Research On Dose Planning Technologies Of Treatment Planning System For Seed Implant Brachytherapy

This paper takes treatment planning system for permanent seed implant brachytherapy as the research object and aim to develop a dose-planning system with wide applicability.Primary contents of research are the non-coplanar needle technology,optimal design in the operation,inverse planning optimization and System platform experiment.Main achievements in research are as follows:Firstly,a 3D treatment planning system based on non-coplanar needles was proposed,which solves the problem that the dose is difficult to meet the requirements of clinical treatment under the condition of large tumor,multi lesion,blocked by bones and tissues of critical organs.The clinical requirements were analyzed and the merits and demerits of the traditional coplanar needle template were discussed.Then,a non-coplanar needle and its 3D guided template were designed.And the key technologies of the whole system were determined.Secondly,the method of dose optimization for particle implantation therapy based on CT image was proposed,which solves the question of whether the seed can be implanted according to preoperative planning.Through the identification of puncture needle in CT images,the model of puncture needle was reconstructed and the preoperative planning results of seed position were inherited,then the surgical program evaluation was performed.The experimental results show that the recognition accuracy of puncture needle meets the clinical requirements.In the end,a hybrid simulated annealing and DVH evaluation was proposed,which improved the efficiency of preoperative dose planning.First step,by analyzing the clinical requirements of particle implantation,the model of simulated annealing algorithm for automatic allocation of particles was established.Then,the morphological significance of the DVH curve was analyzed with the key dose evaluation index,and the evaluation model based on the standard DVH curve was established.Experimental results show that the proposed algorithm can effectively deal with the dose planning of different parts of the body.In this paper,based on the research of treatment planning system for permanent seed implant brachytherapy,a planning method based on non-coplanar needle is proposed,and an optimization method based on puncturing needle recognition and extraction is proposed,and a hybrid simulated annealing and DVH evaluation was proposed,which improve the adaptability,safety and operability of the treatment planning system.