Intraprostatic injections of 99mTc-Nanocoll under transrectal ultrasound
guidance – preliminary experience
Article published in Urologia Polska 2008/61/Supl. 1.
Waldemar Białek, Robert Klijer, Marek Urban, Krzysztof Bar, Beata Chrapko
- Klinika Urologii i Onkologii Urologicznej AM w Lublinie
Zakład Medycyny Nuklearnej AM w Lublinie
Introduction. The sentinel lymph node evaluation with preoperative lymphoscintigraphy and intraoperative gamma probe measurement is being more frequently used for detecting lymph node metastasis in prostate cancer.
Objectives. To analyze technique of intraprostatic administration of the radioisotope under transrectal ultrasound guidance.
Materials and methods. We performed 30 intraprostatic injections of 99mTc-Nanocoll in 15 patients. All administrations were done one day before pelvic lymphadenectomy and radical retropubic prostatectomy. The “Chiba” biopsy needle has been used (22G x 15 cm). The needle used to be inserted into peripheral zone, deep along the peripheral zone, as parallel to the prostate axis as possible, preferably near tumorous leasion (if present on ultrasound). After withdrawal of internal shaft needle has been aspirated to confirm positioning of the tip outside any vessel. During injection of the medium, the needle has been gradually withdrawn so as to allow regular deposition of the radioisotope into prostatic parenchyma. Correct positioning of the ultrasound probe allowed real time visualization of the needle tip as well as iso/ hyperechoic colloid spilling out into the prostatic tissue. Because of hardness of cancerous nodules direct application into a tumor was usually difficult to perform. The
- procedure has been recorded as video clip sequences. The same procedure has been repeated on the other side. After needle withdrawal images depicting distribution of the radiotracer inside prostatic lobes were taken.
Results. In two patients lymphoscyntygraphy did not reveal any regional lymph nodes. Most probably because of the radioisotope leakage through prostatic tubules into urethra and urinary bladder. In one patient because of the presence of the radioisotope in the bladder scintygraphic assessment was possible after voiding. Information provided by most of scintygraphies was sufficient to determine sentinel lymph node localization. Intraoperative use of gamma probe helped in searching for lymph nodes of special clinical relevance. No Nanocoll related side effects were observed during or after injection.
Conclusions. Intraprostatic Nanocoll injection under transrectal ultrasound guidance is a safe procedure. Precise needle insertion and appropriate injection of the radioisotope may prevent its leakage to urethra, urinary bladder, or blood vessels and unreliable scintigraphic results. There is need for further studies to determine the most appropriate sites of radioisotope deposition inside the prostate.