Theranostics with somatostatin receptor antagonists in SCLC: Correlation of 68Ga-SSO120 PET with immunohistochemistry and survival.

Rationale: Positron Emission Tomography (PET) using the somatostatin receptor 2 (SSTR2)-antagonist satoreotide trizoxetan (68Ga-SSO120) is a novel, promising imaging modality for small-cell lung cancer (SCLC), which holds potential for theranostic applications. This study aims to correlate uptake in PET imaging with SSTR2 expression in immunohistochemistry (IHC) and to assess the prognostic value of 68Ga-SSO120 PET at initial staging of patients with SCLC. Methods: We analyzed patients who underwent 68Ga-SSO120 PET/CT during initial diagnostic workup of SCLC as part of institutional standard-of-care. SSTR2 expression in IHC was evaluated on a 4-level scale and correlated with normalized standardized uptake values and tumor-to-liver ratios (SUVmax and TLRpeak) in 68Ga-SSO120 PET on a lesion level. Highest lesion SUVmax/TLRpeak per patient, SSTR2 score in IHC, M status according to TNM classification, and other parameters were analyzed for association with overall survival (OS) and time to treatment failure (TTF) by univariate, multivariate (cut-off values were identified on data for best separation), and stratified Cox regression. Results: We included 54 patients (24 men/30 women, median age 65 years, 21 M0/33 M1 according to TNM classification). In 43 patients with available surplus tumor tissue samples, hottest lesion SUVmax/TLRpeak showed a significant correlation with the level of SSTR2-expression by tumor cells in IHC (Spearman's rho 0.86/0.81, both p < 0.001; ANOVA p < 0.001). High SSTR2 expression in IHC, 68Ga-SSO120 SUVmax and TLRpeak of the hottest lesion per patient, whole-body TLRmean, MTV, TLG, M status, and serum LDH showed a significant association with inferior TTF/OS in univariate analysis. In separate multivariate Cox regression (including sex, age, M stage, and LDH) higher hottest-lesion TLRpeak showed a significant association with shorter OS (HR = 0.26, 95%CI: 0.08-0.84, p = 0.02) and SSTR2 expression in IHC with significantly shorter TTF (HR = 0.24, 95%CI: 0.08-0.71, p = 0.001) and OS (HR = 0.22, 95%CI: 0.06-0.84, p = 0.03). In total, 12 patients (22.2%) showed low (< 1), 21 (38.9%) intermediate (≥ 1 but < 2), 14 (25.9%) high (≥ 2 but < 5), and 7 (13.0%) very high (≥ 5) whole-body mean TLRmean. Conclusion: In patients with SCLC, SSTR2 expression assessed by 68Ga-SSO120 PET and by IHC were closely correlated and associated with shorter survival. More than 75% of patients showed higher whole-body 68Ga-SSO120 tumor uptake than liver uptake and almost 40% high or very high uptake, possibly paving the way towards theranostic applications.

Aspergillus fumigatus: Is Dual-Tracer 18FDG/68Ga-FAPI PET/CT Capable of Distinguishing Fungal Infection and Unspecific Inflammation From Recurrent Lung Cancer?

ABSTRACT: A 61-year-old woman, referred for recurrent pneumonia over a period of 3 months with insufficient response to antibiotic treatment, presented with coughing and intense right-sided chest pain. Previously, she underwent right upper lobectomy for locally advanced non-small cell lung cancer (squamous cell carcinoma) followed by adjuvant chemotherapy and subsequent partial chest wall resection with polytetrafluoroethylene net insert due to a pleurocutaneous fistula. 18FDG plus a 68Ga-labeled fibroblast activation protein inhibitor (68Ga-FAPI) PET/CT scans were performed to rule out non-small cell lung cancer recurrence. Pathological workup with bronchoscopy and endobronchial ultrasound-guided transbronchial fine-needle aspiration of the lymph nodes showed no evidence of malignancy, but microbiology confirmed Aspergillus fumigatus infection of the middle lobe. Thus, the patient transitioned from antibiotic to antifungal therapy; no second-line oncologic treatment was initiated.

2,5-Dimethoxy-4-iodoamphetamine and altanserin induce region-specific shifts in dopamine and serotonin metabolization pathways in the rat brain.

