Corrugated fiberboard as a positioning insert for patients undergoing radiotherapy

Area of Science:

• Medical Physics
• Radiation Oncology
• Materials Science

Background:

• Patient immobilization is critical in radiation therapy to ensure accurate dose delivery.
• Current immobilization systems often utilize materials with varying degrees of photon beam attenuation and structural integrity.
• There is a need for cost-effective, robust, and low-attenuating immobilization solutions.

Purpose of the Study:

• To develop and evaluate a novel single-patient body fixation system.
• To assess the suitability of corrugated fiberboard as a patient-positioning insert.
• To compare the photon beam attenuation and mechanical strength of fiberboard against other materials.

Main Methods:

• A new body fixation system was designed, incorporating a vacuum cushion, thermoplastic sheet, and corrugated fiberboard base plate.
• Photon beam attenuation was measured for fiberboard and carbon-fiber base plates using 4 MV and 10 MV photon beams.
• Mechanical strength was evaluated through weight loading tests and repeated stress application.

Main Results:

• The fiberboard base plate exhibited lower photon beam attenuation (1.9% at 4 MV, 1.6% at 10 MV) compared to carbon-fiber (3.7% at 4 MV, 2.6% at 10 MV).
• The vacuum cushion had minimal impact on photon transmission.
• The fiberboard demonstrated excellent structural integrity, with no subsidence under load and no thickness change after repeated stress testing.

Conclusions:

• Corrugated fiberboard is a robust material with low photon beam attenuation.
• The developed fixation system utilizing fiberboard is effective for patient positioning in radiation therapy.
• Fiberboard offers a promising, high-performance, and potentially cost-effective alternative for patient immobilization devices.