57IN - Molecular imaging of gynecological cancers: Ovarian cancer as role model
|Date||01 October 2012|
|Event||ESMO Congress 2012|
|Session||Emerging diagnostic and therapeutic targets in gynecological cancers: From science to clinical practice|
|Topics|| Ovarian Cancer
|Presenter||E.G. Elisabeth De Vries|
E.G..E. De Vries1, G.M. van Dam2, A.W.J.M. Glaudemans3, A. Reyners1, A. van der Zee4, G. Hospers1, M.N. Lub-De Hooge5
Standard imaging work-up in ovarian cancer comprises chest imaging, ultrasound and abdominal/pelvic CT. To determine the extent of disease however, these modalities have poor sensitivity. In addition, they do not provide information about tumor characteristics such as tumor aggressiveness or presence of possible drug targets. Molecular imaging can provide serial non-invasive information about tumor characteristics and can be performed with various imaging techniques such as PET, SPECT and optical imaging. For this purpose, tumor-directed agents can be labeled with a radioactive nuclide, or a fluorescent dye. The PET-tracer 18F-fluorodeoxyglucose (FDG), visualizes glucose metabolism, which is often increased in tumors. Increasingly, it is possible to image specific drug-targets of tumors, such as hormone receptors, growth factors and growth factor receptors. Molecular imaging in metastatic breast cancer patients is feasible for the estrogen receptor with the 18F-fluoroestradiol PET tracer and for HER2 with 111In- and 89Zr-trastuzumab for SPECT and PET respectively. A trial with 18F-fluoroestradiol in ovarian cancer is ongoing. Imaging of vascular endothelial growth factor (VEGF) with 89Zr-bevacizumab has been performed by us in various tumor types. In addition, modulation of drug targets can be visualized by molecular imaging. Down-regulation of HER2 and VEGF tumor expression by HSP90 inhibition and of VEGF by mTOR inhibition was visualized in a human ovarian cancer bearing mice. Finally, optical imaging can provide real-time visualization of small lesions during surgery, allowing intra-operative staging and image-guided surgery. Folate receptors are often over-expressed in ovarian cancer and in a pilot-study we demonstrated, that ovarian cancer can be imaged intraoperatively by folate-fluorescein-isothiocyanate (folate-FITC). We are currently performing a feasibility fluorescence imaging study with the NIFR 800CW-bevacizumab tracer in primary breast cancer. Molecular imaging is still in its infancy and not part of current standards. However, the emerging possibilities of molecular imaging for staging, treatment decision-making, monitoring of treatment effects and image-guided surgery, justifies further validation of molecular imaging in ovarian cancer.Disclosure
E.G.E. De Vries: Research grant Roche and Novartis.
All other authors have declared no conflicts of interest.