PURPOSE: For understanding the neurochemical mechanism of neuropsychiatric conditions associated with cognitive deficits it is of major relevance to elucidate the influence of serotonin (5-HT) agonists and antagonists on memory function as well dopamine (DA) and 5-HT release and metabolism. In the present study, we assessed the effects of the 5-HT2A receptor agonist 2,5-dimethoxy-4-iodoamphetamine (DOI) and the 5-HT2A receptor altanserin (ALT) on object and place recognition memory and cerebral neurotransmitters and metabolites in the rat. METHODS: Rats underwent a 5-min exploration trial in an open field with two identical objects. After systemic injection of a single dose of either DOI (0.1 mg/kg), ALT (1 mg/kg) or the respectice vehicle (0.9 % NaCl, 50 % DMSO), rats underwent a 5-min test trial with one of the objects replaced by a novel one and the other object transferred to a novel place. Upon the assessment of object exploration and motor/exploratory behaviors, rats were sacrificed. DA, 5-HT and metabolite levels were analyzed in cingulate (CING), caudateputamen (CP), nucleus accumbens (NAC), thalamus (THAL), dorsal (dHIPP) and ventral hippocampus (vHIPP), brainstem and cerebellum with high performance liquid chromatography. RESULTS: DOI decreased rearing but increased head-shoulder motility relative to vehicle. Memory for object and place after both DOI and ALT was not different from vehicle. Network analyses indicated that DOI inhibited DA metabolization in CING, CP, NAC, and THAL, but facilitated it in dHIPP. Likewise, DOI inhibited 5-HT metabolization in CING, NAC, and THAL. ALT facilitated DA metabolization in the CING, NAC, dHIPP, vHIPP, and CER, but inhibited it in the THAL. Additionally, ALT facilitated 5-HT metabolization in NAC and dHIPP. CONCLUSIONS: DOI and ALT differentially altered the quantitative relations between the neurotransmitter/metabolite levels in the individual brain regions, by inducing region-specific shifts in the metabolization pathways. Findings are relevant for understanding the neurochemistry underlying DAergic and/or 5-HTergic dysfunction in neurological and psychiatric conditions.

Fibroblast Activation Protein-Directed Imaging Outperforms 18F-FDG PET/CT in Malignant Mesothelioma: A Prospective, Single-Center, Observational Trial.

The fibroblast activation protein (FAP) is highly expressed in tumor and stromal cells of mesothelioma and thus is an interesting imaging and therapeutic target. Previous data on PET imaging with radiolabeled FAP inhibitors (FAPIs) suggest high potential for superior tumor detection. Here, we report the data of a large malignant pleural mesothelioma cohort within a 68Ga-FAPI46 PET observational trial (NCT04571086). Methods: Of 43 eligible patients with suspected or proven malignant mesothelioma, 41 could be included in the data analysis of the 68Ga-FAPI46 PET observational trial. All patients underwent 68Ga-FAPI46 PET/CT, contrast-enhanced CT, and 18F-FDG PET/CT. The primary study endpoint was the association of 68Ga-FAPI46 PET uptake intensity and histopathologic FAP expression. Furthermore, secondary endpoints were detection rate and sensitivity, specificity, and positive and negative predictive values as compared with 18F-FDG PET/CT. Datasets were interpreted by 2 masked readers. Results: The primary endpoint was met, and the association between 68Ga-FAPI46 SUVmax or SUVpeak and histopathologic FAP expression was significant (SUVmax: r = 0.49, P = 0.037; SUVpeak: r = 0.51, P = 0.030).68Ga-FAPI46 and 18F-FDG showed similar sensitivity by histopathologic validation on a per-patient (100.0% vs. 97.3%) and per region (98.0% vs. 95.9%) basis. Per-region analysis revealed higher 68Ga-FAPI46 than 18F-FDG specificity (81.1% vs. 36.8%) and positive predictive value (87.5% vs. 66.2%). Conclusion: We confirm an association of 68Ga-FAPI46 uptake and histopathologic FAP expression in mesothelioma patients. Additionally, we report high sensitivity and superior specificity and positive predictive value for 68Ga-FAPI46 versus 18F-FDG.

C-reactive protein as robust laboratory value associated with prognosis in patients with stage III non-small cell lung cancer (NSCLC) treated with definitive radiochemotherapy.

