Problems and pitfalls in vulvar and cervical cancer sentinel node scintigraphy

After the introduction for penile cancer, the sentinel lymph node imaging is increasingly applied in various types of cancer. After the initial learning phase, 105 patients with vulvar and 24 with cervical cancer have been investigated. In vulvar cancer all the imaged sentinel nodes were discovered by the portable probe intraoperatively. No false negative sentinel node was observed. The most critical issue is the tracer application. Performed strictly intradermally, the sentinel node shows up immediately. Concomitant use of isosulfan blue dye did not improve the results and was stopped therefore. Similarly, more superficial (intra/subendothelial) application brings up better results as compared to deeper injection in cervical cancer patients. No false negative results were seen. Apparently, an almost 100% detection is possible. Our findings clearly show that tracer application is the key for successful imaging. If not done properly, sentinel node may appear later or may even more likely be missed.