Intro to RT - W1 2hr Lec Flashcards
Where are bunkers located?
- Located at basement level or backing into a hill
- Has to be large enough to enable patients in hospital beds
CCTV Monitoring and Intercom Protocols
- Required to have CCTV monitoring and intercom
- Usually, three cameras
- Ability to move and zoom into the monitor
- Intercom is used for communication
Department Areas
- Public Areas = can be accessed by anyone
- Supervised Areas = dosage is negligible/ RTs are here when is dose is applied
- Controlled Area = bunker and maze
- Designated Area = can be access by radiation therapists
- Restricted Area = where the radiation sources are kept
Exposure limits - members of the public
Effective dose - 1 mSv per year
Dose in the lens of the eye - 15 mSv per year
Dose in the skin - 30 mSv per year
Exposure Limit (Occupationally Exposed)
Effective dose - 20 mSv per year averaged over a 5 year period
Dose in the lens of the eye - 20 mSv per year, averaged over 5 years
Dose in the skin - 500mSv per year
Dose to the hands and feet - 500mSv per year
Quality Assurance in Radiation Therapy
- All procedures that ensure consistency of the medial prescription and safe fulfilment of that prescription
o Regards the dose to target volume, minimal dose to normal tissue, minimal exposure to the personnel and adequate patient monitoring aimed at determining the end result of the treatment - Involves all groups of staff in a cooperative approach
Basic Treatment Techniques
- Parallel Opposed Pair
- Tangential Beams (IMRT)
- Four Field Box
- Sunrise Technique
- Complex Planning (Multiple Target Volumes, Multiple Dose Levels)
- VMAT
Cancer Treatment/ options for patients
- Surgery
- Chemotherapy
- Radiation Therapy
- Do nothing (e.g., cannabis therapy)
Radical Radiation Therapy
- Attempt to cure the patient
- Involves high doses delivered to relatively small volumes of tissue
- Careful planning
Palliative Radiation Therapy
- Aims to improve quality of life by relieving symptoms without causing unacceptable side effects
- Good for patients with metastatic disease or large primary tumours where cure is not possible
- Deliver lower dosage (hypo fractionated)
Brachytherapy
- Sources can be positioned near a tumour or implanted directly in it
- Damages normal tissue less than conventional beams
Patient Side Effects of Radiation Therapy (overall)
- Erythema (inflammation of skin, swollen and sore)
- Temporary hair loss (transient alopecia)
- Diarrhoea (if treating near GI tract)
- Nausea (if treating near brain or GI tract)
- Frequency of Urination (if treating near bladder)
Meaning of CTV, GTV, PTV
CTV - Clinical target volume (potential tumour presence)
PTV - planning target volume (accounts for daily set up uncertainties)
GTV- Gross tumour volume (detectable tumour)
What is DVH and OAR
Dose volume histogram
Organ at risk
Components of radiation treatments
- Linear accelerator
- Treatment couch
- Console
- Bunker
- Maze
