Sequential analysis of cfDNA reveals clonal evolution in neuroblastoma patients receiving ALK targeted therapy.

PURPOSE: The study of cell free DNA (cfDNA) enables sequential analysis of tumor cell-specific genetic alterations in neuroblastoma patients. EXPERIMENTAL DESIGN: Eighteen patients with relapsing neuroblastoma having received Lorlatinib, a 3rd generation ALK inhibitor, were identified (SACHA national registry and/or in the institution). cfDNA was analyzed at relapse for 9 patients, and sequentially for 5 patients (blood/bone marrow plasma) by performing WGS library construction followed by ALK-targeted ddPCR of the hotspot mutations (F1174L, R1275Q, I1170N) (variant allele fraction (VAF) detection limit 0.1%) and WES to evaluate disease burden and clonal evolution, following comparison with tumor/germline WES. RESULTS: Overall response rate to Lorlatinib was 33% (CI 13-59%), with response observed in 6/10 cases without versus 0/8 cases with MYCN amplification (MNA). ALK VAFs correlated with the overall clinical disease status, with a VAF<0.1% in clinical remission, versus higher VAFs (>30%) at progression. Importantly, sequential ALK ddPCR detected relapse earlier than clinical imaging. cfDNA WES revealed new SNVs, not seen in the primary tumor, in all instances of disease progression after Lorlatinib treatment, indicating clonal evolution, including alterations in genes linked to tumor aggressivity (TP53) or novel targets (EGFR). Gene pathway analysis revealed an enrichment for genes targeting cell differentiation in emerging clones, and cell adhesion in persistent clones. Evidence of clonal hematopoiesis could be observed in follow-up samples. CONCLUSION: We demonstrate the clinical utility of combining ALK cfDNA ddPCR for disease monitoring and cfDNA WES for the study of clonal evolution and resistance mechanisms in neuroblastoma patients receiving ALK targeted therapy.

Fine needle aspiration as a diagnostic modality for Warthin tumors identified as fluorodeoxyglucose positron emission tomography/computed tomography-positive.

Limited evidence exists regarding the 2-deoxy-2-[fluorine-18]-fluoro-D-glucose (FDG) avidity of Warthin tumors, the second most common benign parotid gland tumor. This study aims to clarify this aspect by analyzing patients who underwent FDG positron emission tomography/computed tomography (PET/CT) and quantifying tumor standardized uptake values (SUV). Medical records of 29 patients with fine needle aspiration (FNA)-confirmed Warthin tumors who underwent FDG-PET/CT near the diagnosis of Warthin tumor were reviewed. Key parameters included cancer history, cytologic diagnosis of Warthin tumor, maximum SUV on FDG PET/CT, and tumor localization. Among the cohort, 18 males and 11 females (average age: 67.9 years) were included. Most patients had malignant neoplasms (lung, head and neck, breast, others). One patient had synchronous liver cancer. Three individuals had bilateral Warthin tumors, and three had bifocal tumors, resulting in 35 tumors for analysis. Tumors were located in the parotid gland (28) and vicinity (7). SUVmax for the Warthin tumors ranged from 3.6 to 26.8, with an average SUVmax of 10.1. Warthin tumors exhibit significant and variable FDG accumulation, exceeding expectations and mimicking high-grade malignancies. Awareness of this phenomenon is crucial for accurate staging and timely management. In cases of positive FDG PET/CT uptake in periparotid, perimandibular, and upper jugular areas, FNA is recommended to avoid misinterpretation or delays in management.

[18F]DCFPyL PET/CT versus [18F]fluoromethylcholine PET/CT in Biochemical Recurrence of Prostate Cancer (PYTHON): a prospective, open label, cross-over, comparative study.

