TomoTherapy: High-Tech Therapy Delivers High Hopes
TomoTherapy, a state-of-the-art radiation therapy system that delivers precise image-guided radiation therapy, allows veterinarians to pinpoint a tumor’s size, shape, and location seconds before radiation therapy begins. Though fairly expensive and meticulous, the benefit and accuracy of this treatment certainly exceeds the costs when your best friend’s life is at stake.
“TomoTherapy literally means slice therapy,” said Dr. Michael Deveau, assistant professor at the Texas A&M College of Veterinary Medicine & Biomedical Sciences. “While standard radiation therapy is currently delivered using a few static fields, helical TomoTherapy delivers treatment with a rotating beam.”
Performing a 360 degrees rotation around the patient, this allows for accurately directing radiation dose at the tumor itself while minimizing dose to the neighboring normal tissues. As the location or shape of the tumor evolves over time, the angles and intensity of the beams are also adapted to enhance the accuracy of the treatment.
“The TomoTherapy concept evolved to address deficiencies in radiation therapy and provides more precise radiation delivery to the tumor, allowing for fewer side effects to normal tissue,” said Deveau. “It basically is hybridization between all the functional parts of a conventional C-arm style linear accelerator, a commonly used machine for radiation delivery in human and veterinary patients, and a diagnostic imaging CT scanner.”
Radiation is not a benign form of therapy, and tolerance to it is dependent on tumor type, tumor volume, and the volume of normal tissue irradiated. “The objective of radiation therapy used to treat cancer is to eradicate the disease without producing unacceptable normal tissue complications,” said Deveau. “The tolerance to radiation of normal tissues depends on the volume and dose received. Unique to this radiation technique, the tumor itself is being treated while excluding or minimizing the dose to surrounding normal tissue structures. The conformal radiation beams provide more assurance that the dose will be confined to the tumor, in turn, producing far more favorable toxicity profiles when compared to similar treatments with inferior techniques and machines.
Ranging anywhere from $6,000 to $7,000 for a four-week session, this treatment only lasts for an average of 20 minutes, but the preparation is fastidious. Combining linear radiation therapy and CT scanning technology, TomoTherapy has the ability to treat tumors that were once considered untreatable and offers new armament for modernizing the management of cancer in veterinary patients.
“Suitable for almost all clinical presentations, it is one of the best, if not the best, machine for treating large complex tumors or clinical presentations requiring extended treatment fields,” said Deveau. When it comes to our beloved pets, this high-tech therapy brings high hopes for their ability to live long, healthy lives.
Pet Talk is a service of the College of Veterinary Medicine & Biomedical Sciences, Texas A&M University. Stories can be viewed on the Web at vetmed.tamu.edu/news/pet-talk. Suggestions for future topics may be directed to editor@cvm.tamu.edu.
