Brainstem-sparing craniospinal irradiation delivered with pencil beam scanning proton therapy

Delivery of craniospinal irradiation (CSI) is a curative approach to recurrent ependymoma, but is associated with risks from re-irradiation, particularly of the brainstem. Pencil beam scanning proton therapy allows delivery of CSI with sparing of normal tissues. Here, we describe a case of brainstem-sparing CSI that resulted in excellent coverage of the craniospinal axis with minimal radiation to brainstem. This is a novel concept that compares favorably to previously described methods using x-rays that may result in underdosing of surrounding tissues in effort to spare brainstem.