Evaluating response to radium-223 using 68Ga-PSMA PET/CT imaging in patients with metastatic castration-resistant prostate cancer.

AIM: Conventional imaging techniques and prostate-specific antigen (PSA) values are not useful to follow-up patients during Radium-223 treatment. The study aimed to evaluate the predictive value of prostate-specific membrane antigen PSMA PET/CT-based response in patients with metastatic castration-resistant prostate cancer (mCRPC) receiving Radium-223 dichloride treatment. MATERIALS AND METHODS: Patients treated with radium-223, having performed two 68Ga-PSMA-11 PET/CT scans (baseline 1 month before treatment initiation and follow-up 2 weeks after the third cycle), were retrospectively evaluated. Visual and quantitative PET image analyses were performed, and patients were dichotomized into progressive (PD) and non-PD according to Response Evaluation Criteria in PSMA­imaging (RECIP1.0) and PSMA-PET Progression criteria (PPP). The primary endpoint was overall survival (OS). Cohen's Kappa (κ) was used to test the agreement between the two criteria. The Cox regression hazard model and Kaplan-Meier method were used for survival analyses. RESULTS: Twenty-eight mCRPC patients were evaluated. Sixteen (43%) and 18 (64%) patients had PD according to RECIP1.0 and PPP, respectively; κ = 0.85 (95% CI 0.65-1.00). After a median follow-up of 16 months (interquartile IQR 9-33), 20 (71%) patients died. Patients with PSMA PD showed a higher risk of death than non-PD according to RECIP1.0 (HR = 2.9; 95% CI 1.14-7.46; p = 0.029) and PPP (HR = 2.8; 95% CI 1.04-7.64; p = 0.042). For both criteria, the median OS was shorter for PD than non-PD (37 vs. 12 months, Log-rank; p < 0.05). The C-index for RECIP1.0 and PPP were almost equal (0.66 and 0.63; respectively). CONCLUSION: This study demonstrated that PSMA-PET/CT imaging is valuable for monitoring radium-223 treatment. Both PSMA PET/CT response criteria (RECIP1.0 and PPP) perform similarly predicting OS at follow-up after three cycles of radium-223. These findings urge further validation in prospective trials.

Theranostic strategies in sarcoma: preliminary clinical evidence.

INTRODUCTION: Sarcomas encompass a highly diverse range of malignancies, characterized by varied morphological and molecular profiles. Treatment options in case of therapy-refractory or advanced disease are limited. In this context, theranostics emerges as an innovative platform seamlessly integrating diagnosis and therapy, offering promising prospects. AREAS COVERED: This special report delves into the initial clinical applications of theranostic-based approaches in sarcomas. Specifically, it examines various strategies targeting biomarkers associated with sarcomas, including fibroblast activation protein (FAP), prostate-specific membrane antigen (PSMA), C-X-C chemokine receptor type 4 (CXCR4) and somatostatin receptor 2 (SSTR2). EXPERT OPINION: The heterogeneous uptake of the CXCR4-targeted radioligand in lesions, along with its poor correlation with immunohistochemistry data, diminishes the attractiveness of this theranostic approach in the sarcoma oncological setting. SSTR2-targeted approaches in sarcoma, although potentially effective, are limited to a single case. Early experiences with FAP inhibitors in sarcoma patients have shown particularly promising outcomes, indicating effective disease control with minimal toxicity. While PSMA presents an enticing target for theranostic approaches in sarcomas, its utilization remains anecdotal and requires further investigation. Prospective and well-designed clinical trials are imperative to delineate the potential impact of FAPI- and PSMA-based approaches on sarcoma therapeutic landscapes, offering innovative and personalized treatment options.

Granzyme B PET/CT Imaging Evaluates Early Response to Immunotherapy in Gastric Cancer.

