BERKELEY -- Decades of study at Lawrence Berkeley Laboratory on the use of charged particle beams to treat human diseases have led to the opening of the University of California Eye Program.
The new medical facility, located at the Crocker Nuclear Laboratory on the UC Davis (UCD) campus, is dedicated to the treatment of uveal melanoma (eye cancer). Using a proton beam emanating from a cyclotron, the therapy program will save not only lives but useful eyesight in the majority of its patients.
The establishment of the UC Eye Program was a joint effort of LBL, the Crocker Nuclear Lab and the Cancer Center at UCD, and the UC San Francisco Radiation Oncology Department. Staff, funding, and equipment were supplied by all four institutions along with partial funding from the National Cancer Institute. With the guidance and assistance of the former LBL Radiotherapy and Biomedical Operations groups, the staff of the Crocker Lab was able to build a state-of-the-art eye treatment facility. The clinical program was developed by UCSF faculty with the aid of the UC Davis Cancer Center.
The UC Eye Program is a direct descendant of LBL's clinical treatment program, which began about 50 years ago and ended in 1992, with the closure of LBL's Bevatron. In all, more than 2,000 patients were treated at LBL for diseases that include eye cancer as well as life-threatening blood clots (arterial venal malformations) too deep in the brain for conventional surgery.
In addition to the program at Davis, LBL also has signed a two-year agreement to transfer charged particle beam technology dedicated to the treatment of arterial venal malformations to Loma Linda University's Medical Center in Southern California. LBL also is collaborating with other charged particle medical facilities throughout the world, notably at the National Institute of Radiological Sciences in Japan and the University of Heidelberg-GSI in Germany.
With the approval of LBL Director Charles Shank, LBL not only has transferred several generations of know-how to the team at Davis, but has also provided on long loan most of the equipment required to precisely focus the proton beam so it can destroy tumors.
LBL's contributions range from the computer system that controls the treatment, to power supplies for the accelerator operation, to the patient positioner used to accurately align the patient for proton treatment. An interesting historical footnote is that part of the Crocker cyclotron magnet came from one of LBL founder Ernest Lawrence's original cyclotrons, which itself was used to treat cancer patients some 50 years ago.
The LBL team responsible for transferring this technology to UCD included radiation oncologist Joe Castro, physicist Tim Renner, administrative coordinator Jackie Iler, medical physicist Inder Daftari, electronic engineer Mark Nyman, software engineer R.P. Singh, mechanical technician Mario Cepeda, and former employees Ron Stradtner and Charlie Pascale.
Uveal melanoma is a relatively rare condition. About 2,500 patients are diagnosed in this country every year. In the past, the usual means of treatment was to remove the eye in order to prevent the spread of cancer.
Charged particle radiotherapy -- the targeting of the energy of a beam of charged particles on a tumor -- can save the eye and preserve at least partial eyesight in about 90 percent of all patients. Importantly, cancer is no more likely to recur after radiotherapy than after surgical removal of the eye. This technique was pioneered at LBL and the Harvard Cyclotron and has now spread to facilities in more than 10 countries around the world.
Another current alternative treatment involves the temporary surgical implant on the surface of the eye of a plaque containing radioactive seeds. As it destroys the tumor, the implant also damages healthy surrounding tissue.
A proton beam, on the other hand, can be calibrated and shaped to deposit much of its radiation dose in a three-dimensional space that coincides with that of the tumor. This is possible because of the unique properties of charged particles (such as protons). Targeting the energy dose is particularly valuable when the lesion lies close to the optic nerve, as it does about 40 percent of the time.
Like x-rays, charged particles have the ability to pass through tissue. However, whereas x-rays begin to give up their energy immediately upon encountering tissue, charged particles deposit almost all of their energy or radiation dose where they stop. This stopping point depends upon the energy of the beam and can be precisely manipulated using a beam delivery system developed at LBL.
Dr. Devron Char, head of UCSF's Ocular Oncology Clinic, is the referring physician to the Davis clinic. As of this week, ten patients with uveal melanoma have been treated at the new facility.
These patients travel to UCD for a succession of four treatments that take place over as many days. The patient's eye is anesthetized and the dose of proton energy is administered without pain over about 90 seconds.
With the launching of the UC Eye Program at Davis, LBL's own clinical radiotherapy program will become part of medical history. But what was learned lives on in the patients who will be treated at Davis, and in the numerous new charged particle treatment facilities around the world that LBL is helping to develop.
LBL is a national laboratory that conducts unclassified scientific research for the U.S. Department of Energy. It is located in Berkeley, California, and is managed by the University of California.
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