Development of all-in-one phantom dosimeter to measure multidimensional dose distribution for 60 Co radiotherapy unit

In this study, we used square-type organic scintillating fibers and polymethyl methacrylate phantoms to develop an all-in-one phantom dosimeter measure the multidimensional dose distributions for a 60Co radiotherapy source. Multidimensional dose distributions, which include the transverse, depth, and surface dose distributions, can be obtained by measuring scintillating light simultaneously in real time. An additional phantom for quality assurance before radiotherapy is not required because square-type organic scintillating fibers are directly inserted into the polymethyl methacrylate phantom. Multidimensional dose distributions can also be measured simultaneously by changing the arrangement of one-dimensional phantom dosimeters, which are very thin and can be stacked, similar to books placed on a shelf. Therefore, the proposed dosimeter can be applied as an all-in-one phantom dosimeter with a variable structure that can respond to changes in various radiotherapy treatment environments. Through experiments, the multidimensional dose distributions for the 60Co radiotherapy unit were measured to evaluate the performance of the proposed all-in-one phantom dosimeter. The results were compared and evaluated using external beam therapy films and Monte Carlo simulations. Based on the results of this study, significant time is expected to be saved during dose measurements for quality assurance in radiotherapy, as simultaneous measurements can yield multidimensional data on the transverse, depth and surface dose distributions in real time.