In several malignancies, only a limited number of patients respond to immune checkpoint inhibitors. Predicting and monitoring responses to these inhibitors represent an unmet clinical need. Here, we developed a PET/CT probe targeting granzyme B, [68Ga]Ga-NOTA-Gly-Gly-Gly-Ile-Glu-Pro-Asp-CHO (GSI), and aimed to investigate whether it can be used to monitor the effects of immune checkpoint inhibitors early in the course of therapy. Methods: Seventy-two patients with gastric cancer (stages III-IV) were recruited for [68Ga]Ga-DOTA-GSI PET/CT imaging after 2 or 3 cycles of the immunotherapy, and 40 patients were included in the final analysis. The SUVmax of primary tumors (SUVmax-t), SUVmax of metastatic lymph nodes (SUVmax-LN), and SUVmax of normal tissues (liver and blood pool) were measured, and their target-to-liver background ratio (TLR) and target-to-blood background ratio (TBR) were denoted for primary tumors as TLRtumor and TBRtumor and for metastatic lymph nodes as TLRLN and TBRLN, respectively. The treatment responses were assessed within 1 wk after full-course treatment according to RECIST version 1.1. Wilcoxon rank-sum tests were used to compare the PET/CT parameters between responders and nonresponders. Receiver operating characteristic curve analysis was used to assess the diagnostic efficacy of [68Ga]Ga-DOTA-GSI PET/CT parameters in identifying responders. Two-tailed P value of less than 0.05 was considered statistically significant. Results: We found that SUVmax-t, TLRtumor, TBRtumor, SUVmax-LN, and TBRLN were higher in responders than in nonresponders (2.49 ± 0.58 vs. 1.55 ± 0.48, P = 0.000; 2.24 ± 0.48 vs. 1.74 ± 0.67, P = 0.007; 1.38 ± 0.43 vs. 0.90 ± 0.23, P = 0.000; 2.24 ± 0.99 vs. 1.42 ± 0.55, P = 0.003; and 1.28 ± 0.68 vs. 0.83 ± 0.32, P = 0.012, respectively). According to receiver operating characteristic curve analysis, the area under the curve for SUVmax-t, TBRtumor, TLRtumor, SUVmax-LN, TLRLN, and TBRLN was 0.886, 0.866, 0.746, 0.772, 0.648, and 0.731, respectively. The threshold of SUVmax-t was 2.05, and its sensitivity and specificity were 81.0% and 84.2%, respectively. In addition, multivariate logistic regression indicated that TBRtumor was an independent predictor of treatment response (P = 0.03). Conclusion: Our results indicated that [68Ga]Ga-DOTA-GSI PET/CT is a promising tool for predicting early response to combined immunotherapy in gastric cancer patients.

Feasibility of shortening scan duration of 18F-FDG myocardial metabolism imaging using a total-body PET/CT scanner.

PURPOSE: To evaluate 18F-FDG myocardial metabolism imaging (MMI) using a total-body PET/CT scanner and explore the feasible scan duration to guide the clinical practice. METHODS: A retrospective analysis was conducted on 41 patients who underwent myocardial perfusion-metabolism imaging to assess myocardial viability. The patients underwent 18F-FDG MMI with a total-body PET/CT scanner using a list-mode for 600 s. PET data were trimmed and reconstructed to simulate images of 600-s, 300-s, 120-s, 60-s, and 30-s acquisition time (G600-G30). Images among different groups were subjectively evaluated using a 5-point Likert scale. Semi-quantitative evaluation was performed using standardized uptake value (SUV), myocardial to background activity ratio (M/B), signal to noise ratio (SNR), contrast to noise ratio (CNR), contrast ratio (CR), and coefficient of variation (CV). Myocardial viability analysis included indexes of Mismatch and Scar. G600 served as the reference. RESULTS: Subjective visual evaluation indicated a decline in the scores of image quality with shortening scan duration. All the G600, G300, and G120 images were clinically acceptable (score ≥ 3), and their image quality scores were 4.9 ± 0.3, 4.8 ± 0.4, and 4.5 ± 0.8, respectively (P > 0.05). Moreover, as the scan duration reduced, the semi-quantitative parameters M/B, SNR, CNR, and CR decreased, while SUV and CV increased, and significant difference was observed in G300-G30 groups when comparing to G600 group (P < 0.05). For myocardial viability analysis of left ventricular and coronary segments, the Mismatch and Scar values of G300-G30 groups were almost identical to G600 group (ICC: 0.968-1.0, P < 0.001). CONCLUSION: Sufficient image quality for clinical diagnosis could be achieved at G120 for MMI using a total-body PET/CT scanner, while the image quality of G30 was acceptable for myocardial viability analysis.

Investigation of the distribution of inguinal lymph nodes and delineation of the inguinal clinical target volume using 18F-FDG PET/CT.

