Digestive disorders

III./3.7.: Therapy monitoring with imaging methods

Following therapy not only the primary tumor but also the metastases (hepatic, mesenteric, etc.) become hypovascular. Increased attention is necessary, since even cystic degeneration does not indicate their entire inactivity, e.g. MR may show some enhancement inside the tumor. The size of GIST often does not shrink on the course of the therapy (thus RECIST criteria are not sufficient for monitoring the patient ), though the applicated therapy is efficient. Hence Choi introduced a criteria system based on CT density changes, which is suitable for the cathegorization of GIST along with lymphomas. These criteria make the efficient therapy to continue, and introducement of other therapy in case of inefficiency.