This is a overview of the devices used in the radiotherapy planning. These are specifically designed for patient proper positioning, reproducibility and immobilization of patient during radiotherapy treatment.

1. Patient positioning and
immobilization techniques
for radiation therapy
Dr. Subhash Thakur
PGIMER, Chandigarh

2. Patient positioning, fixation and
reproducibility of setup
• Whether you are doing conventional radiotherapy, 3D
conformal or IMRT treatments – accurate,
reproducible positioning and rigid fixation are
important factors for precise dose delivery to the
treatment portals.
• Thermoplastic shells offers a reliable method for
accurate positioning and immobilization.
• There are three essential components required for
making these shells. (i) Base plate: made up of
acrylic material or carbon fibre. Available for head
and neck cases, chest, pelvic regions. (ii) Neck
supports: foam type poly urethane material or silver
man standard supports. (iii) Thermoplastic masks.

3. What is
patient immobilization?
 a reproducible localization of the patient with a device
into which the patient is locked, to aid in the restriction
of anatomical movement

4. Why use positioning and
immobilization devices?
 increase target accuracy
 easy to use
 quick to set up
 comfortable for the patient
 durable enough to withstand an entire course of treatment

5. What is patient
positioning?
 a reproducible localization of the patient with the use of
a device onto which a patient lays a specific part of
their anatomy
 designed to guide the patient into the original
simulation position for radiation beam administration

6. History of patient positioning
 sand bags
 tape
 bite block
 plaster casts
 “home-made devices”

7. Considerations
for selecting a device
 cost
 convenience
 accuracy
 compatibility
 attenuation
 durability

8. Positioning and
immobilization
devices must be ...
 comfortable to minimize movement
 reproducible for the treatment plan

9. Consistency
 Consistency in patient positioning and immobilization
from treatment planning to simulation, and from
simulation to treatment must be maintained.
Differences in table/couch geometry, “tennis-racket”
sag and mechanical wear of simulator/accelerator,
must be kept to an absolute minimum.

11. verbal statements to
immobilize patients
1. ONLY INVOLUNTARY MOVEMENTS, PLEASE.
2. HOLD VERY, VERY STILL.
3. LIE QUIET
4. BE MOTIONLESS.
5. LET A CALM FALL UPON YOU.
6. NO MOVEMENTS, PLEASE.
7. PLEASE DO NOT MOVE.
8. DON’T WIGGLE, NOW.
9. LAY HEAVY, BECOME AS ONE WITH THE TABLE.

12. Head and neck
positioning and
immobilization

13. Challenges of
the head and neck region
 neck extension must be controlled
 claustrophobic patients
 inserting bite blocks or shunts in a
thermoplastic mask
 reproducibility of daily setup

14. Current methods for
positioning and immobilization
 thermoplastic mask of the head
 thermoplastic mask of the head and
shoulders
 treatment chair
 positioning aids

15. Thermoplastic masks

16. Thermoplastic masks
 thin sheets (usually 1.6mm to 3.2mm) of solid or
perforated plastic sheets bonded to a rigid frame
 water temperatures for perforated thermoplastic must
be 165oF

21. Top 10 Uni-frame® tips
 Set up your warming pan with 2”-3” of water and heat
to 165° F. Use a digital thermometer to check the water
temperature. Do not overheat.
 Place the baseplate on the treatment table with the
appropriate head and neck support.
 Apply a light coating of baby oil or other lubricant to the
side of the mask that will contact the patient’s face to
keep thermoplastic from sticking to skin, hair and head
rest; apply to entire surface.

22. Top 10 Uni-frame® tips
 Place the Uni-frame into heated water , until
thermoplastic turns clear (1-3 minutes).
 Remove Uni-frame from water and shake excess
water from holes; this should be done quickly, before
mask begins to harden.
 Center the Uni-frame over the patient’s face; starting
under the chin, gently pull the mask toward you over
the face and head and down to the baseplate. Align
holes in the frame to pins in the baseplate; lock clamps
to frame.

23. Top 10 Uni-frame® tips
 Gently mold soft thermoplastic material to patient’s
facial contours (eyes, nose, cheeks, etc.) to form a
mask. Total working time is 2-5 minutes.
 As the thermoplastic cools, it returns to its original
white color and becomes rigid. Allow to cool
completely! Removing the mask too soon will cause
additional shrinkage, and a too-tight refit.
 If desired, the thermoplastic can be cut to create
treatment portals after the mask has hardened. Cut
with a cast cutter

24. The question mark
technique
 Stand behind your patient’s head, position the
edge of the thermoplastic approximately 1.5
to 2” under the patient’s chin.

25. The question mark
technique
 Begin by catching the patient’s chin
approximately 1.5” inches into the
thermoplastic mesh. Gently pull the Uni-
frame eight to ten inches in the superior
direction, just above the patient’s nose.

