Radioisotope guided pelvic lymph node dissection for prostate cancer.
OBJECTIVE
The localization of lymph node metastases in prostate cancer varies enormously. Due to high morbidity complete pelvic lymphadenectomy is often decreased to modified staging lymphadenectomy, resulting in loss of sensitivity for detecting micrometastases. Based on the promising results of intraoperative gamma probe application for identifying sentinel lymph nodes in malignant melanoma, breast and penis cancer, we identified sentinel lymph nodes in prostate cancer using a comparable technique.


METHODS
In 117 patients 99mtechnetium nanocolloid was transrectally injected directly into the prostate under ultrasound guidance 1 day before pelvic lymphadenectomy. Thereafter dynamic lymphoscintigraphy was done. Initially lymph nodes identified as sentinel lymph nodes by the gamma probe were removed and subsequently modified pelvic lymphadenectomy was performed.


RESULTS
Lymphatic metastasis was detected in 28 cases. An average of 4 sentinel lymph nodes were identified per patient in 25 of 27 patients with micrometastasis, of which those in 24 contained micrometastasis for 96% sensitivity. In contrast, sensitivity of modified pelvic lymphadenectomy was 81.5%. In 16 patients only sentinel lymph nodes were positive. An average of 21.8 lymph nodes (range 10 to 51) was dissected per patient at pelvic lymphadenectomy. Lymph node metastasis was noted in 6 of the 46 patients with a prostate specific antigen between 4 and 10 ng./ml. and in 8 of the 64 with a stage pT2 tumor.


CONCLUSIONS
Our study shows individual variability of lymphatic drainage of the prostate and limited sensitivity for detecting positive lymph nodes when the pelvic dissection area is limited. Furthermore, our experience implies that the identification of sentinel lymph nodes is feasible, not only in breast cancer and malignant melanoma, but also in prostate cancer using a comparable technique.
Wawroschek
F
F
Department of Urology, Zentralklinikum Augsburg, Augsburg, Germany.
Vogt
H
H
Weckermann
D
D
Wagner
T
T
Hamm
M
M
Harzmann
R
R
D000368:Aged; D006801:Humans; D008197:Lymph Node Excision; D008207:Lymphatic Metastasis / Q000175:diagnosis; D008297:Male; D008875:Middle Aged; D011471:Prostatic Neoplasms / Q000473:pathology* / Q000628:therapy*; D021701:Sentinel Lymph Node Biopsy; D013668:Technetium Tc 99m Aggregated Albumin
D013668:Technetium Tc 99m Aggregated Albumin; C083602:technetium Tc 99m nanocolloid