OBJECTIVE: Radiotherapy is a crucial treatment modality for pelvic cancers, but uncertainties persist in defining the clinical target volume (CTV) for the inguinal lymphatic drainage region. Suboptimal CTV delineation may compromise treatment efficacy and result in subpar disease control. This study aimed to investigate and map the distribution of lymph node metastases (LNM) in the groin area to facilitate an improved and detailed CTV definition using 18F-fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDG PET/CT). METHODS: Inguinal LNM in patients with biopsy-proven pelvic malignancies were identified using 18F-FDG PET/CT scan. The longitudinally nearest axial plane was determined based on six typical bony landmarks, and the axial direction relative to the femoral artery of LNM was recorded. The distances from the LNM to the nearest edge of the femoral artery were measured on the axial plane. An optimal margin to cover 95% of LNM was estimated to develop contouring recommendations. RESULTS: In this study, 500 positive LNM were identified by 18F-FDG PET/CT among 185 patients with primary pelvic malignancies. Relative to the femoral artery, lymph nodes were distributed laterally (10:00-11:00, n = 35), anteriorly (12:00-1:00, n = 213), and medially (2:00-4: 00, n = 252). For CTV delineation, the recommended distances from the femoral artery on the SFH were lateral 19 mm, anterior 19 mm, and medial 25 mm; on the SGT were lateral 26 mm, anterior 20 mm, and medial 25 mm; on the SPS were lateral 28 mm, anterior 29 mm, and medial 26 mm; on the IPS were anterior 29 mm and medial 28 mm; on the IIT were anterior 27 mm and medial 27 mm; on the ILT were anterior 25 mm and medial 23 mm. Use interpolation to contour the area between six axial slices, including any radiographically suspicious LNM. CONCLUSIONS: Using 18F-FDG PET/CT, we investigated the distribution pattern of inguinal LNM and propose a more comprehensive guideline for inguinal CTV delineation.

Case report: Dynamic 18F-FDG PET/CT display of a bronchial mass as a second primary cancer mimicking mediastinal lymph node in a gastric carcinoma survivor.

A 70-year-old woman underwent distal gastrectomy due to gastric adenocarcinoma in 2015. After 6 years, the follow-up CT revealed a suspicious mass in the right hilar of the lung mimicking mediastinal lymph nodes. Further dynamic PET/CT images showed a mass located in the right intermediate bronchus with increased FDG uptake and relatively high Ki value, which may imply the possibility of malignancy. However, the symmetrical mediastinal lymph nodes had intense FDG uptake but relatively low Ki value, suggesting benign lesions. The initial pathological result of the bronchoscopy biopsy was considered suspicious for metastatic gastric adenocarcinoma. However, it was then found consistent with middle-grade mucoepidermoid carcinoma, considered a second primary cancer without metastatic lymph nodes as confirmed by a surgical procedure (lower bilobectomy + hilar and mediastinal lymphadenectomy). 18F-FDG PET/CT has an important value in the follow-up of indeterminate findings for patients with a tumor history. Moreover, dynamic quantification parameters such as Ki may be additionally helpful in identifying malignancies in some equivocal situations.

The Diagnostic Value of Endobronchial Ultrasound-Guided Fine Needle Aspiration (EBUS-FNA) in Diagnosing FDG-PET-Avid Lymph Nodes in Extrapulmonary Malignancies.

Background and objective The accurate diagnosis of extrapulmonary malignancies with mediastinal lymphadenopathy is crucial for effective patient management. Endobronchial ultrasound-guided fine-needle aspiration (EBUS-FNA) has emerged as a valuable tool in assessing fluorodeoxyglucose (FDG)-positron emission tomography (PET)-avid lymph nodes (LNs). In this study, we aimed to evaluate the diagnostic value of EBUS-FNA in patients with mediastinal lymphadenopathy in extrapulmonary malignancies and compare its efficacy with PET-CT.  Methodology This retrospective, cross-sectional study was conducted at Shaukat Khanum Memorial Cancer Hospital and Research Center, Lahore, from February 2018 to February 2023. It included patients with extrapulmonary malignancies with mediastinal lymphadenopathy displaying abnormal PET-CT uptake, with LN diameters ≥5 mm, excluding lung cancer cases. Data on demographics, malignancy type, LN involvement, PET-CT findings, and EBUS-FNA histopathology were collected. EBUS-FNA procedures involved a 22-gauge needle, and samples were analyzed cytologically and histologically. SPSS Statistics version 20 (IBM Corp., Armonk, NY) was used to perform the statistical analysis. Results The study analyzed a total of 216 patients. Males comprised 56.3% of the cohort, and females 43.7%. The most common malignancy was lymphoma (33.0%), followed by breast cancer (12.6%). EBUS-FNA exhibited a sensitivity of 90.9% compared to PET-CT's sensitivity of 72.7%. Lymph node morphology on EBUS showed low echogenicity and irregular borders in malignant cases. Subcarinal and right hilar were the most frequently sampled lymph nodes. The study found significant differences in lymph node characteristics between non-malignant and malignant groups, with EBUS-FNA effectively identifying malignancies.  Conclusions EBUS-FNA demonstrates high sensitivity and diagnostic utility in identifying malignant lymph nodes in patients with extrapulmonary malignancies. Its effectiveness in detecting true positive cases highlights its importance as a complementary diagnostic tool to PET-CT in oncological diagnostics.

