Exploration of Personalized Biomarkers During Neoadjuvant Radiation Therapy for Spinal and Sacral Chordoma

brief summary

In this study the investigators will study the effects of neoadjuvant radiation therapy (RT), in the form of either proton therapy or stereotactic body radiation therapy (SBRT), on the Circulating tumor DNA (ctDNA), radiographic changes and radiomics, and the validity of these findings will be compared using the current gold standard- pathologic findings. The purpose of this work is to explore whether the biomarkers may be used diagnostically to better understand radiographic changes following RT. The investigators hypothesize that ctDNA levels in combination with imaging biomarkers identified through radiomics will be a sensitive and specific tool for predicting histopathologic response to RT.