDG PET/CT prior to treatment. The data set was divided into a training set (n = 72) and a testing set (n = 32). Two different PET/CT models were constructed using multivariate logistic regression with cross-validation: radiomics model A and an alternative ensemble learning-based model B. The superior model was then selected to develop a radiomics nomogram. Separate models were also developed for the ADT and metastatic PCa subgroups. RESULTS: Model A, which integrates eight radiomics features showed excellent performance with an area under curve (AUC) of 0.844 in the training set and 0.804 in the testing set. The radiomics nomogram incorporating the radiomics score (radscore) from model A and the tumor-to-liver ratio (TLR) showed good prognostic accuracy in the testing set with an AUC of 0.827. In the subgroup analyses for endocrine therapy and metastatic cancer, the PET/CT radiomics model showed AUCs of 0.845 and 0.807 respectively, suggesting its potential effectiveness. CONCLUSION: The study establishes the utility of the 18F-FDG PET/CT radiomics nomogram in predicting the prognosis of intermediate to high-risk PCa patients, indicating its potential for clinical application.

Application value of 18F-FDG PET/CT in primary spleen angiosarcoma with liver metastasis: a case report and literature review.

Background: Primary splenic angiosarcoma (PSA) is a rare neoplasm. It is a malignant tumor derived from endothelial cells of the splenic sinuses. PSA has an unknown etiology, a high degree of malignancy, easy early metastasis, atypical clinical symptoms and imaging findings, and difficult early diagnosis. This paper reports the 18F-FDG PET/CT findings of a case of PSA with intrahepatic metastasis; summarizes its clinical, imaging, and pathological data; and reviews the literature. Case description: A 64-year-old male patient presented with left lower abdominal distending pain without obvious causes on 13 March 2022. The pain was persistent and dull and worsened after sitting and eating. Blood routine examination results were RBC ↓ 3.33 × 1012/L, WBC ↑ 12.32 × 109/L, and PLT ↓ 40 × 109/L. The tumor markers indicated CA125 ↑ 47.0 U/ml, AFP (-), CEA (-), CA199 (-), and CA724 (-). Non-contrast-enhanced CT scan of the abdomen showed that the spleen was significantly enlarged in volume and irregular in shape and had multiple nodules and clumpy low-density shadows, unclear boundaries, uneven density, and multiple necrotic areas. Enhanced CT showed diffuse uneven mild enhancement of the spleen, and the degree of enhancement increased with time. Multiple nodular low-density shadows were seen in the liver, which were slightly enhanced by the enhanced scan.18F-FDG PET/CT showed multiple nodular and massive lesions in the spleen with multiple necrotic areas. There were multiple nodular lesions in the liver, the level of FDG metabolism increased, the SUVmax of the spleen lesions was 9.0, and the SUVmax of the liver lesions was 5.6. The 18F-FDG PET/CT diagnosis was splenic malignancy with liver metastasis. Finally, after a multidisciplinary discussion, it was decided to perform laparoscopic total splenectomy and portal vein infusion chemotherapy. Pathological examination showed that the tumor cells were round, oval, or fusiform, with obvious atypia, arranged into a cable or anastomosed vascular lumen. The final diagnosis was primary splenic angiosarcoma with massive necrosis. After surgery, the patient received antitumor combined therapy and died 5 months later. Conclusion: The incidence of PSA is very low, and its clinical and radiological manifestations lack specificity. 18F-FDG PET/CT imaging has a certain diagnostic value for PSA and significant utility in preoperative staging, guiding biopsy procedures, evaluating postoperative treatment response, and monitoring disease recurrence. PSA should be considered in the presence of a space-occupying lesion within the spleen that exhibits necrotic areas, shows progressive enhancement on contrast-enhanced scans, and demonstrates heterogeneous increases in FDG uptake.

A Case of Large Vessel Giant Cell Arteritis Presenting With Cough and Diagnosed Using an FDG-PET Scan.

