<b>CT Evaluation of the Response of Gastrointestinal Stromal Tumors After Imatinib Mesylate Treatment:</b> A Quantitative Analysis Correlated with FDG PET Findings

Abstract

FDG PET is sensitive and specific for evaluating tumor response but cannot be used in patients whose baseline FDG PET results are negative for tumors. Although subjective evaluation was a better indicator of treatment response than was tumor density alone, the tumor density measurement is a good indicator and provides a reliable quantitative means of monitoring the tumor. RECIST, using only tumor size, was unreliable for monitoring GISTs during the early stage of imatinib mesylate treatment.