[Desmoplastic round cell tumor]. / Tumor desmoplásico de células redondas.

Desmoplastic small round cell tumor is a rare and very aggressive neoplasm that belongs to the family of "small round blue cell tumors". It has a higher incidence in males in the second decade of life. It is due to translocation t(11;22) (p13;q12). It can be located both in the abdomen and in the retroperitoneum and is characterized by nonspecific symptoms. The treatment is very varied and the one that guarantees the total cure of the patient has not yet been detected. The objective of this study is to expose a clinical case of desmoplastic tumor as an rare abdominal disease and its imaging expression.

El tumor desmoplásico de células pequeñas y redondas es una neoplasia poco frecuente y muy agresiva que forma parte de la familia de los "tumores de células pequeñas, redondas y azules". Presenta una mayor incidencia en el sexo masculino en la segunda década de la vida. Se debe a la translocación t(11;22) (p13;q12). Se puede localizar tanto en el abdomen como en el retroperitoneo caracterizándose por presentar síntomas inespecíficos. El tratamiento es muy variado y no se ha detectado todavía aquel que garantice la cura total del paciente. El objetivo del presente estudio es exponer un caso clínico de tumor desmoplásico como enfermedad abdominal infrecuente y su expresión imagenológica.

Exploring the applicability of a lesion segmentation method on [18F]fluorothymidine PET/CT images in diffuse large B-cell lymphoma.

BACKGROUND AND PURPOSE: The determination of the total metabolic tumour volume based on [18F]fluorothymidine ([18F]FLT) PET/CT images in diffuse large B-cell lymphoma has a potential clinical value for detecting early relapse in this type of heterogeneous lymphoproliferative tumours. Tumour segmentation is a key step in this process. For this purpose, our objective was to determine a segmentation threshold of [18F]FLT PET/CT images, based on a reference tissue uptake, on a cohort of patients with diffuse large B-cell lymphoma (DLBCL) that have been scanned at different stages of the treatment. METHODS: We enrolled 23 adult patients with DLBCL confirmed in II-IV stages without nervous system compromise. All patients were scanned using [18F]FLT PET/CT at the time of diagnosis (baseline PET), interim PET (iPET), and at the end of treatment (fPET). The administered activity was 1.8-2.6 MBq/kg body weight, performed 60-70 min after injection and without use of contrast-enhanced CT. First, we assessed the [18F]FLT uptake stability in liver and bone marrow along the patient follow-up. For the lesion segmentation, three threshold values were assessed. RESULTS: Both, liver, and bone marrow can be indistinctly taken as reference tissue. The SUV threshold for a voxel to be considered as belonging to a lesion is expressed in terms of a percentage relative to the patient's uptake in the reference tissue. Found thresholds were: for liver, 62%, 33%, 27%; and for bone marrow, 35%, 21% and 22%, for baseline, iPET and fPET stages, respectively. The relative threshold throughout the treatment has a decreasing tendency along the stages. CONCLUSION: Based on the results obtained with [18F]FLT PET/CT during staging and follow-up in patients with DLBCL, reference values were obtained for each stage referring to liver and bone marrow uptake that could be used in clinical practice oncology.

Prospective study on the clinical relevance of 18F-DOPA positron emission tomography/computed tomography in patients with medullary thyroid carcinoma.

PURPOSE: 18F-DOPA Positron Emission Tomography/Computed Tomography (18F-DOPA PET/CT) is a sensitive functional imaging method (65-75%) for detecting disease localization in medullary thyroid cancer (MTC). We aimed: (i) to assess the clinical usefulness of 18F-DOPA PET/CT in patients with MTC and elevated calcitonin (Ctn) and CEA levels and, (ii) to evaluate changes in disease management secondary to the findings encountered with this methodology. METHODS: Thirty-six patients with MTC and Ctn levels ≥150 pg/ml were prospectively included. Neck ultrasound, chest contrast-enhanced CT, liver magnetic resonance imaging/abdominal three-phase contrast-enhanced CT and bone scintigraphy were carried out up to 6 months before the 18F DOPA PET/CT. RESULTS: Seventy eight percent of patients were female and 27% had hereditary MTC. Median Ctn level was 1450 pg/ml [150-56620], median CEA level 413 ng/ml [2.9-7436]. Median Ctn DT was 37.5 months [5.7-240]; median CEA DT was 31.8 [4.9-180]. 18F-DOPA PET/CT was positive in 33 patients (91.6%); in 18 (56%) uptake was observed in lymph nodes in the neck or mediastinum, in seven cases (22%) distant metastases were diagnosed, and in eight additional patients (24%) both locoregional and distant sites of disease were found. Ctn and CEA levels were higher in patients with ≥3 foci of distant metastases. In 14 patients (38.8%), findings on 18F-DOPA PET/CT led to changes in management; surgery for locoregional lymph nodes was the most frequent procedure in 8 patients (22%). CONCLUSION: 18F-DOPA PET/CT was useful for the detection of recurrent disease in MTC, providing incremental value over conventional imaging procedures that led to modification in treatment strategies in nearly 40% of patients.

Tumor desmoplásico de células redondas / Desmoplastic round cell tumor

Resumen El tumor desmoplásico de células pequeñas y redon das es una neoplasia poco frecuente y muy agresiva que forma parte de la familia de los "tumores de célu las pequeñas, redondas y azules". Presenta una mayor incidencia en el sexo masculino en la segunda década de la vida. Se debe a la translocación t(11;22) (p13;q12). Se puede localizar tanto en el abdomen como en el re troperitoneo caracterizándose por presentar síntomas inespecíficos. El tratamiento es muy variado y no se ha detectado todavía aquel que garantice la cura total del paciente. El objetivo del presente estudio es exponer un caso clínico de tumor desmoplásico como enfermedad abdo minal infrecuente y su expresión imagenológica.

Abstract Desmoplastic small round cell tumor is a rare and very aggressive neoplasm that belongs to the family of "small round blue cell tumors". It has a higher incidence in males in the second decade of life. It is due to trans location t(11;22) (p13;q12). It can be located both in the abdomen and in the retroperitoneum and is character ized by nonspecific symptoms. The treatment is very varied and the one that guarantees the total cure of the patient has not yet been detected. The objective of this study is to expose a clinical case of desmoplastic tumor as an rare abdominal disease and its imaging expression.