Feasibility of Using SPECT/CT Imaging to Map Lymphatic Drainage Patterns in Prostate Cancer Patients

The entire study procedure involves 1) preparation of 99mTc-sulfur nanocolloid, 2) administration of 99mTc-sulfur nanocolloid with transrectal ultrasound guidance, 3) transfer of the patient to the Nuclear Medicine clinic for SPECT/CT (Infinia Hawkeye, GE Healthcare) imaging, and 4) tomographically capturing distributions of 99mTc-sulfur nanocolloid uptake in the patient's lymphatic drainage sites within a practical image acquisition time (1-3 h postinjection) considering the patient transit time between injection and imaging. Administration of 99mTc-sulfur nanocolloid will be performed at the UCSF Urology clinic. The injection will be performed following the clinically accepted method that has been described by European investigators. 99mTc-sulfur nanocolloid imaging utilizes trace amounts of radioactivity. 100-200 MBq (2.7-5.4 mCi) of 99mTc-sulfur nanocolloid will be administered into two lobes of the prostate gland under transrectal ultrasound guidance with three fractions each into peripheral and central zone of the prostatic apex, mid portion, and base. 1% Lidocaine may be administered for local anesthesia per routine clinical protocol as deemed appropriate by the performing urologist. The procedure will be considered feasible if the practice procedure (from injection to completion of imaging) is successfully implemented within 3 hours of injection (including patient transport time). Imaging will be considered successful if radiotracer is qualitatively detected within the prostate and local lymphatic system.