Personalized conformal radiotherapy dose verification with 3D printing cerebral radiation equivalent phantom / 中华放射医学与防护杂志

ABSTRACT

Objective To establish a method based on 3D printing radiology equivalent phantom for individual radiotherapy dose verification,and to offer an assurance for the safety of 3D conformal radiotherapy.Methods Two patients' CT data was collected,reconstructing the first patient's skull and brain tissue to generate a skull-brain phantom for the purpose of testing the equivalent material.The second patient's data was used for whole head tissue reconstruction to produce a head phantom with equivalent material.By inserting ionization chamber dosimeters to target region for radiotherapy program,equivalent phantom dose distribution of lesions location was obtained in order to verify and calibrate the actual radiation treatment planning for patients.Results DR,CT images of the phantoms revealed that the difference of X-ray gray value between brain skull phantom and patient's skull was 13 721,CT value difference between equivalent tissue of brain skull phantom and that part of the patient was 35-40 HU,and CT difference between head phantom temporalis and that of the patient tissue was 18-28 HU.The imaging data indicated that the radiation equivalence of 3D printing phantom was similar to that of human body tissue,and the equivalent dose distribution accorded well with the normal range of treatment.The dose verification of phantom model can effectively improve the accuracy of the radiotherapy system.Conclusions The personalized radiotherapy phantom which based on the 3D printing and tissue equivalent technology is suitable for personalized radiation therapy validation.With advantages of easy accessibility,highly-personalized degree and high precision,this technology provides a reliable and safe way for radiation therapy.