No abstract

In CUP patients, PET has a certain impact on detection of the primary as well as of the disseminated disease. and may also have a certain impact on therapeutic management.

In patients with CUP the PET result is not only of great value for detection of the primary tumor, but in case of initially localized disease also for diagnosis of a possible dissemination. The PET result often has relevant influence on therapeutic management.

18F-Fluorodesoxyglucose-Positron-Emission-Tomography (18F-FDG-PET) is a novel imaging modality for malignancies. This study was initiated to define the efficiency of PET in detecting and characterizing metabolically the primaries and in preoperatively assessing of lymphonodal metastases of cervical cancer. 15 patients with histologically proven cervical carcinoma were studied with 18F-FDG-PET regarding 18F-FDG-uptake of primary tumor and evidence as well as extent of lymphonodal metastases. 18F-FDG-PET and histopathological results were compared after radical hysterectomy with pelvic and supplementary in 7 cases paraaortal lymphadenectomy. All primary tumours showed 18F-FDG accumulation and had a mean maximal standardized uptake value (SUV) of 8.0 +/- 5.3. 3/6 lymph node metastases were obtained with 18F-FDG-PET. Micrometastases (size of metastasis < or = 0.2 cm) were present in 2 patients with false negative PET results. Regarding the subgroup with paraaortal lymph node dissection, PET detected one patient with metastases, the other one had micrometastasis, while metastasis was not observed by PET. The accuracy of PET is 73% for assessment of pelvic lymph nodes and 86% for assessment of paraaortal lymph nodes. In conclusion 18F-FDG accumulates reliably in primaries of cervical cancer. Regarding assessment of lymph node metastases PET seems to be of potential use, offering metabolic information independent of the size of metastatic lymph nodes. An improvement of accuracy can be expected if combined evaluation of morphologic and metabolic images is performed.