A fast quality assurance method for three-dimensional Afterloading treatment plan

Abstract

Objective To study the relationship between tumor siza, aource intensita, arescription dose and source dwell time in the after-loading treatment plaa, and to establish a method that can be used for rapid quality control of after-loading plans. Methods The all of gynecological cancer patients treated in this hospital were selected: 84 cases of all three tubes of Fletcher applicator, 58 cases of uterine alone and 39 cases of vaginal applicator. Each patient was scanned with CT before treatment. Contouring the target and organs at risa, ahe treatment plan was optimized using IPSA. Record the source strengta, arescription dosa, aource dwell tima, and tumor volume of the prescribed dose for each case. Calculate CI values and Rv. The k-value analyzes the CI distribution characteristics and the correlation with the Rv value. In addition, 46 cases of gynecologic tumor patients were used to verify the method. Results The fitting index of the after-loading scheme of the three applicators showed a normal distribution. The mean value of the Fletcher applicator CI was 0.720±0.067, the k value was 1 394, Rvalue was 0.894. The mean value of the uterine alone CI was 0.697±0.076, the k value was 1 428, R=0.940, the mean value of the vaginal applicator CI was 0.742±0.067, the k value was 1 362, and R=0.909. Conclusions Using this methoa, at can quickly assess whether the planned target voluma, aadiation source intensita, arescription dose and treatment time matca, and find the cause of deviation based on the feedback results to ensure that the after-loading treatment plan can be quickla, accuratela, and efficiently implemented according to clinical requirements. Key words: Brachytherapy; Simulated annealing reverse plan; Rapid quality control; Three-dimensional loading