Adverse Side Effects of Radiation Therapy

Question 1

What two types of side effects can RT therapy have?

Answer 1

Acute effects and Late side effects.

Question 2

Which type of radiation therapy will produce which type of adverse effects?

Answer 2

Curative radiation - acute effects.

Palliative radition - long term effects.

Question 3

What type of organs can be affected with acute effects?

Answer 3

Usually affect fast dividing tissues. Skin/Dermis, mucous membranes, eyes, brain/SC.

Question 4

How long will acute side effects usually last? When will they usually show up?

Answer 4

Will usually resolve around 2-3 weeks later. Usually show up 7-10 days post RT.

Question 5

How long will late effects usually last? When will they usually show up?

Answer 5

They are permanent, as usually don’t expect animal to live long enough for onset. Earliest onset is around 6m, usually around 1 year.

Question 6

What type of tissues are effected by late side effects?

Answer 6

Usually slow/non-dividing tissues. Skin/dermis, Eyes, Brain/SC

Question 7

How can the skin be affected by acute effects? How would you treat this?

Answer 7

Alopecia, dermatitis, erythema (because stratum basale affected).
Treatment - No cream/gel/ointment! Analgesia, collars.

Question 8

How can the mucous membranes be affected by acute effects? How would you treat this?

Answer 8

Hypersalivation, nasal discharge, MUCOCITIS, pain, anorexia.

Treat - analgesia, Abx, feeding tubes, metamucil for colitis.

Question 9

How can the eyes be affected by acute effects? How would you treat this?

Answer 9

Decreased tear production, conjunctivitis, cornea ulceration.
Treatment - Optimmune, Vit A ointment, check tear production.

Question 10

How can the brain/SC be affected by acute effects? How would you treat this?

Answer 10

Oedema (8-12 weeks post RT) due to transient demyelination. May look like neurological signs of tumour but IT’S NOT.
Treat - corticosteroids (anti-inflam)

Question 11

How can the skin be affected by late effects?

Answer 11

Damage to vasculature and fibroblasts. Fibrosis (esp. in dogs), alopecia and pigment changes.

Question 12

How can the eyes be affected by late effects?

Answer 12

Cataracts, chronic keratoconjunctivitis

Question 13

How can the brain/SC be affected by late effects?

Answer 13

Necrosis of the white matter, vasculopathy (1-4 years), treat with corticosteroids