Radiation Therapy Exam A+ Pass
Brand New!!
When radiation was first used to treat cancer treatment length was based on the
amount of time it took - Answer- for their skin to become eurythmic
What does fractionation mean? - Answer- that treatment was better tolerated and more
effective when treatment consisted of smaller doses per day over several weeks
First body part to be treated? - Answer- breast
Rad tx is used 2 different ways - Answer- 1) to cure cancer
2) To reduce symptoms and improve quality of life
The Goal of radiation therapy - Answer- To maximize the dose to the tumor while
minimizing the dose to surrounding normal tissues
The difference between the dose for the probability of tumor control and the dose that
minimizes normal tissue damage... Is known as? - Answer- Therapeutic Ratio
Describe radiosensitive cells - Answer- 1) rapidly dividing,
2) Poorly differentiated
3) Have a long mitotic period
Radiation first kills cells that are - Answer- rapidly dividing
Radiation delivered during external beam radiation is produced by a machine called a -
Answer- linear accelerator
This machine generates high-energy radiation by accelerating electrons to nearly the
speed of light - Answer- linear accelerator
The radiation produced by a linear accelerator is measured in - Answer- millions of volts
--Cyclotron
--Van de Graff generator
--Betterton
--Cobalt-60
--Linear accelerator
Describes what type of equipment? - Answer- Megavoltage equipment
First used in 1937
Machines that are capable of producing an x-ray beam of at least one MV
, Precursors to the linear accelerator - Answer- Megavoltage Equipment
Describe linear accelerators - Answer- Electrons can be extracted from the unit and
used for treatment of shallow lesions.
OR they can be directed to strike a target to produce high energy x-rays (photons) to
treat deep-seated tumors
What is the isocenter - Answer- The point around which the gantry, collimator and table
rotate
Linear accelerators (and cobalt) can be rotated _____ around a patient - Answer- 360°
Major components of a Linear Accelerator - Answer- Drive stand
Gantry
Treatment couch
Describe how patients are staged - Answer- 1) TNM Staging
A) Tumor size
B) Nodal Involvement
C) Distant Metastasis
2) Histopathologic Grade of Cancer
a) Well differentiated, moderately, poorly or undifferentiated
Refers to the energy deposited at that point
and is measured at a specific point in a medium - Answer- absorbed dose
Absorbed dose is measured in - Answer- gray
Methods of dose determination - Answer- 1) Ionization chambers
2) Thermoluminescent dosimeters (TLDs)
3) Photographic film
Distance from source or target of machine to surface of patient - Answer- Source-Skin
Distance (SSD)
Distance from source of photons to the isocenter - Answer- Source-Axis Distance (SAD)
3 Specific Target Volumes - Answer- Gross Tumor Volume (GTV)
Clinical Target Volume (CTV)
Planning Target Volume (PTV)
Gross palpable or visible tumor is known as what target volume? - Answer- Gross
Tumor Volume (GTV)
Brand New!!
When radiation was first used to treat cancer treatment length was based on the
amount of time it took - Answer- for their skin to become eurythmic
What does fractionation mean? - Answer- that treatment was better tolerated and more
effective when treatment consisted of smaller doses per day over several weeks
First body part to be treated? - Answer- breast
Rad tx is used 2 different ways - Answer- 1) to cure cancer
2) To reduce symptoms and improve quality of life
The Goal of radiation therapy - Answer- To maximize the dose to the tumor while
minimizing the dose to surrounding normal tissues
The difference between the dose for the probability of tumor control and the dose that
minimizes normal tissue damage... Is known as? - Answer- Therapeutic Ratio
Describe radiosensitive cells - Answer- 1) rapidly dividing,
2) Poorly differentiated
3) Have a long mitotic period
Radiation first kills cells that are - Answer- rapidly dividing
Radiation delivered during external beam radiation is produced by a machine called a -
Answer- linear accelerator
This machine generates high-energy radiation by accelerating electrons to nearly the
speed of light - Answer- linear accelerator
The radiation produced by a linear accelerator is measured in - Answer- millions of volts
--Cyclotron
--Van de Graff generator
--Betterton
--Cobalt-60
--Linear accelerator
Describes what type of equipment? - Answer- Megavoltage equipment
First used in 1937
Machines that are capable of producing an x-ray beam of at least one MV
, Precursors to the linear accelerator - Answer- Megavoltage Equipment
Describe linear accelerators - Answer- Electrons can be extracted from the unit and
used for treatment of shallow lesions.
OR they can be directed to strike a target to produce high energy x-rays (photons) to
treat deep-seated tumors
What is the isocenter - Answer- The point around which the gantry, collimator and table
rotate
Linear accelerators (and cobalt) can be rotated _____ around a patient - Answer- 360°
Major components of a Linear Accelerator - Answer- Drive stand
Gantry
Treatment couch
Describe how patients are staged - Answer- 1) TNM Staging
A) Tumor size
B) Nodal Involvement
C) Distant Metastasis
2) Histopathologic Grade of Cancer
a) Well differentiated, moderately, poorly or undifferentiated
Refers to the energy deposited at that point
and is measured at a specific point in a medium - Answer- absorbed dose
Absorbed dose is measured in - Answer- gray
Methods of dose determination - Answer- 1) Ionization chambers
2) Thermoluminescent dosimeters (TLDs)
3) Photographic film
Distance from source or target of machine to surface of patient - Answer- Source-Skin
Distance (SSD)
Distance from source of photons to the isocenter - Answer- Source-Axis Distance (SAD)
3 Specific Target Volumes - Answer- Gross Tumor Volume (GTV)
Clinical Target Volume (CTV)
Planning Target Volume (PTV)
Gross palpable or visible tumor is known as what target volume? - Answer- Gross
Tumor Volume (GTV)
