Impact of Gated PET/CT in the Diagnosis of Advanced Ovarian Cancer

This study directly compares standard CT scanning with PET/CT scanning with gating (computer adjusted for breathing excursions) in patients with advanced EOC. The primary objective of this study is to obtain definitive evidence on the value of gated PET/CT compared to current standard imaging (CT scan) for the diagnosis of extra-abdominal and thoracic involvement. This study will give precise estimates on the sensitivity and specificity of CT compared with gated PET/CT, and allow calculation of the positive predictive value and negative predictive value. The proportion of patients upstaged to Stage IV (extra-abdominal involvement) from Stage III by gated PET/CT will be calculated. Secondary objectives are to establish: * The impact of gated PET/CT images on clinical management (changes to planned treatment; detection of metastatic spread to "unexpected" sites). * The validity of gated PET/CT positive (FDG avid) findings through histological evaluation. * We will also receive information of "unusual" (unexpected) FDG positive metastatic lesions that would normally not noticed on CT scans. Current standard treatment for patients with advanced EOC is upfront surgery as long as all tumour is confined to the pelvis and the abdomen. Unfortunately, EOC is often found at distant sites where it was not suspected during surgery (which is too late). If the surgeon had had prior knowledge of this disease distribution, the surgeon would not have subjected the patient to a long and invasive surgical procedure. Instead they but would have referred the patient to upfront chemotherapy, which is widely accepted clinical practice throughout Australia. This study aims to increase the diagnostic accuracy of preoperative medical imaging and subject a larger group of patients with advanced EOC to accurate management.