[GIST: Imaging diagnosis, staging, and response assessment]

Area of Science:

• Gastroenterology and Radiology
• Oncology imaging techniques
• Tumor response assessment

Context:

• Gastrointestinal stromal tumors (GIST) diagnosis and staging rely on various imaging modalities.
• Endoscopy is key for stomach and colon GIST, while multidetector-CT (MDCT) is standard for midgut GIST.
• Advanced techniques like enteroclysis-MDCT improve small bowel visualization.

Purpose:

• To outline current imaging standards for GIST diagnosis and staging.
• To discuss the limitations of RECIST criteria in assessing chemotherapy response in GIST.
• To introduce the modified Choi criteria as a superior method for evaluating treatment efficacy.

Summary:

• Contrast-enhanced MDCT is recommended for GIST staging, with MRI for rectal tumors and liver lesion evaluation.
• The Choi criteria provide a more accurate assessment of chemotherapy response compared to RECIST, accounting for tumor necrosis.
• FDG-PET/CT is the preferred modality for follow-up in GIST patients at risk of metastasis.

Impact:

• Improved diagnostic accuracy for GIST, particularly small bowel tumors.
• More reliable monitoring of treatment response, guiding therapeutic decisions.
• Enhanced patient management through optimized follow-up strategies using PET/CT.