PET/CT with 18F-fluorodeoxyglucose as metabolic alternative to biopsy for gastrointestinal stromal tumor?

The usefulness of 18F-fluorodeoxyglucose (FDG) PET/CT in different clinical settings of many malignancies is well documented. Early evaluation of therapeutic response by means of functional imaging providing important predictive and prognostic information is particularly interesting. Furthermore, certain anticancer agents show significant therapeutic specificity for certain types of malignancies and therapeutic test evaluated by functional imaging my serve as metabolic surrogate for histology (metabolic biopsy). Gastrointestinal stromal tumours are FDG avid mesenchymal tumours, in most cases well responding to treatment by tyrosine-kinase inhibitors (imatinib mesylate, sunitinib maleate). Therapeutic test by imatinib mesylate evaluated by FDG PET/CT may potentially serve as metabolic biopsy in patients presenting tumour evocative of GIST. This article illustrates the potential role of metabolic biopsy in routine management of patients with abdominal tumour evocative of GIST. (author)