Objectives: The aim of this study was to verify the treatment planning systems (TPSs). The next aim was to validate IMSure QA software for patient-specific QA in radiotherapy clinics. Material and Methods: We used IMSure QA software (standard Imaging, v 3.5) for verification of 92 non-IMRT plans (540 fields) in 10 radiotherapy clinics. To validate the IMSure, dose measurement was performed in CIRS phantom. Then, IMSure Calculations were compared with dose measurements. Finally, 92 patient plans (540 fields) were re-calculated including abdomen-pelvic, head & neck, breast & chest treatment sites. Results: IMSure shows good agreement with dose measurements in the phantom. In the analysis of 540 fields, the mean difference of dose between IMSure and TPS was 0.62% (~3% SD) and for MU calculation was 1.5% (5.5% SD). Per site-treatment analysis shows mean differences of MU for abdomen-pelvic, head & neck, breast & chest treatments 1.3%(5.35% SD), 0.52%(5.22% SD) and 2.5% (7.13%SD), respectively. In addition, it was found that among different treatment planning systems, AAA algorithm has the best agreement with IMSure in mean difference of 0.68% for MU and 1.33% for total dose.Conclusion: Our results show that IMSure can be a suitable tool for routine and patient-specific QA, especially when a treatment plan is complex. Based on our results, we suggest re-assessment of agreement criteria for chest site treatment.