26. The question mark
technique
 Push the thermoplastic down diagonally
toward your chest and onto the baseplate.

27. The question mark
technique
 Pull the thermoplastic down and onto the
black indexing pins of the baseplate. Lock the
Uni-frame to the baseplate with the quick-
release locks.

28. The question mark
technique
 Reach under the mesh at the patient’s throat
and “flair” the mesh out about 90o away from
the patient’s throat to create a smooth. Apply
the three finger pinch at the bridge of the
nose. Mold the mesh against the nose and
face to replicate the contours of the face for
30 to 45 seconds. Allow the mask to harden.

29. Head and
shoulder
thermoplastic
mask

30. Head and shoulder
thermoplastic mask
 designed to provide maximum head
and upper body fixation by capturing
the head, neck, and shoulders under a
continuous thermoplastic sheet

33. Benefits of thermoplastic masks
 economical
 disposable
 can re-use PVC frame (with re-loadable systems)
 markers can be placed on the mask rather than the
patient
 reproducible positioning is achieved

34. Treatment chair

35. Treatment chair
 comfortable, reproducible positioning for patients who require
vertical positioning
 accurate positioning for claustrophobic patients
 reclining back that adjusts to six positive-locking positions

37. Benefits of the treatment chair
 can accurately re-position claustrophobic patients
 can choose “arms-up” or “arms-down”
 can use thermoplastic mask or thermoplastic bra support options

38. Limitations
of the treatment chair
 large device may be difficult to store
 there isn’t a large percentage of patients who will require this type
of positioning

39. Positioning aids

40. Positioning aids
 Timos
 Silverman
 shoulder retractors
 bite bock
 foam wedge
 prone pillow

47. Benefits of positioning aids
 work with positioning devices to increase stability,
comfort and reproducibility

48. Breast and thorax positioning
and immobilization

49. Current methods for
positioning and immobilization
 wingboard
 breastboards
 thermoplastic sheet immobilization
 lungboard
 two-part foam
 vacuum cushion

50. Wingboard

51. Wingboard
 polycarbonate material with head and
arm rests
 designed to fit through CT scanner,
used for both treatment and diagnostic
imaging procedures of the thorax,
breast and lung

53. Benefits of wingboards
 patient can rest arms and elbows
comfortably
 designed to fit through CT scanners
 can be indexed to various breastboards

54. Breastboards

55. Breastboards
 primarily used to elevate the patient’s
upper torso above the treatment couch
to bring the sternum parallel to the table
 creates a uniform surface dose
distribution across the treatment area

56. Breastboards
 acrylic
 composite
 carbon fiber

58. Thermoplastic breast
immobilization

59. Thermoplastic
breast immobilization
 thermoplastic breast support system
used in conjunction with a breast board
 side-mount or back-mount handles
attach of the breastboard

61. Treatment brassiere

62. Treatment brassiere
 plastic material
 attenuation factors similar to a Silverman
 reshapes the ipsilateral breast
reproducible setups
 reshapes the contralteral breast to
move it away from the beam

64. Benefits of the
treatment brassiere
 reduced dose to lungs, heart and ribs
 shape and position are reproducible
 All sizes of cup sizes are available
 eliminates mammary folds
 marks can be made on the device and/or
patient for re-alignment

65. Lungboards

66. Lungboards
 Primarily used to for lung treatment,
however, it can be used for other
treatments where immobilization of the
upper torso and arms-up positioning is
required.

68. Benefits of
breastboards and lungboards
 brings the sternum parallel to the table.
 simplifies treatment set-ups
 eliminates skin folds

69. Vacuum cushions

70. Vacuum cushions
 bead filled polyvinyl or nylon-reinforced
bags

73. Benefits of vacuum cushions
 cost-effective
 re-usable
 quick to set up
 full range of sizes
 treatment portals are available
 safe to set up
 longevity is dependent on care and use

74. Limitations of vacuum cushions
 vacuum or wall suction is required
 storage space is required
 may puncture or develop leaks
 can not “cut-away” into the cushion

75. Hip and pelvis
positioning and
immobilization

76. Thermoplastic
positioning devices

77. Thermoplastic positioning
 thin sheets (usually 1.6mm to 3.2mm) of
solid or perforated plastic sheets
 cross linked linear polyester softens in
warm water
 water temperature for solid
thermoplastic must be 150oF
 water temperatures for perforated
thermoplastic can range from 160oF
to 170oF

78. HipFix

85. Benefits of thermoplastic
positioning devices
 can be used with prone or supine treatments
 exact cast negative of patient anatomy provides
precise reproducibility
 marks can be made on the thermoplastic rather than
the patient
 portals can be cut out of the thermoplastic
 can be integrated with vacuum cushions for
increased comfort and accuracy

86. Limitations of
thermoplastic immobilization
 thermoplastic sheets are expensive
 technique sensitive application requires
hands-on training by vendor
 must have a large water bath

87. Integrated
immobilization

88. Integrated
positioning and immobilization
 combining several positioning or immobilization
devices to adequately position a patient

91. Thank you