To evaluate the prognostic value of biomarkers from peripheral blood obtained as routine laboratory assessment for overall survival in a cohort of stage III non-small cell lung cancer (NSCLC) patients treated with definitive radiochemotherapy at a high-volume cancer center. Seven blood biomarkers from 160 patients treated with definitive radiochemotherapy for stage III NSCLC were analyzed throughout the course treatment. Parameters were preselected using univariable and multivariable proportional hazards analysis and were assessed for internal validity using leave-one-out cross validation. Cross validated classifiers including biomarkers in addition to important clinical parameters were compared with classifiers containing the clinical parameters alone. An increased C-reactive protein (CRP) value in the final week of radiotherapy was found as a prognostic factor for overall survival, both as a continuous (HR 1.099 (1.038-1.164), p < 0.0012) as well as categorical variable splitting data at the median value of 1.2 mg/dl (HR 2.214 (1.388-3.531), p < 0.0008). In the multivariable analysis, the CRP value-maintained significance with an HR of 1.105 (1.040-1.173) and p-value of 0.0012. The cross validated classifier using CRP at the end of radiotherapy in addition to clinical parameters separated equally sized high and low risk groups more distinctly than a classifier containing the clinical parameters alone (HR = 2.786 (95% CI 1.686-4.605) vs. HR = 2.287 (95% CI 1.407-3.718)). Thus, the CRP value at the end of radiation therapy has successfully passed the crucial cross-validation test. The presented data on CRP levels suggests that inflammatory markers may become increasingly important during definitive radiochemotherapy, particularly with the growing utilization of immunotherapy as a consolidation therapy for stage III NSCLC.

The Incidence of Distant Metastases in Patients with Pleural Mesothelioma Screened for a Multimodal Approach: How Much Staging Do We Really Need?

Pleural mesothelioma (PM) is a very aggressive malignancy with a poor prognosis. Most patients receive systemic treatment only; however, some patients may benefit from multimodality treatment. A precise staging of patients undergoing multimodal treatment is mandatory. We investigated the pattern of metastasis in a cohort of patients screened for multimodal treatment to define the extent of staging examinations. Additionally, we investigated the occurrence of metastasis during follow-up. We investigated a single-center experience of 545 patients newly diagnosed and/or treated with PM between the years 2010 and 2022. Patients who were treated naïvely and had a whole set of imaging of the brain were included and further analyzed. A total of 54% of all patients with cerebral imaging had an available 18FDG-PET CT scan. We also recorded metastasis during treatment follow-up. There were 110 patients who had a whole set of imaging (CT = 89% and MRI = 11%) of the brain, and 54% of all patients with cerebral imaging had an available 18FDG-PET CT scan. We identified four patients with cerebral metastasis at the time of first diagnosis, which means that 5.4% of the cohort had cerebral metastasis and 13.3% of all patients in the subgroup with complete data of 18FDG-PET CT had distant non-cerebral metastasis. During the longitudinal follow-up, we found 11 patients with newly diagnosed metastases after a median time of 1.6 years (range: 2 months to 3.3 years) after first diagnosis without metastases. Distant metastases are more frequent in mesothelioma patients than previously thought. This implies that extensive staging is needed for patients selected for multimodal treatment, including brain imaging and 18FDG-PET CT.

Prognostic Implications of 68Ga-FAPI-46 PET/CT-Derived Parameters on Overall Survival in Various Types of Solid Tumors.

Tumoral fibroblast activation protein expression is associated with proliferation and angiogenesis and can be visualized by PET/CT. We examined the prognostic value of [68Ga]Ga-fibroblast activation protein inhibitor (FAPI) (68Ga-FAPI)-46 PET/CT for different tumor entities in patients enrolled in 2 prospective imaging studies (NCT05160051, n = 30; NCT04571086, n = 115). Methods: Within 4 wk, 145 patients underwent 68Ga-FAPI-46 and [18F]FDG (18F-FDG) PET/CT. The association between overall survival (OS) and sex, age, tumor entity, total lesion number, highest SUVmax, and the presence of each nodal, visceral, and bone metastasis was tested using univariate Cox regression analysis. Multivariate analyses were performed for prognostic factors with P values of less than 0.05. Results: In the univariate analysis, shorter OS was associated with total lesion number and the presence of nodal, visceral, and bone metastases on 68Ga-FAPI-46 PET/CT (hazard ratio [HR], 1.06, 2.18, 1.69, and 2.05; P < 0.01, < 0.01, = 0.04, and = 0.02, respectively) and 18F-FDG PET/CT (HR, 1.05, 2.31, 1.76, and 2.30; P < 0.01, < 0.01, = 0.03, and < 0.01, respectively) and with SUVmax on 68Ga-FAPI-46 PET/CT (HR, 1.03; P = 0.03). In the multivariate analysis, total lesion number on 68Ga-FAPI-46 PET/CT was an independent risk factor for shorter OS (HR, 1.05; P = 0.02). In patients with pancreatic cancer, shorter OS was associated with total lesion number on 68Ga-FAPI-46 PET/CT (HR, 1.09; P < 0.01) and bone metastases on 18F-FDG PET/CT (HR, 31.39; P < 0.01) in the univariate analysis and with total lesion number on 68Ga-FAPI-46 PET/CT (HR, 1.07; P = 0.04) in the multivariate analyses. In breast cancer, total lesion number on 68Ga-FAPI-46 PET/CT (HR, 1.07; P = 0.02), as well as bone metastases on 18F-FDG PET/CT (HR, 9.64; P = 0.04), was associated with shorter OS in the univariate analysis. The multivariate analysis did not reveal significant prognostic factors. In thoracic cancer (lung cancer and pleural mesothelioma), the univariate and multivariate analyses did not reveal significant prognostic factors. Conclusion: Disease extent on 68Ga-FAPI-46 PET/CT is a predictor of short OS and may aid in future risk stratification by playing a supplemental role alongside 18F-FDG PET/CT.

