Dosimetry / Treatment planning Exam
Actual Questions and Answers 2026
Which type of treatment conforms the radiation beam so that the
target volume receives the prescribed dose and the surrounding
healthy tissue receives a much lower dose? -
correct answer ✅3D Conformal Radiation Therapy
Which type of treatment uses a monoenergetic beam to treat
superficial tumors? -
correct answer ✅Electron Beam
Why is an electron cone required when treating with electrons? -
correct answer ✅Electrons scatter very easily in air. A cone is
required to confine the beam closer to the patients skin surface
Why do the edges of the electron fields balloon out on? -
correct answer ✅The field edges balloon out because of scatter
Electron treatments have rapid fall off. What does this mean? -
correct answer ✅When a beam has rapid falloff of dose, this
means that the deeper organs will get little to no dose
,Dosimetry / Treatment planning Exam
Actual Questions and Answers 2026
What type of treatment consist of a radiation beam that has
varying intensities throughout the beam? -
correct answer ✅IMRT
IMRT consists of many smaller beams called ________________ -
correct answer ✅IMRT consists of many smaller beams called
BEAMLETS
They're commonly as small at 1x1 cm
When treating with IMRT, is the dose uniform? Explain -
correct answer ✅No
IMRT allows for higher dose to the tumors while minimizing the
doses to surrounding healthy tissues
What type of treatment planning is used for IMRT plans? -
correct answer ✅INVERSE PLANNING is used for IMRT plans
What type of treatment treats small tumors within the cranium at a
high dose with only 1 fraction? -
correct answer ✅Stereotactic Radiosurgery SRS
,Dosimetry / Treatment planning Exam
Actual Questions and Answers 2026
Tumors treated with SRS are usually less than _______ in size -
correct answer ✅Tumors treated with SRS are usually less than 3
cm in size
What is the treatment accuracy limit for SRS treatments? -
correct answer ✅+-1 mm
The smallest possible
What are some common diseases treated with SRS? -
correct answer ✅Arteriovenous malformations
Trigeminal neuralgia
Acoustic neuromas
Meningiomas
Pituitary adenomas
Metastatic tumors
Primary tumors
What type of treatment treats small tumors outside the cranium
with a very high dose for 3-5 fractions? -
correct answer ✅SBRT
, Dosimetry / Treatment planning Exam
Actual Questions and Answers 2026
What is the radiation therapy called when the whole body is
targeted to prepare for bone marrow transplants and possibly other
malignancies? -
correct answer ✅TBI
________________ beam radiation therapy uses high-energy
particles, such as protons, alpha particles, and carbon ions -
correct answer ✅PARTICLE beam radiation therapy uses high-
energy particles, such as protons, alpha particles, and carbon ions
Describe the dose curve of a proton beam -
correct answer ✅The dose curve of a proton beam starts off low at
the beginning, but then rapidly rises towards the end of the path
then abruptly falls to 0 (Bragg peak)
What helps position the patient for treatment? Describe them -
correct answer ✅Positioning aids help position the patient for
treatment. Positioning aids do NOT limit the patients movement
and they can be used for multiple patients
Examples: Pillow, head holders, foam cushions, neck rolls, etc.
Actual Questions and Answers 2026
Which type of treatment conforms the radiation beam so that the
target volume receives the prescribed dose and the surrounding
healthy tissue receives a much lower dose? -
correct answer ✅3D Conformal Radiation Therapy
Which type of treatment uses a monoenergetic beam to treat
superficial tumors? -
correct answer ✅Electron Beam
Why is an electron cone required when treating with electrons? -
correct answer ✅Electrons scatter very easily in air. A cone is
required to confine the beam closer to the patients skin surface
Why do the edges of the electron fields balloon out on? -
correct answer ✅The field edges balloon out because of scatter
Electron treatments have rapid fall off. What does this mean? -
correct answer ✅When a beam has rapid falloff of dose, this
means that the deeper organs will get little to no dose
,Dosimetry / Treatment planning Exam
Actual Questions and Answers 2026
What type of treatment consist of a radiation beam that has
varying intensities throughout the beam? -
correct answer ✅IMRT
IMRT consists of many smaller beams called ________________ -
correct answer ✅IMRT consists of many smaller beams called
BEAMLETS
They're commonly as small at 1x1 cm
When treating with IMRT, is the dose uniform? Explain -
correct answer ✅No
IMRT allows for higher dose to the tumors while minimizing the
doses to surrounding healthy tissues
What type of treatment planning is used for IMRT plans? -
correct answer ✅INVERSE PLANNING is used for IMRT plans
What type of treatment treats small tumors within the cranium at a
high dose with only 1 fraction? -
correct answer ✅Stereotactic Radiosurgery SRS
,Dosimetry / Treatment planning Exam
Actual Questions and Answers 2026
Tumors treated with SRS are usually less than _______ in size -
correct answer ✅Tumors treated with SRS are usually less than 3
cm in size
What is the treatment accuracy limit for SRS treatments? -
correct answer ✅+-1 mm
The smallest possible
What are some common diseases treated with SRS? -
correct answer ✅Arteriovenous malformations
Trigeminal neuralgia
Acoustic neuromas
Meningiomas
Pituitary adenomas
Metastatic tumors
Primary tumors
What type of treatment treats small tumors outside the cranium
with a very high dose for 3-5 fractions? -
correct answer ✅SBRT
, Dosimetry / Treatment planning Exam
Actual Questions and Answers 2026
What is the radiation therapy called when the whole body is
targeted to prepare for bone marrow transplants and possibly other
malignancies? -
correct answer ✅TBI
________________ beam radiation therapy uses high-energy
particles, such as protons, alpha particles, and carbon ions -
correct answer ✅PARTICLE beam radiation therapy uses high-
energy particles, such as protons, alpha particles, and carbon ions
Describe the dose curve of a proton beam -
correct answer ✅The dose curve of a proton beam starts off low at
the beginning, but then rapidly rises towards the end of the path
then abruptly falls to 0 (Bragg peak)
What helps position the patient for treatment? Describe them -
correct answer ✅Positioning aids help position the patient for
treatment. Positioning aids do NOT limit the patients movement
and they can be used for multiple patients
Examples: Pillow, head holders, foam cushions, neck rolls, etc.
