ABSTRACT
BACKGROUND AND AIM: currently it is recognized the usefulness of 18F-FDG PET in assessing response to therapy with imatinib (Gleevec®) in the gastrointestinal tract sarcomas (GIST). To facilitate the follow-up of these studies is important to know the patterns of metastatic spread. The aim of this paper is to describe patterns observed in the 18F-FDG PET/CT. METHOD: retrospective study included 29 patients who underwent 18F-FDG PET/CT after being diagnosed with unresectable or metastatic GIST. In total, 87 PET/CT studies were performed (1-6 controls per patient) with a mean time of follow-up 6-36 months. We analyzed the location of the lesions evidenced in PET, CT and fusion. Images were evaluated visually and semiquantitatively (SUV). In cases in which has been considered necessary, additional images have been undertaken: PET delayed imaging, intravenous contrast CT and inspiratory chest CT. RESULTS: the most common primary site was the stomach (41%), small bowel (35%), and rectum (24%). Significant changes in the location of metastatic disease between pre-treatment and the monitoring were observed, with the appearance of more extra-abdominal disease. CONCLUSIONS: individualization of protocol studies and interpretation of PET, CT and fused images were required for evaluation of treatment response to imatinib. Hybrid 18F-FDG PET/CT provides an accurate determination of the extent of GIST. While the most common metastatic site is the liver and peritoneum, in the following cases are common extra-abdominal disease.
Subject(s)
Antineoplastic Agents/therapeutic use , Drug Monitoring , Gastrointestinal Neoplasms/drug therapy , Gastrointestinal Stromal Tumors/drug therapy , Multimodal Imaging , Piperazines/therapeutic use , Positron-Emission Tomography , Pyrimidines/therapeutic use , Tomography, X-Ray Computed , Aged , Benzamides , Female , Fluorodeoxyglucose F18 , Follow-Up Studies , Gastrointestinal Neoplasms/diagnostic imaging , Gastrointestinal Neoplasms/pathology , Gastrointestinal Stromal Tumors/diagnostic imaging , Gastrointestinal Stromal Tumors/pathology , Humans , Imatinib Mesylate , Male , Middle Aged , Neoplasm Metastasis , Radiopharmaceuticals , Retrospective Studies , Treatment OutcomeABSTRACT
Introducción y objetivo: actualmente está reconocida la utilidad de la 18F-FDG-PET en la evaluación de la respuesta a la terapia con imatinib (Gleevec®) en los sarcomas del tracto gastrointestinal (GIST). Para facilitar la valoración comparativa de estos estudios es importante conocer sus patrones de diseminación metastásica. El objetivo de este trabajo es describir estos patrones evidenciados en la 18F-FDG-PET/TC. Método: estudio retrospectivo de 29 pacientes a los que se les realizó una 18F-FDG-PET/TC, tras haber sido diagnosticados de un GIST irresecable o metastásico. En total se realizaron 87 estudios PET/TC (1-6 controles por paciente) con tiempo medio posterior de seguimiento entre 6-36 meses. Se analizó la localización de las lesiones evidenciadas en las imágenes PET, TC y de fusión, y se valoraron las imágenes de forma visual y semicuantitativa (SUV). En aquellos casos en los que para la valoración de las imágenes se ha considerado necesario se han realizado exploraciones adicionales: imágenes tardías PET, TC con contraste endovenoso y TC inspiratorio torácico. Resultados: la localización primaria más frecuente fue la gástrica (41%), el intestino delgado (35%) y el recto (24%). Son muy significativos los cambios en la localización de la enfermedad metastásica entre el estudio pre-tratamiento y los controles de seguimiento, observándose evolutivamente la aparición de mayor enfermedad extra-abdominal. Conclusiones: para la evaluación de la respuesta a la terapia es necesaria la valoración de las imágenes integradas y la individualización del protocolo de la exploración. La exploración híbrida PET/TC proporciona una precisa determinación de la extensión del GIST. Si bien la localización metastásica más habitual es el hígado y el peritoneo, en el seguimiento son frecuentes los casos con enfermedad extra-abdominal(AU)
Background and aim: currently it is recognized the usefulness of 18F-FDG PET in assessing response to therapy with imatinib (Gleevec ®) in the gastrointestinal tract sarcomas (GIST). To facilitate the follow-up of these studies is important to know the patterns of metastatic spread. The aim of this paper is to describe patterns observed in the 18F-FDG PET/CT. Method: retrospective study included 29 patients who underwent 18F-FDG PET/CT after being diagnosed with unresectable or metastatic GIST. In total, 87 PET/CT studies were performed (1-6 controls per patient) with a mean time of follow-up 6-36 months. We analyzed the location of the lesions evidenced in PET, CT and fusion. Images were evaluated visually and semiquantitatively (SUV). In cases in which has been considered necessary, additional images have been undertaken: PET delayed imaging, intravenous contrast CT and inspiratory chest CT. Results: the most common primary site was the stomach (41%), small bowel (35%), and rectum (24%). Significant changes in the location of metastatic disease between pre-treatment and the monitoring were observed, with the appearance of more extra-abdominal disease. Conclusions: individualization of protocol studies and interpretation of PET, CT and fused images were required for evaluation of treatment response to imatinib. Hybrid 18F-FDG PET/CT provides an accurate determination of the extent of GIST. While the most common metastatic site is the liver and peritoneum, in the following cases are common extra-abdominal disease(AU)