5-HT1A and 5-HT2A receptor effects on recognition memory, motor/exploratory behaviors, emotionality and regional dopamine transporter binding in the rat.

Both dopamine (DA) and serotonin (5-HT) play key roles in numerous functions including motor control, stress response and learning. So far, there is scarce or conflicting evidence about the effects of 5-HT1A and 5-HT2A receptor (R) agonists and antagonists on recognition memory in the rat. This also holds for their effect on cerebral DA as well as 5-HT release. In the present study, we assessed the effects of the 5-HT1AR agonist 8-OH-DPAT and antagonist WAY100,635 and the 5-HT2AR agonist DOI and antagonist altanserin (ALT) on rat behaviors. Moreover, we investigated their impact on monoamine efflux by measuring monoamine transporter binding in various regions of the rat brain. After injection of either 8-OH-DPAT (3 mg/kg), WAY100,635 (0.4 mg/kg), DOI (0.1 mg/kg), ALT (1 mg/kg) or the respective vehicle (saline, DMSO), rats underwent an object and place recognition memory test in the open field. Upon the assessment of object exploration, motor/exploratory parameters and feces excretion, rats were administered the monoamine transporter radioligand N-o-fluoropropyl-2b-carbomethoxy-3b-(4-[123I]iodophenyl)-nortropane ([123I]-FP-CIT; 8.9 ± 2.6 MBq) into the tail vein. Regional radioactivity accumulations in the rat brain were determined post mortem. Compared vehicle, administration of 8-OH-DPAT impaired memory for place, decreased rearing behavior, and increased ambulation as well as head-shoulder movements. DOI administration led to a reduction in rearing behavior but an increase in head-shoulder motility relative to vehicle. Feces excretion was diminished after ALT relative to vehicle. Dopamine transporter (DAT) binding was increased in the caudateputamen (CP), but decreased in the nucleus accumbens (NAC) after 8-OH-DPAT relative to vehicle. Moreover, DAT binding was decreased in the NAC after ALT relative to vehicle. Findings indicate that 5-HT1AR inhibition and 5-HT2AR activation may impair memory for place. Furthermore, results imply associations not only between recognition memory, motor/exploratory behavior and emotionality but also between the respective parameters and the levels of available DA in CP and NAC.

Early Metabolic Response by PET Predicts Sensitivity to Next-Line Targeted Therapy in EGFR-Mutated Lung Cancer with Unknown Mechanism of Acquired Resistance.

Targeted therapy with epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs) has established the precision oncology paradigm in lung cancer. Most patients with EGFR-mutated lung cancer respond but eventually acquire resistance. Methods: Patients exhibiting the EGFR p.T790M resistance biomarker benefit from sequenced targeted therapy with osimertinib. We hypothesized that metabolic response as detected by 18F-FDG PET after short-course osimertinib identifies additional patients susceptible to sequenced therapy. Results: Fourteen patients with EGFR-mutated lung cancer and resistance to first- or second-generation EGFR TKI testing negatively for EGFR p.T790M were enrolled in a phase II study. Five patients (36%) achieved a metabolic 18F-FDG PET response and continued osimertinib. In those, the median duration of treatment was not reached (95% CI, 24 mo to not estimable), median progression-free survival was 18.7 mo (95% CI, 14.6 mo to not estimable), and median overall survival was 41.5 mo. Conclusion: Connecting theranostic osimertinib treatment with early metabolic response assessment by PET enables early identification of patients with unknown mechanisms of TKI resistance who derive dramatic clinical benefit from sequenced osimertinib. This defines a novel paradigm for personalization of targeted therapies in patients with lung cancer dependent on a tractable driver oncogene.

Neoadjuvant nivolumab with or without relatlimab in resectable non-small-cell lung cancer: a randomized phase 2 trial.

