Novel rotatable tabletop for total-body irradiation using a linac-based VMAT technique

Area of Science:

• Radiation Oncology
• Medical Physics
• Cancer Treatment Technology

Background:

• Volumetric Modulated Arc Therapy (VMAT) is increasingly used for Total Body Irradiation (TBI).
• Current VMAT-TBI methods often rely on specialized or self-made immobilization devices.
• A limitation in VMAT-TBI is patient repositioning for those exceeding couch shift capacity.

Purpose of the Study:

• To evaluate the clinical results of a newly developed rotatable tabletop for VMAT-TBI.
• To assess the efficiency and safety of the rotatable tabletop in clinical practice.

Main Methods:

• A novel carbon fiber rotatable tabletop with an integrated ball bearing rotation unit was developed.
• The tabletop allows rapid 180° patient rotation from head-first supine (HFS) to feet-first supine (FFS) position.
• This rotation is performed without patient repositioning, overcoming linac couch shift limitations for VMAT-TBI.

Main Results:

• The study included 20 patients (median age 47 years) undergoing VMAT-TBI for acute myeloid leukemia.
• Most patients received 4 Gy in 2 fractions, twice daily, with a mean of 6476 MU per treatment.
• Mean overall treatment time (OTT) was 57 minutes for the first fraction and 38 minutes for the second.

Conclusions:

• The rotatable tabletop enables efficient and reproducible patient rotation during VMAT-TBI.
• It eliminates the need for repositioning, saving time and reducing risks of collisions and errors.
• The device facilitates acceptable treatment times for VMAT-TBI, enhancing clinical workflow.