Breast technique Flashcards
(49 cards)
What are the signs and symptoms of breast cancer?
- Breast or Axilla lump
- Changes in shape or size
- skin changes: puckered, redness or peau d’orange
- Nipple changes: Inverted, discharge or ulcers
Factors associated with breast cancer?
- Being female
- Increasing age
- Personal or family history
- Inherited genes
- radiation exposure
- Alcohol
- menopause or children at older age
Is nipple retraction normal?
- It can be if doctor is satisfied no abnormality (only 1 in 100 may become sinister)
- may indicate cancer behind areola
Late signs include?
- Bone pain
- Nausea
- Weight loss
- Pleural effusion:cough or dyspnoea
- Jaundice
- Double vision`
Patient setup?
- Comfortable
- Supine, arms out of beam
- headrest, elbow, armrests, knee support and footboard
- reduce skin folds
How can you reduce lung dose?
Make sure sternum is flat
How can you reduce heart dose?
Move arms out of field moves breast superiorly
How can we reduce the need for collimator angulation?
Inclined plane to bring the chest wall parallel to the treatment couch
How can we reduce skin folds in SCF?
Move neck away from treatment field
What are considerations for women with large or pendulous breasts?
Prone or immobilisation such as breast casts
Procedures completed during CT simulation
Record all Board Settings
RO to mark up ME, LE, SUP & INF limits
RO to mark Electron Boost
Using readout on scanner, find central axis (Half way between SUP & INF)
Place radio-opaque markers on RO’s marks so as to visualise on CT
What are the benefits of a breast cast?
- Loss of skin sparing effect
- reduces severity of skin reaction in inframmamary fold
- Moves lateral and anterior part of breast anterior from OAR
What are the issues with a prone setup?
- under dosage of medial and lateral borders of PTV
- Patient’s ability to lie prone
- distinguishing between obese or pendulous breasts.
- cannot treat lymph nodes or bilateral tumours
- Large CT bore
What are appropriate limits for CT simulation?
Superior - chin of neck
inferior-5cm below breast tissue
Why are CT limits important
prognostic factor for determing fibrosis or pneumonitis using DVH
What measurements should be placed on the central slice?
Three reference tattoos are placed on the central slice and in the medial and lateral positions on right and
left sides so that measurements can be made to subsequent beam centres
-index breast board
What are the critical structures for breast treatment?
Heart
Lung
Contralateral breast
What is an appropriate slice thickness?
2-3mm
What are some planning considerations?
- Tumour bed delineated by gold seeds or titanium clips
- CLD no less than 2cm
- LAD should be excluded
- MHD no less than 1cm
- consider cardiac shielding
What are the different techniques for breast treatment?
- Forward planning field in field out both supine and prone
- DIBH IMRT
- VMAT
Why would we consider a higher energy beam?
- Large separation
- Deep seated tumours
What are some common breast volumes?
- Whole breast after BCS
- Chest wall after masectomy
- Nodal irradiation:-SCF, Axilla and IM
Where should the isocentre be defined?
- Within treatment volume
- can be at mid-separation between medial and latral edges
- Can be placed at the superior border for SCF irradiation
How can beam divergence be reduced to the lungs
Using posterior zero jaws
