Radiation Therapy Exam A+ Pass
Answered
How does radiation help? - Answer- -high energy particles/waves destroy cancer cells
-damage is caused by breaking DNA strands and prevents cell replication
What is the goal of radiation? - Answer- -to deliver the most therapeutic dose of
radiation to the tumor cells while sparing the surrounding healthy tissue
Use in leukemia and lymphoma?? - Answer- can prevent CNS disease
Emergent radiation is used when? - Answer- -used to treat tumors causing SVC
syndrome, spinal cord compression, airway compromise, or those interfering with vital
organ functions
Radiation Simulation - Answer- focuses on size and orientation of the beams, permits
maximum Tx of tumor with minimal damage to normal tissue, uses immobilization
devices to help patient maintain a stable position, targets tumor defined using: variety of
imaging techniques, physical examination and surgical reports, marks placed on skin to
outline Tx field: critical normal structures in tx field are protected
Radiation and fertility - Answer- -use sperm banking and egg freezing when possible
External Beam - Answer- -two dimensional beam of radiation that is aimed toward a
specific anatomic site or tumor volume
-ex. xray, gamma rays, or electrons
brachytherapy radiation - Answer- -A permanent or temporary implantation of small,
sealed containers (seeds) of radioactive material directly into the tumor or in a cavity of
the tumor.
-primarily soft tissue tumors, retinoblastoma, CNS tumors
-tumor beds <5-10cm
-may be alone or in conjunctions with external beam
ALARA - Answer- As Low As Reasonably Achievable (time, distance, shielding)
3 goals of ALARA - Answer- 1. minimizing time of direct exposure
2. increse distance
3. shield patient
(barriers)
Conformal Therapy - Answer- -3 dimensional and delivers radiation to contours of the
tumor area to be treated
-benefits if precise delivery sparing healthy tissue
, Intensity Modulated Radiation Therapy (IMRT) - Answer- -high-dosage radiation
delivered via a beam that changes its dosage and shape
-maximum dose is delivered, while sparing surrounding tissue
-can treat multiple sites simultaneously
Intraoperative Radiation - Answer- -single dose directed at exposed tumor, tumor bed,
and surrounding area
-allows us to ensure RT is at tumor site and not surrounding tissue
-this single delivery has biologic effect of several daily fractions
Proton Radiation Therapy - Answer- -external beam therapy using proton charged
particles that deliver energy over a distance known as the bragg peak
-low dose is delivered to the front of the tumor and a max dose is delivered to the entire
tumor, with minimal exit radiation
-lessens risk of secondary cancer
-decreased toxicity to healthy tissues
-limited sites available in US
stereotactic radiosurgery - Answer- use of a specialized instrument to locate and treat
targets in the brain
Molecular Targeting Agents - Answer- -potential radiation sensitizers in pediatric solid
tumors and brain tumors
-may inhibit cell proliferation with given during radiation
Tissue Tolerance Dose (TTD) - Answer- -radiation dose to an organ correlates to the
relative probability of a radiation induced complication
-varies from organ to organ
acute, subacute, and late effects timelines - Answer- acute: during course of radiation
subacute: 3-9 months post
late: 1 year post
When to expect acute RT toxicities? - Answer- -several weeks into treatment and may
persist several months post
Common general symptoms of RT toxicity? - Answer- -FATIGUE! regardless of RT
location
-myelosupporession--esp. when RT to pelvis, sternum and long bones or when chemo
and RT occur
Contradindication to radiation therapy? - Answer- -less than 3 years old due to
neurocognitive impairment
Answered
How does radiation help? - Answer- -high energy particles/waves destroy cancer cells
-damage is caused by breaking DNA strands and prevents cell replication
What is the goal of radiation? - Answer- -to deliver the most therapeutic dose of
radiation to the tumor cells while sparing the surrounding healthy tissue
Use in leukemia and lymphoma?? - Answer- can prevent CNS disease
Emergent radiation is used when? - Answer- -used to treat tumors causing SVC
syndrome, spinal cord compression, airway compromise, or those interfering with vital
organ functions
Radiation Simulation - Answer- focuses on size and orientation of the beams, permits
maximum Tx of tumor with minimal damage to normal tissue, uses immobilization
devices to help patient maintain a stable position, targets tumor defined using: variety of
imaging techniques, physical examination and surgical reports, marks placed on skin to
outline Tx field: critical normal structures in tx field are protected
Radiation and fertility - Answer- -use sperm banking and egg freezing when possible
External Beam - Answer- -two dimensional beam of radiation that is aimed toward a
specific anatomic site or tumor volume
-ex. xray, gamma rays, or electrons
brachytherapy radiation - Answer- -A permanent or temporary implantation of small,
sealed containers (seeds) of radioactive material directly into the tumor or in a cavity of
the tumor.
-primarily soft tissue tumors, retinoblastoma, CNS tumors
-tumor beds <5-10cm
-may be alone or in conjunctions with external beam
ALARA - Answer- As Low As Reasonably Achievable (time, distance, shielding)
3 goals of ALARA - Answer- 1. minimizing time of direct exposure
2. increse distance
3. shield patient
(barriers)
Conformal Therapy - Answer- -3 dimensional and delivers radiation to contours of the
tumor area to be treated
-benefits if precise delivery sparing healthy tissue
, Intensity Modulated Radiation Therapy (IMRT) - Answer- -high-dosage radiation
delivered via a beam that changes its dosage and shape
-maximum dose is delivered, while sparing surrounding tissue
-can treat multiple sites simultaneously
Intraoperative Radiation - Answer- -single dose directed at exposed tumor, tumor bed,
and surrounding area
-allows us to ensure RT is at tumor site and not surrounding tissue
-this single delivery has biologic effect of several daily fractions
Proton Radiation Therapy - Answer- -external beam therapy using proton charged
particles that deliver energy over a distance known as the bragg peak
-low dose is delivered to the front of the tumor and a max dose is delivered to the entire
tumor, with minimal exit radiation
-lessens risk of secondary cancer
-decreased toxicity to healthy tissues
-limited sites available in US
stereotactic radiosurgery - Answer- use of a specialized instrument to locate and treat
targets in the brain
Molecular Targeting Agents - Answer- -potential radiation sensitizers in pediatric solid
tumors and brain tumors
-may inhibit cell proliferation with given during radiation
Tissue Tolerance Dose (TTD) - Answer- -radiation dose to an organ correlates to the
relative probability of a radiation induced complication
-varies from organ to organ
acute, subacute, and late effects timelines - Answer- acute: during course of radiation
subacute: 3-9 months post
late: 1 year post
When to expect acute RT toxicities? - Answer- -several weeks into treatment and may
persist several months post
Common general symptoms of RT toxicity? - Answer- -FATIGUE! regardless of RT
location
-myelosupporession--esp. when RT to pelvis, sternum and long bones or when chemo
and RT occur
Contradindication to radiation therapy? - Answer- -less than 3 years old due to
neurocognitive impairment
