CT findings after laparoscopic pelvic lymph node dissection and transperineal radioactive seed implantation for prostatic carcinoma.

Abstract

The purpose of this paper is to describe the CT findings in patients undergoing transperineal sonographically guided radioactive seed implantation with and without laparoscopic lymph node dissection for treatment of carcinoma of the prostate gland. Ninety-six CT scans of the pelvis were retrospectively reviewed in patients who had undergone radioactive seed implantation of the prostate gland. The CT readings were correlated with the type of procedure each patient had and the pathologic results of laparoscopic lymph node dissection. Of 73 patients who underwent laparoscopic lymph node dissection, 42 were found at CT to have low-attenuation masses along lymph node chains. These masses resembled necrotic nodes. Only one patient who did not undergo laparoscopic lymph node dissection had similar findings. Fourteen patients had fluid collections within the pelvis, 13 of whom had undergone laparoscopic lymph node dissection. Other imaging findings included ectopic seeds (10 patients) and subcutaneous and intrapelvic air (11 patients). All except two patients had negative pathology reports for the removed lymph nodes. A wide variety of imaging findings may be seen after radioactive seed implantation and laparoscopic lymph node dissection, including masses that resemble necrotic lymph nodes. Radiologists should be aware of these findings in asymptomatic patients.