Hossein Jadvar MD, PhD, Presenter: Nothing to Disclose

Xiankui Li PhD, Abstract Co-Author: Nothing to Disclose

Antranik Shahinian BS, Abstract Co-Author: Nothing to Disclose

Ryan Park BS, Abstract Co-Author: Nothing to Disclose

Michel Tohme MS, Abstract Co-Author: Nothing to Disclose

Peter Stephen Conti MD, PhD, Abstract Co-Author: Nothing to Disclose

We compared the uptake levels of radiolabeled acetate and radiolabeled choline in murine implanted xenografts of human prostate cancer.

In-vivo biodistribution studies were performed after s.c. injection of androgen-independent (PC3) and androgen-dependent (CWR22) cells at a concentration of 10 x 10E6 cells per 0.2 mL in 4-6 week old, 20-30 g, non-castrated male athymic mice and allowing enough time for tumors to grow to at least 1 cm3. Animals were sacrified at 5 min, 10 min, and 20 min after tail vein administration of 1.25 μCi of a radiotracer (C-14 acetate, C-14 choline). Prostate tumors and organs were then harvested, weighed, and counted for radioactivity. Tissue tracer uptake was calculated as %ID/g. In a separate group of mice, autoradiography was performed at 5 min and at 20 min after tracer administration. Two-tailed Student t test with unequal variance was used for comparing the difference in the means and a probability of less than 0.05 was considered as significant.

The PC3:muscle acetate uptake ratio (mean+sd) was 1.21+/-0.48 at 5 min (n=5), 1.59+/-0.18 at 10 min (n=4), and 1.58+/-0.39 at 20 min (n=5), respectively. The PC3:muscle choline uptake ratio was 1.3+/-0.8 at 5 min (n=5), 0.82+/-0.38 at 10 min (n=3), and 0.80+/-0.36 at 20 min (n=4), respectively. The CWR22:muscle acetate uptake ratio was 0.71+/-0.21 at 5 min (n=5), 0.84+/-0.21 at 10 min (n=4), 1.16+/-0.29 at 20 min (n=5), respectively. The CWR22:muscle choline uptake ratio was 0.76+/-0.35 at 5 min (n=5), 0.42+/-0.03 at 10 min (n=2), 0.62+/-0.45 at 20 min (n=4), respectively. There was no statistically significant difference between the mean acetate uptake and the mean choline uptake in either of the two tumors at all three time points (p>0.6). The autoradiography imaging studies demonstrated no significant qualitative difference between acetate and choline images of the implanted tumors.

There is no significant difference between the mean uptake levels of acetate and choline for a given prostate tumor type implanted in non-castrated host. However, there may be a tendency for uptake of both tracers to be higher in androgen-independent tumor than in androgen-dependent tumor.

Jadvar, H, Li, X, Shahinian, A, Park, R, Tohme, M, Conti, P, Comparison of Acetate and Choline in Mouse Xenografts of Human Prostate Cancer.  Radiological Society of North America 2005 Scientific Assembly and Annual Meeting, November 27 - December 2, 2005 ,Chicago IL. http://archive.rsna.org/2005/4408268.html