A new system for patient fixation in radiotherapy

Area of Science:

• Medical Physics
• Radiation Oncology
• Biomedical Engineering

Background:

• Accurate patient positioning is critical for effective radiation therapy.
• Conventional fixation methods, such as foam casts, can have limitations in reproducibility.
• Improving patient immobilization enhances treatment precision and reduces side effects.

Purpose of the Study:

• To introduce and evaluate a new patient fixation system for radiation therapy.
• To compare the reproducibility of the new system against conventional foam casts.
• To assess the clinical utility and cost-effectiveness of the novel fixation method.

Main Methods:

• Development of a vacuum-formed fixation system using an airtight plastic bag with polystyrene microspheres.
• Comparison study involving 29 breast cancer patients undergoing radiation treatment over 22 fractions.
• Analysis of portal X-ray images to measure variations in the center cross position (cranio-caudal, transversal) and rotation.

Main Results:

• The new microsphere fixation system demonstrated considerably improved daily reproducibility of patient setup.
• In 50% of cases, the deviation between the actual radiation field and the intended field's center cross was less than 1 mm.
• The system proved to be time-saving and cost-effective compared to conventional foam casts.

Conclusions:

• The vacuum-formed polystyrene microsphere system offers superior patient fixation reproducibility in radiation therapy.
• This novel system enhances treatment accuracy and efficiency for breast cancer patients.
• The technology presents a cost-effective and time-saving alternative to traditional immobilization techniques.