Giant-cell arteritis (GCA) is a type of vasculitis characterised by the presence of granulomas. It is the predominant form of systemic vasculitis in adults and primarily affects the larger arteries in individuals aged ≥ 50 years. GCA affects the major arteries, such as the aorta and its branches, particularly the outer branches of the external carotid artery. Signs and symptoms can be categorised into cranial, extracranial, and systemic manifestations. Patients with headaches, jaw claudication, and vision disturbances usually have extracranial branches of the external carotid artery. Aside from being the prevailing manifestation of GCA, our primary concern regarding this variant is the potential for irreversible vision loss if not properly identified and addressed. Conversely, the GCA can also affect other major blood vessels such as the aorta. Here, we present the case of a 70-year-old Caucasian female patient with cranial GCA who had experienced a temporal headache three years prior. The patient was successfully treated with prednisolone, which was gradually reduced to a very low level with the assistance of methotrexate. Recently, the patient presented with a dry cough that lasted for two months and elevated inflammatory markers. After thorough research, it was determined that there was no evidence of infection, including atypical infections, and that no abnormalities were found in the lungs. Ultimately, via an 18F-fluorodeoxyglucose-positron emission tomography (FDG-PET) scan, the patient was diagnosed with large vessel giant cell arteritis (LV-GCA). This impacted the aorta, carotid arteries, and subclavian arteries. The patient experienced notable improvement in her cough and a reduction in inflammatory markers after receiving a high dosage of oral prednisolone. This case exemplifies the unusual manifestation of LV-GCA and verifies that recurring symptoms may differ from the original presentation. While dry cough is not commonly listed as a symptom of LV-GCA, it can be present as a manifestation or the sole presentation in certain patients, particularly when inflammatory markers are consistently high and there is no pulmonary disease.

Development and validation of an 18F-FDG PET/CT-based radiomics nomogram for predicting the prognosis of patients with esophageal squamous cell carcinoma.

RATIONALE AND OBJECTIVES: The aim of this study was to develop and validate a nomogram, integrating clinical factors and radiomics features, capable of predicting overall survival (OS) in patients diagnosed with esophageal squamous cell carcinoma (ESCC). METHODS: In this study, we retrospectively analyzed the case data of 130 patients with ESCC who underwent 18F-FDG PET/CT before treatment. Radiomics features associated with OS were screened by univariate Cox regression (p < 0.05). Further selection was performed by applying the least absolute shrinkage and selection operator Cox regression to generate the weighted Radiomics-score (Rad-score). Independent clinical risk factors were obtained by multivariate Cox regression, and a nomogram was constructed by combining Rad-score and independent risk factors. The predictive performance of the model for OS was assessed using the time-dependent receiver operating characteristic curve, concordance index (C-index), calibration curve, and decision curve analysis. RESULTS: Five radiomics features associated with prognosis were finally screened, and a Rad-score was established. Multivariate Cox regression analysis revealed that surgery and clinical M stage were identified as independent risk factors for OS in ESCC. The combined clinical-radiomics nomogram exhibited C-index values of 0.768 (95% CI: 0.699-0.837) and 0.809 (95% CI: 0.695-0.923) in the training and validation cohorts, respectively. Ultimately, calibration curves and decision curves for the 1-, 2-, and 3-year OS demonstrated the satisfactory prognostic prediction and clinical utility of the nomogram. CONCLUSION: The developed nomogram, leveraging 18F-FDG PET/CT radiomics and clinically independent risk factors, demonstrates a reliable prognostic prediction for patients with ESCC, potentially serving as a valuable tool for guiding and optimizing clinical treatment decisions in the future.

Two cases of misleading Epstein-Barr virus infection and the role of EBV-DNA.

Two atypical cases of infectious mononucleosis in two teenagers with initially negative serology and non-evocative blood examinations are reported. The first patient had recently traveled to Africa, and Epstein-Barr virus negative serology led us to make many extensive investigations. The second patient complained of asthenia for a month, and PET/CT was performed to suspicion of lymphoma. PET scan revealed hypermetabolic lymph nodes in the supradiaphragmatic and subdiaphragmatic stations, along with18F-FDG uptake in the spleen and pharynx, raising more suspicion of lymphoma. Fortunately, Epstein-Barr virus DNA testing was performed and turned positive in both cases, and Epstein-Barr virus serology subsequently became positive. Diagnosing EBV infection can be challenging in rare cases, as EBV-specific serology may be negative in the early stages and confounding factors may be present. Therefore, Epstein-Barr virus DNA testing should be considered early in the diagnostic algorithm to prevent unnecessary investigations in similar cases.