Diagnostic Performance and Interobserver Agreement of Diuretic 18F-Fluorodeoxyglucose Positron Emission Tomography/Computed Tomography in the Diagnosis of Upper Urinary Tract Cancer.

BACKGROUND: Previous reports attempted to evaluate bladder cancer using 18 F-fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) by washing out the excreted FDG with a diuretic. The purpose of this study was to evaluate the value of diuretic FDG PET/plain CT (drtPET/CT) and diuretic FDG PET/contrast-enhanced CT (drtPET/ceCT) in the assessment of upper urinary tract cancers. MATERIALS AND METHODS: A total of 66 patients underwent drtPET/CT for suspected upper urinary tract cancer (UUTC). The study targeted 29 patients who were strongly suspected of having UUTC and underwent magnetic resonance imaging (MRI) of the upper urinary tract. A total of 29 (24 male, five female) patients, with a mean ± SD age of 73 ± 3 (range, 43-84) years, had a suspected neoplasm in the upper urinary tract. They underwent FDG PET/plain and contrast-enhanced CT before and after a diuretic and MRI including diffusion-weighted imaging (DWI). A urologist and a physician board-certified in nuclear medicine and radiology independently interpreted the standard PET/CT (stdPET/CT), drtPET/CT, drtPET/ceCT, ceCT, and MRI with DWI images. Interobserver agreement and the diagnostic performance of each modality were evaluated. RESULTS: The kappa values of stdPET/CT, drtPET/CT, drtPET/ceCT, ceCT, and MRI were 0.381, 0.567, 0.7031, 0.448, and 0.185, respectively, with drtPET/ceCT showing the highest kappa value and the only one with good interobserver agreement (>60%). The area under the curve of drtPET/ceCT was 0.92, which was significantly higher than those of stdPET/CT (P=0.027) and MRI (P=0.047). CONCLUSIONS: In the present study, drtPET/ceCT had the best diagnostic performance and the highest interobserver agreement for detecting upper urinary tract urothelial cancers.

[Position paper of the Austrian Society for Rheumatology and the Austrian Society for Pneumology on the diagnosis and treatment of sarcoidosis 2024]. / Positionspapier der ÖGR und ÖGP zur Diagnose und Therapie der Sarkoidose 2024.

In many cases sarcoidosis is a multisystemic disease that requires interdisciplinary medical cooperation in the diagnostics, treatment and medical care during follow-up. Due to the often chronic course, it is of utmost importance to include patients with their priorities and wishes at an early stage and extensively in disease management and to establish a shared decision making whenever possible. In the process of writing this joint position paper, the expert group on interstitial and orphan lung diseases of the Austrian Society for Pulmonology and the working group on rheumatological lung disorders of the Austrian Society for Rheumatology and Rehabilitation sought to include patient advocacy groups as well as experts for rare organ manifestations of sarcoidosis. This position paper is not only meant to reflect current scientific and clinical standards but should also focus the national expertise and by networking and exchange to be a first step to strengthen cooperation between stakeholders to ultimately improve care for patients with sarcoidosis.

[18F]TFB PET/CT misses intense [124I]iodine-avid metastases after redifferentiation therapy in metastatic thyroid cancer.