Antibodies targeting the immune checkpoint molecules PD-1, PD-L1 and CTLA-4, administered alone or in combination with chemotherapy, are the standard of care in most patients with metastatic non-small-cell lung cancers. When given before curative surgery, tumor responses and improved event-free survival are achieved. New antibody combinations may be more efficacious and tolerable. In an ongoing, open-label phase 2 study, 60 biomarker-unselected, treatment-naive patients with resectable non-small-cell lung cancer were randomized to receive two preoperative doses of nivolumab (anti-PD-1) with or without relatlimab (anti-LAG-3) antibody therapy. The primary study endpoint was the feasibility of surgery within 43 days, which was met by all patients. Curative resection was achieved in 95% of patients. Secondary endpoints included pathological and radiographic response rates, pathologically complete resection rates, disease-free and overall survival rates, and safety. Major pathological (≤10% viable tumor cells) and objective radiographic responses were achieved in 27% and 10% (nivolumab) and in 30% and 27% (nivolumab and relatlimab) of patients, respectively. In 100% (nivolumab) and 90% (nivolumab and relatlimab) of patients, tumors and lymph nodes were pathologically completely resected. With 12 months median duration of follow-up, disease-free survival and overall survival rates at 12 months were 89% and 93% (nivolumab), and 93% and 100% (nivolumab and relatlimab). Both treatments were safe with grade ≥3 treatment-emergent adverse events reported in 10% and 13% of patients per study arm. Exploratory analyses provided insights into biological processes triggered by preoperative immunotherapy. This study establishes the feasibility and safety of dual targeting of PD-1 and LAG-3 before lung cancer surgery.ClinicalTrials.gov Indentifier: NCT04205552 .

Impact of Bronchoscopic Lung Volume Reduction with Valves on the Pulmonary Gas Exchange.

Introduction: Bronchoscopic lung volume reduction (BLVR) with endobronchial valves has been shown to be a safe and effective treatment for patients with severe lung emphysema. Previous studies have reported a benefit in pulmonary function, exercise capacity, and quality of life after BLVR-treatment. The effect of BLVR with valves on the pulmonary gas exchange and its association with clinical outcomes has not been analyzed to date. The primary goal of this study was to investigate the impact of BLVR on the pulmonary gas exchange and the impact of the target lobe selection in patients with discordant target lobes in high-resolution computed tomography (HRCT) scan and perfusion scan on the pulmonary gas exchange and clinical outcomes. Methods: In this single-center study, we retrospectively analyzed pulmonary function tests, 6-min-walk-tests, HRCT scans, perfusion scans, and blood gas analyses in 77 patients over the course of 6 months following BLVR treatment. Results: We observed that complete lobar occlusion with bronchoscopic valves leads to a transient impairment of pulmonary gas exchange. Despite this, an overall positive clinical outcome could be shown in patients treated with endobronchial valves. If the target lobe selection based on HRCT and perfusion scans is discrepant, a selection based on the HRCT scan tends to be associated with a better outcome than a selection based on the perfusion scan. Conclusions: Complete lobar occlusion with bronchoscopic valves leads to a transient impairment of pulmonary gas exchange but nevertheless results in an overall positive clinical outcome.

Body composition impacts outcome of bronchoscopic lung volume reduction in patients with severe emphysema: a fully automated CT-based analysis.

Chronic Obstructive Pulmonary Disease (COPD) is characterized by progressive and irreversible airflow limitation, with individual body composition influencing disease severity. Severe emphysema worsens symptoms through hyperinflation, which can be relieved by bronchoscopic lung volume reduction (BLVR). To investigate how body composition, assessed through CT scans, impacts outcomes in emphysema patients undergoing BLVR. Fully automated CT-based body composition analysis (BCA) was performed in patients with end-stage emphysema receiving BLVR with valves. Post-interventional muscle and adipose tissues were quantified, body size-adjusted, and compared to baseline parameters. Between January 2015 and December 2022, 300 patients with severe emphysema underwent endobronchial valve treatment. Significant improvements were seen in outcome parameters, which were defined as changes in pulmonary function, physical performance, and quality of life (QoL) post-treatment. Muscle volume remained stable (1.632 vs. 1.635 for muscle bone adjusted ratio (BAR) at baseline and after 6 months respectively), while bone adjusted adipose tissue volumes, especially total and pericardial adipose tissue, showed significant increase (2.86 vs. 3.00 and 0.16 vs. 0.17, respectively). Moderate to strong correlations between bone adjusted muscle volume and weaker correlations between adipose tissue volumes and outcome parameters (pulmonary function, QoL and physical performance) were observed. Particularly after 6-month, bone adjusted muscle volume changes positively corresponded to improved outcomes (ΔForced expiratory volume in 1 s [FEV1], r = 0.440; ΔInspiratory vital capacity [IVC], r = 0.397; Δ6Minute walking distance [6MWD], r = 0.509 and ΔCOPD assessment test [CAT], r = -0.324; all p < 0.001). Group stratification by bone adjusted muscle volume changes revealed that groups with substantial muscle gain experienced a greater clinical benefit in pulmonary function improvements, QoL and physical performance (ΔFEV1%, 5.5 vs. 39.5; ΔIVC%, 4.3 vs. 28.4; Δ6MWDm, 14 vs. 110; ΔCATpts, -2 vs. -3.5 for groups with ΔMuscle, BAR% < -10 vs. > 10, respectively). BCA results among patients divided by the minimal clinically important difference for forced expiratory volume of the first second (FEV1) showed significant differences in bone-adjusted muscle and intramuscular adipose tissue (IMAT) volumes and their respective changes after 6 months (ΔMuscle, BAR% -5 vs. 3.4 and ΔIMAT, BAR% -0.62 vs. 0.60 for groups with ΔFEV1 ≤ 100 mL vs > 100 mL). Altered body composition, especially increased muscle volume, is associated with functional improvements in BLVR-treated patients.

