TomoTherapy HDA

TomoTherapy HDA is a complement to Turville Bay’s Varian TrueBeam linear accelerator. TomoTherapy adds another tool in Turville Bay’s technological array with its unique delivery system. Turville Bay Radiation Oncology teams use its interactive planning, and TomoTherapy HDA then delivers highly sculpted doses of radiation therapy for personalized and consistent treatments. With on-board daily CT image guidance when needed, Helical TomoTherapy is an adaptive technology that is able to accurately respond to the ever-changing tumor.

TomoTherapy clinical image of skullSkin Cancer of the forehead: Patient Positioning – Gray: Planning CT, Light Blue: MVCT
TomoTherapy clinical image of chestHomogeneous dose distributions for small, large, deep-seated or superficial target volumes.
TomoTherapy clinical image of bone marrowNo Field Matching needed, efficiently treat large fields of up to 160 cm without junctions.


This technology spares normal tissue with its helical mode of treatment. Certain cancers that are difficult to treat benefit from TomoTherapy such as prostate cancer patients with hip replacements, certain breast cancers in close proximity to the heart, and other cancers of the head and neck. Additionally, TomoTherapy HDA uses Dynamic Jaws to sculpt the dose to the edge of the treatment area.

Developed on the UW-Madison campus, TomoTherapy was acquired by Accuray, an international health technology company with roots in the cancer community.

TomoTherapy Accuray with Dr. Mackay

In use for almost a decade, TomoTherapy combines 360-degree fan-beam delivery of intensity-modulated radiation therapy (IMRT) and megavoltage CT (MVCT) imaging for a gold-standard treatment and targeting of complex tumors. During treatment delivery, the linear accelerator completes multiple 360-degree rotations around the patient while the couch passes through the center bore of the system. The treatment system’s linac is mounted to a CT scanner-like ring gantry delivering radiation therapy continuously from all angles, making TomoTherapy a counterpart to Turville Bay’s TrueBeam delivery system.