Patients and IMRT planning

The object of this study was IMRT QA for the pelvic region, for which dose differences were within a certain range in the study of Puliam et al. [8]. A seven-field coplanar treatment plan with beam angles of 27°, 78°, 129°, 180°, 231°, 282° and 333° was generated with a 6-MV flattened or an 11-MV unflattened X-ray beam using an ARTISTE^TM accelerator with 160 multileaf collimator (MLC) (Siemens, Erlangen, Germany). The beam property of the ARTISTE^TM is described elsewhere [14]. Fifteen patients who had undergone IMRT for uterine cancer in our institution between February 2014 and December 2014 were enrolled in this study. A radiation oncologist delineated the contouring of the clinical target volume as the target, and then a medical physicist created the IMRT plan. A mean dose of 50.4 Gy was prescribed for the planning target volume (PTV) over 28 fractions for all patients [15]. Treatment plans were created using the XiO TPS (Elekta, Stockholm, Sweden), and a dose calculation algorithm was a superposition with a voxel size of 2.0 × 2.0 × 2.0 mm³.