PURPOSE: Primary objective was to compare the per-patient detection rates (DR) of [18F]DCFPyL versus [18F]fluoromethylcholine positron emission tomography/computed tomography (PET/CT), in patients with first prostate cancer (PCa) biochemical recurrence (BCR). Secondary endpoints included safety and impact on patient management (PM). METHODS: This was a prospective, open label, cross-over, comparative study with randomized treatment administration of [18F]DCFPyL (investigational medicinal product) or [18F]fluoromethylcholine (comparator). Men with rising prostate-specific antigen (PSA) after initial curative therapy were enrolled. [18F]DCFPyL and [18F]fluoromethylcholine PET/CTs were performed within a maximum time interval of 12 days. DR was defined as the percentage of positive PET/CT scans identified by 3 central imaging readers. PM was assessed by comparing the proposed pre-PET/CT treatment with the local treatment", defined after considering both PET/CTs. RESULTS: A total of 205 patients with first BCR after radical prostatectomy (73%; median PSA = 0.46 ng/ml [CI 0.16;27.0]) or radiation therapy (27%; median PSA = 4.23 ng/ml [CI 1.4;98.6]) underwent [18F]DCFPyL- and/or [18F]fluoromethylcholine -PET/CTs, between July and December 2020, at 22 European sites. 201 patients completed the study. The per-patient DR was significantly higher for [18F]DCFPyL- compared to [18F]fluoromethylcholine -PET/CTs (58% (117/201 patients) vs. 40% (81/201 patients), p < 0.0001). DR increased with higher PSA values for both tracers (PSA ≤ 0.5 ng/ml: 26/74 (35%) vs. 22/74 (30%); PSA 0.5 to ≤ 1.0 ng/ml: 17/31 (55%) vs. 10/31 (32%); PSA 1.01 to < 2.0 ng/ml: 13/19 (68%) vs. 6/19 (32%);PSA > 2.0: 50/57 (88%) vs. 39/57 (68%) for [18F]DCFPyL- and [18F]fluoromethylcholine -PET/CT, respectively). [18F]DCFPyL PET/CT had an impact on PM in 44% (90/204) of patients versus 29% (58/202) for [18F]fluoromethylcholine. Overall, no drug-related nor serious adverse events were observed. CONCLUSIONS: The primary endpoint of this study was achieved, confirming a significantly higher detection rate for [18F]DCFPyL compared to [18F]fluoromethylcholine, in men with first BCR of PCa, across a wide PSA range. [18F]DCFPyL was safe and well tolerated.

Succinate: A Serum Biomarker of SDHB-Mutated Paragangliomas and Pheochromocytomas.

CONTEXT: Pheochromocytomas and paragangliomas (PPGL) are rare neuroendocrine tumors that are frequently associated with succinate dehydrogenase (SDH) germline mutations. When mutated, SDH losses its function, thus leading to succinate accumulation. OBJECTIVE: In this study, we evaluated serum succinate levels as a new metabolic biomarker in SDHx-related carriers. METHODS: Retrospective monocentric study of 88 PPGL patients (43 sporadic, 35 SDHB, 10 SDHA/C/D), 17 tumor-free familial asymptomatic carriers (13 SDHB, 4 SDHC/D), and 60 healthy controls. Clinical, biological, and imaging data were reviewed. Serum succinate levels (n = 280) were quantified by an ultra-performance liquid chromatography coupled to a tandem mass spectrometry method and correlated to SDHx mutational status, disease extension, and other biological biomarkers. RESULTS: Serum succinate levels > 7 µM allowed identification of tumor-free asymptomatic SDHB-mutated cases compared to a healthy control group (100% specificity; 85% sensitivity). At PPGL diagnosis, SDHB-mutated patients had a significantly increased median succinate level (14 µM) compared to sporadic patients (8 µM) (P < 0.01). Metastatic disease extension was correlated to serum succinate levels (r = 0.81). In the SDHB group, patients displaying highest tumor burdens showed significant increased succinate levels compared to the sporadic group (P < 0.0001). CONCLUSIONS: In this pilot study, we showed that serum succinate level is an oncometabolic biomarker that should be useful to identify SDHB-related carriers. Succinate levels are also a marker of metabolic tumor burden in patients with a metastatic PPGL and a potential marker of treatment response and follow-up.

18F-FDG PET/CT for early response assessment of jaw osteoradionecrosis after the PENTOCLO protocol: A promising imaging modality.