BACKGROUND: Fluorine 18-labelled tetrafluoroborate ([18F]TFB) is a substrate for the sodium/iodide symporter. In thyroid cancer, [18F]TFB-PET/CT may be an alternative to iodine imaging to evaluate the extent of disease, eligibility for radioiodine treatment, and success of redifferentiation therapies. We report the results of a pilot study to determine tumor uptake of [18F]TFB and compare its properties to [124I]IodinePET/CT in patients with metastatic thyroid cancer. METHODS: Five patients were included in a prospective study. All patients received PET/CT 1 h after injection of 356 ± 12 MBq [18F]TFB and were given 230 ± 9 MBq [124I]Iodine orally on the same day, followed by PET/CT after 48 h. Before redifferentiation therapy, patients underwent an additional baseline [124I]Iodine PET/CT. Cases were analyzed by two board-certified specialists. Detection rates and Spearman correlation for [18F]TFB and [124I]Iodine were calculated. RESULTS: Three patients had poorly differentiated thyroid cancer and received trametinib in a redifferentiation trial. Two patients had papillary thyroid cancer and did not receive redifferentiation therapy. Of the 33 lesions seen before/without redifferentiation therapy, 19 (58%) were visible on [18F]TFB and 30 (91%) on [124I]Iodine imaging. In the patients who underwent redifferentiation therapy, 48 lesions were newly seen on [124I]Iodine PET/CT with a median SUVmax of 3.3 (range, 0.4-285.0). All of these lesions were [18F]TFB-negative. CONCLUSION: [18F]TFB failed to predict radioactive iodine uptake in patients with poorly differentiated thyroid cancer who underwent redifferentiation therapy with trametinib. It is unclear whether such discrepancies may also occur in other redifferentiation therapies or may even be encountered in redifferentiation-naïve thyroid cancer. TRIAL REGISTRATION NUMBER: NCT03196518, registered on June 22, 2017.

Characteristics of 18F-FDG PET/CT in patients with Kimura's disease from China.

BACKGROUND: 'Kimura's disease (KD) is a rare chronic inflammatory disorder of unknown etiology and is difficult to diagnose due to poor clinical presentation and imaging features. Few studies on characteristics of 18F-FDG PET/CT of KD have been reported. This study aimed to observe the reliable characteristics and usefulness of 18F-FDG PET/CT for the evaluation of consecutive patients with KD. METHODS: The clinical data and 18F-FDG PET/CT imaging findings of 8 patients with pathologically confirmed KD were reviewed retrospectively.18F-FDG PET/CT images were evaluated visually and semiquantitatively by measuring the maximum standardized uptake value (SUVmax). The correlations between clinical data and 18F-FDG PET/CT features were analyzed by simple linear regression. RESULTS: This study included 7 males and one female ranging in age from 17 to 79 years. The longest diameter of lesions ranged from 0.8 cm to 4.8 cm, and regional or generalized lymphadenopathy was found in all 8 patients with eosinophilia, while subcutaneous masses and salivary gland involvement concurrently were found in 4 patients. 18F-FDG PET/CT revealed that these involved lesions had high 18F-FDG uptake with SUVmax > 2.5 (2.6 to 6.3). Moreover, the margin of the lesions was well defined in 6 cases and ill defined in 2 cases, and homogeneous density and 18F-FDG uptake were both found in all these lesions. There was negative correlation between eosinophils and SUVmax (R2 = 0.538). CONCLUSIONS: Kimura's disease should be considered when 18F-FDG PET/CT is characterized by homogeneous lesions of regional or generalized lymphadenopathy, accompanied with subcutaneous masses and salivary gland involvement concurrently, especially in patients with eosinophilia.

Outstanding increase in tumor-to-background ratio over time allows tumor localization by [89Zr]Zr-PSMA-617 PET/CT in early biochemical recurrence of prostate cancer.

BACKGROUND: Positron emission tomography/computed tomography (PET/CT) using prostate-specific membrane antigen (PSMA)-targeted radiotracers labeled with zirconium-89 (89Zr; half-life ~ 78.41 h) showed promise in localizing biochemical recurrence of prostate cancer (BCR) in pilot studies. METHODS: Retrospective analysis of 38 consecutive men with BCR (median [minimum-maximum] prostate-specific antigen 0.52 (0.12-2.50 ng/mL) undergoing [89Zr]Zr-PSMA-617 PET/CT post-negative [68Ga]Ga-PSMA-11 PET/CT. PET/CT acquisition 1-h, 24-h, and 48-h post-injection of a median (minimum-maximum) [89Zr]Zr-PSMA-617 tracer activity of 123 (84-166) MBq. RESULTS: [89Zr]Zr-PSMA-617 PET/CT detected altogether 57 lesions: 18 local recurrences, 33 lymph node metastases, 6 bone metastases in 30/38 men with BCR (78%) and prior negative conventional PSMA PET/CT. Lesion uptake significantly increased from 1-h to 24-h and, in a majority of cases, from 24-h to 48-h. Tumor-to-background ratios significantly increased over time, with absolute increases of 100 or more. No side effects were noted. After [89Zr]Zr-PSMA-617 PET/CT-based treatment, prostate-specific antigen concentration decreased in all patients, becoming undetectable in a third of patients. LIMITATIONS: retrospective, single center design; infrequent histopathological and imaging verification. CONCLUSION: This large series provides further evidence that [89Zr]Zr-PSMA-617 PET/CT is a beneficial imaging modality to localize early BCR. A remarkable increase in tumor-to-background ratio over time allows localization of tumor unidentified on conventional PSMA PET/CT.

