The main goal of the study is to expand cancer preclinical research results on the usefulness of CCK-2/gastrin receptor in clinical practice. On the basis of last few years preclinical research outcome on new biomarkers, conjugate CP04 was chosen on the basis of its good stability and affinity to CCK-2/gastrin receptor in vitro, as well as its favourable biodistribution and pharmacodynamic properties in vivo, preclinically. Within this project the tracer may get a chance to be introduced to clinical practice as a more selective and efficient tool for the diagnosis, early detection and therapy of recurrent and metastatic MTC.