Diagnostic Accuracy of 68Ga-FAPI Versus 18F-FDG PET in Patients with Various Malignancies.

To assess the diagnostic accuracy of 68Ga-labeled fibroblast activation protein inhibitor (FAPI) and 18F-labeled FDG PET for the detection of various tumors, we performed a head-to-head comparison of both imaging modalities across a range of tumor entities as part of our ongoing 68Ga-FAPI PET observational trial. Methods: The study included 115 patients with 8 tumor entities who received imaging with 68Ga-FAPI for tumor staging or restaging between October 2018 and March 2022. Of those, 103 patients received concomitant imaging with 68Ga-FAPI and 18F-FDG PET and had adequate lesion validation for accuracy analysis. Each scan was evaluated for the detection of primary tumor, lymph nodes, and visceral and bone metastases. True or false positivity and negativity to detected lesions was assigned on the basis of histopathology from biopsies or surgical excision, as well as imaging validation. Results: 68Ga-FAPI PET revealed higher accuracy than 18F-FDG PET in the detection of colorectal cancer (n = 14; per-patient, 85.7% vs. 78.6%; per-region, 95.6% vs. 91.1%) and prostate cancer (n = 22; per-patient, 100% vs. 90.9%; per-region, 96.4% vs. 92.7%). 68Ga-FAPI PET and 18F-FDG PET had comparable per-patient accuracy in detecting breast cancer (n = 16, 100% for both) and head and neck cancers (n = 10, 90% for both modalities). 68Ga-FAPI PET had lower per-patient accuracy than 18F-FDG PET in cancers of the bladder (n = 12, 75% vs. 100%) and kidney (n = 10, 80% vs. 90%), as well as lymphoma (n = 9, 88.9% vs. 100%) and myeloma (n = 10, 80% vs. 90%). Conclusion: 68Ga-FAPI PET demonstrated higher diagnostic accuracy than 18F-FDG PET in the diagnosis of colorectal cancer and prostate cancer, as well as comparable diagnostic performance for cancers of the breast and head and neck. Accuracy and impact on management will be further assessed in an ongoing prospective interventional trial (NCT05160051).

LIONS PREY: A New Logistic Scoring System for the Prediction of Malignant Pulmonary Nodules.

OBJECTIVES: Classifying radiologic pulmonary lesions as malignant is challenging. Scoring systems like the Mayo model lack precision in predicting the probability of malignancy. We developed the logistic scoring system 'LIONS PREY' (Lung lesION Score PREdicts malignancY), which is superior to existing models in its precision in determining the likelihood of malignancy. METHODS: We evaluated all patients that were presented to our multidisciplinary team between January 2013 and December 2020. Availability of pathological results after resection or CT-/EBUS-guided sampling was mandatory for study inclusion. Two groups were formed: Group A (malignant nodule; n = 238) and Group B (benign nodule; n = 148). Initially, 22 potential score parameters were derived from the patients' medical histories. RESULTS: After uni- and multivariate analysis, we identified the following eight parameters that were integrated into a scoring system: (1) age (Group A: 64.5 ± 10.2 years vs. Group B: 61.6 ± 13.8 years; multivariate p-value: 0.054); (2) nodule size (21.8 ± 7.5 mm vs. 18.3 ± 7.9 mm; p = 0.051); (3) spiculation (73.1% vs. 41.9%; p = 0.024); (4) solidity (84.9% vs. 62.8%; p = 0.004); (5) size dynamics (6.4 ± 7.7 mm/3 months vs. 0.2 ± 0.9 mm/3 months; p < 0.0001); (6) smoking history (92.0% vs. 43.9%; p < 0.0001); (7) pack years (35.1 ± 19.1 vs. 21.3 ± 18.8; p = 0.079); and (8) cancer history (34.9% vs. 24.3%; p = 0.052). Our model demonstrated superior precision to that of the Mayo score (p = 0.013) with an overall correct classification of 96.0%, a calibration (observed/expected-ratio) of 1.1, and a discrimination (ROC analysis) of AUC (95% CI) 0.94 (0.92-0.97). CONCLUSIONS: Focusing on essential parameters, LIONS PREY can be easily and reproducibly applied based on computed tomography (CT) scans. Multidisciplinary team members could use it to facilitate decision making. Patients may find it easier to consent to surgery knowing the likelihood of pulmonary malignancy. The LIONS PREY app is available for free on Android and iOS devices.