A radiomics-boosted deep-learning for risk assessment of synchronous peritoneal metastasis in colorectal cancer.

OBJECTIVES: Synchronous colorectal cancer peritoneal metastasis (CRPM) has a poor prognosis. This study aimed to create a radiomics-boosted deep learning model by PET/CT image for risk assessment of synchronous CRPM. METHODS: A total of 220 colorectal cancer (CRC) cases were enrolled in this study. We mapped the feature maps (Radiomic feature maps (RFMs)) of radiomic features across CT and PET image patches by a 2D sliding kernel. Based on ResNet50, a radiomics-boosted deep learning model was trained using PET/CT image patches and RFMs. Besides that, we explored whether the peritumoral region contributes to the assessment of CRPM. In this study, the performance of each model was evaluated by the area under the curves (AUC). RESULTS: The AUCs of the radiomics-boosted deep learning model in the training, internal, external, and all validation datasets were 0.926 (95% confidence interval (CI): 0.874-0.978), 0.897 (95% CI: 0.801-0.994), 0.885 (95% CI: 0.795-0.975), and 0.889 (95% CI: 0.823-0.954), respectively. This model exhibited consistency in the calibration curve, the Delong test and IDI identified it as the most predictive model. CONCLUSIONS: The radiomics-boosted deep learning model showed superior estimated performance in preoperative prediction of synchronous CRPM from pre-treatment PET/CT, offering potential assistance in the development of more personalized treatment methods and follow-up plans. CRITICAL RELEVANCE STATEMENT: The onset of synchronous colorectal CRPM is insidious, and using a radiomics-boosted deep learning model to assess the risk of CRPM before treatment can help make personalized clinical treatment decisions or choose more sensitive follow-up plans. KEY POINTS: Prognosis for patients with CRPM is bleak, and early detection poses challenges. The synergy between radiomics and deep learning proves advantageous in evaluating CRPM. The radiomics-boosted deep-learning model proves valuable in tailoring treatment approaches for CRC patients.

PET-based radiomic feature based on the cross-combination method for predicting the mid-term efficacy and prognosis in high-risk diffuse large B-cell lymphoma patients.

Objectives: This study aims to develop 7×7 machine-learning cross-combinatorial methods for selecting and classifying radiomic features used to construct Radiomics Score (RadScore) of predicting the mid-term efficacy and prognosis in high-risk patients with diffuse large B-cell lymphoma (DLBCL). Methods: Retrospectively, we recruited 177 high-risk DLBCL patients from two medical centers between October 2012 and September 2022 and randomly divided them into a training cohort (n=123) and a validation cohort (n=54). We finally extracted 110 radiomic features along with SUVmax, MTV, and TLG from the baseline PET. The 49 features selection-classification pairs were used to obtain the optimal LASSO-LASSO model with 11 key radiomic features for RadScore. Logistic regression was employed to identify independent RadScore, clinical and PET factors. These models were evaluated using receiver operating characteristic (ROC) curves and calibration curves. Decision curve analysis (DCA) was conducted to assess the predictive power of the models. The prognostic power of RadScore was assessed using cox regression (COX) and Kaplan-Meier plots (KM). Results: 177 patients (mean age, 63 ± 13 years,129 men) were evaluated. Multivariate analyses showed that gender (OR,2.760; 95%CI:1.196,6.368); p=0.017), B symptoms (OR,4.065; 95%CI:1.837,8.955; p=0.001), SUVmax (OR,2.619; 95%CI:1.107,6.194; p=0.028), and RadScore (OR,7.167; 95%CI:2.815,18.248; p<0.001) independently contributed to the risk factors for predicting mid-term outcome. The AUC values of the combined models in the training and validation groups were 0.846 and 0.724 respectively, outperformed the clinical model (0.714;0.556), PET based model (0.664; 0.589), NCCN-IPI model (0.523;0.406) and IPI model (0.510;0.412) in predicting mid-term treatment outcome. DCA showed that the combined model incorporating RadScore, clinical risk factors, and PET metabolic metrics has optimal net clinical benefit. COX indicated that the high RadScore group had worse prognosis and survival in progression-free survival (PFS) (HR, 2.1737,95%CI: 1.2983, 3.6392) and overall survival (OS) (HR,2.1356,95%CI: 1.2561, 3.6309) compared to the low RadScore group. KM survival analysis also showed the same prognosis prediction as Cox results. Conclusion: The combined model incorporating RadScore, sex, B symptoms and SUVmax demonstrates a significant enhancement in predicting medium-term efficacy and prognosis in high-risk DLBCL patients. RadScore using 7×7 machine learning cross-combinatorial methods for selection and classification holds promise as a potential method for evaluating medium-term treatment outcome and prognosis in high-risk DLBCL patients.

