In these last two anatomical locations, they are difficult to treat because they are close to important organs. Because of this, surgery is often incomplete but it can be associated with proton therapy that can deliver a dose high enough to stop the tumour from growing.
Chordomas account for 1 to 4% of malignant bone tumours, similar to sarcomas although they do not belong to this category They occur after age 30 and most often around age 60. They affect the spine and especially the sacrum (60%) and the base of the skull (25%) or other places in the spine. They are generally slow growing but have a tendency to recur after surgery.
Chondrosarcomas and chordomas of the base of the skull and spine, and other sarcomas or tumours requiring high doses of radiotherapy (sometimes called “radioresistant” tumours) close to the spine and therefore the spinal cord and base of the skull are key indications of proton therapy. The fact that proton therapy is rooted in these indications is due to its physical superiority over conventional photon irradiation techniques.
Proton therapy treatment of other types of sarcomas with complex anatomical locations may be discussed.