INTRODUCTION: The Pentoxifylline, Tocopherol and Clodronate protocol (PENTOCLO) showed promising results for jaw osteoradionecrosis (ORN) management. However, the clinical and radiological improvements are often delayed, leading to unwanted long-term treatment, with potential loss of opportunity for more radical surgical treatments. Our objective was to assess the diagnosis performance of 18F-FDG PET/CT to early predict ORN response to the PENTOCLO protocol. MATERIALS AND METHODS: All patients from our center who were treated with the PENTOCLO protocol and with a 18F-FDG PET/CT performed at diagnosis and three months after the end of antibiotherapy were retrospectively included. The PENTOCLO protocol was always combined with prior appropriate antibiotherapy for six weeks. The healing endpoint was divided into healing, stability or worsening, according to the combination of clinical and radiological assessments at the date of last follow-up. For each patient, the difference between the maximal standardized uptake value (ΔSUVmax) of the ORN lesion at three months and baseline were computed. Diagnostic performance of 18F-FDG PET/CT was evaluated by sensitivity, specificity and the area under the receiver operating characteristic curve (ROC-AUC) of ΔSUVmax. RESULTS: 24 patients were included with an average follow-up of 29.3 months. The healing, stability and worsening rate were 25%, 62.5% and 12.5% respectively. The AUC for discriminating worsening vs stability or healing was 0.92 (IC95 [0.81-1.00]). A ΔSUVmax greater than or equal to 0 was predictive of a worsening with a sensitivity and specificity of 84 and 66% respectively. CONCLUSION: 18F-FDG PET/CT imaging could be useful for early prediction of PENTOCLO treatment resistance with appropriate antibiotherapy.

Long Term Efficacy and Assessment of Tumor Response of Transarterial Chemoembolization in Neuroendocrine Liver Metastases: A 15-Year Monocentric Experience.

BACKGROUND: transarterial chemoembolization (TACE) is an established treatment for neuroendocrine tumor (NET) liver metastases. The aim was to evaluate the long-term treatment efficacy of TACE for NET liver metastases, and correlate imaging response with survival. METHODS: this IRB-approved, single-center, retrospective study evaluated all TACE procedures performed for NET liver metastases from 2003-2017 for imaging tumor response (RECIST and mRECIST), time to liver progression (TTLP), time to untreatable progression with TACE (TTUP), and overall survival (OS). Patient, tumor, and treatment characteristics were analyzed as prognostic factors. Survival curves according to the Kaplan-Meier method were compared by Log-rank test. Tumor responses according to RECIST and mRECIST were correlated with OS. RESULTS: 555 TACE procedures were performed in 202 NET patients (38% grade 1, 60% grade 2) with primary tumors originating from pancreas, small bowel, and lung (39, 26, and 22% respectively). Median follow-up was 8.2 years (90-139 months). Median TTLP and TTUP were 19.3 months (95%CI 16.3-22.3) and 26.2 months (95%CI 22.3-33.1), respectively. Median OS was 5.3 years (95%CI 4.2-6.7), and was higher among mRECIST responders (80.5 months; 95%CI 64.6-89.8) than in non-responders (39.6 months; 95%CI = 32.8-60.2; p < 0.001). In multivariable analysis, age, tumor grade and liver involvement predicted worse OS, whereas administration of somatostatin analogs correlated with improved OS. CONCLUSION: TACE for NET liver metastases provides objective response and sustained local disease control rates. RECIST and mRECIST responses correlate with OS.

Immune Checkpoint Inhibitor Therapy Aggravates T Cell-Driven Plaque Inflammation in Atherosclerosis.

BACKGROUND: Immunotherapy has revolutionized cancer treatment. However, immune checkpoint inhibitors (ICIs) that target PD-1 (programmed cell death protein-1) and/or CTLA-4 (cytotoxic T lymphocyte-associated antigen-4) are commonly associated with acute immune-related adverse events. Accumulating evidence also suggests that ICIs aggravate existing inflammatory diseases. OBJECTIVES: As inflammation drives atherosclerotic cardiovascular disease, we studied the propensity of short-term ICI therapy to aggravate atherosclerosis. METHODS: We used 18F-FDG (2-deoxy-2-[fluorine-18]fluoro-D-glucose) positron emission tomography-computed tomography to detect macrophage-driven vascular and systemic inflammation in pembrolizumab and nivolumab/ipilimumab-treated melanoma patients. In parallel, atherosclerotic Ldlr -/- mice were treated with CTLA-4 and PD-1 inhibition to study the proinflammatory consequences of immune checkpoint inhibition. RESULTS: ICI treatment did not affect 18F-FDG uptake in the large arteries, spleen, and bone marrow of melanoma patients, nor myeloid cell activation in blood and lymphoid organs in hyperlipidemic mice. In contrast, we found marked changes in the adaptive immune response (i.e., increased CD4+ effector T cell and CD8+ cytotoxic T cell numbers in lymphoid organs and the arterial wall of our hyperlipidemic mice). Although plaque size was unaffected, plaques had progressed toward a lymphoid-based inflammatory phenotype, characterized by a 2.7-fold increase of CD8+ T cells and a 3.9-fold increase in necrotic core size. Increased endothelial activation was observed with a 2.2-fold and 1.6-fold increase in vascular cell adhesion molecule-1 and intercellular adhesion molecule-1, respectively. CONCLUSIONS: This study demonstrates that combination therapy with anti-CTLA-4 and anti-PD-1 antibodies does not affect myeloid-driven vascular and systemic inflammation in melanoma patients and hyperlipidemic mice. However, short-term ICI therapy in mice induces T cell-mediated plaque inflammation and drives plaque progression.

