OBJECTIVE: We aimed to describe radiologic signs and time-course of imatinib-associated fluid retention (FR) in patients with gastrointestinal stromal tumor (GIST), and its implications for management. MATERIALS AND METHODS: In this Institutional Review Board-approved, retrospective study of 403 patients with GIST treated with imatinib, 15 patients with imaging findings of FR were identified by screening radiology reports, followed by manual confirmation. Subcutaneous edema, ascites, pleural effusion, and pericardial effusion were graded on a four-point scale on CT scans; total score was the sum of these four scores. RESULTS: The most common radiologic sign of FR was subcutaneous edema (15/15, 100%), followed by ascites (12/15, 80%), pleural effusion (11/15, 73%), and pericardial effusion (6/15, 40%) at the time of maximum FR. Two distinct types of FR were observed: 1) acute/progressive FR, characterized by acute aggravation of FR and rapid improvement after management, 2) intermittent/steady FR, characterized by occasional or persistent mild FR. Acute/progressive FR always occurred early after drug initiation/dose escalation (median 1.9 month, range 0.3-4.0 months), while intermittent/steady FR occurred at any time. Compared to intermittent/steady FR, acute/progressive FR was severe (median score, 5 vs. 2.5, p = 0.002), and often required drug-cessation/dose-reduction. CONCLUSION: Two distinct types (acute/progressive and intermittent/steady FR) of imatinib-associated FR are observed and each type requires different management.
Adult ; Aged ; Aged, 80 and over ; Antineoplastic Agents/*adverse effects/therapeutic use ; Ascites/pathology/radiography ; Benzamides/*adverse effects/therapeutic use ; Echocardiography/methods ; Edema/pathology/radiography ; Female ; Gastrointestinal Stromal Tumors/drug therapy/pathology/*radiography ; Gastrointestinal Tract/pathology/*radiography ; Heart Failure/radiography ; Humans ; Male ; Middle Aged ; Molecular Targeted Therapy/*adverse effects ; Pericardial Effusion/pathology/radiography ; Peritoneal Neoplasms/diagnosis/radiography/secondary ; Piperazines/*adverse effects/therapeutic use ; Pleural Effusion/pathology/radiography ; Pyrimidines/*adverse effects/therapeutic use ; Radiology ; Retrospective Studies ; Tomography, X-Ray Computed

Imatinib, the first-line treatment in patients with advanced gastrointestinal stromal tumors (GIST), is generally well tolerated, although some patients have difficulty tolerating the standard dose of 400 mg/day. Adjusting imatinib dosage by plasma level monitoring may facilitate management of patients who experience intolerable toxicities due to overexposure to the drug. We present two cases of advanced GIST patients in whom we managed imatinib-related toxicities through dose modifications guided by imatinib plasma level monitoring. Imatinib blood level testing may be a promising approach for fine-tuning imatinib dosage for better tolerability and optimal clinical outcomes in patients with advanced GIST.
Aged ; Antineoplastic Agents/blood/*therapeutic use ; Benzamides/blood/*therapeutic use ; Drug Monitoring ; Exons ; Gastrointestinal Neoplasms/*drug therapy/pathology/radiography ; Gastrointestinal Stromal Tumors/*drug therapy/pathology/radiography ; Humans ; Liver Neoplasms/secondary ; Male ; Mutation ; Piperazines/blood/*therapeutic use ; Positron-Emission Tomography ; Proto-Oncogene Proteins c-kit/genetics ; Pyrimidines/blood/*therapeutic use ; Tomography, X-Ray Computed

OBJECTIVE: This study was undertaken for the purpose of describing the CT features of intra-abdominal extra-hepatic metastases from gastrointestinal stromal tumors in patients who were treated with imatinib. MATERIALS AND METHODS: Eleven patients with intra-abdominal extra-hepatic metastases from gastrointestinal stromal tumors, who were treated with imatinib between May 2001 and December 2003, were included in this study. The clinical findings and CT scans were retrospectively reviewed. The metastatic lesions were assessed according to the location, size (greatest diameter), attenuation, and the enhancing pattern before and after imatinib treatment. RESULTS: Prior to the treatment, the sizes and attenuation values of the metastatic lesions ranged from 5 to 20 cm and from 63 to 131 H, respectively. The metastatic lesions showed a heterogeneous enhancement pattern on the contrast-enhanced CT scans. After the treatment, the metastatic lesions became smaller in all 11 patients, and the corresponding attenuation value ranged from 15 to 51 H. The metastatic lesions became homogeneous and cystic in appearance on the follow-up CT scans, mimicking ascites. CONCLUSION: Intra-abdominal extra-hepatic metastases of patients with gastrointestinal stromal tumors treated with imatinib may appear as well-circumscribed cystic lesions on contrast-enhanced CT. These metastases are likely to become smaller and resemble ascites, but may persist indefinitely on the follow-up CT.
Adult ; Aged ; Antineoplastic Agents/*therapeutic use ; Contrast Media ; Gastrointestinal Stromal Tumors/*pathology/surgery ; Humans ; Iohexol/*analogs & derivatives/diagnostic use ; Liver Neoplasms/drug therapy/*radiography/secondary ; Male ; Middle Aged ; Peritoneal Neoplasms/drug therapy/*radiography/secondary ; Piperazines/*therapeutic use ; Protein-Tyrosine Kinase/antagonists & inhibitors ; Pyrimidines/*therapeutic use ; Research Support, Non-U.S. Gov't ; Retrospective Studies ; Tomography, X-Ray Computed/methods

Bevacizumab (Avastin(R)) is a monoclonal antibody against the vascular endothelial growth factor (VEGF) receptor that increases the overall survival rate when added to standard chemotherapy regimens in patients with metastatic colorectal cancer. The known toxicities of bevacizumab are hypertension, proteinuria, wound healing complications, arterial thrombosis, bleeding, and gastrointestinal complications. Especially ischemic colitis can rapidly develop into bowel perforation, so an emergency operation often is needed. Recently, a 65-year-old male patient developed ischemic pancolitis after FOLFOX (85 mg/m2 Oxaliplatin, d1;200 mg/m2 Leucovorin, d1;400 mg/m2 5-FU iv bolus, d1-2;and 600 mg/m2 5-FU, d1-2, every two wk) and Bevacizumab combination chemotherapy was administered. However, he recovered after early conservative care without surgery. We report this case with a review of literature.
Aged ; Antibodies, Monoclonal, Humanized/administration & dosage/*adverse effects ; Antineoplastic Combined Chemotherapy Protocols/therapeutic use ; Colitis, Ischemic/*chemically induced/radiography ; Colorectal Neoplasms/drug therapy/pathology ; Drug Administration Schedule ; Fluorouracil/administration & dosage ; Humans ; Intubation, Gastrointestinal ; Leucovorin/administration & dosage ; Male ; Organoplatinum Compounds/administration & dosage ; Tomography, X-Ray Computed