Concepts for shuttling multileaf collimators for intensity-modulated radiation therapy

Area of Science:

• Medical Physics
• Radiation Oncology
• Radiotherapy Technology

Background:

• Shuttling multileaf collimators (SMLCs) offer potential MU efficiency gains in intensity-modulated radiation therapy (IMRT).
• Previous research demonstrated an SMLC's improved MU efficiency for highly modulated fields compared to multiple-static-field (MSF-MLC) techniques.
• Conventional MLC techniques like MSF-MLC and dynamic MLC (DMLC) have limitations in MU efficiency.

Purpose of the Study:

• To evaluate the MU efficiency of novel SMLC arrangements in IMRT.
• To compare the performance of new SMLC designs against existing MSF-MLC and previously reported SMLC techniques.
• To assess the impact of SMLC design on tongue-and-groove underdose in the orthogonal direction.

Main Methods:

• Investigated two new SMLC arrangements with reduced mechanical complexity.
• Evaluated a novel SMLC concept designed for enhanced MU efficiency.
• Compared MU efficiency and underdose characteristics with MSF-MLC and a prior SMLC design.

Main Results:

• Two new SMLC arrangements, while simpler, were less MU efficient than the previously reported SMLC.
• A novel SMLC concept demonstrated increased MU efficiency compared to MSF-MLC.
• This novel SMLC often outperformed the previous SMLC for highly modulated intensity distributions.
• The novel SMLC achieved zero tongue-and-groove underdose in the across-the-rows direction.

Conclusions:

• Novel SMLC designs can enhance MU efficiency in IMRT.
• A specific new SMLC design offers advantages in both MU efficiency and reduction of underdose.
• These findings suggest SMLC technology advancements for improved radiotherapy delivery.