Visualization of canine and human prostatic lymph nodes following intraprostatic injection of technetium-99m-antimony sulfide colloid.

Clinically occult lymph node metastases are a frequent finding in patients with carcinoma of the prostate. At present, lymph node dissection is the only reliable method of detecting local nodal spread; we have investigated a nonsurgical technique for demonstrating nodes using intraprostatic injections of 99mTc-Sb2S3. 99mTc-Sb2S3 (1.0 mCi/0.1--0.2 ml) was injected into the prostate glands of nine male mongrel dogs. Scintillation camera images revealed from one to four lymph nodes in each animal with earliest nodal visualization at 1 hour. A study performed on a 64-year-old man with prostatic cancer allowed visualization of seven pelvic lymph nodes, all of which were found to be histologically normal. The simplicity of this technique suggests the potential for both pre- and intraoperative identification of the prostatic lymph nodes. Clinical trials presently underway will allow assessment of the sensitivity and specificity of this technique for the detection of nodal metastases.