Optimized Response Assessment of Gastrointestinal Stromal Tumors Using Dual-Energy CT: A Prospective Multicenter-Multinational Trail in Patients Undergoing Targeted Therapy with a tyrosine-kinase-inhibitor

Interventions: Group 1: Patients with Gastrointestinal Stromal Tumors undergoing tyrosine kinase inhibitor treatment will be assessed regarding progression-free survival and overall survival within 2 years using the standard response criteria, in particular Response Evaluation Criteria In Solid Tumors, the WHO criteria for response, the tumor lesion volume as well as tumor density (according to Choi).
Group 2: Patients with Gastrointestinal Stromal Tumors undergoing tyrosine kinase inhibitor treatment will be assessed regarding progression-free survival and overall survival within 2 years using the response criteria, in particular tumor lesion iodine uptake.
Primary outcome(s): Progression-free survival within 2 years.
Study Design: Allocation: Non-randomized controlled study; Masking: Open (masking not used); Control: active; Assignment: parallel; Study design purpose: treatment