Optimal clinical implementation of the Siemens virtual wedge

Area of Science:

• Medical Physics
• Radiation Oncology
• Radiotherapy Technology

Background:

• A Siemens Primus linear accelerator was installed at the Northern Centre for Cancer Treatment (NCCT).
• This enabled investigation into the optimal clinical use of the Siemens virtual wedge filter.
• Previous research focused on specific virtual wedge angles (15-60 degrees).

Purpose of the Study:

• To investigate the optimal clinical implementation of the Siemens virtual wedge filter.
• To compare the efficiency of two virtual wedge delivery methods: wedge angle and wedge fraction.
• To assess dosimetric stability with low monitor unit delivery.

Main Methods:

• Siemens virtual wedge filter implementation on a Siemens Primus linear accelerator.
• Comparison of wedge angle and wedge fraction methods for treatment planning and delivery.
• Timing studies for planning and treatment delivery procedures.
• Investigation of wedge profile stability and dose delivery with low monitor units.

Main Results:

• The wedge fraction method was found to be the most efficient for virtual wedge treatment delivery, considering both planning and treatment times.
• The wedge fraction method is now exclusively used for virtual wedge treatments at Newcastle.
• No unfavorable dosimetric consequences were observed with the practical implementation of the wedge fraction method.

Conclusions:

• The wedge fraction method offers superior efficiency for virtual wedge radiotherapy.
• Clinical implementation of the wedge fraction method is dosimetrically safe and efficient.
• Optimized virtual wedge implementation enhances radiotherapy treatment delivery.