고려대학교

초록/요약

We present preliminary results for a 3-dimensional dose evaluation software system (P DRESS,patient-specific 3-dimensional dose real evaluation system). Scanned computed tomography (CT)images obtained by using dosimetry were transferred to the radiation treatment planning system(ECLIPSE, VARIAN, Palo Alto, CA) where the intensity modulated radiation therapy (IMRT)nasopharynx plan was designed. We used a 10 MV photon beam (CLiX, VARIAN, Palo Alto,CA) to deliver the nasopharynx treatment plan. After irradiation, the TENOMAG dosimeterwas scanned using a VISTATM scanner. The scanned data were reconstructed using VistaReconsoftware to obtain a 3D dose distribution of the optical density. An optical-CT scanner was used toreadout the dose distribution in the gel dosimeter. Moreover, we developed the PDRESS by usingFlatform, which were developed by our group, to display the 3D dose distribution by loading theDICOM RT data which are exported from the radiotherapy treatment plan (RTP) and the optical-CT reconstructed VFF file, into the independent PDRESS with an ionization chamber and EBTfilm was used to compare the dose distribution calculated from the RTP with that measured byusing a gel dosimeter. The agreement between the normalized EBT, the gel dosimeter and RTP datawas evaluated using both qualitative and quantitative methods, such as the isodose distribution,dose difference, point value, and profile. The profiles showed good agreement between the RTPdata and the gel dosimeter data, and the precision of the dose distribution was within ±3%. Theresults from this study showed significantly discrepancies between the dose distribution calculatedfrom the treatment plan and the dose distribution measured by a TENOMAG gel and by scanningwith an optical CT scanner. The 3D dose evaluation software system (P DRESS, patient specificdose real evaluation system), which were developed in this study evaluates the accuracies of thethree-dimensional dose distributions. Further applications of the system utility are expected toresult from future studies.