RESUMO
Chondrosarcoma is a cartilaginous tumor of mesenchymal origin. The histology and grade of the tumor determine the chances of relapse and survival. These tumors usually respond poorly to chemo-radiotherapy in cases of non-resectable and recurrent disease. 18F-FDG PET/CT has been used in evaluation of recurrence. However, these tumors show only mild to moderate FDG avidity due to their lower mitotic activity and large acellular matrix. These tumors are known to have a high degree of angiogenesis, especially in those of higher grade. We present a case of a 53-year-old man with grade II chondrosarcoma of the left femur showing only mild avidity on 18F-FDG PET/CT but showing moderate to intense tracer avidity on 68Ga-DOTA-RGD2PET/CT. This may enable the use of angiogenesis-targeted positron and beta-emitting radiopharmaceuticals as a potentially new theranostic alternative treatment in cases of refractory metastatic chondrosarcoma.
RESUMO
OBJECTIVE: To evaluate whether the use of [F-18]-FDG-PET/CT can accurately predict pelvic lymph node metastasis in patients with muscle invasive TCC of the bladder undergoing radical cystectomy. MATERIALS AND METHODS: Fifteen patients with muscle invasive bladder cancer had undergone FDG-PET/CT scan from the skull base to the mid-thighs after IV injection of 6.5MBq (Mega-Becquerel)/Kg of FDG. After intravenous hydration IV furosemide was given to overcome the difficulties posed by urinary excretion of 18F-FDG. PET/ CT data were analyzed as PET and CT images studied separately as well as fused PET/ CT images. The imaging findings were correlated with the histopathology of the nodes (gold standard). RESULTS: CT and FDG-PET had demonstrated positive lymph nodes in 9 & 8 patients respectively. Among the 15 patients 3 had documented metastasis on histopathology. Both CT and PET could detect the nodes in all these 3 patients (100% sensitivity). Nodes were histologically negative amongst 6&5 patients who had node involvement by CT and PET respectively. Therefore, specificity, positive predictive value (PPV) & negative predictive value (NPV) for CT and PET/CT were 50%, 33.3%, 100% and 58.3%, 37.5%, 100% respectively. CONCLUSION: The theoretical advantage of this cutting edge technology for whole body imaging has not been translated into clinical practice as we found minimal advantage of combined FDG-PET/CT over CT alone for nodal staging of muscle invasive bladder cancer. This may be due to substantial overlap between standardized uptake values (SUVs) from active inflammatory processes with those of malignant lesion.
Assuntos
Carcinoma de Células de Transição/diagnóstico por imagem , Carcinoma de Células de Transição/patologia , Fluordesoxiglucose F18 , Tomografia por Emissão de Pósitrons combinada à Tomografia Computadorizada/métodos , Compostos Radiofarmacêuticos , Neoplasias da Bexiga Urinária/diagnóstico por imagem , Neoplasias da Bexiga Urinária/patologia , Adulto , Idoso , Cistectomia/métodos , Feminino , Humanos , Linfonodos/patologia , Metástase Linfática , Masculino , Pessoa de Meia-Idade , Invasividade Neoplásica , Estadiamento de Neoplasias , Estudos Prospectivos , Reprodutibilidade dos Testes , Sensibilidade e EspecificidadeRESUMO
ABSTRACT Objective: To evaluate whether the use of [F-18]-FDG-PET/CT can accurately predict pelvic lymph node metastasis in patients with muscle invasive TCC of the bladder undergoing radical cystectomy. Materials and Methods: Fifteen patients with muscle invasive bladder cancer had undergone FDG-PET/CT scan from the skull base to the mid-thighs after IV injection of 6.5MBq (Mega-Becquerel)/Kg of FDG. After intravenous hydration IV furosemide was given to overcome the difficulties posed by urinary excretion of 18F-FDG. PET/CT data were analyzed as PET and CT images studied separately as well as fused PET/CT images. The imaging findings were correlated with the histopathology of the nodes (gold standard). Results: CT and FDG-PET had demonstrated positive lymph nodes in 9 & 8 patients respectively. Among the 15 patients 3 had documented metastasis on histopathology. Both CT and PET could detect the nodes in all these 3 patients (100% sensitivity). Nodes were histologically negative amongst 6&5 patients who had node involvement by CT and PET respectively. Therefore, specificity, positive predictive value (PPV) & negative predictive value (NPV) for CT and PET/CT were 50%, 33.3%, 100% and 58.3%, 37.5%, 100% respectively. Conclusion: The theoretical advantage of this cutting edge technology for whole body imaging has not been translated into clinical practice as we found minimal advantage of combined FDG-PET/CT over CT alone for nodal staging of muscle invasive bladder cancer. This may be due to substantial overlap between standardized uptake values (SUVs) from active inflammatory processes with those of malignant lesion.
