This study by the Mayo Clinic group compared recurrence in patients with chordomas who received proton versus photon radiotherapy following resection, by using tree-based machine learning models. Based on the data of 53 patients treated with adjuvant PT (84.9%), RT (9.4%) and SBRT (5.7%), this study reported that patients receiving PT exhibited a 40% likelihood of having recurrence, significantly lower than the 88% likelihood observed in those treated with nonproton therapy. The lowest risk of recurrence observed in patients receiving gross-total resection with adjuvant proton therapy (23%).