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Harper Dickson

Beams of hope

September 2009

by Karen Stamm

New device delivers powerful performance in war against cancer

Faster than a speeding scalpel, more precise than a pinpoint, and able to destroy some tumors in a single zap.

Novalis Tx™, one of the latest and most advanced weapons in the war against cancer, arrived at The Cancer Therapy & Research Center at the UT Health Science Center San Antonio this past spring. The CTRC is the only cancer center in South Central Texas to have this mammoth machine in its arsenal.

A versatile tool, Novalis Tx is a linear accelerator manufactured by Varian Trilogy™, fitted with impressive bells and whistles. Its Rapid Arc technology delivers highly customized radiation treatments with increased speed and accuracy. Imaging capabilities and software from BrainLAB make it the most advanced technology to perform noninvasive radiosurgery, killing tumors and other lesions without an incision and often in only one treatment.

For Chul S. Ha, M.D., professor and chairman of the radiation oncology department, the arrival of Novalis Tx fulfills a promise made when he was recruited from M.D. Anderson Cancer Center in 2006. "The UT Health Science Center made a major financial commitment to invest in Novalis Tx technology,"

Dr. Ha said. "We want to provide our physicians the best tools to offer our patients the most effective treatment possible. Novalis Tx takes IMRT to the next level."

IMRT stands for intensity-modulated radiation therapy, a relatively new way of delivering highly precise radiation to tumors which would not have been possible with more conventional radiation treatments. Novalis Tx allows the delivery of IMRT in as little as two minutes as it rotates 360 degrees around the patient in a single motion. Treatment by other IMRT machines takes about 20 to 30 minutes because of necessary pauses at numerous intervals during their rotation.

"A two-minute treatment time means patients do not have to hold still for long," Dr. Ha said. Faster treatment is more comfortable and potentially more accurate. Novalis Tx's targeted beam offers added safety by continuously adapting to the patient's breathing and body movements.

"Our goal is to deliver the lowest dose possible to the healthy tissue surrounding the tumor, while maximizing the radiation to the cancerous cells of the tumor," said medical physicist Nikos Papanikolaou, Ph.D., professor of radiation oncology.

Alonso N. Gutiérrez, Ph.D.
Alonso N. Gutiérrez, Ph.D., a medical physicist and professor of radiation oncology at the CTRC at the UT Health Science Center, prepares an 18-year-old patient for a procedure with Novalis Tx.

Top Image: Harper Dickson shines one week after having a brain tumor removed at the CTRC at the UT Health Science Center. Her physicians used Novalis Tx to deliver a single high dose of radiation. The procedure allowed Dickson to forgo having to shave her beautiful hair.
Sometimes all it takes is one treatment
Radiosurgery substitutes the need to make a traditional incision by delivering high-energy X-ray beams through the skin and into the tumor or lesion. As with traditional radiation therapy, the goal is to slow or stop the growth of the tumor without harming surrounding sensitive healthy tissue. In most cases, the procedure itself is not painful and does not require anesthesia. There is no scarring or disfigurement and little risk of infection. For those undergoing a brain procedure, no incision means no need to shave the patient's head.

For patient Harper Dickson, radiosurgery offered the best hope for a full recovery. Dickson is a 40-year-old civilian program analyst at Fort Sam Houston and the single mother of three boys, ages 5, 6 and 7. She suffers from a vestibular schwannoma, a benign tumor on the hearing and balance nerves supplying the inner ear. In 2008, Dickson had the tumor in her left ear removed with conventional surgery elsewhere. A year later, it was back. She consulted with neurosurgeon, John D. Day, M.D., associate professor of neurosurgery, who discussed with her the pros and cons of having a second conventional surgery versus stereotactic radiosurgery. "Even if conventional surgery were successful in removing the tumor, he told me the probability was very high that I could have facial paralysis following surgery and that it could be major and long-term," she said.

Dickson opted for radiosurgery. On June 18, Dr. Day and a highly trained team led by Aidnag Z. Diaz, M.D., associate professor of radiation oncology, used Novalis Tx to deliver a single high-dose of radiation to Dickson's tumor in the hope it will stop growing once and for all.

This image represents the X-rays Novalis Tx sends into a tumor or lesion.
A tumor can be compared to a small rock, irregular in shape. Imagine the rock as it's bombarded with tiny beams of light - the size of a pencil tip - from all directions. Illustration courtesy of Novalis Tx.
From radiosurgery to home repairs in three days
Dickson's case permits a comparison between conventional surgery and Novalis Tx radiosurgery for the same condition in the same patient. Conventional surgery took 12 hours and full recovery took weeks. Radiosurgery took less than an hour, plus about five hours for preparatory tests and computer-assisted treatment planning. Dickson was able to walk to her car when it was over. Two days later she was shopping for groceries and fixing the back door of her house.

For Dickson, the ultimate test will come when she receives her next scan to monitor the tumor's activity. She says she's confident that Novalis Tx can vanquish the enemy.

"Coping with this disease has been very personal, emotional and stressful for me," Dickson said. "But the doctors, staff and innovations at the CTRC have helped ease my mind and soul. The CTRC made me feel like Harper Dickson the person, instead of Harper Dickson the patient or number."

In the war against cancer, the CTRC offers a winning combination - some of the most advanced technology in the region and highly skilled and compassionate physicians. As a result, patients emerge as the true victors on their mission to defeating this deadly disease.

For more information about Novalis Tx at the CTRC, call (210) 450-1016.

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