A Case of Pediatric Sacral Malignancy in Which a Bio-Absorbable Spacer was Placed to Address Tumor Recurrence After Removal of a Non-Absorbable Spacer

Abstract

Proton beam therapy for pediatric cancer has been covered by the Japanese health insurance since 2016, and surgical spacer placement for particle therapy has been covered by this insurance since 2019. The currently approved spacer is a sheet-type absorbable material made from polyglycolic acid (PGA); however, before this type of spacer was developed, non-absorbable medical materials were often used as spacers. During this transition period, we experienced treating a case in which two different types of spacer, one non-absorbable and the other bio-absorbable, were placed. An 11-year-old boy with sacral malignancy underwent spacer placement using a stretched polytetrafluoroethylene sheet for proton beam therapy. This non-absorbable spacer was removed after the completion of irradiation; however, the tumor recurred later. A bio-absorbable PGA spacer was available at the time of recurrence, and this spacer was placed. Because the PGA spacer is absorbed by the body, it does not need to be removed after irradiation, and it is considered to be an excellent material in clinical settings.