OVERVIEW Flashcards
tx of Ca less commonly (TD, BD, NCG)
RADIOTHERAPY
radthera uses this ionizing radiation
HIGH ENERGY XRS
Fx of radiotherapy
- disrupt ability CA CELLS to GROW/ DIVIDE
- KILL ca cells
- SLOWing their GROWTH
- SHRINKING TUMORS (for surgery)
radt is given as
OUTPATIENT (5x a week)
Whys is radt given in a short period of time
for normal cells to - RECOVER, REPAIR, REPOPULATE
has sufficient energy to alter atomic structure
IONIZING RADIATION
characteristics of ionizing rad
- INVISIBLE
- SILENT
- PAIN FREE
has suff. energy to cause EXCITATION
NON IONIZING RADIATION
based on tertiary hospitals
RADIOTHERAPY DEPARTMENTS
radiotherapy in combi with chemotherapy
CHEMORADIATION
4 intents
- RADICAL/CURATIVE
- ADJUVANT
- PALLIATIVE
- NEO ADJUVANT
- way of curing ca
- uses rad to kill ca cells but min. damage to normal tissues
- often combi w/ chemo
RADICAL/CURATIVE
- addition to curative surgery
- POSTOPERATIVE IRRADIATION / AFTER SURGERY
- reduce risk of local recurrence
fx: avoid/kill/remove microscopic spread
ADJUVANT
- accepts ca as INCURABLE
- control the symptoms
- All ca sites
e: prostate ca w/ bone metastasis
PALLIATIVE
- radthera + chemo to shrink ca cell
- prior to surgery = higher success of surgery
NEO ADJUVANT
- high energy xrs
- penetrate deeper into body tissue but spare over-lying skin
- produce: SECONDARY ELECTRONS w/in tissue
- cause: DNA DAMAGE to both ca + normal cells
PHOTONS`
- for superficial maligancies
- damage dna directly
- deliver dose superficially
- continue to travel
ELECTRONS
this generates and delivers the 2 main ways of delivering radt
LINAC (linear accelerator)
- gen. reserved for v. specific circumstances such as children w brain tumor
- very little dose is delivered to NORML tissues
- deliver to specific areas only, no further penetration
PROTONS
can often repair damage and survive except when radt is too much or not calibrated which results in being stiill damaged
NORMAL TISSUE
- once ca cells are irradiated they die
APOPTOSIS
absorbed dose/ rad
GRAY (Gy)
series of small doses delivered in radt rather than in single dose
FRACTIONS
reqs LARGE DOSE of radt divided into multiple small fractions
RADICAL
deliver in SMALLER no of fractions and Lower total dose
PALLIATIVE
____ is dep on which part of the body is receiving tx
caused by: transient damage to normal cells
that given time will repair and result to _____
TOXICITY/SIDE EFFECTS
ACUTE TOXICITY
Common toxicities assoc w. most radthera txs
FATIGUE. SKIN REACTION
-skin rxn (rad dermatitis)
- muscositis- pain
thick oral secretions
loss of taste
fatgue
dry mouth
MANAGEMENT: oral care
HEAD NECK CA
management: analgesic
need to exclude to cure uti first before radt
PROSTATE CA
odynophagia (painful swallowing) / oesophagitis
due to: mucositis in oesophagus
- cough / SOB / chest pain / rarely nausea
LUNG CA
occurs 6-8 wks after rad
progressive SOB & cough
tx: high dose of steroids & oxygen generator
pneumonitis
for hgiher effectivity of radt
often used in curative / neoadjuvant setting
but w/ increased toxicity (CHEMOTHERAPY TOXICITY)
added in esp INCREASED RISK OF NEUTROPENIA (low type of wbc)
CHEMORADIOTHERAPY
total duration of tx
no of days b/n 1st and last session
PROTRACTION
in 4 intents, is it ok for radt-surgery-radt
radthera-adjuvant-neoadjuvant
radt cant be 2x a day
if ever secondary ca caused by radt can radt heal it
What is its TREATMENT PLAN
true
- HORMONAL THERAPY
- TARGETED THERAPY
- MOLECULAR THERAPY
radt as emergency tx
T - PALLIATIVE
radt not avail in most hospitals
T
delivered accurately in 2mm
T
not visible
causes burns
T
radt and chemo given at the same time
T
in 4 intents, what is commonly applied in all stages of ca
radical / neoadjuvant / adjuvant
important components of radiotherapy
CONSENT IMMOBILIZATION CT SIMULATOR VOLUME DEFINITION RADIOTHERAPY TREATMENT
discuss w the pt what youre going to do, why. possible side fx, altnv options
CONSENT
- head neck immobilization
- whole body “”
- v rigid / hot water flexible / animated
perplex mask
vacuum bag
thermoplastic shell
reason for immobilization
- target right spot
- keep positioning
to locate tumor accurately
CT simulation
reference point for laser
to refrain irradiation to other body areas
TATTOO
volume definitions
GTV (gross tumor volume)
CTV (clinical target volume)
PTV (planning target volume)
margin of tumor that we can see
GTV
not visible possiblt cancerous
margin of microscopic spread
CTV
margin to take account of day to day variability and potential tumor motion
PTV
close clinical follow up during radt
radiotherapy treatment
began w superficial and orthovoltage therapy w xray tubes and teletherapy w sealed radioactive sources
external beam radiotherapy
sealed sources used by brachytherapy
Radium-226 (1901), Radon-222 seeds Caesium-137 Iridium-192 Cobalt-60 Iodine-125 Gold-198
Brachytherapy with beta sources
Strontium-90 and Ruthenium-106
Various manual loading systems have been superseded by modern high-dose-rate
Iridium 192 and Cobalt-60
automated systems for delivery of ___ to the prostate.
Iodine-125
three commonly used radiotherapy technologies
- External beam radiation therapy (EBRT or XRT or teletherapy)
- Brachytherapy or sealed source radiation therapy
- Systemic radioisotope therapy or unsealed source radiotherapy
Other highly specialized radiotherapy technologies also include:
- Particle therapy
- Intraoperative radiation therapy
- Stereotactic radiation therapy
using protons or heavy particles
Particle therapy
delivering radiotherapy during the peri-operative
period at time of the surgical removal of the tumour
Intraoperative radiation therapy
delivering very high radiation dose called ablative
dose to a well-defined small tumour
Stereotactic radiation therapy
ultimate foal of all the changes and developmetns and improvemens
- effective destruction of ca tissue while delivering mnimal dose of radiaiton to adjacent healthy tossues
- make tx easier and shorter for pt to sustain and physicians and other healthcare professionals to perform
- act of emitting radiation spontaneously
- giving off rays of energy or particles by breaking apart atoms of certain elements
- done by atomic nucleus when unstable
Radioactivity
pierre curie suggested to Dr Henri Danlos
if radioactive source could be near or close proximity / inserted into a tumor (interstitial brachytherapy)
foundation of brachytherapy
types of radiotherapy treatments
teletherapy
brachytherapy
delivers radiaiton externallly
aplication of co 60
external beam radiotherapy
teletherapy
places radiaiton internally
gk word close
internal beam radiotherapy
brachytherapy
uses high energy radiation from xrays to kill or shrink ca cells
roentgen therapy
close proximity
earliest form of brachytherapy
using radioactive drugs that gives of energy to kill thru vein the ca cells
Radium therapy
different radiotherapy techniques
3DCRT (3D conformal radiotherapy)
IMRT (Intensiy modulated therapy)
IGRT (image guided radiation therapy)
started in 1990 wherefields used are designed that the radiaiton is mostly towards the tumor (tumoricidal dose) and the surronding tissues have little to no dose
- has 3d info about patients body supplied by CT simultaneous process
3DCRT
advance form of 3DCRT that manipulates photons to be directed to tumor and also shape the beam
uses sophisticated software and hardware
it varies the shape and intensity of radiaiton DELIVERED TO THE DIFF PARTS OF THE TX AREA
IMRT
most expensive includes imaging while having tx
growing popularity primarily due to widespread adoption of new linac
IGRT
fundamental principle of matter
building blocks
atom
anything that takes up space and has mass
matter
3 parts of an atom
proton neutron electron
positive charged particles found inside nucleus
proton
