Patients with certain
types of lung cancer, head and neck tumors, prostate cancer, recurrent
tumors with prior history of radiation therapy and tumors close proximity of
normal critical tissues, are all potential TomoTherapy candidates.
Because the radiation source rotates around the patient, it
can deliver radiation with extreme flexibility. Built-in daily CT imaging
ensures significant precision.
“This allows treatments that are difficult or impossible for
conventional radiotherapy machines to deliver, such as treating tumors in
the lung while minimizing dose to normal lung tissue, or treating tumors
close to the spinal cord while limiting dose to the spinal cord itself. It
also allows patients to be treated for multiple metastases (different
cancerous sites) simultaneously,” says St. John's radiation oncologist Dr.
Nathan Kim.
TomoTherapy treatment times are slightly longer than the
regular radiation therapy treatments, going from 10-15 minutes per day to
15-25 minutes per day per patient.
For some tumor sites, such as cancers of the prostate gland,
there can be day-to-day movement of the gland due to differences in patient
position or anatomical changes due to rectum or bladder distension. The
daily CT scan is used to precisely place the radiation beam and allows the
operator to modify the treatment.
“This ability is known as image-guided radiation therapy,
which is the new standard for radiation therapy for certain tumors,” says
Dr. Kim. “The addition of TomoTherapy is a great complement to St. Johns’
radiation and radiosurgery technology, which includes standard IMRT,
brachytherapy and the CyberKnife. We anticipate that this new therapy will
benefit patients whose cancers are not optimal to treat using IMRT with
conventional LINAC-based technology due to the location or position of the
tumor, but not appropriate for treatment with the CyberKnife.”
Most patients receive daily TomoTherapy for six to eight
weeks, Dr. Kim says. Because TomoTherapy’s radiation delivery is so precise,
he anticipates that patients will experience fewer side effects of radiation
therapy.
MORE ABOUT TOMOTHERAPY
TomoTherapy shares a lot of technology with CT scanners,
otherwise known as computerized tomography. The machine even looks like a CT
scanner. Some of its capabilities are: