Purpose Gastroenteropancreatic neuroendocrine tumors are a heterogeneous group of low incidence neoplasms characterized
by a low proliferative activity and slow growth. Their response to targeted therapies is heterogeneous and often does not lead
to tumor shrinkage. Thus, evaluation of the therapeutic response should difer from other kind of tumors.
Methods To answer relevant questions about which techniques are best in the assessment of progression or treatment
response a RAND/UCLA-based consensus process was implemented. Relevant clinical questions were listed followed by
a systematic search of the literature. The expert panel answered all questions with recommendations, combining available
evidence and expert opinion. Recommendations were validated through a questionnaire and a participatory meeting.
Results Expert recommendations regarding imaging tools for tumor assessment and evaluation of progression were agreed
upon. Available imaging techniques were reviewed and recommendations for best patient monitoring practice and the best
way to evaluate treatment response were formulated