Regularity and correlation analysis of regional lymph node metastasis in nonoperative patients with non-small cell lung cancer based on positron emission tomography/computed tomography images.

BACKGROUND: Definitive concurrent chemoradiotherapy (CCRT) is the standard treatment for locally advanced, inoperable non-small cell lung cancer (NSCLC). Previous studies have mainly focused on examining local failure and recurrence patterns after surgery and the principles of lymph node metastasis (LNM) in surgical candidates with NSCLC. However, these studies were just only able to guide postoperative radiotherapy (PORT) and the patterns of LNM in patients with resected NSCLC was inadequate to represent that in locally advanced inoperable NSCLC patients for guiding target volume delineation of CCRT. In this study, we aimed to analyze the metastasis regularities and establish the correlations between different lymph node levels in NSCLC patients without any intervention using positron emission tomography/computed tomography (PET/CT) images. METHODS: Overall, 358 patients with N1-N3 NSCLC admitted in our hospital between 2018 and 2022 were retrospectively analyzed. The diagnosis of metastatic lymph nodes was reviewed and determined using the European Organization for Research and Treatment of Cancer standard and the standardized value of the PET/CT examination. Univariate and multivariate analysis were performed to investigate the correlations between the different levels were evaluated by using of the chi-square test and logistic regression model. RESULTS: The lymph nodes with the highest metastasis rates in patients with left lung cancer were in order as follows: 10L, 4L, 5, 4R, and 7; while in those with right lung cancer they were 10R, 4R, 7, 2R, and 1R. Notably, we found left lung patients were more likely to have contralateral hilar, mediastinal and supraclavicular lymph nodes involved, and the right lung group exhibited a higher propensity for ipsilateral mediastinum and supraclavicular lymph node invasion. Furthermore, correlation analysis revealed there were significant correlative patterns in the LNM across different levels. CONCLUSIONS: This study elucidated the patterns of primary LNM in patients with NSCLC who had not undergone surgery (without any treatment interventions) and the correlations between lymph node levels. These findings were expected to provide useful reference for target volume delineation in definitive concurrent chemoradiotherapy in locally advanced NSCLC patients.

Blood culture-negative Haemophilus endocarditis with large vegetation and the role of bronchoalveolar lavage: a case report.

Background: Blood culture-negative endocarditis (BCNE) is a significant condition associated with cardiac vegetation. It often occurs alongside sepsis, auto-immune diseases, or malignancies, posing a risk of vegetation and embolization. Notable pathogens include Haemophilus species, Cardiobacterium hominis, Eikenella corrodens, and Kingella species. Case summary: A 60-year-old white male Belgian patient presented with worsening dyspnoea. His recent medical history included chronic infections over the past 6 months. Transthoracic echocardiography revealed severe aortic stenosis with an 18 × 12 mm vegetation. Despite normal inflammatory markers and negative blood tests, 18F-fluorodeoxyglucose positron emission tomography with computed tomography excluded malignancy but identified multiple bilateral septic lung emboli. Sputum cultures and tuberculosis polymerase chain reaction (PCR) were negative. Facing the high risk of cardiac embolization and the need for aortic valve replacement, surgery was scheduled with an intraoperative bronchoalveolar lavage (BAL) to investigate the lung lesions. Intraoperative findings confirmed valvular lesions, and a biological aortic valve was successfully implanted. The post-operative course was uneventful. Aortic valve cultures and eubacterial PCR results were negative, but BAL cultures were positive for Haemophilus influenzae, indicating a chronic infection. The patient showed favourable progress at 6 months post-surgery with ongoing antibiotherapy. Discussion: This case illustrates a rare BCNE associated with large vegetation and symptomatic H. influenzae chronic respiratory tract colonization (CRTC). For BCNE cases with negative sputum cultures and suspected bacterial CRTC, we recommend performing BAL cultures for accurate diagnosis.

Exophthalmos as the initial presentation of metastatic prostate cancer.

