<qa>  What is the average time of the study participants are monitored during adjuvant treatment?The study participants are monitored during adjuvant treatment and following adjuvant treatment. Physical examination, weight and ECOG performance status are assessed at 4- to 26-week intervals. Adverse events are collected using structured forms at the times of the evaluation visits. Blood cell counts and blood biochemistry are measured at 2- to 6-week intervals during imatinib therapy, and at 6-month intervals following completion of adjuvant therapy. CT or MRI examinations of the abdomen and pelvis are performed at 6-month intervals during the study. 