Radiation Oncology

Question 1

what does depth of penetration of ionizing radiation vary by?

Answer 1

energy

Question 2

what does dose of radiation vary based on?

Answer 2

tumor type
location
treatment goals
long-term side effects

Question 3

what is definitive radiation like?

Answer 3

more of curative intent
prevent local tumor regrowth
improve life expectancy

Question 4

what is a side effect of radiation in the lungs?

Answer 4

fibrosis

Question 5

what is the risk of radiation associated tumors?

Answer 5

2%

Question 6

what tumor locations warrant radiation treatment planning?

Answer 6

nasal tumors
brain tumors
heart base tumors
abdominal tumors

Question 7

for what neoplasias is radiation recommended?

Answer 7

acanthomatous ameloblastoma
squamous cell carcinoma
soft tissue sarcoma
malignant melanoma
nasal tumors

Question 8

which squamous cell carcinomas do not respond to radiation well?

Answer 8

tonsillar squamous cell carcinoma
cats

Question 9

what are canine nasal tumors commonly associated with?

Answer 9

epistaxis

Question 10

what most commonly causes feline nasal tumors?

Answer 10

lymphoma

Question 11

what is radiation?

Answer 11

high energy photons and electrons are generated by a linear accelerator

Question 12

are photons or electrons high energy?

Answer 12

photons

Question 13

is radiation from linear accelerators absorbed systematically?

Answer 13

no

Question 14

where do electrons deliver energy to?

Answer 14

surface

Question 15

what are the types of direct DNA damage?

Answer 15

single strand bread
double strand break: lethal, cell death

Question 16

what is radiation dose calculated in?

Answer 16

units of gray/Gy

Question 17

what is stereotactic radiation?

Answer 17

type of definitive radiation therapy
tumor ablative
high dose over a short time

Question 18

why is radiation delivered with fractionation (over time)?

Answer 18

to allow normal tissues to repair and repopulate

Question 19

when are acute radiation side effects seen?

Answer 19

first 1-3 months
effects directly proportional to dose

Question 20

where can acute side effects be worse?

Answer 20

in head and neck region

Question 21

what types of tissues do late side effects impact?

Answer 21

slowly growing tissues
lungs
eye
hair

Question 22

when is radiation used for palliative treatments?

Answer 22

bone tumors
tumors with minimal or no treatment options

Question 23

what is acanthomatous ameloblastoma?

Answer 23

benign tumor that is locally malignant
required removal of bone to achieve good margins
arises from odontogenic ligament

Question 24

how is oral malignant melanoma treated?

Answer 24

palliative radiation acts like definitive radiation therapy
response rates >80%, remission 44-70%

Question 25

what can cause canine nasal tumors?

Answer 25

carcinoma
adenocarcinoma
rarely sarcoma

Question 26

do cats or dogs tend to have fewer side effects to radiation therapy?

Answer 26

cats