Three-dimensional radiation therapy treatment planning with render-plan. Summary, value and prospect of 3-D treatment planning system

Treatment planning of three-dimensional radiation therapy was tried with using Render-Plan. In the case of the breast tangent line irradiation after the breast conserving surgery of breast cancer, the procedure was as follows. CT image of a patient obtained by the same position as radiotherapy was handled with Render-Plan. ROIs of body outline, target, and, if necessary, the risk internal organs were obtained. Most favorite irradiation beam was established by simulation. Collimator angle was decided easily by using three dimensional Beam's eye view. Accurate dose distribution of radioactivity was provided. Based on these data, two dimensional image and three dimensional image were displayed and its appropriateness was considered. Wedge filter, bolus or block was added if necessary. Finally digital reconstructed radiography was displayed, identified that there was no difference with X-ray radiotherapy simulation, and compared with linac imaging. From dose volume histogram was calculated and a dose of radioactivity of target and internal organs to be not irradiated was checked quantitatively. An error between a dose of radioactivity that was calculated with Render-Plan and a dose of radioactivity that measured, was less than 2%. (K.H.)