Primary metastatic prostate cancer to the orbit is exceedingly rare. Benign lesions, including meningioma, have demonstrated PSMA expression and can be visualized using PSMA-based PET tracers. We report the findings of 18F-PSMA-1007 PET/CT in a 76-year-old man with progressive confusion and long-standing blindness of the left eye. PET/CT scan revealed increased uptake of PSMA in the orbital and temporal region, and other sites throughout the body. Histopathological examination after biopsy of the left orbit showed adenocarcinoma of the prostate. This case substantiates the diverse clinical and radiological presentations of metastatic prostate cancer and underscores the diagnostic significance of targeted biopsy.

High-Grade Hepatic Spindle Cell Carcinoma as a Cause of Diffuse Right Hepatic Lobe Hypermetabolism Identified With 18F-Fluorodeoxyglucose Positron Emission Tomography/Computed Tomography (18F-FDG PET/CT) Imaging.

We present a rare case of high-grade spindle cell liver carcinoma investigated using 18F-fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDG PET/CT) in a 70-year-old man with worsened clinical symptoms for more than three months. These include hiccups, belching, loss of appetite, and significant weight loss of 30 kg over the last three months. 18F-FDG PET/CT was employed as part of the initial diagnostic assessment, revealing intense diffuse right hepatic lobe hypermetabolism. Fused PET/CT images revealed a locally confined right hepatic lobe tumor exhibiting heterogeneous metabolic activity with predominant hypermetabolism surrounding two internally contained hypometabolic islands. These findings suggested an aggressive and unusual neoplastic pattern. Ultrasound-guided biopsy confirmed high-grade spindle cell sarcoma of the liver. Unfortunately, the patient passed away shortly thereafter, precluding therapeutic decisions.

Impact of NBP on acute ischemic stroke: Tracking therapy effect on neuroinflammation.

BACKGROUND: Ischemic stroke is the leading cause of death and long-term disability worldwide. After stroke, microglia exhibit not only pro-inflammatory phenotype to aggravate the neuroinflammation, but also anti-inflammatory phenotype to play a neuroprotective role. Studies on the spatial and temporal changes in microglia and the underlying mechanisms help to elucidate the inflammatory cascade after stroke. The regulation of microglia polarization provides new insights for the intervention of post-stroke inflammation. OBJECTIVE: We aimed to investigate the phenotypic change of microglia in the acute phase of ischemic stroke and the effects of Dl-3-n-butylphthalide (NBP) on microglia. TSPO-PET was used to image microglia and evaluate the efficacy of NBP. METHODS: We constructed an MCAO model in rats and administered NBP daily. The infarct volumes in the NBP-treated and control groups were measured. TSPO-PET/CT was used to demonstrate the activation of microglia and the effects of NBP. Additionally, we investigated the effects of NBP on TSPO expression. In vitro, microglia were exposed to glucose oxygen deprivation, and the effects of NBP on microglia and TSPO expression were verified. RESULTS: NBP improved neurological severity scores and reduced infarct volume in the acute phase of ischemic stroke. NBP facilitated microglia to adopt the anti-inflammatory phenotype and reduce the pro-inflammatory phenotype. NBP decreased the expressions of inflammatory cytokines. TSPO-PET/CT observed increase in uptake in the infarct lesion, and this uptake was reduced in response to NBP. NBP reduced TSPO expression in microglia after stroke. In vitro experiments further verified that NBP facilitated the transition of microglia towards the anti-inflammatory phenotype, and inhibited inflammatory cytokine secretion and TSPO expression. CONCLUSION: We illustrated that NBP fosters the shift of microglia towards the anti-inflammatory phenotype while diminishing their inclination towards the pro-inflammatory phenotype, thereby exerting neuroprotective effects. NBP reduces TSPO expression in microglia, which can be observed by TSPO-PET/CT imaging.

Unusual Prostate-Specific Membrane Antigen (PSMA) Splenic Uptake in a Patient With Prostate Cancer.

There are many benefits to early detection of prostate cancer, including improved survival rates, less invasive treatment options, and better quality of life. Apart from traditional tests and imaging (including the prostate-specific antigen (PSA) test, digital rectal exam, biopsy, computed tomography (CT), and magnetic resonance imaging (MRI)), an imaging technique called prostate-specific membrane antigen positron emission tomography (PSMA PET) is more specific and sensitive, targeting PSMA expressed by prostate cancer cells on their surface. This case report describes a 62-year-old male with metastatic prostate adenocarcinoma and unusual PSMA uptake in the spleen. Elevated PSA levels and MRI indicated aggressive prostate cancer, confirmed by a Gleason score of 7 from biopsies. A PSMA PET/CT scan showed intense activity in both the prostate and spleen, initially suggesting metastasis. However, further imaging identified the splenic lesion as a benign hemangioma. This case showcases the importance of thorough diagnostic evaluations for distinguishing metastatic disease from benign conditions to ensure accurate diagnosis and appropriate treatment.

