In a patient with an R1 resection of a chordoma who has declined proton therapy, what alternative radiation modality would you recommend?

Chordomas are aggressive and locally invasive tumors that commonly arise in the sacrum, skull base, or rarely the mobile spine. Resection is considered the first-line treatment; however, wide margins are difficult to achieve without significant morbidity. By nature of their site of origin near or ad...

The question does not say whether this is a skull base or a spinal chordoma, or why a patient would turn down proton therapy. My answer below relates to skull base chordoma.

Unless there is an overriding logistical (not wanting 8 weeks of fractionation or insurance refusal) or clinical reason(not fit...

First a historical footnote that is important for interpreting the chordoma literature. Early in my career I headed the Musculoskeletal tumor service in Radiation Oncology at Cleveland Clinic and among other things also treated CNS tumors. In that setting I was treating chordomas in both the clivus ...