NET-Induced Carcinoid Heart Disease Affecting Both Tricuspid and Aortic Valves Due to Patent Foramen Ovale and Right/Left Shunt: A Multi-imaging Challenge to Nuclear Medicine.

ABSTRACT: Carcinoid heart disease (Hedinger syndrome) is a long-term consequence in hormone-active neuroendocrine tumors with hepatic metastases and carcinoid syndrome. Because of serotonin, excess multiple cardiac and pulmonary symptoms evolve, which are further complicated by a patent foramen ovale due to right-left shunting. We present a 53-year-old man with an ileum-neuroendocrine tumor including gross liver metastases and long-term stable disease who subsequently developed Hedinger syndrome. Initially experiencing progressive dyspnea, he eventually experienced severe hypoxemia due to patent foramen ovale. 99mTc-MAA lung perfusion scintigraphy quantitatively identified the right-left shunting, whereas 68Ga-FAPI-46 PET/CT characterized the typical fibrous heart valve thickening due to serotonin-induced fibroblast proliferative properties.

Oncologic Staging with 68Ga-FAPI PET/CT Demonstrates a Lower Rate of Nonspecific Lymph Node Findings Than 18F-FDG PET/CT.

Nonspecific lymph node uptake on 18F-FDG PET/CT imaging is a significant pitfall for tumor staging. Fibroblast activation protein α expression on cancer-associated fibroblasts and some tumor cells is less sensitive to acute inflammatory stimuli, and fibroblast activation protein-directed PET may overcome this limitation. Methods: Eighteen patients from our prospective observational study underwent 18F-FDG and 68Ga fibroblast activation protein inhibitor (FAPI) PET/CT scans within a median of 2 d (range, 0-22 d). Lymph nodes were assessed on histopathology and compared with SUV measurements. Results: On a per-patient basis, lymph nodes were rated malignant in 10 (56%) versus 7 (39%) patients by 18F-FDG PET/CT versus 68Ga-FAPI PET/CT scans, respectively, with a respective accuracy of 55% versus 94% for true lymph node metastases. Five of 6 (83%) false-positive nodes on the 18F-FDG PET/CT scans were rated true negative by the 68Ga-FAPI PET/CT scans. On a per-lesion basis, tumor detection rates were similar (85/89 lesions, 96%). Conclusion: 68Ga-FAPI PET/CT imaging demonstrated higher accuracy for true nodal involvement and therefore has the potential to replace 18F-FDG PET/CT imaging for cancer staging.

68Ga-SSO-120 PET for Initial Staging of Small Cell Lung Cancer Patients: A Single-Center Retrospective Study.

