SM_283b: Radiation Oncology Flashcards
Goal of radiation of therapy is to ___
Goal of radiation of therapy is to prevent disease spread or stop the disease
Describe treatment paradigms for radiation
Treatment paradigms for radiation
- Curative: primary (radiotherapy alone), ± chemo (concurrent, sequential), ± surgery (preoperative, postoperative)
- Palliative
Describe when radiation is primary treatment
Radiation is primary treatment
- Small cell lung cancer
- Locally advanced cervical cancer
- Anal cancer
- Laryngeal cancer
- Medically inoperable early stage NSCLC
- Locally advanced head and neck cancer
- Localized lymphoma
Radiation is used preoperatively to ___
Radiation is used preoperatively to improve the chance or margin of resection and reduce risk of locoregional recurrrence
- T3 or N+ rectal cancer
- Stage IIIA lung cancer
- Sarcoma
- Borderline resectable pancreatic cancer
Radiation is used postoperatively with the goal of ___
Radiation is used postoperatively with the goal of eradicating subclinical disease
- Breast conservation
- Breast cancer after mastectomy (node +)
- Endometrial cancer
Radiation is used as salvage therapy if there is ___
Radiation is used as salvage therapy if there is evidence of recurrence after surgery
- Post-prostatectomy recurrence
- Vaginal recurrence after hysterectomy for endometrial cancer
Radiation is used as palliative therapy when there is ___, ___, ___, and ___
Radiation is used as palliative therapy when there is pain, bleeding, compression, and SVC syndrome
Describe goals of radiotherapy for cancer
Goals of radiotherapy for cancer
- Deliver precise measured dose to targeted volume
- Eradicate tumor and microscopic disease
- Cure / prolong survival
- Minimize damage to adjacent normal tissue
- Minimize side effects
- Provide pts with high QOL
- Provide effective palliatipn
Describe steps of radiotherapy
Radiotherapy steps
- Consultation
- Treatment planning
- Simulation: positioning, immobilization device
- 3D reconstruction
- Target definition
- Planning / optimization
Stereotactic treatment is used to treat ___
Stereotactic treatment is used to treat cranial and extracranial treatment
- Stereotactic radiosurgery: intracranial
- Stereotactic ablative body radiation: lung, liver, spine lesions
- Small well-defined targets
- Advanced image guidance
- High dose per fraction
- Use of multiple beams
Describe GammaKnife stereotactic radiosurgery
GammaKnife stereotactic radiosurgery
- Stereotactic frame and immobilization
- Intracranial treatment (single fraction)
- MRI done same day
- 192 beamlets converge on single point / isocenter
X-rays are produced ___ in ___
X-rays are produced extranuclearly in powerful electrical devices that accelerate e- to high energy
Gamma rays are produced ___ in ___
Gamma rays are produced intranuclearly when emitted by radioactive isotopes
Brachytherapy is ___
Brachytherapy is type of radiotherapy that involves placing radiation inside the body
___ is used to shape beams
3D conformal treatment via computerized MLCs is used to shape beams
Intensely modulated radiotherapy uses ___
Intensely modulated radiotherapy uses linear accelerators to safely deliver radiation to a tumor while minimizing dose to surrounding normal tissue
Describe role of oxygen in radiobiology
Role of oxygen in radiobiology
- Radiolysis of water
- Oxygen: binds H radicals forming hydrogen peroxide, binds electrons to create superoxide, binds organic radicals to form peroxides
Four R’s of fractionation in radiobiology are ___, ___, ___, and ___
Four R’s of fractionation in radiobiology are re-oxygenation, redistribution, repair, and repopulation
Fraction of radiation ___ important than total dose
Fraction of radiation more important than total dose
Biologically equivalent dose is ___
Biologically equivalent dose is determined by a linear quadratic theory
