For years, radiation administered to treat head and neck cancers has damaged patients salivary glands so badly they were left unable to produce adequate saliva. For the rest of their lives, theyd eat with a glass of water at hand, be awakened repeatedly at night by dry mouth, and suffer frequent discomfort at other times. The damage was irreversible.


That type of treatment is changing.


Late last month, Cancer Care Northwest PS, of Spokane, began treating Spokane resident David Wilson, who has a brain tumor, with an emerging technology called intensity modulated radiation therapy, or IMRT, which allows radiation to be targeted more precisely and doses to be varied dramatically. Cancer Care Northwest believes its the first health-care provider here to offer IMRT.


This patient should be able to go through treatment and the rest of his life without having dry mouth, says Dr. Robert Fairbanks, a radiation oncologist at Cancer Care Northwest. That is a remarkable step forward.


Says Wilson, I havent had dry mouth whatsoever. Ive got about a month and a week of treatment to go.


Cancer Care Northwest expects by the middle of this month to be using IMRT to provide a total of at least eight patients with the daily regimens of radiation necessary to kill tumors. In some cases, the technology will be used to treat prostate and rectal cancers with higher doses of radiation than usual, which can increase the odds of success.


Radiation used in combination with chemotherapy is becoming the preferred treatment for what are referred to as locally advanced head and neck cancers, because it produces improved results in terms of sparing the larynx and the tongue, Fairbanks says. Cancers are referred to as locally advanced when they have progressed in the areas where they originated, but have not spread to other parts of the body.


To implement IMRT, Cancer Care Northwest added to one of its linear accelerators a sophisticated computer system, Fairbanks says. Dr. Bruce Cutter, Cancer Care Northwests president, says the medical practice will spend about $500,000 on hardware, software, and equipment upgrades to implement IMRT fully.


In addition to those outlays, Cancer Care Northwest has contracted with D3 Advanced Radiation Planning Services, of Pittsburgh, for help in developing treatment plans for patients. Fairbanks calls D3, a spinoff from the University of Pittsburghs medical school, the industry leader and principal pioneer in IMRT.


We wanted to offer this from the very beginning at the highest level, Fairbanks says. Thats why we affiliated with the pioneers in the field.


To plan treatment with IMRT, patients are given a computerized axial tomographic scan, or CAT scan, to define their structures and anatomy and map it specifically, Fairbanks says. That mapping includes three-dimensional depictions of patients cancers and the parts of their physiology, such as the optic nerves, the jawbone, and the salivary glands, to which their doctors hope to minimize radiation exposure.


Via high-speed communications lines, Cancer Care Northwest doctors and their counterparts at D3 simultaneously can pull up on computer screens the same treatment plan and discuss modifications, Fairbanks says.


While D3 doesnt sign off on Cancer Cares treatment plans for patients, they will not send them back unless they meet their standards, he says.


IMRT has particular promise to ease the side effects that head and neck cancer victims suffer from treatment.


Specifically, with head and neck cancers, we generally have a pretty good chance of cure, says Fairbanks. Still, he adds, Anytime with head and mouth, its almost universal that patients have problems with saliva production.


Fairbanks once treated a 17-year-old boy who was left unable to produce adequate saliva. Its a very difficult thing to be 17 years old and know that for the rest of your life youre going to have dry mouth, Fairbanks says.


He also treated a politician who didnt run for office afterwards because dry mouth left him unable to give a speech. When the politicians cancer returned, he regarded the loss of his ability to make speeches as more grievous than the return of his cancer, even though at that point there was no hope for curing his disease, Fairbanks says.


IMRT achieves its targeting precision and sweeping capability to vary doses by shifting metal pieces in a leaf system in a linear accelerator to block transmission of different parts of the radiation beam from the machine. The technology can varyindividuallythe length of time in which 250 to 5,000 beamlets of radiation in the main beam are delivered. For example, Fairbanks says, the technology might command hundreds, or even thousands, of beamlets to transmit radiation from two to 50 seconds a treatment.


That degree of accuracy and flexibility enables treatment to be mapped with much greater precision than before and directs dosages to tumors more precisely while limiting exposure to nearby tissue, Fairbanks says.


It takes an enormous number of mathematical calculations to handle so many beamlets of radiation so precisely, and Fairbanks says, It is only our computer capabilities getting to where they are that allow us to do this. A computer that isnt much bigger than a standard home desktop model makes the computations necessary to manipulate the individual beamlets of radiation. When a treatment plan is printed out, it appears in columns of numbers that seem unending.


Such precise targeting of a tumor and dramatic variations in dosage are important, because the margin for error is small, Fairbanks says.


It usually takes a cumulative 7,000 rads of radiation, typically administered in dosages of 200 rads a day, Monday through Friday for several weeks, to treat a head or neck cancer, Fairbanks says. Yet, the jawbone can tolerate a cumulative total of only 5,000 rads of radiationand the salivary glands can tolerate just 2,000 radsso its vital to reduce their exposure to radiation while still delivering enough rads to combat the cancer.


Even with IMRT, the goal is just to leave 50 percent of the salivary glands undamaged, Fairbanks says. That will allow patients to produce an adequate amount of saliva, he says.


While saliva helps the body break down foods through enzymatic action and is essential to a patients mouth comfort, it plays another vital role in helping to maintain the health of the lining of the mouth, Fairbanks says. Without adequate saliva, he says, the mouths lining doesnt heal as quickly, grow back as well when its been damaged, protect as well.


Adequate saliva is so important in fighting infection that if theres any chance the teeth of a patient might become infected, we have their teeth pulled before they receive radiation treatment for head and neck cancers, Fairbanks says. Otherwise, he says, You cant control the infection, and it can get into the jawbone. When that happens, sections of the jawbone likely will dieand have to be removed.


IMRT also is used in prostate cancer cases because dose-escalation studies have shown that 8,500 rads of radiation, an amount thats possible to deliver with IMRT without worsening the risk of side effects, can produce better cure rates than the 7,100 to 7,600 rads delivered heretofore, Fairbanks says.


Given the precision and variability of IMRT, it likely will be used before long to treat other types of cancer, such as breast cancer when internal mammary lymph nodes need treatment, Fairbanks says. He says conventional techniques dont provide an easy way to treat both the breast, or the chest wall after a mastectomy, and the lymph nodes in the internal mammary chain.


There are definitely a lot more possibilities than what weve explored up to this point, he says of the technology. We estimate that 20 percent of our patients could benefit from IMRT.