PET imaging using the somatostatin receptor 2 (SSTR2) antagonist satoreotide trizoxetan (SSO-120, previously OPS-202) could offer accurate tumor detection and screening for SSTR2-antagonist radionuclide therapy in patients with SSTR2-expressing small cell lung cancer (SCLC). The aim of this single-center study was to investigate tumor uptake and detection rates of 68Ga-SSO-120 in comparison to 18F-FDG PET in the initial staging of SCLC patients. Methods: Patients with newly diagnosed SCLC who underwent additional whole-body 68Ga-SSO-120 PET/CT during the initial diagnostic workup were retrospectively included. The mean administered activity was 139 MBq, and the mean uptake time was 60 min. Gold-standard staging 18F-FDG PET/CT was evaluated if available within 2 wk before or after 68Ga-SSO-120 PET if morphologic differences in CT images were absent. 68Ga-SSO-120- or 18F-FDG-positive lesions were reported in 7 anatomic regions (primary tumor, thoracic lymph node metastases, and distant metastases including pleural, contralateral pulmonary, liver, bone, and other) according to the TNM classification for lung cancer (eighth edition). Consensus TNM staging (derived from CT, endobronchial ultrasound-guided transbronchial needle aspiration, PET, and brain MRI) by a clinical tumor board served as the reference standard. Results: Thirty-one patients were included, 12 with limited and 19 with extensive disease according to the Veterans Administration Lung Study Group classification. 68Ga-SSO-120-positive tumor was detected in all patients (100%) and in 90 of the 217 evaluated regions (41.5%). Thirteen patients (42.0%) had intense average 68Ga-SSO-120 uptake (region-based mean SUVmax ≥ 10); 28 patients (90.3%) had average 68Ga-SSO-120 uptake greater than liver uptake (region-based mean peak tumor-to-liver ratio > 1). In 25 patients with evaluable 18F-FDG PET, primary tumor, thoracic lymph node metastases, and distant metastases were detected in 100%, 92%, and 64%, respectively, of all investigated patients by 68Ga-SSO-120 and in 100%, 92%, and 56%, respectively, by 18F-FDG PET. 68Ga-SSO-120 PET detected additional contralateral lymph node, liver, and brain metastases in 1, 1, and 2 patients, respectively (no histopathology available), and 18F-FDG PET detected additional contralateral lymph node metastases in 3 patients (1 confirmed, 1 systematic endobronchial ultrasound-guided transbronchial needle aspiration-negative, and 1 without available histopathology). None of these differences altered Veterans Administration Lung Study Group staging. The region-based monotonic correlation between 68Ga-SSO-120 and 18F-FDG uptake was low (Spearman ρ = 0.26-0.33). Conclusion: 68Ga-SSO-120 PET offers high diagnostic precision with comparable detection rates and additional complementary information to the gold standard, 18F-FDG PET. Consistent uptake in most patients warrants exploration of SSTR2-directed radionuclide therapy.

Accuracy of nodal staging by 18F-FDG-PET/CT in limited disease small-cell lung cancer.

BACKGROUND: Small-cell lung cancer (SCLC) is highly aggressive with a nearly incurable disease in most cases. The most important prognostic factor is the status of the mediastinal lymph nodes. Only a small proportion of patients can be diagnosed at early stages and directed to curative multimodal treatment. Therefore, accuracy of nodal staging by (18F)-Fluoro-2-deoxyglucose (FDG) positron emission tomography (PET) computed tomography (18F-FDG-PET/CT) in (very) limited disease SCLC, although not well investigated, is highly important. METHODS: Treatment naive, non-bulky patients treated or diagnosed with SCLC between June 2012 and April 2020 with complete data including FDG-PET/CT and invasive mediastinal staging were retrospectively analyzed (n = 19). Sensitivity, specificity, negative predictive value (NPV), positive predictive value (PPV) and accuracy of mediastinal lymph node staging of 18F-FDG-PET/CT was calculated. RESULTS: The FDG-PET/CT showed a sensitivity of 91%, and the specificity was calculated as 87.5%. In this cohort, the disease prevalence in lymph nodes was 58% (n = 11). Positive predictive value was 91%, NPV 88% and accuracy calculated at 89%. One patient was upstaged from single-level N2 to multilevel N2. In one patient, upstaging in invasive staging was performed from N2 to N3, and one patient was downstaged from N1 to N0. CONCLUSIONS: FDG-PET/CT is a valuable tool for the detection of distant metastases, but in mediastinal staging of SCLC some limitations might remain. Invasive methods remain the gold standard. Therefore, the mediastinal lymph nodal status of patients with SCLC screened for multimodal treatment should be further evaluated by additional invasive techniques to verify the exact N-staging and to optimize treatment stratification.

DOTATOC PET/CT imaging of a typical carcinoid tumor in a human ex-vivo perfused lung lobe.

The use of Isolated lung perfusion (ILP), combined with medical imaging modalities such as positron emission tomography-computed tomography (PET/CT), provides real-time visualization of tumors in ventilated and perfused vital lung tissue. This experiment intends to show the feasibility and benefits of using ILP combined with PET/CT imaging. Following lung surgery on a 49-year-old male, his left lower lobectomy specimen, which held a typical carcinoid tumor, was preserved on normothermic ILP. Gallium-68-Edotreotide ([68Ga]-DOTATOC) was administered into the ILP circuit, and dynamic emission data from PET/CT was acquired. ILP was carried out for 120 minutes. Near physiologic gas exchange and glucose metabolism were preserved throughout the experiment. The time activity curves (TAC) of 5 different volumes of interest (VOI) showed notable differences in tracer uptake over time. The peripheral area of the carcinoid exhibited delayed but high somatostatin receptor agonist uptake compared to the surrounding parenchyma and the intrapulmonary artery. However, the central area of the carcinoid showed very low [68Ga]-DOTATOC uptake. This experiment demonstrates the potential of ILP combined with PET/CT for kinetic modeling in experimental nuclear medicine imaging. By providing visualization of tracer uptake in perfused lung tissue, this model could potentially improve our understanding of tumor physiology and molecular imaging.