Role of positron emission tomography in pretreatment lymph node staging of uterine cervical cancer: A prospective surgicopathologic correlation study

We evaluated the accuracy of FDG-PET in diagnosing metastatic para-aortic and pelvic lymph nodes in patients with cervical cancer by comparing this noninvasive imaging technique with surgicopathologic results. We performed FDG-PET in 54 patients with cervical cancer at FIGO stages IB-IVA who were about to undergo lymphadenectomy. For region-specific comparisons, we divided the nodes into eight regions (four on each side: para-aortic, common iliac, external iliac, and internal iliac/obturator). Histological examination revealed metastases in 15 (28%) of the patients, with region-specific analysis identifying 37 (8.6%) metastases in 432 regions. The region-specific findings of FDG-PET exhibited a sensitivity of 38% and a positive predictive value (PPV) of 56%. The sensitivity increased to 52% and 65% when we restricted the pathologic criterion for metastases to tumour-invasion diameters of >5 and >10 mm, respectively. These results indicate that FDG-PET exhibited low sensitivity and PPV (especially for microscopic metastases) and hence cannot replace surgical staging, although it might still be useful for detecting metastases in patients with clinical conditions that make surgical staging inappropriate.