Immobilization devices help maintain a patient's position during radiotherapy to limit movement. Examples include vac-locks, thermoplastics, head rests, breast boards, tilt boards, belly boards, bite blocks, wing boards, and base plates. These devices provide patient comfort and stability while restricting movement to allow for precise, reproducible treatment positioning.

1. MUHAMMED ANEES.K

2. Definition
Any device that helps to maintain the patient in a fixed position
Immobilization devices
 Prevent the patient movement from treatment to
treatment over a course of radiotherapy

3. Examples

4. Examples

5. Examples

6. Examples

8. Examples

9. Examples

10. Vac-Loc

11. Vac Lock
Main:
 To limit the patient movement
 To reduce the probability of positioning errors
Incidental benefits:
 Radiation in daily set up time
 Radiation in patient’s fear and worry
 No need for patient to be awake, alert & co-operate
 Conversion into a rigid body

12. Characteristics of Vac-Lock
 Easy to use
 Easy to constructing the device
 Patient Comfort: Fully comfortable and relaxed position
 All movements be constrained
 Device conforms to the patient’s external surface contours
 The device be appropriate to the particular patient (e.g. obese)
and anatomy(e.g. abdomen) under treatment.

13. o Washable
o Reusable

14. Comfort
&
stability

16. Thermoplastics
 It is a soft & flexible material, almost like a Cloth
 When it soaked in a warm water, It becomes soft & flexible state
 Plastic can be stretched around any part of the patient’s body
 Once it cools, It becomes rigid again & maintain its new shape

17. Head & Neck case

19. Head Rests

20. Why Head Rests?
Maxillary antrum tumors-
-patient's head positioned with
chin hyper extended to include the
superior extent of the maxillary
antrum in the anterior field
without including the eye.

21. Why Head Rests?
Pituitary or small brain tumors head
positioned with neck in extreme flexion
Anterior beam can avoid the dose-limiting
structures such as the optic chiasm, the
retina, and much of the brain tissue

22. Increased stability,
Reproducible
Position
High Precision of
Immobilization
Head Rests

23. Upper limb positioning
 Arm best treated with 90 degree
extension & treatment couch rotated
90 degrees
 Axis of the arm aligned with the axis
of gantry rotation for planning &
delivering precise isocentric
treatment

24. Patient elevation systems

25. Patient Elevation Systems
1. Tilt board
 Severe obesity
 lung disease
 Built-in hand grips or arm supports that provide
comfortable and reproducible arms-up support.
 Used for treating lung cancer
 through lateral fields without the interference of arms or
shoulders.

26. Tilt board

27. Breast Board

28. Breast Board
 Arm support to bring the arm above the shoulders
& out of the lateral field
 Provide unobstructed access to the breast

29. Breast Board
Used in the treatment of breast cancer with parallel
opposed tangential fields.
Advantages:
 Provides arm support to bring the arm above the shoulders
and out of the way of the lateral field.
 Allows the patient to be positioned with the chest wall
horizontal avoiding angulation of the collimator.
 Takes advantage of gravity to pull the large breast down into a
better treatment position.

30. breast board

31. Modern Breast Board
 Rigid plastic.
 wide range of indexed tilt angles .
 The back support includes a head holder.
 It is cut away to prevent interference with the
tangential field for steep beam angles.
 Also contains an arm support system.

32. 1,Wing board
It Comfortably
Supports The
Patients Arms
During Treatment

33. 2,Belly board
 Thick mattress for supporting the patient prone with a window
cutout for the patient's belly.
 provide more comfort and stability in the prone position (obese
patient) .
 Reduces the amount of intestine in the lateral radiation

34. Belly board

35. Bite Block
To treat the patient with the mouth open
OR
To move the tongue away from the target volume during treatment
 Bite Block Maintaining the mouth in the open position
 Ensuring that the tongue remains depressed

36. Bite Block

37. Base Plate

38. Base Plate
 Base plate for a reproducible positioning of all body regions
 Made of a low density carbon fibre laminate sandwich structure
 Excellent dosimetric properties (minimum attenuate the beam)
 Indexing bar-the two pin indexing bar is designed for reproducible
positioning & stable fixation of base plates on the treatment couch

39. Prone Position

41. Goal of Immobilization Devices
1. PRECISION/ACCURACY
Limit patient movement
2. REPRODUCIBILITY
Reduce daily shifts
3. PATIENT COMFORT
Increase acceptance