Am I on the right track here?

Pt. Dx w/ uterine ca s/p successful hysterectomy, cancer free 4 yrs., however recent metastasis to the brain. Presenting for radiation therapy today.

I choose:

Z51.0, Radiation therapy

C79.31 Secondary malignant neoplasm of brain

Z90.710 Acquired absence of both cervix and uterus

Am I missing anything? Is C79.31 right?