Follow-up/Toxicity

Question 1

Above what cumulative dose (standard fractionation) is lens opacification seen?

Answer 1

Lens opacification is seen with doses >13–16 Gy.

Question 2

What toxicities are associated with radioimmunotherapy?

Answer 2

Myelosuppression, myelodysplastic syndrome, and acute myeloid leukemia

Question 3

What is the min dose to induce cataracts with a single fx vs. multiple fx of RT?

Answer 3

Doses of 2 Gy (single fx) and 4–5 Gy (multiple fx) can induce cataracts.

Question 4

Is cataract induction a stochastic or deterministic late effect? Explain.

Answer 4

Deterministic. There is a threshold and the severity/latency is dose related.

Question 5

Which region of the lens is affected most by RT?

Answer 5

The postsubcapsular region of the lens is affected most by RT.

Question 6

What are the side effects associated with intravitreal chemo?

Answer 6

Cataracts, glaucoma, corneal epitheliopathy, maculopathy, vitreous hemorrhage, optic atrophy, and sterile endophthalmitis

Question 7

What is the dose tolerance of the lacrimal glands?

Answer 7

The mean dose tolerance of the lacrimal apparatus is 26–30 Gy.

Question 8

Above what dose can painful keratitis be seen?

Answer 8

Doses >60 Gy can cause painful keratitis. (Kwok et al., Ophthalmology 1998)