Radiation Therapy Exam A+ Pass
Verified Solutions Brand New!!
What is it called when the total radiation dose is divided into multiple smaller doses? -
Answer- Fractionation
What is it called when the radiation source is on or in the patient? - Answer-
Brachytherapy
Use caution with __________ - if implanted in your patient, you can "get blasted" with
radiation just by being near them. It is also expensive and difficult to transport due to the
risk of terrorism - Answer- Iridium
What is it called when the beam is aimed into the patient? - Answer- Teletherapy
This type of radiation is basically an x-ray machine on steroids (higher energy) -
Answer- Orthovoltage radiation
What are the disadvantages of orthovoltage radiation? - Answer- -lacked energy to treat
deep-seated tumors
-high surface dose
-too much absorption in bone (leading to osteonecrosis)
-bone could "shelter" tumors
In this form of radiation, there is a piece of radioactive cobalt in the head of the machine
- Answer- Cobalt-60
What is the advantage of using a Cobalt-60? - Answer- It can reach deeper tumors than
orthovoltage
What are the disadvantages of Cobalt-60? - Answer- -leakage from head is a hazard to
workers
-homeland security regulations
-irregular dose at edge of field
Most veterinary radiation therapy is now done with _________ - Answer- linear
accelerators (linacs)
Linacs are a form of brachytherapy/teletherapy (pick one) - Answer- teletherapy
What are the advantages of using a linac? - Answer- -provides deep penetration in
tissues
-provides less variation in absorption within various tissues than with keV radiation
-megavoltage electrons and photons are SKIN SPARING (max dose is below the skin)
, -no radioactive materials
Linacs can treat with both _____________ radiation and ______________ radiation -
Answer- particulate radiation (electrons, beta particles) and electromagnetic radiation (x
rays and gamma rays_
Gamma rays come from ___________ - Answer- an unstable nucleus
X rays come from ____________ - Answer- an electron cloud
________________ radiation penetrates deeply into tissue - Answer- Electromagnetic
radiation
________________ radiation has a high probability of interaction in tissue - Answer-
Particulate radiation
Both particulate and electromagnetic radiation have enough energy to cause
______________ of atoms and molecules in tissue - Answer- ionization
What are the disadvantages of linacs? - Answer- financial costs!!
physics support
technical staff
______________ are not as skin sparing, and do not get as deep - Answer- Electrons
________________ are skin sparing, don't have a high dose at the skin surface, but
gets deep into tissue - Answer- X-rays
Why would we use electrons over x-rays? - Answer- It's good for superficial cancer like
on skin, and important when something vital is underneath the cancer (i.e. skin cancer
on the thorax or abdomen)
The ____________ the energy, the deeper the tissue penetration - Answer- higher
What is the goal of radiation therapy? - Answer- To cause the most damage possible to
the tumor and the least damage possible to the surrounding normal tissue
What impacts radiation therapy success? - Answer- The limiting factor in the ability to
completely eradicate a tumor is the response of the normal tissue in the irradiated field
Success of radiation therapy depends on the difference between tumor _____________
and normal tissue _____________ - Answer- sensitivity
T/F: Only tumor cells get damaged by radiation - Answer- False - normal cells are
damaged as well
Verified Solutions Brand New!!
What is it called when the total radiation dose is divided into multiple smaller doses? -
Answer- Fractionation
What is it called when the radiation source is on or in the patient? - Answer-
Brachytherapy
Use caution with __________ - if implanted in your patient, you can "get blasted" with
radiation just by being near them. It is also expensive and difficult to transport due to the
risk of terrorism - Answer- Iridium
What is it called when the beam is aimed into the patient? - Answer- Teletherapy
This type of radiation is basically an x-ray machine on steroids (higher energy) -
Answer- Orthovoltage radiation
What are the disadvantages of orthovoltage radiation? - Answer- -lacked energy to treat
deep-seated tumors
-high surface dose
-too much absorption in bone (leading to osteonecrosis)
-bone could "shelter" tumors
In this form of radiation, there is a piece of radioactive cobalt in the head of the machine
- Answer- Cobalt-60
What is the advantage of using a Cobalt-60? - Answer- It can reach deeper tumors than
orthovoltage
What are the disadvantages of Cobalt-60? - Answer- -leakage from head is a hazard to
workers
-homeland security regulations
-irregular dose at edge of field
Most veterinary radiation therapy is now done with _________ - Answer- linear
accelerators (linacs)
Linacs are a form of brachytherapy/teletherapy (pick one) - Answer- teletherapy
What are the advantages of using a linac? - Answer- -provides deep penetration in
tissues
-provides less variation in absorption within various tissues than with keV radiation
-megavoltage electrons and photons are SKIN SPARING (max dose is below the skin)
, -no radioactive materials
Linacs can treat with both _____________ radiation and ______________ radiation -
Answer- particulate radiation (electrons, beta particles) and electromagnetic radiation (x
rays and gamma rays_
Gamma rays come from ___________ - Answer- an unstable nucleus
X rays come from ____________ - Answer- an electron cloud
________________ radiation penetrates deeply into tissue - Answer- Electromagnetic
radiation
________________ radiation has a high probability of interaction in tissue - Answer-
Particulate radiation
Both particulate and electromagnetic radiation have enough energy to cause
______________ of atoms and molecules in tissue - Answer- ionization
What are the disadvantages of linacs? - Answer- financial costs!!
physics support
technical staff
______________ are not as skin sparing, and do not get as deep - Answer- Electrons
________________ are skin sparing, don't have a high dose at the skin surface, but
gets deep into tissue - Answer- X-rays
Why would we use electrons over x-rays? - Answer- It's good for superficial cancer like
on skin, and important when something vital is underneath the cancer (i.e. skin cancer
on the thorax or abdomen)
The ____________ the energy, the deeper the tissue penetration - Answer- higher
What is the goal of radiation therapy? - Answer- To cause the most damage possible to
the tumor and the least damage possible to the surrounding normal tissue
What impacts radiation therapy success? - Answer- The limiting factor in the ability to
completely eradicate a tumor is the response of the normal tissue in the irradiated field
Success of radiation therapy depends on the difference between tumor _____________
and normal tissue _____________ - Answer- sensitivity
T/F: Only tumor cells get damaged by radiation - Answer- False - normal cells are
damaged as well
