<style>.lazy{display:none}</style>The Building of Free-Form Customized Immobilizers with Alpha Cradle ® Foaming Agents - Customized Repositioning and Immobilization in Radiation Therapy

The Building of Free-Form Customized Immobilizers with Alpha Cradle ® Foaming Agents

extended form for radiation therapy

THE BUILDING OF FREE-FORM CUSTOMIZED IMMOBILIZERS
Max Buscher
Tufts New England Medical Center
Boston, Massachusetts

The immobilization required for patients’ limbs or achieving the decubitus position can be solved using the Smithers Medical Products ALPHA CRADLE® MOLD MAKER II, polyform bag and foaming agents. This department has been using a different method which has advantages over the slotted board technique.

The materials required are ½” thick Styrofoam® blocks (approximately 3” thick), Mylar sheeting and foaming agents, all of which are available from Smithers Medical Products, Inc. An example of immobilizing a leg with our method is given here.

The patient’s leg is centered on a sheet of ½” thick Styrofoam®. Blocks of 3” Styrofoam® are fashioned and placed in position surrounding the leg.

These blocks are then taped securely with masking tape along their lengths to the ½” base piece. The taping serves two purposes – it secures the blocks in position and it prevents leakage of the foam from these places.
The patient’s leg is lifted up and the Mylar sheet is laid over the form and tucked down into the area between the blocks. The leg is then lowered back into the form.

The mylar is lifted up on one side and foam is poured into the form – the same is then done for the other side. The expanding foam is controlled by hand pressure so as to make a tight fit with the patient’s leg. The top and bottom of the form are a potential source of leaks. These can be avoided by holding the mylar against the blocks in these places.

The mylar should be pulled away from the leg while the Alpha Cradle foam is expanding. This prevents the possibility of “locking” the patient into the form by preventing the foam from expanding around the leg’s anterior surface.

After the Alpha Cradle foam has hardened, the form is removed and excess material is trimmed using a saw and scissors. The immobilizer is now complete and ready for use.

In the slotted board system the entire volume of foam is poured into a plastic bag and if the Alpha Cradle foam is not spread out evenly a lopsided form can result. Our technique gives much more control over where the foam is poured.

With the slotted board system the user must rush to insert the boards which control the shape of the form because the foam has already begun to expand. In our method the blocks that outline the form are already in place before the foam is poured. Also our blocks can be set at any angle whereas with the board one is restricted to the rectangular system of slots.

With the slotted board system the depth of the form is limited by the height of the boards. With our technique any desired depth is achieved by stacking and taping 3” blocks to the required height. This is particularly useful for the decubitus position.

This technique produces light and reliable repositioning devices and has very general application. It has been used in this department for over five years.