Doctors take a CAT scan of the cancer tumor and a computer directs the angle and intensity of the radiation beam.A prominent Israeli doctor at the prestigious Memorial Sloan-Kettering cancer clinic in New York played a major role in the development of a treatment technique for prostate cancer that has contributed significantly to helping control the disease.

Radiation oncologist Dr. Zvi Fuks is credited by the developer of the system, Varian Medical Systems of Palo Alto, Calif., as being the leader in overcoming clinical resistance to the system at Sloan-Kettering, a hospital that helps set the standard for cancer care throughout the world. Studies conducted in the United States five years after treatment with the Varian program have shown that the success rate for curing prostate cancer improved from 46 percent to 92 percent and the rate of complications declined from 6 percent to 2 percent.

Fuks, now deputy physician-in-chief of planning and holder of the Alfred P. Sloan chair at Sloan-Kettering, was convinced of the effectiveness of the treatment technique and drove his staff to learn to use the system within six months versus the 18 months the hospital had originally planned.

Fuks was raised in Israel and received his medical training at Hebrew University-Hadassah Medical School in Jerusalem. He was on the staff at Hadassah Hospital in Tel Aviv in the 70s, following a stint at Stanford University Medical Center in California and prior to joining Sloan-Kettering.

“It takes a true leader to put the whole process in operation and make it happen and he did that,” said Richard Levy, president and chief executive officer of Varian Medical Systems. “He inspired the hospital, inspired his staff to do all the testing and clinical work, and has contributed to making a lot of people’s lives better.”

Fuks was also a key member of a team of advisors to the program who began working with Varian in 1988 to develop ways to increase the radiation reaching diseased tissue and minimize the impact of the radiation on surrounding healthy tissue, Levy said.

At the beginning of the treatment, called IMRT or Intensity Modulated Radiation Therapy, doctors take a CAT scan to determine the size and shape of the cancer tumor. The software programmed into the system directs the pulses of radiation and the correct levels of radiation according to doctors’ directions based on analysis of the size and composition of the tumor.

The computer arranges a series of panels in the machine that block radiation to healthy areas and allow the radiation to penetrate to the cancerous areas. The system also allows doctors to increase the level of radiation directed at the cancerous tissue by as much as 20 percent without fear of doing unacceptable damage to the healthy tissue.

IMRT is a major improvement on older technology whereby technicians create a block with a hole in it that is the same shape as the tumor. The technique requires a custom-shaped block for each beam angle.

“Before you had a big, even dose of radiation, which led to higher levels of complications when you started stepping up the dose,” said Varian spokesman Spencer Sias. “Now you can stay outside the room and modulate the amount of time, modulate the intensity of the dose, and treat from four or five different beam angles.”

About 60 percent of cancer patients in the United States receive some form of radiation therapy. Two-thirds of them receive the treatments in an effort to completely cure the disease, while the other third is treated as a means of prolonging their lives.

About 3,600 of the machines made by Varian, which cost about $1 million apiece, are in use in about 10 percent of hospitals worldwide, with a high concentration in the United States, Israel and Saudi Arabia, according to Levy. The company now has about 60 percent of the orders for new machines, compared with 40 percent divided between two competitors, German-based Siemens and Elektra, a Swedish firm.

“Israel is among the most advanced countries in the world in radiation treatments,” Levy said. “Japan is not well equipped, and someone receiving treatment in Britain is really unlucky, since the equipment there is frightfully outdated. The British health care system is aware of this and has now decided to invest $100 million in upgrading the radiation therapy equipment in hospitals throughout the country.”