Lymphatic mapping and gamma probe guided laparoscopic biopsy of sentinel lymph node in patients with clinical stage I testicular tumor.

PURPOSE: We attempted to detect lymphatic drainage and sentinel lymph node with radioactive tracer in patients with testicular tumor. We then tried to determine if sentinel lymph node biopsy with gamma probe guided laparoscopic procedure was feasible as a staging tool for patients with clinical stage I testicular tumor.
MATERIALS AND METHODS: Technetium-labeled phytate was injected around the tumor in 15 consecutive patients with clinical stage I testicular tumor. Lymphatic drainage and sentinel lymph nodes were imaged by a gamma camera. Localization of the sentinel lymph node was confirmed with a handheld gamma probe. After we confirmed that sentinel lymph nodes were detected in the initial 10 patients, gamma probe guided laparoscopic sentinel lymph node biopsy was performed after routine orchiectomy in the next 4. To confirm whether the radioactive node was really a sentinel lymph node the final patient in this series underwent laparoscopic retroperitoneal lymph node dissection with a unilateral template.
RESULTS: Sentinel lymph nodes were detected in all patients by lymphoscintigraphy and handheld gamma probe, and each node varied. Right tumors in sentinel lymph node were detected at the inter-aortocaval, paracaval or common iliac region. Para-aortic lymph nodes were detected as sentinel lymph node in cases of left tumor. In the 4 patients who underwent gamma probe navigated laparoscopic procedure sentinel lymph nodes were easily detected and safely removed for pathological examination. In the last patient who underwent laparoscopic lymph node dissection micrometastasis was found only at the sentinel lymph node.
CONCLUSIONS: Sentinel lymph node can be detected by lymphoscintigraphy and handheld gamma probe. Gamma probe guided laparoscopic biopsy of sentinel lymph node is technically possible. These techniques may have a role in the management of clinical stage I testicular tumor but further trials are required for establishment of the concept of sentinel lymph node in testicular tumor.