Palliative RT Flashcards
what is the issue with size of trt volume
GTV, CTV, PTV not usually defined
adequate margins, organ movement, set up margins
areas defined by pt need
what is the issue of the complexity of trt
pragmatic approach
imaging areas which need to be traa was ted
osteolytic + sclerotic lesions
issue with accessory set up
pt comfortable
simple
immobilisation
appropriate
linac or kv equipment
issues with pt care
analgesia
special care required
care would need to be site related
IP/OP
transport
family support
end of life
what is given alongside brain met patients
corticosteroids
what is the survival for corticosteroids alone
2 months
brain met RT is given to what lesions
single or multiple deposits
how long does WBRT lengthen life for
6 months
is there a difference between WBRT and SRS
no survival difference
what is SRS for
single or limited met deposits
improved local control with focal therapy - high dose with rapid fall off to normal tissue
what is WBRT less likely to cause
neurological death (brain has lost its function)
what machines offer SRS
gamma knife
cyber knife
gantry based linac with micro MLCs
PBT
what is the SRS dose
16.2-25 Gy
WBRT dose
30-40Gy in 15-20# in 3-4 wks
what treatment is given got aggressive disease
surgery, post op RT, chemo
what high grade gliomas are treated
anaplastic astrocytoma and GBM
what is the survival for surgery alone with brain mets
6 months
what is surgery and post op RT survival for AA and GBM
AA = 36 months
GBM = 9-10 months
what is the survival for surgery, post op and chemo for AA and GBM
15% relative reduction in risk of death
AA = 37% 2 year survival
GBM = 9-13% 2 year survival
what are the cranial SE
vasculature
- endothelial cell death
- blood vessel wall thickening
- vessel occulsion
glial cells useful
- cerebral atrophy
- cognitive defects
WBRT TV
WB, olfactory groove and middle cranial fossa
inf border = supra orbital ridge and EAM
covers scalp 5mm margin
what is the technique for WBRT
POP
isocentric fixed FSD
6MV
what is the dose for WBRT
30Gy in 10
30-40Gy in 15-20
20Gy in 5
12Gy in 2 over a week
what would a pt need that has multiple bone mets
a field match
what is the TV of a bone met based on
pt symptoms
what is the role of RT for bone mets
control pain
prevent pathological fractures
what should be treated/avoided in RT for bone mets
whole bone/structure should be treated (vertebrae, hemipelvis) intervertebral discs)
channel of normal tissue (preserve lymphatic drainage)
joint spaces should be avoided
what happens to bone due to osteolytic lesions
they replace normal bone with a blast portion showing a lower attenuation with the normal cancellous bone, this comprises lesions with fatty liquid and solid soft tissue components
what is the characteristics of a bone met
matrix mineralisation, osteoid, chondroid, fibrous
septations and trabeculations
moth eaten
margin types: sclerotic, well
defined, poorly defined or indistinct
described as wide or narrow zone of transition
cortical involvement: cortical expansion, cortical destruction
periosteal reaction: benign or aggressive
what is the RT for local bone pain
single direct or POP
300kv @ 3cm depth
SC depth to body is 5-8cm
8Gy in 1
however alternatives are 20Gy in 5 or 30Gy in 10
what is the post op RT for bone mets
for pt with longer prognosis
8Gy in 1, 20Gy in 5 or 30Gy in 10
lymphatic channel margin
TV is not clear either whole bone or prosthesis and a margin for micro mets (3cm)
what is the sup borders for hemibody irradiation
top of scalp - umbilicus or
chin (extended) - umbilicus
what is the inf borders for hemi body irradiation
umbilicus - soles of feet
RT field hemibody iradiation
field: 4cm or extended FSD
field matching due to divergent beams
doses for hemibody
8Gy in 1
20Gy in 5
30Gy in 10
what is the gap between the different fields for hemibody
6 weeks
what is the max lung dose for hemibody
6Gy
what are the considerations for hemibody
QoL and co-morbidities
travel
RT outcome
single exposure might be preferred
possibility of path fracture
what is the aetiology for bladder cancer - palliative
70+
smoking
poor health
co-morbidities: muscle invasive bladder cancer
what is the trt for bladder cancer
surgery or chemo
if not suitable for chemo then RT
indications for RT for bladder cancer
haematuria: heavy bleeding, clots
urinary symptoms
local pain
what is the RT volume for bladder cancer
empty bladder
minimal volume
CT sim
location
what is the potential issues for bladder cancer
failure of treatment (30-40%)
fistuala (uncommon)
- vesico-vaginal
- vesico - colic
- vesico - rectal
what are the doses which can be given for bladder cancer if they have 6 months or more.
21Gy in 3# over 5 days
35Gy in 10# over 12 days
what are the doses given for pall bladder cancer pts with poor prognosis
17Gy in 2# over 3 days
14Gy in 4# once per month
8Gy in 1#
what is the percentage reduction for haematuria in fractionated and conventional regimes
fractionated: 60-65% reduction
conventional: 70%
what does the primary for lung mets tend to be
breast
colon
prostate
lung
indications for RT for lung Mets
symptomatic with advanced disease
80% response with haemopytsis
60% response with chest pain
30% response with dyspnoea
what is the immobilisation for lung Mets
non
supine
arms by side
what is the volume for lung Mets
primary + nodes + 2cm margin
what is the field for lung Mets
non complex POP (A+P)
isocentric/fixed FSD
complex iso technique = radical approach, palliative intent
verification
what are the doses for lung Mets
6MV
39Gy in 13# in 2.5 weeks
16Gy in 2# once a week
10Gy in 1 #
what is the acute toxicity for cranial RT
cerebral oedema
transient worsening of pre treatment symptoms
required corticosteroids (dexamethasone 4mg)
radiation dermatitis and permanent alopecia
nausea and vomiting (antiemetics)
