Development of a biocompatible radiotherapy spacer using 3D printing and microcellular foaming process for enhanced prostate cancer treatment

In this study, a new active spacer was developed using three-dimensional (3D) printing technology and microcellular foaming process to overcome the limitations of current spacers used in prostate cancer treatment. In prostate cancer treatment, a spacer is inserted between the prostate and rectum to increase the distance between the two organs so as to reduce the radiation dose to the rectum. Radiotherapy spacer is widely used in particle therapy, such as proton and carbon beams, and X-ray radiation therapies, including intensity-modulated radiotherapy and stereotactic body radiation therapy. However, existing spacers have been reported to cause significant side effects. Therefore, this study introduces a 3D printing technique using polycaprolactone to develop a spacer that provides customized treatment and minimizes side effects. This technique utilizes the volume expansion that occurs when a 3D spacer printed to fit a patient’s organs undergoes foaming through a supercritical carbon dioxide (scCO2)-assisted microcellular foaming process. Additionally, the use of scCO2 allows simultaneous gas absorption and sterilization, thereby reducing the number of process steps. This study confirms the potential of the newly developed spacer to provide effective and safe radiotherapy for prostate cancer, reduce patient discomfort, and minimize rectal side effects during radiation treatment.