Small direct right ventricular cardiac metastasis of osteosarcoma in a 10-year-old boy affirmed by cardiac MRI.

BACKGROUND: Metastatic osteosarcoma with direct cardiac involvement is an exceptionally rare finding. Reliable detection of cardiac metastases is known to be crucial for patients therapy and prognosis. CASE SUMMARY: In a 10-year-old boy affected by osteosarcoma of the left femur, a baseline Fluorine-18-fluorodeoxy-glucose positron emission tomography/computed tomography (18F-FDG PET/CT) was performed to assess the full extent of disease. Whole-body scan detected numerous bone metastases together with a single pulmonary metastasis. Moreover, increased tracer uptake was observed in the intracavitary right cardiac ventricle in the position of a subtle spot of calcification. Because of nondetectability of a cavitary lesion on echocardiography, cardiac magnetic resonance imaging (CMRI) examination was performed to evaluate cardiac 18F-FDG PET/CT finding. CMRI revealed a small nodule in the right ventricle attached to the trabeculae, highly suspicious of a direct cardiac metastasis. After 4 cycles of chemotherapy, complete regression of tracer uptake of the lesion was observed on a follow-up 18F-FDG PET/CT scan. CONCLUSION: CMRI is able to detect even small, clinically asymptomatic cardiac metastases in young patients affected by osteosarcoma.

Genomic EWSR1 Fusion Sequence as Highly Sensitive and Dynamic Plasma Tumor Marker in Ewing Sarcoma.

PURPOSE: The application of the tumor-specific genomic fusion sequence as noninvasive biomarker for therapy monitoring in Ewing sarcoma (EwS) has been evaluated. EXPERIMENTAL DESIGN: EwS xenograft mouse models were used to explore detectability in small plasma volumes and correlation of genomic EWSR1-FLI1 copy numbers with tumor burden. Furthermore, 234 blood samples from 20 EwS patients were analyzed before and during multimodal treatment. EWSR1 fusion sequence levels in patients' plasma were quantified using droplet digital PCR and compared with tumor volumes calculated from MRI or CT imaging studies. RESULTS: Kinetics of EWSR1 fusion sequence copy numbers in the plasma are correlated with changes of the tumor volume in patients with localized and metastatic disease. The majority of patients showed a fast reduction of cell-free tumor DNA (ctDNA) during initial chemotherapy. Recurrence of increasing ctDNA levels signalized relapse development. CONCLUSIONS: Genomic fusion sequences represent promising noninvasive biomarkers for improved therapy monitoring in EwS. Until now, response assessment is largely based on MRI and CT imaging, implying restrictions on closely repeated performance and limitations on the differentiation between vital tumor and reactive stromal tissue. Particularly in patients with prognostic unfavorable disseminated disease, ctDNA is a valuable addition for the assessment of therapy response. Clin Cancer Res; 22(17); 4356-65. ©2016 AACR.

18Fluoroethyl-L-tyrosine-PET in long-term epilepsy associated glioneuronal tumors.

PURPOSE: Long-term epilepsy associated tumors (LEATs) are a frequent cause of drug-resistant partial epilepsy. A reliable tumor diagnosis has an important impact on therapeutic strategies and prognosis in patients with epilepsy, but often is difficult by magnetic resonance imaging (MRI) only. Herein we analyzed a large LEAT cohort investigated by 18fluoroethyl-L-tyrosine-positron emission tomography (FET-PET). METHODS: Thirty-six patients with chronic partial epilepsy and a LEAT-suspect MRI lesion were analyzed by FET-PET using visual inspection and quantitative analysis of standard uptake values (SUV). PET results were correlated with clinical and histopathologic data. RESULTS: FET-PET study was positive in 22 of 36 analyzed lesions and in 14 of 22 histologically verified LEAT lesions. The precise World Health Organization (WHO) tumoral entity was not predicted by FET-PET. Notably, FET uptake correlated strikingly with age at epilepsy onset (p = 0.001). Further correlations were seen for age at surgery (p = 0.007) and gadolinium-contrast enhancement on MRI (p < 0.05). DISCUSSION: FET-PET is a helpful tool for LEAT diagnosis, particularly when MRI readings are ambiguous. FET uptake, which is likely mediated by the l-amino acid transporter (LAT) family, might indicate a principally important biologic property of certain LEATs, since LAT molecules also are involved in cell growth regulation.