Clinical value of 18F-FDG PET-CT in detecting primary tumor for patients with carcinoma of unknown primary
Menée sur 120 patients atteints de carcinomes d'origine inconnue, cette étude évalue la sensibilité, la spécificité et la précision d'une tomographie numérique utilisant le 18-fluorodésoxyglucose et couvrant la totalité du corps pour détecter et identifier la tumeur primitive occulte
Objective : To investigate the clinical value in detecting occult primary tumors with 18F-FDG PET-CT whole body imaging. Methods : 120 patients with unknown primary origin were referred for 18F-FDG PET-CT whole body imaging. All patients were performed 18F-FDG PET-CT whole body scan. PET-CT images were interpreted by visual inspection and semi-quantitative analysis (standardized uptake value, SUV). Histopathological and formal clinical follow-up findings were used to assess the value of FDG PET-CT. Results: FDG PET-CT was able to detect the primary tumor in 54/120 patients (42.5%). The primary tumors were confirmed by histopathologic and formal clinical follow-up findings, and located in the head and neck (n = 17), the lung (n = 19), the breast (n = 2), the esophagus (n = 1), the stomach (n = 2), the bile ducts (n = 1), the pancreas (n = 3), the co1on (n = 3), the ovary (n = 2), the prostate (n = l), others (n = 3). FDG PET results were proved false positive in 9 patients (7.5%), which were located in the head and neck (n = 3), the lung (n = 1), the gastric (n = 1), the colon (n = 2), the ovary (n = 1), the prostate (n = l). During the clinical follow-up of median 32 months (range, 2–45 months), primary tumor was found in only 5 patients of 60 cases unidentified by PET-CT (breast cancer, gastric cancer, co1on cancer, prostate cancer and urinary tumors, respectively). The sensitivity, specificity, and accuracy of 18F-FDG PET-CT in the detection of the primary tumor site were 91.5%, 85.2%, and 88.3%, respectively. Conclusion : 18F-FDG PET-CT whole body imaging is both a noninvasive and a very sensitive tomographic whole-body imaging modality, allowing for the detection of a primary tumor and complete tumor staging in single examination, which can contribute substantially to selecting appropriate therapeutic methods and evaluating prognosis. Perhaps 18F-FDG PET-CT whole body imaging should be used as a first-line imaging modality for patients with carcinoma of unknown primary rather than using it after other diagnostic procedures have failed to identify a primary tumor.
Cancer Epidemiology , résumé, 2011