A 74yrs old male, status post resection of Gastrointestinal Stromal Tumor (GIST) and history of adjuvant Gleevec (Imatinib mesylate) therapy 3 years ago, was referred for PET-CT imaging because of interval increase in size of the right lower quadrant soft tissue density mass, seen on a follow up CT scan.

PET-CT case of the month (06/09): GIST Treated with Gleevec This case was compiled by Dr. David He, BCM A 74yrs old male, status post resection of Gastrointestinal Stromal Tumor (GIST) and history of adjuvant Gleevec (Imatinib mesylate) therapy 3 years ago, was referred for PET-CT imaging because of interval increase in size of the right lower quadrant soft tissue density mass, seen on a follow up CT scan.

PET-CT showed intense FDG uptake in the mass (maximum SUV 12.4) and multiple smaller hypermetabolic lesions in the abdomen, consistent with neoplastic involvement with GIST. Gleevec therapy was restarted and the follow up PET-CT in 3 weeks demonstrated resolution of hypermetabolism in all lesions, suggesting good response to therapy . The SUV of the RLQ mass decreased to 2.5.

This case was compiled by Dr. David He, BCM