Multileaf shielding design against neutrons produced by medical linear accelerators

Area of Science:

• Medical Physics
• Radiation Oncology
• Nuclear Engineering

Background:

• Radiotherapy treatments, particularly those using medical linear accelerators, can produce unwanted neutrons.
• Patient exposure to these neutrons can lead to long-term health risks.
• Shielding solutions are necessary to mitigate this radiation hazard.

Purpose of the Study:

• To evaluate the effectiveness of a Multileaf Shielding (MLS) system in reducing neutron dose.
• To assess neutron dose reduction for patients undergoing radiotherapy.
• To simulate neutron transport in radiotherapy equipment.

Main Methods:

• Monte Carlo simulation using the MCNP5 code.
• Modeling a Varian Clinac 2,100/2,300 with MLC-120 operating at 18 MeV.
• Calculating ambient dose equivalent, H (10), with and without the MLS.

Main Results:

• The simulation demonstrated a significant reduction in neutron dose.
• The proposed Multileaf Shielding system proved effective in shielding.
• Neutron dose was measured at various points on the patient's plane.

Conclusions:

• The Multileaf Shielding system is a viable solution for reducing neutron exposure in radiotherapy.
• Implementing MLS can enhance patient safety during radiation treatment.
• Further studies can optimize MLS design for different linear accelerators.