Baseline [18F]FDG PET/CT and MRI first-order breast tumor features do not improve pathological complete response prediction to neoadjuvant chemotherapy.

PURPOSE: To verify the ability of pretreatment [18F]FDG PET/CT and T1-weighed dynamic contrast-enhanced MRI to predict pathological complete response (pCR) after neoadjuvant chemotherapy (NAC) in breast cancer (BC) patients. METHODS: This retrospective study includes patients with BC of no special type submitted to baseline [18F]FDG PET/CT, NAC and surgery. [18F]FDG PET-based features reflecting intensity and heterogeneity of tracer uptake were extracted from the primary BC and suspicious axillary lymph nodes (ALN), for comparative analysis related to NAC response (pCR vs. non-pCR). Multivariate logistic regression was performed for response prediction combining the breast tumor-extracted PET-based features and clinicopathological features. A subanalysis was performed in a patients' subsample by adding breast tumor-extracted first-order MRI-based features to the multivariate logistic regression. RESULTS: A total of 170 tumors from 168 patients were included. pCR was observed in 60/170 tumors (20/107 luminal B-like, 25/45 triple-negative and 15/18 HER2-enriched surrogate molecular subtypes). Higher intensity and higher heterogeneity of [18F]FDG uptake in the primary BC were associated with NAC response in HER2-negative tumors (immunohistochemistry score 0, 1 + or 2 + non-amplified by in situ hybridization). Also, higher intensity of tracer uptake was observed in ALN in the pCR group among HER2-negative tumors. No [18F]FDG PET-based features were associated with pCR in the other subgroup analyses. A subsample of 103 tumors was also submitted to extraction of MRI-based features. When combined with clinicopathological features, neither [18F]FDG PET nor MRI-based features had additional value for pCR prediction. The only significant predictors were estrogen receptor status, HER2 expression and grade. CONCLUSION: Pretreatment [18F]FDG PET-based features from primary BC and ALN are not associated with response to NAC, except in HER2-negative tumors. As compared with pathological features, no breast tumor-extracted PET or MRI-based feature improved response prediction.

Vesicourachal Diverticulum: An Uncommon Incidental Finding on Staging 18F-FDG PET/CT in a Patient with Suspected Malignant Transformation of Neurofibromatosis.

In a 32-y-old man with neurofibromatosis type 1, 18F-FDG PET/CT incidentally revealed a vesicourachal diverticulum, a rare anatomic variant. The PET/CT, performed for staging a malignant peripheral nerve sheath tumor, highlighted a distinctive 18F-FDG-avid pattern crucial for accurate diagnosis. Recognizing such features enhances disease assessment and clarifies distinctions between benign urogenital anomalies and malignancies in 18F-FDG PET/CT staging.

Detection of Esophageal Tuberculosis, a Rare Cause of Abdominal Pain, on 18F-FDG PET/CT.

The esophagus is rarely affected by Mycobacterium A 75-y-old man presented with upper abdominal pain and significant weight loss for 2 mo. Contrast-enhanced CT, upper gastrointestinal endoscopy, and abdominal vessel angiography gave normal results. To clarify the facts, 18F-FDG PET/CT was performed, revealing an 18F-FDG-avid lesion in the posterior wall of the lower thoracic esophagus. On endoscopic ultrasound-guided fine-needle aspiration of this lesion, puslike material was released. On microscopic examination, acid-fast bacilli were noted. The patient then began receiving standard antitubercular therapy.