immobilisation

Question 1

hint there is 5

characteristics of good immobilisation equipment

Answer 1

• easy to use
• easy to construct
• comfort for the patient
• resistance to bending and stretching
• usable on CT/MRI machines

Question 1

Hint there is 4 reasons

Why do we immobilise

Answer 1

• keeps the patient still
• ensures patient position reproducibility.
• reduces risk of high-dose OAR
• reduces under or over dosing the target

Question 2

what is the purpose of indexing

Answer 2

improves patient positioning reproducibility by fixating an index bar to a set point on the couch.

Question 3

how are breast patients immobilised?

Answer 3

Breastboard, the angle of the breastboard should match the angle of the sternum. Women with larger breasts can have bras manufactured or lie prone.

Question 4

What is important about tattoos on breast and chest patients

Answer 4

special boards or breast boards laid flat, it is important that the arms are in the same position every day as the tattoos can be in different positions relative to underlying anatomy.

Question 5

Characteristics of Area-specific immobilisation devices: pelvis

Answer 5

two main immobilisation devices can be used for pelvis:

1. knee fix which ensures the patient does not rotate their pelvis and provides lower back support for the patient.
2. Ankle stocks prevent the feet from leaning to one side as this rotates the femoral head.

Question 6

Characteristics of Area-specific immobilisation devices: head and neck

Answer 6

Custom-made shell for each patient made of thermoplastic. There is a special base required to fix the shell to the couch.

Question 7

what is the difference Gill-Thomas-Cosman frame and the Brown-Robert-Wells frame

Answer 7

The Gill-Thomas-Cosman frame is a non-invasive frame which is fixed to the same position on the patient during fractionated RT whereas the Brown-Robert-Wells frame is attached to the patient through burr holes meaning it is pinned to the skulls - only used for single fraction RT.

Question 8

what is the couch and the immobilisation devices made out of

Answer 8

carbon fibre