Objective: To evaluate the value of (99 m)Tc-sandostatin scintigraphy in targeted diagnosis of pancreas carcinoma and the correlation with expression of somatostatin receptor (SSTR) reporter gene in tumor tissue.
Methods: Nude mice bearing human pancreas carcinoma xenograft were established in advance. (99 m)Tc-sandostatin imaging was performed in 18 nude mice and tumor to normal tissue ratio (T/NT) was calculated. mRNA expression of SSTR1, SSTR2 and SSTR5 in tumor tissue was detected by RT-PCR.
Results: Out of 18 nude mice, 13 mice showed intense uptake of (99 m)Tc-sandostatin. Six hours after (99 m)Tc-sandostatin administration, the T/NT ratio was 2.53 +/- 0.84. Five mice showed negative findings, and the T/NT ratio was 1.04 +/- 0.06. Positive correlations were obtained between the T/NT ratio and the expression of SSTR1 and SSTR2 mRNA, especially SSTR2 (r = 0.807, P < 0.01).
Conclusion: High expression of SSTR1, SSTR2 and SSTR5 mRNA were found in human pancreas tumor xenograft in nude mice, especially SSTR2. There is a significant correlation between the tumor uptake of (99 m)Tc-sandostatin and SSTR2 mRNA level. This approach may allow SSTR-targeted diagnosis and therapy of human pancreas cancer.