The Effect Of Three Dimensional Breathing Exercise On The Superficial Dose Of The Chest Wall In Patients With Radical Mastectomy With HexaMotion System

In radiotherapy,respiratory movement has great influence on the dynamics of the organs in the thoracic and abdominal tumor target area.It is easy to cause the difference between the actual absorbed dose and the planned system and the results in radiotherapy,and affect the therapeutic effect of the patients.According to the data show lumpectomy followed by breast irradiation continues to be appropriate therapy for women with breast cancer.In the postoperative radiotherapy of breast cancer,the accuracy of chest wall dose is related to the success of radiotherapy.Superficial area and lateral chest wall,is the most important area for the target area,the area may have surgery without removing the tumor cells,at the same time,the region also includes a very sensitive to radiation dose of high skin,resulting in dry skin,redness,and even ulceration and interruption of radiotherapy,the dose is too low may lead to local recurrence.Skin dose is a key problem in clinical radiotherapy;the calculation of the currently used Treatment Planning System(TPS)in the electronic disequilibrium area is not accurate,leaving unclearness as to the dose levels actually received by the patient's skin during radiotherapy.Therefore,the accuracy of this area directly affects the efficacy of radiotherapy for breast cancer.This study used a metal oxide semiconductor field effect transistor detector with Hexa Motion system simulation in patients undergoing resection of chest wall in static,three-dimensional respiratory motion case of breast cancer were analyzed in intensity-modulated irradiation technique and helical tomotherapy system of breast cancer with chest wall dose distribution,and effects of different doses of respiratory amplitude on the chest wall.The Hexa Motion system was used to simulate the three-dimensional breathing movement of patients undergoing radical mastectomy,and combined with metal oxide conductor field-effect transistor to study the effect of respiratory movement on the superficial dose distribution of chest wall during radiotherapy for breast tumors.Investigation of 57 cases of breast cancer patients with chest wall in X,Y and Z average amplitude of motion direction of the measurement in our hospital 9 cases of breast cancer patients with RPM average amplitude of respiratory system,synthesis of three-dimensional motion curve by respiratory motion generator,then the respiration curve file input Scandi Dose Hexa Motion software,drive the Delta4 phantom to simulate the patient's respiratory motion.For the simulation of the left(right)breast cancer patients with chest wall medial,middle and lateral position measurement,in Delta4 in the frame angle of 0 degrees and 30 degrees(330 degrees)and 60 degrees(300 degrees)fixed dose of MOSFET instrument under the cross wire projection,respectively in Varian 23 EX and Tometherapy performed on the patient verification plan,dose measurement model and the movement in the static state,assessment of respiratory exercise on breast chest wall superficial effect dose distribution.In the IMRT treatment,the relative dose difference model in stationary and motion state of the basic average amplitude is within 3%,the whole is less than 5%,and at 0 degrees and 60 degrees(300 degrees)between the stationary and moving state measurements were not significant,the p value was less than 0.05 at 30°(330°)and the difference was statistically significant(p values were 0.27,0.01,and 0.23,respectively).In the Tomotherapy treatment,the relative dose difference model in stationary and motion state of the basic average amplitude is within 1%,the whole is less than 2%,and at 0 degrees and 30 degrees(330 degrees)and 60 degrees(300 degrees)between the stationary and moving state measurements were not significant(p the values were0.13?0.47 and 0.39)and.The two way of treatment is for breast tumor.When chest wall motion amplitude is in a certain range,it has little effect on the superficial dose distribution of chest wall,but with the increase of amplitude,when the amplitude of motion increases to the order of CM,the superficial dose distribution of chest wall increases significantly.In conclusion,the slight change of respiratory curve amplitude does not cause obvious changes in chest wall superficial dose,but with the increase of respiratory motion amplitude,the superficial dose distribution of chest wall also increases.