First-in-human infection imaging with 89Zr-labelled leukocytes and comparison of scan quality with [99mTc]Tc-HMPAO-labelled leukocytes.

Introduction: Nuclear medicine infection imaging is routinely performed with the use of leukocytes radiolabelled with technetium-99m hexamethylpropyleneamine oxime ([99mTc]Tc-HMPAO) and single-photon emission computed tomography (SPECT). Positron emission tomography (PET) is more sensitive than SPECT and results in higher-quality images. Zirconium-89 (89Zr) is a positron emitter with a half-life of 78.4 h, which translates to the biological half-life and slow biodistribution of intact cells and allows delayed PET imaging for more accurate biodistribution of the labelled leukocytes to infection foci. A first-in-human study with [89Zr]Zr-oxine-leukocytes in four healthy volunteers was reported in 2022. Our first-in-human study utilising the cell surface labelling approach aimed to image infection in patients with the use of 89Zr-labelled leukocytes, using p-isothiocyanatobenzyl-desferrioxamine B (Df-Bz-NCS) as a bifunctional chelating agent, and to compare the scan quality and biodistribution of [89Zr]Zr-Df-Bz-NCS-labelled leukocytes on PET images to SPECT images obtained with [99mTc]Tc-HMPAO-labelled leukocytes. Methods: Leukocytes were isolated from whole-blood samples of eight patients with clinically and/or radiologically confirmed infection. Isolated leukocytes were labelled with [99mTc]Tc-HMPAO according to standardised methods, and [89Zr]Zr-Df-Bz-NCS according to our previously published radiolabelling method. Whole-body SPECT imaging was performed 2 and 18 h post injection of [99mTc]Tc-HMPAO-labelled leukocytes, and whole-body PET/CT was performed 3 and 24 h post injection of [89Zr]Zr-Df-Bz-NCS-labelled leukocytes in seven patients. Results: Successful [89Zr]Zr-Df-Bz-NCS-leukocyte labelling was achieved. High labelling efficiencies were obtained (81.7% ± 3.6%; n = 8). A mean high viability of [89Zr]Zr-Df-Bz-NCS-labelled leukocytes was observed (88.98% ± 12.51%). The [89Zr]Zr-Df-Bz-NCS-leukocyte labelling efficiency was not significantly affected by the white blood cell count of the patient. The performance of [99mTc]Tc-HMPAO- and [89Zr]Zr-Df-Bz-NCS-labelled leukocytes, in terms of the ability to accurately detect infection, were similar in two out of seven patients, and [99mTc]Tc-HMPAO-labelled leukocytes outperformed [89Zr]Zr-Df-Bz-NCS-labelled leukocytes in one patient with femoral osteomyelitis. However, in two cases of pulmonary pathology, [89Zr]Zr-Df-Bz-NCS-labelled leukocytes demonstrated improved pathological uptake. No skeletal activity was observed in any of the patients imaged with [89Zr]Zr-Df-Bz-NCS-labelled leukocytes, illustrating the in vivo stability of the radiolabel. Discussion: Although the [89Zr]Zr-Df-Bz-NCS-leukocyte labelling aspect of this study was noteworthy, infection imaging did not yield convincingly positive results due to the pulmonary trapping of intravenously administered [89Zr]Zr-Df-Bz-NCS-labelled leukocytes.

Glut-1-Negative Choroidal Malignant Melanoma with Liver Metastasis Recurrence 12 Years after Surgery without FDG Accumulation in a Recurrent Lesion on FDG-PET/CT: a Case Report.

Choroidal malignant melanoma is a rare malignant tumor that develops in adult eyeballs. It causes early lymph node and distant metastasis. Fluorodeoxyglucose (FDG)-positron emission tomography/computed tomography (CT) is widely used for screening malignant melanoma metastases. We encountered a 58-year-old man with choroidal malignant melanoma in whom liver metastasis recurred 12 years after surgery, without any observable FDG accumulation. Immunostaining revealed the absence of glucose transporter type 1 (GLUT-1) expression, crucial for intracellular FDG uptake. The lack of FDG accumulation in the lesion could be attributed to the diminished cellular FDG uptake due to the absence of GLUT-1 expression.