Imaging ovarian cancer and peritoneal metastases--current and emerging techniques

Peritoneal metastases are often the first presentation of ovarian malignancy. Evaluating the extent of disease critically determines tumor resectability and can also predict outcome. Standard CT, however, frequently fails to identify small sites of peritoneal spread. Moreover, it does not provide a quantitative index of disease response to cytotoxic therapy as it relies on macroscopic morphological changes in tumor volume, and does not reflect preceding molecular events in the microenvironment of the tumor. We describe the emerging role of functional imaging techniques, such as radioimmunoscintigraphy, PET/CT, diffusion-weighted MRI, dynamic contrast-enhanced MRI, and magnetic resonance spectroscopy in staging ovarian cancer and assessing treatment response. The combination of functional information with conventional anatomical visualization holds promise to accurately characterize peritoneal disease, and provides noninvasive biomarkers of therapeutic performance and patient prognosis.