survival­ (Mironov et al. 2011). Lung or liver parenchymal metastases are also typical manifestations in stage IVB disease. It is particularly important to differentiate liver parenchymal metastases from liver surface metastases, which display smooth margins and an elliptic or biconvex shape. Umbilical metastasis (Fig. 13), the Sister Mary Joseph node, is now classified as stage IVB disease. It usually ranges from 1 to 1.5 cm in size but can attain a size of up to 10 cm. Cardiophrenic lymph node metastases are a typical findings in stage IV disease. They occur in approximately 30% of advanced ovarian cancer and are typically located in the anterior prepericardiac region, more commonly on the right than on the left side (Kim et al. 2016). A recent study reported a PPV of 86% for histologically proven cardiophrenic lymph nodes when a short-axis diameter of >7 mm was used in CT (Kim et al. 2016). Inguinal lymph node metastases are also classified as distant metastases (IVB).

Value of Imaging

CT and MRI perform similarly in staging of ovarian cancer, with reported accuracies of 70%– 90%, sensitivities of 63–69%, and specificities of 100% (Mitchell et al. 2013; Forstner et al. 2010, 2016b; Nougaret et al. 2012; Sala et al. 2013; Javadi et al. 2016). The decision to use CT or MRI is based on many factors, including cost, availability, contraindications, radiologist expertise, and clinician’s preference. Thus currently, CT is the primary imaging modality for staging ovarian cancer because of better availability and shorter examination times (Mitchell et al. 2013; Forstner et al. 2010). MRI is emerging as a potent alternative technique for staging ovarian cancer when standard MR sequences are combined with DWI (Forstner et al. 2010; Rockall 2014). This technique is recommended for staging of suspected ovarian cancer in pregnancy or in contraindications of IV contrast media (Forstner et al. 2010). In the latter PET/CT serves as an alternative modality to provide the relevant information for treatment decision. Similar to CT it is limited in small-volume peritoneal disease, but PET/CT seems most beneficial in advanced disease to assess metastases outside the peritoneal cavity

(Forstner et al. 2010; Javadi et al. 2016). Detection of lymph node metastases is a major limitation of imaging. Based on a threshold of 1 cm in diameter, the sensitivity for lymph node metastases is only 50%, and the specificity is 95% for CT and MRI. PET/CT performs superiorly but is also limited by lymph node metastases in the size of less than 1 cm (Pfanneberg et al. 2013; Javadi et al. 2016).

7.3.2\ Prediction of Resectability

Multidisciplinary consensus conferences (MDC) are the platform to define individualized optimal treatment regimen. If a patient with ovarian cancer will benefit from upfront surgery or rather from a neoadjuvant approach has to be decided on patient-related factors, e.g., the medical condition, surgical risks, and institutional preferences (Rockall 2014; Sala et al. 2013; Forstner et al. 2016b). The major limitation in the preoperative assessment of resectability is that no general accepted models exist and the impaired reproducibility due to different clinical practice (Forstner et al. 2016b). Imaging, mostly by CT, plays a pivotal role in patient triage by visualization of the size, site, and distribution of metastatic disease (Sala et al. 2013). Various CT criteria assessing different sites throughout the abdomen and CT scores without and with the incorporation of CA-125 or other clinical criteria have been proposed to predict preoperatively the success of optimal resectability (Suidan et al. 2014; Borley et al. 2015; Bristow et al. 2000; Quayyum et al. 2005). According to the ESUR guidelines for staging ovarian cancer, large disease (>2 cm) in the upper abdomen around the liver and spleen (Fig. 14), mesenteric deposits, and lymph node metastases above the renal hilum are sites likely to be nonoptimally resectable (Forstner et al. 2010). However, it has to be emphasized that resectability criteria may differ from center to center and predictive parameters have to be specified and agreed on in MDC (Forstner et al. 2010). CT and MRI performed similarly in detecting inoperable tumor and prediction of suboptimal debulking in ovarian cancer, with reported sensitivity of 76%, specificity of 99%, PPV of 99%, and NPV of 96% (Quayyum et al. 2005).