FOLH1 and neoplasm: On the other hand, the MAS3-chelating 99mTc-labeled tracer showed substantially decreased in vivo stability compared to the mas3-derivative 99mTc-PSMA-I&S (PSMA-I&S for Imaging and Surgery), for which only intact tracer was detected in blood, urine and kidney at 1 h p.i. Furthermore, 99mTc-PSMA-I&S uptake in kidney and LNCaP-tumor was found to be high (186 ± 23, 8.28 ± 3.27 % IA/g at 1 h p.i., respectively) and specific, as shown by the blocking studies.