All patients were treated with the oral administration of 400 mg of imatinib daily. The clinical symptoms, duration of imatinib therapy, and CT scan reports were reviewed. The institutional review board at our hospital did not require approval or informed patient consent for the review www.selleckchem.com/products/Bicalutamide(Casodex).html of the medical records and images. All patients underwent CT scans prior to the administration of imatinib and 4-10 weeks after the initiation of the imatinib therapy. Ten patients underwent two or more follow-up CT scans 4-22 months after the initiation of the treatment with imatinib. The CT scan data were available on a picture archiving and communications system (PACS; Marotech, Seoul, Korea) for all patients.

The CT scans were performed using a Somatom Plus-4 (Siemens Medical Systems, Erlangen, Germany), a HiSpeed Advantage scanner (General Electric Medical Systems, Milwaukee, WI), or a MX8000 four-detector row CT scanner (Philips Medical Systems, Cleveland, OH). Each patient received 120 mL of a nonionic contrast material (Iopromide, Ultravist 370; Schering Korea, Seoul, Korea) through an 18-gauge angiographic catheter inserted into a forearm vein. The contrast material was injected at a rate of 2.5 mL/sec using an automatic injector. In the case of the single-detector scanner, a helical CT scan was performed with the following parameters: 5-7 mm collimation, 1:1 table pitch, and 5-7 mm reconstruction intervals. In the case of the MX8000 scanner, the parameters were 2.5 mm detector collimation, 20 mm/sec table speed, 5 mm slice thickness, and a 5 mm reconstruction interval.

The delay between the contrast material administration and scanning was 55-70 seconds. Two radiologists reviewed all of the CT scans retrospectively, and the final interpretations were reached by consensus. All images were reviewed on a 2,000��2,000 PACS monitor. The presence of the metastatic lesion and its size before and after the imatinib treatment were compared. The metastatic lesions were assessed according to their location, size (greatest diameter), attenuation, and enhancing pattern. If multiple metastatic lesions were detected, the largest lesion was recorded. For the objective analysis, the CT attenuation value was measured in a circular region of interest with a diameter of 10 mm. The CT attenuation value was measured three times by a single radiologist and the mean value was recorded.

In the case of a heterogeneous mass, the CT attenuation value was measured in the solid portion of the GSK-3 tumor. The CT attenuation value before and after the imatinib treatment was compared using the paired t-test. Statistical analyses were performed using a computer software package (SPSS, version 10.0; SPSS, Chicago, Ill). A p value of less than .05 was considered to indicate a statistically significant difference. RESULTS The clinical and radiologic findings are summarized in Table 1.