Oncology - Radiation Flashcards Preview

Small Animal Medicine > Oncology - Radiation > Flashcards

Flashcards in Oncology - Radiation Deck (41)
Loading flashcards...
1

*Gastrointestinal (GI) lymphoma diagnosed in cats is most frequently low/high grade and B-cell/T-cell in origin?

low, T-cell

2

*Lymphoma is currently diagnosed most commonly in older, feline leukemia virus (FeLV) positive/negative cats.

negatiive

3

*Most commonly used oral chemotherapeutic to treat low grade GI lymphoma in cats?

Prednisone and chlorambucil

4

*Diagnostic test utilized to determine clonality of lymphocyte population?

PCR (PARR)

5

What are the realistic challenges for radiation therapy in veterinary oncology?

Availability, logistics/time, cost, side effects, and perception

6

When are X-rays produced?

when charged particles (such as electrons) strike dense material and suddenly decelerate

7

When are gamma rays produced?

when naturally unstable atomic nuclei decay

8

What is the direct action on DNA of radiation?

It breaks the double strand

9

What is the indirect action on DNA of radiation?

70% of biologic effect of RT comes from free-radical formation

10

The biologic effects of radiation result from what?

damage of DNA

11

In order of decreasing sensitivity, what is the degree of tissue susceptibility to radiation?

Blood-forming organs, reproductive organs, skin, bone and teeth, muscle, and the nervous system

12

In a general sense, what cells are more susceptible to radiation?

rapidly dividing cells because they have less time to repair

13

In what phase of replication are cells most sensitive to radiation?

Cells in the Late S phase, G2, or Active mitosis

14

*The most important mechanism by which external beam radiation therapy causes DNA damage and results in cell death is via:
a. Direct action of ionizing radiation causing double strand breaks in the cellular DNA
b. Thermal damage to cells caused by ionizing radiation
c. Indirect action of ionizing radiation via free radical induction and subsequent DNA damage
d. Inhibition of topoisomerase II

c. Indirect action of ionizing radiation via free radical induction and subsequent DNA damage

15

We see acute/chronic radiation side effects more often.

acute

16

What are some examples of acute radiation side effects?

Moist desquamation of skin, mucositis, conjunctivitis, colitis, proctitis, rhinitis, and more

17

How do you manage acute radiation side effects?

Based on the symptoms they are showing

18

Pain medication for acute radiation side effects are central/peripheral.

central

19

What tissues are commonly effected by acute radiation side effects?

rapidly dividing cells/tissues

20

What tissues are commonly effected by chronic radiation side effects?

Late responding tissues - lens, bone, fibrous tissue, and nerves

21

In tissues affected by chronic radiation, DNA damage results in _____ catastrophe months to years after radiation.

mitotic

22

*Which of the following would be a possible early side effect following radiation therapy in a dog with a nasal tumor?
a. Cataract OS
b. Oral mucositis
c. Necrosis of the hard palate
d. Change in hair color in area treated

b. Oral mucositis

23

What tumors can radiation therapy be used for?

Nasal, oral/craniofacial, brain, ear canal, thyroid, mediastinal, bone/spinal, mast cell tumors, soft tissue sarcomas, urinary bladder, prostate, and anal sac

24

What is the indication for palliative-intent radiation therapy?

Absence of curable disease OR when co-morbidities preclude definitive-intent RT

25

What is the goal of palliative-intent RT?

Improve/maintain quality of life

26

What is the goal of definitive-intent RT?

Deliver enough dose to achieve durable local tumor control
Maximize quantity and quality of life

27

True or False: Radiation therapy is only used after surgery.

False - it can be used before or after surgery

28

What are the pros to palliative-intent RT?

Low cost, convenient schedule, and low risk of severe acute toxicity

29

What are the cons to definitive-intent RT?

Expensive, inconvenient schedule, and may be associated with bad side effects

30

What are the pros and cons to stereotactic RT?

Expensive, convenient schedule, low risk of severe acute toxicity

Decks in Small Animal Medicine Class (100):