What dose and fractionation would you use for metastasis to the rectus muscle of the eye?

Breast carcinoma is the most common cause of metastasis to the orbit. Although overall rare, its incidence may be underreported, and up to 15-20% of presentations are bilateral. Multidisciplinary discussion is encouraged to rule out other potential causes on the differential diagnosis, such as MALT lymphoma or benign inflammatory etiologies.

In my personal experience, I treated a patient with bilateral orbital metastases from breast cancer, with one lesion in the left superior rectus and one lesion in the right inferior rectus. We used the standard palliative regimen of 30 Gy in 10 fractions delivered to both lesions (GTV with PTV margin; no CTV was used) in a single IMRT plan, avoiding hot spots on the optic nerve. The patient is now 1 yea...