The latest in radiation therapy at Torrance Memorial Medical Center is TrueBeam, a state-of-the-art linear accelerator that helps zero in on tumors while sparing normal tissue.
“The TrueBeam has two great strengths: high precision and flexibility,” notes Dr. Thyra Endicott, a radiation oncologist at Torrance Memorial. “It can be used for treating tiny tumors with very tight dose margins and highly exact setup, and it can be used to treat broader areas if the cancer has already spread to adjacent lymph nodes.”
Qinan Bao, the lead physicist working with the TrueBeam, notes that it enables better treatment by targeting the tumor volume more precisely. As a result, it “gives less dose to the critical organs, so the patient may experience fewer side effects.” Because normal tissue is less likely to be damaged, higher doses of radiation can be delivered to the tumor to increase the chance of cure.
The precision of the radiation beam—giving sub-millimeter accuracy—allows the radiation to go exactly where physicians want it to go. In addition, imaging technology integral to the machine allows physicians to receive a high-resolution image of the target both at setup and throughout the treatment process.
“Patients are dynamic, breathing human beings; they don’t stay still like a statue when you treat them,” notes Dr. Endicott. “TrueBeam helps us to adapt the treatment to the human being on the table. And it allows us to deliver the dose much more quickly, so the patient tolerates treatment better.”
Torrance Memorial is the first hospital in the South Bay to have a True Beam system, but it was not an easy set-up process. “The TrueBeam was installed in March 2013, but that was just the first step. There were several months of testing of all the possible beam energies, shielding, imaging and treatment modes—both by our own physicists and by an independent group of physicists, and then a licensing process with the state and county. It was tested over and over to make sure that any possible treatment variation would be extremely reliable. We treated our first patient with it in mid- September,” says Endicott.
Physicians are currently using it to treat brain tumors, cancer of the oral cavity and throat, and for prostate cancers that need very tight margins. TrueBeam does not necessarily provide an advantage for every cancer patient, however, and radiation oncologists determine whether a patient is an appropriate candidate for the high-precision therapy.
If he or she is a candidate, radiation oncologists bring a team of experts together to develop a treatment plan. They work with one of three physicists on staff—Peter Rosemark, John Belotti, and Qinan Bao—to develop the best course of treatment for each patient. Dosimetrists—members of the radiation oncology team— are involved, as are physicians like neurosurgeons and pulmonary specialists, to fine-tune the target and ensure as much critical tissue as possible is spared.
“It’s a wonderful machine,” says Dr. Endicott, “but the people behind it are the most important variable.”