Clinical Research
Copyright ©2008 The WJG Press and Baishideng. All rights reserved.
World J Gastroenterol. Feb 14, 2008; 14(6): 892-898
Published online Feb 14, 2008. doi: 10.3748/wjg.14.892
Assessment of gastrointestinal stromal tumors with computed tomography following treatment with imatinib mesylate
Sith Phongkitkarun, Cholada Phaisanphrukkun, Janjira Jatchavala, Ekaphop Sirachainan
Sith Phongkitkarun, Cholada Phaisanphrukkun, Janjira Jatchavala, Department of Radiology, Faculty of Medicine, Ramathibodi Hospital, Mahidol University, Rama VI Rd., Ratchathewi, Bangkok 10400, Thailand
Ekaphop Sirachainan, Department of Medicine, Faculty of Medicine, Ramathibodi Hospital, Mahidol University, Rama VI Rd., Ratchathewi, Bangkok 10400, Thailand
Author contributions: Phongkitkarun S and Jatchavala J designed the research; Phongkitkarun S and Phaisanphrukkun C performed the data collection, data analysis/ interpretation, and statistical analysis; Sirachainan E performed the clinical studies; Phongkitkarun S, Phaisanphrukkun C, Jatchavala J, and Sirachainan S drafted and revised the manuscript and approved the final version; and Phongkitkarun S and Jatchavala J edited the manuscript.
Correspondence to: Sith Phongkitkarun, MD, Department of Radiology, Faculty of Medicine Ramathibodi Hospital, Rama VI Rd., Ratchathewi, Bangkok 10400, Thailand. rasih@mahidol.ac.th
Telephone: +66-2-2011260
Fax: +66-2-2011297
Received: August 30, 2007
Revised: November 22, 2007
Published online: February 14, 2008
Abstract

AIM: To evaluate and characterize the patterns of disease progression of metastatic or unresectable gastrointestinal stromal tumor (GIST) treated with imatinib mesylate, and to determine the prognostic significance associated with disease progression.

METHODS: Clinical data and computed tomography (CT) images were retrospectively reviewed in 17 GIST patients who were treated with imatinib mesylate from October 2002 to October 2006. Apart from using size measurement for evaluation of tumor response [Response Evaluation Criteria in Solid Tumors (RECIST) criteria], patterns of CT changes during treatment were evaluated and correlated with clinical data.

RESULTS: There were eight non-responders and nine responders. Five patterns of CT change during treatment were found: focal progression (FP), generalized progression (GP), generalized cystic change (GC), new cystic lesion (NC) and new solid lesion (NS). At the end of study, all non-responders showed GP, whereas responders showed cystic change (GC and NC) and response according to RECIST criteria. Overall survival was significantly better in patients with cystic change or response within the RECIST criteria compared with GP patients (P = 0.0271).

CONCLUSION: Various patterns of CT change in patients with GIST who responded to imatinib mesylate were demonstrated, and might determine the prognosis of the disease. A combination of RECIST criteria and pattern of CT change are proposed for response evaluation in GIST.

Keywords: Computed tomography; Gastrointestinal stromal tumor; Imatinib mesylate