IMMOBILIZATION DEVICES

MUHAMMED ANEES.K

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

Examples

Examples

Examples

Examples

Examples

Examples

Vac - LocVac-Loc

Main: To limit the patient movement To reduce the probability of positioning errorsIncidental 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

Vac Lock

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.

o Washableo Reusable

Comfort&

stability

Thermoplastics

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

Head & Neck case

Head Rests

comfortable

support

for head

used to get body parts in

way of the beam or

into a better position

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.

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

Why Head Rests?

Increased stability,

Reproducible Position

High Precision of Immobilization

Head Rests

Upper limb positioningArm 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

Patient elevation systemsTilt b

oard

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.

Tilt board

Breast Board

Breast Board

Arm support to bring the arm above the shoulders & out of the lateral field

Provide unobstructed access to the breast

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.

breast board

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.

1,Wing board

It Comfortably Supports The Patients Arms During Treatment

Eg: Breast, Lung,Thorax.

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

2,Belly board

Belly board

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

Bite Block

Base Plate

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

Prone Position

Goal of Immobilization Devices

1. PRECISION/ACCURACY Limit patient movement

2. REPRODUCIBILITY Reduce daily shifts

3. PATIENT COMFORT Increase acceptance

Thank You very much for your attention!