Figure 7.

Static whole-body SPECT/CT images of SCID mice bearing AsPC-1 xenografts in their flanks at 4 h pi of (a) [^99mTc]Tc-DT11 alone or (b) together with excess NT for in vivo NTS₁R blockade, (c) with results from [^99mTc]Tc-DT1 for comparison purposes; orange arrows are pointing to the human NTS₁R-expressing xenografts and yellow arrows are directed toward the kidneys. The AsPC-1 tumor was well-delineated by [^99mTc]Tc-DT11 in (a) but not in (b), consistent with an NTS₁R-mediated process, and the kidneys were visible too. In contrast, rapidly biodegradable [^99mTc]Tc-DT1 failed to effectively target the implanted tumor while displaying excessive kidney uptake (c). The color bars indicate radioactivity levels (purple being the lowest and white the highest level of accumulation).