Supplementary Material for: Treatment Response of Sacrococcygeal Chordoma to Palliative Stereotactic Body Radiotherapy: A Case Report

Chordomas are rare and locally aggressive tumours that arise from embryonic remnants of the notochord, with a predilection for the skull base, mobile spine and sacrum. Sacral or sacrococcygeal chordomas can be particularly difficult to manage because of their large size at presentation and involvement of adjacent organs and neural structures. Although the recommended definitive therapy for such tumours is either en-bloc resection with or without adjuvant radiotherapy (RT) or definitive fractionated RT with charged particle therapy, older and/or less-fit patients may not necessarily be accepting of said approaches due to the potential morbidities and challenging logistic requirements. Here, we report a case of a 79-year-old male presenting with intractable lower limb pain and neurological deficits due to a large de-novo sacrococcygeal chordoma. The patient was successfully treated with a 5-fraction course of stereotactic body radiotherapy (SBRT) given with palliative intent, with complete relief of his symptoms achieved approximately 21 months after RT and without the development of any iatrogenic toxicities. In view of this case, ultra-hypofractionated SBRT may be a suitable option for the palliation of large de-novo sacrococcygeal chordomas for selected patients to reduce their symptom burden and improve their quality-of-life (QOL).