Whole-brain radiation therapy without a thermoplastic mask

Area of Science:

• Radiation Oncology
• Medical Physics

Background:

• Thermoplastic masks are traditionally used for patient immobilization during whole-brain radiation therapy.
• Ensuring accurate patient positioning and minimizing intra-fractional motion are critical for effective radiation delivery.

Purpose of the Study:

• To assess the clinical feasibility of performing whole-brain radiation therapy without a thermoplastic mask.
• To evaluate the efficacy of optical surface scanning for motion monitoring in this context.

Main Methods:

• Whole-brain radiation therapy was delivered without a thermoplastic mask.
• Patient positioning and intra-fractional motion were monitored using optical surface scanning.
• A motion threshold of 3 mm/3 degrees was established.

Main Results:

• The group mean vector deviation was 1.1 mm, with roll being more significant than pitch and rotation.
• Two out of 30 patients were unable to remain still during treatment.
• The remaining 28 patients successfully completed treatment without a mask.

Conclusions:

• Whole-brain radiation therapy without a thermoplastic mask is a clinically feasible method.
• Optical surface scanning provides effective motion monitoring for mask-free radiation therapy.
• A 93% success probability supports the adoption of this technique.