Class notes
radiotherapy lecture notes
- Course
- Institution
includes: what is radiotherapy, radiation spectrum, ionising radiation, photoelectric radiation, radiotherapy mechanisms, terminology, clinical application
[Show more]
Seller
Follow
lauryndavison
Content preview
1Thursday, 28/10/2021
Week 6, Lecture
Dr Azeem Saleem
Radiotherapy
What is radiotherapy?
Use of ionising radiation to treat disease
Treatment modality
Mainly used to treat cancer
50% of patients with cancer have radiotherapy
Can also be used for other diseases such as keloids and COVID
Radiation spectrum
Frequency increases towards the right
Electromagnetic spectrum has a wave
As the frequency gets higher the energy gets higher
Starts with ultraviolet and goes to where radiotherapy is
Start getting ionising radiation at this point
Ionising radiation
Any radiation over a certain frequency which can create ions
Water – any radiation can dislodge electrons from the water molecule and create an
electron
Bound together by chemical bonds so the radiation needs to be strong enough to
break the bonds
Carcinogenic in nature
Typically used for X-Rays and CT scans
Megavoltage radiation
Main sources are gamma rays and photons
Have no mass
Photoelectric effect versus Compton scattering
Megavoltage
o Compton scattering
o Produces ongoing cascade of electrons
o Independent of the atomic number
o No absorption of rays in the bone
o Radiation therapy – not absorbed in the bones so less side effects
Kilovoltage radiation
o x-rays
o photo-electric effect
o energy is deposited onto an atom
o depends on the atomic number – higher the number the more absorbed
o as bones have a high atomic number this is absorbed by the bones showing
the picture
Radiotherapy: Mechanism
When it ionises it creates free radicals
Very highly reactive
Creates DNA damage which results in damage to the radiated area
Both to normal tissue and the tumour
The aim is to damage the tumour
Oxygen very important for effectiveness
The benefits of buying summaries with Stuvia:
Guaranteed quality through customer reviews
Stuvia customers have reviewed more than 700,000 summaries. This how you know that you are buying the best documents.
Quick and easy check-out
You can quickly pay through credit card or Stuvia-credit for the summaries. There is no membership needed.
Focus on what matters
Your fellow students write the study notes themselves, which is why the documents are always reliable and up-to-date. This ensures you quickly get to the core!
Frequently asked questions
What do I get when I buy this document?
You get a PDF, available immediately after your purchase. The purchased document is accessible anytime, anywhere and indefinitely through your profile.
Satisfaction guarantee: how does it work?
Our satisfaction guarantee ensures that you always find a study document that suits you well. You fill out a form, and our customer service team takes care of the rest.
Who am I buying these notes from?
Stuvia is a marketplace, so you are not buying this document from us, but from seller lauryndavison. Stuvia facilitates payment to the seller.
Will I be stuck with a subscription?
No, you only buy these notes for $10.01. You're not tied to anything after your purchase.
Can Stuvia be trusted?
4.6 stars on Google & Trustpilot (+1000 reviews)
83637 documents were sold in the last 30 days
Founded in 2010, the go-to place to buy study notes for 14 years now