MRI and Magnetometer-guided Sentinel Lymph Node Detection in Vulvar Cancer

Patients will receive superficial and interstitial injection with a 23 G needle with of a total volume of 0.1 - 1 ml Magtrace at four sites in or near the tumor in vulva, the same localization as the injections of Technetium99m and Patent blue for tracing SLNs performed at the surgery. The injection is performed by one of the gynecologic cancer surgeons participating in this study.The time of migration of SPIO to the groin nodes is not known for vulvar cancer. Transportation by dynamic MRI, with selective sequences repeated during a time span of 1- 60 minutes after the injection.