Once chordoma is diagnosed, MRI is recommended every 6 months for the first 4 to 5 years (at the primary site and at sites where there is a risk of tumor implantation), and thereafter, if the tumor does not progress, it can be changed to annual MRI for at least 15 consecutive years. Of course, the time is relative and should be reviewed at any time if various discomforts occur to avoid delaying the disease.