Part I Flashcards
- treatment usually to cancer using ionizing radiation
- referred as high energy x-rays
Radiation Therapy
4 different intent of radiation therapy
Radical/Curative
Adjuvant
Neo Adjuvant
Palliative
way of curing a cancer, often in combination with chemotherapy (ex. head/neck)
Radical/Curative
in addition to curative surgery to reduce risk of local recurrence (ex. breast cancer)
Adjuvant
to help symptom control (ex. incurable cancer)
Palliative
prior to surgery to shrink tumor
Neo-adjuvant
based in tertiary hospital
Radiotherapy Department
T/F Radiation therapy is given as an outpatient (on weekdays)
True
describe ionizing radiation
invisible
silent
pain free to receive
2 Main Ways in Delivering Radiation Therapy
Photons and Electrons
- high energy x-rays - penetrate into deep body tissue and spare the overlying skin.
- produce secondary electrons within tissue
- cause damage in both cancer and normal cells
Photons (high energy x-rays)
-damage DNA directly and deliver their dose superficially just below the skin surface
Electrons
- generally reserved for specific circumstances such as children with brain tumor
- little dose is delivered to normal tissues
- deliver to specific area
Protons
absorbed dose is expressed as [ ]
Gray (Gy)
series of small doses
Fractions
Components related to Radiation Therapy
Consent
Immobilization
CT stimulator
Treatment Plan
[component] discuss with patient all information about procedure
Consent
[component] masks used for head and neck cancers and brain tumor patients
- used to target the right spot
- PERSPEX MASK, THERMOPLASTIC SHELL, VACUUM BAG
Immobilization
[component] locate tumor
-makes use of tattoo to mark the reference point
CT stimulator
[component] involves volume definitions
Treatment Plan
volume definitions
a. gross tumour volume (GTV)
b. clinical target volume (CTV)
c. planning target volume (PTV)
[volume definitions] margin of tumour we can see
Gross Tumour Volume (GTV)
[volume definitions] margin of microscopic spread
Clinical Target Volume (CTV)
[volume definitions] margin to take account of day to day variability and potential tumour motion
Planning Target Volume (PTV)
- dependent on which part of the body is receiving treatment
- caused by transient damage damage to normal cells
Side Effects (Toxicity)
common toxicities associated with most radiation therapy treatment
Fatigue and Skin Reaction
T/F radiotherapy can cure secondary cancer cased by radiotherapy
False - There are many other treatments for cancer (hormonal, molecular etc.)
T/F UTI should be cured before radiation therapy for prostate cancer
True
occurs 6-8 weeks after radiation therapy progressive SOB and rough treated with high dose steroids and oxygen
Pneumonitis
therapy often used in curative/neo-adjuvant setting; makes radiation therapy more effective; increase toxicity
Chemo-radiotherapy
T/F 40% of cancer patients undergo radiation therapy
True
T/F Radiation therapy can be done outpatient
True
T/F Radiation therapy can be used for emergency treatment
True - for palliative patients in intense pain
T/F Radiation therapy is within 2mm of target
True
T/F Radiation therapy is invisible
True - ionization radiation is invisible
T/F Radiation therapy can cause burns
True
T/F Radiation therapy can cause secondary cancer
True
T/F Radiation therapy and chemotherapy can be done at the same time
True
1896
Becquerel discovered radioactivity
1898
Marie/Pierre Curie - discover radium
1903
- Nobel Prize for the Curies and Becquerel
- first successful case of malignancy basal cell carcinoma of face
November 8, 1895
Wilhelm Conrad Roentgen discovered x-ray
first x-ray was of [ ]
Bertha (wife) left hand
- first to recognize that radiation might cure cancer
- med student in Chicago
- peeling of hand due to exposure
- 90 surgeries for multiple cancers
Emil Grubbe
1896 - first person treated with radiatio, carcinoma of breast
Rose Lee, 65
1901
everyone thought that radiation is the absolute cure for cancer
- found single dose and fractionated dose
- found out that if original dose will be fractionated or broken into smaller doses, less damaging to skin
Claude Regaud
(1920-1930) animal and animal part Claude Regaud experimented on
ram, scrotum
- early French Radiation Oncologist
- pioneered the use of fractionated radiotherapy in a wide variety of tumour
- impressive results in locally advanced laryngeal cancers in 1934
Henri Coutard
- 1938 - discovery of Co 60 isotope
- transuranium elements - 1951 Nobel Prize in Chemistry
Glenn Seaborg and Edwin M. McMilan
-October 27, 1951 - world’s first cancer treatment with Cobalt 60
Dr. Harold E. John (1949)
first patient for cancer treatment with Cobalt 60
43 year old cervical cancer
- known for effectiveness, reliability and easy to use
- main radiotherapy machine
Cobalt 60
-capable of producing high energy deeply penetrate beams without excessive damage to skin and normal tissue
Linear Accelerators
developed first medical LINAC - 1956
Dr. Henry Kaplan and Edward Ginzton
first LINAC [year]
1953
first patient treated with LINAC [case and year]
1956, Gordon Isaac, 2 yr old with retinoplasma
discovered radioactivity in 1901
Antoine Henri Becquerel
discovered Pulonium and Radium
Marie Curie
[year] first brachytherapy
1901
- internal beam therapy
- radiation therapy of close proximity or within tumour
Brachytherapy
- external beam therapy
- LINAC, Co 60
Teletherapy
- delivered in tumor while surrounding tissues receive little to no radiation dose
- attempts to deliver a tumoricidal dose to the tumor while minimizing damage in surrounding tissues
- 3D info about patient’s body is supplied by CT stimulation process
3D conformal Radiotherapy
- advanced term of 3D Conformal Radiotherapy (3DCRT)
- sophisticated software and hardware to vary shape and intensity of radiation delivered to different parts of the tumor area
Intensity Modulated Radiation Therapy
-growing in popularity to widespread adoption of new LINAC which function both as treatment and imaging machines
Image Guided Radiation Therapy
anything that takes up space and has mass
Matter
- building blocks of matter
- have a diameter of 10⁻¹⁰m
Atoms
[mass/kg]
PROTON
1.67262 x 10⁻²⁷ or 1.673 x 10⁻²⁷
[mass/kg]
NEUTRON
1.67493 x 10⁻²⁷ or 1.675 x x 10⁻²⁷
[mass/kg]
ELECTRON
9.109 X 10⁻³¹
[mass/amu]
PROTON
1.00727(8)
[mass/amu]
NEUTRON
1.00866(7)
[mass/amu]
ELECTRON
0.000549
[charge relative]
PROTON
1+
[charge relative]
NEUTRON
0
[charge relative]
ELECTRON
-1`
contains/determine identity of element and atomic mass
nucleus
mass of nucleus
99.95%