Tissue-equivalent materials used to develop phantoms in radiation dosimetry: A review

Abstract

Abstract Present paper provides a review on different types of phantom materials. Radiotherapy phantom is to simulate as closely as possible the human body for improving the accuracy and measurements of radiation dosimetry. It also helps in determining the amount of radiation is being absorbed in various layers by the human body. Water was the first tissue equivalent material which was used for radiation measurement as water had unit density similar to human body; in reality anatomy of human body is completely different. It is made up of heterogeneous medium of different densities like bone, tissue, muscle, air cavities and teeth. These heterogeneities in human body produce perturbation in dose-distribution during radiation therapy. Therefore, the exact evaluation of energy imparted to the human body may not be feasible by water based measurements which is highly desirable for understanding the effect of energy absorbed. Thus, there is need to develop a phantom composed of such materials which could absorb radiation like human body structures and the selected phantom material also remains stable. Its overall efficacy is to improve the accuracy of dosimetry and hence radiation treatment outcomes.