Left ventricular ejection fraction determined with the simulation of a very low-dose CZT-SPECT protocol and an additional count-calibration on planar radionuclide angiographic data.

PURPOSE: To determine whether the left ventricular ejection fractions (EFs), measured on a high-sensitivity CZT single photon emission computed tomography (SPECT)-camera with a 70% reduction in recording times and a prevention of EF overestimation through an additional count-calibration, are concordant with reference EF from planar radionuclide angiography (2D-RNA). METHODS: An additional 10-minute CZT-SPECT recording was performed in patients referred to 2D-RNA for cardiomyopathy (n = 23) or chemotherapy monitoring (n = 50) with an in vivo red blood cell labeling with 850 MBq [Formula: see text]. The EF, obtained from CZT-SPECT with 100% (SPECT100) or 30% (SPECT30) projection times and with a SPECT-count calibration on the 2D-RNA counts of corresponding cavity volumes, were compared to EF from 2D-RNA. RESULTS: Strong and equivalent relationships were documented between the EF from 2D-RNA and the calibrated EF from SPECT100 (y = 0.89x + 6.62; R2 = 0.87) and SPECT30 (y = 0.87x + 8.40; R2 = 0.85), and the mean EF from SPECT100 (54% ± 15%) and SPECT30 (53% ± 16%) were close to that from 2D-RNA (55% ± 15%). However, upward shifts in these mean values were documented in the absence of count calibration for both SPECT100 (60% ± 18%) and SPECT30 (60% ± 18%). CONCLUSION: Left ventricular EF may be determined on a high-sensitivity CZT-camera, a 70% reduction in injected activities, and an additional count-calibration for further enhancing the concordance with 2D-RNA values.

An enlarged left adrenal gland is an indirect sign of infection on 18F-FDG PET/CT.

OBJECTIVES: To determine whether hypermetabolisms of the spleen and bone marrow and an enlarged adrenal gland are significant indirect signs of infection on fluorine-18-fluorodeoxyglucose (F-FDG) PET/CT performed in patients with known or suspected infectious disease. PATIENTS AND METHODS: Potential indirect signs of infection were as follows: (i) investigated in a retrospectively selected group of patients referred to F-FDG PET/CT for a known or suspected infectious disease and among whom the presence or absence of infectious foci was ascertained in 43 and 12 cases, respectively, and (ii) further validated in groups prospectively constituted of 12 patients with severe sepsis and of 39 control patients with no sign of any infectious disease. Standardised uptake values were determined on left adrenal gland, spleen and bone marrow, whereas the size of left adrenal gland was assessed by its maximal surface on unenhanced axial computed tomography (CT) slices. RESULTS: Only the maximal surface of the left adrenal gland was a predictor in the initial study group (infection: 2.72±0.99 cm vs. no infection: 1.85±0.76 cm, P=0.004) and further validation groups (sepsis: 2.79±0.83 cm vs. controls: 1.91±0.67 cm, P=0.001). Patients with a greater than 1.8 cm maximal surface had more than two-fold higher infection rate than the other patients in the initial study group [88 (36/41) vs. 36% (4/11), P=0.001], even when only considering the subgroup with no evident infectious focus on F-FDG PET/CT [76 (16/21) vs. 30% (3/10), P=0.02]. CONCLUSION: An enlarged left adrenal gland is a significant sign of infection on F-FDG PET/CT, even in the absence of any evident infectious focus on F-FDG PET/CT images.

123I-FP-CIT-SPECT in Encephalitis Involving Substantia Nigra.

I-FP-CIT-SPECT is currently used to detect functional impairment of striatal structures. We report herein a case where I-FP-CIT abnormalities are seemingly related to an encephalitis involving substantia nigra. A few months after a documented encephalitis, a 19-year-old woman experienced a Parkinsonism with a right dominance. There was a reduction in the striatal binding of I-FP-CIT, especially on the left side, in accordance with the right dominance of the Parkinsonism.