Head & Neck Flashcards
What is the most common form of radiation therapy?
Photon
An electron produces ___ penetration and is ideal radiation therapy for the ___. (structure)
An electron produces superficial penetration and is ideal radiation therapy for the skin.
A neutron is a ___-energy particle and is highly ___.
Neutrons are a form of radiation used for ___ malignancies.
A neutron is a high-energy particle and is highly toxic.
Neutrons are a form of radiation used for salivary gland malignancies.
A proton is a __-energy particle w/a sharp peak in delivered dose, followed by a rapid falloff beyond the target (Bragg peak).
Protons are used for ___ malignancies, where dose to critical adjacent structures must be minimized.
A proton is a low-energy particle w/a sharp peak in delivered dose, followed by a rapid falloff beyond the target (Bragg peak).
Protons are used for skull-base malignancies, where the dose to critical adjacent structures must be minimized.
A Carbon ion is a ___-energy particle with a sharp Bragg peak (delivered target dose).
A Carbon ion is a high-energy particle with a sharp Bragg peak (delivered target dose).
Radiation Therapy is delivered via what forms (1-4)?
- Conventional radiation
- Intensity-modulated radiation therapy (IMRT)
- Brachytherapy
- Stereotactic body radiation therapy (SBRT)
The ideal radiation dose for Intensity-Modulated Radiation Therapy (IMRT) is based on ___.
Imaging.
(A computer algorithm is applied to achieve the ideal distribution)
Intensity-Modulated Radiation Therapy (IMRT) offers precise control, by ___.
Multiple small beamlets converging on a target
What form of Radiation Therapy is best to dose the following critical structures (salivary glands, pharyngeal constrictors, temporal lobe, optic nerve, cochlea, spinal cord)?
Intensity-Modulated Radiation Therapy (IMRT)
Brachytherapy works by Radioisotopes applied to tumor bed, that create ___, and have a ___ dose falloff of radiation.
Brachytherapy works by Radioisotopes applied to tumor bed, that create permanent implants (beads) or interstitial catheters, and have a rapid dose falloff of radiation.
What form of radiation therapy is best to treat the following?
- Lip cancer
- Nasopharyngeal recurrence
- BOT recurrence
Brachytherapy
The indications for Post-op Radiotherapy are:
1. _____
2. Multiple positive nodes
3. Positive surgical margins
4. Perineural invasion
The indications for Post-Op Radiotherapy are:
1. Advanced stage (pT3, pT4)
2. Multiple positive nodes
3. Positive surgical margins
4. Perineural invasion
The indications for Post-op Radiotherapy are:
1. Advanced stage (pT3, pT4)
2. _____
3. Positive surgical margins
4. Perineural invasion
The indications for Post-op Radiotherapy are:
1. Advanced stage (pT3, pT4)
2. Multiple positive nodes: (w/o ENE radiation alone); (w/ENE, concurrent chemorads)
3. Positive surgical margins
4. Perineural invasion
The indications for Post-op Radiotherapy are:
1. Advanced stage (pT3, pT4)
2. Multiple positive nodes
3. _____
4. Perineural invasion
The indications for Post-op Radiotherapy are:
1. Advanced stage (pT3, pT4)
2. Multiple positive nodes
3. Positive surgical margins -> (may undergo reresection or concurrent chemorads if re-resection is not possible)
4. Perineural invasion
The indications for Post-op Radiotherapy are:
1. Advanced stage (pT3, pT4)
2. Multiple positive nodes
3. Positive surgical margins
4. _____
The indications for Post-op Radiotherapy are:
1. Advanced stage (pT3, pT4)
2. Multiple positive nodes
3. Positive surgical margins
4. Perineural invasion
What is the timing of Primary Radiation Therapy?
2 weeks after necessary dental extractions
What is the timing of Adjuvant Radiation Therapy?
Within 4-6 weeks after surgery
Delays in initiation of post-op adjuvant radiation are associated with decreased ___ and ___.
Delays in initiation of post-op adjuvant radiation are associated with decreased locoregional control and overall survival.
Conventional Radiation fractionation is performed ___ (frequency)
5 days/week x 7 weeks
Radiation Hyperfractionation is a ___ total dose.
Decreased dose/fraction, increased # of fractions, thus larger total dose.
An Accelerated fractionation is a ___ total dose and ___ treatment duration.
Conventional dose/fraction, increased # of fractions, thus a similar total dose and decreased treatment duration
Hypofraction is a ___ total dose and ___ treatment duration
Smaller total dose and decreased treatment duration
Which form of radiation therapy is least likely to cause ORN?
Intensity-Modulated Radiation Therapy (IMRT)
(B/c there is minimization of the dose to critical structures)
ORN of the mandible is most likely to occur above what radiation therapy dose?
Radiation dose >60 Gy.
(Remember, 1 Gy = 1 Joule of energy deposited/kg;
Radiation-absorbed dose (rada): 100 rad = 1 Gy)
What area of the mandible is more likely to be affected by ORN?
Posterior mandible.
What secondary malignancy are patients most at risk for from radiation therapy?
Sarcomas
