Lymphatic mapping and detection of sentinel nodes in patients with bladder cancer

Purpose: We examined the possibility for detecting sentinel nodes in patients with bladder cancer and whether the histopathological status of identified sentinel nodes reflected that of the lymphatic field. Materials and Methods: A total of 13 patients with bladder cancer who met the criteria qualifying them for radical cystectomy had intravesical injections of radioactive tracer and blue dye marker around the tumor followed by lymphoscintigraphy to visualize lymphatic drainage and detect sentinel nodes. Sentinel nodes were identified preoperatively by the blue color and increased radioactivity and were compared histopathologically with other routinely excised lymph nodes. Results: Sentinel nodes were detected in 85% (11 of 13) of patients. There were 4 patients who had sentinel nodes containing tumor cells, and each metastasis was only seen in the detected sentinel node. There were no false-negative sentinel nodes. Of the metastatic sentinel nodes 3 were located outside the normally excised lymph nodes of the obturator fossa. Conclusions: Sentinel nodes can be detected in patients with bladder cancer. The histopathological status of the identified sentinel nodes was diagnostic for all other excised lymph nodes. Sentinel nodes often seem to be located outside the obturator lymphatic field, which is normally examined during preoperative staging of bladder cancer.