Risk vs. Reality:
Radiation therapy and safety

How a ‘Phantom’ — and a culture of vigilance — help keep patients safe.


Since recent media stories shone a spotlight on errors made in radiation therapy, patients might question the risk of undergoing such treatment. Experts at Fox Chase and elsewhere talk about the realities of this valuable therapy and how to ensure that patients—and practitioners—play it safe.

Alain Guemnie Tafo

(photo: Justin Hunt)

It’s 10 p.m., but Alain Guemnie Tafo’s workday isn’t over. In a room on a lower floor at Fox Chase, the tall postdoctoral researcher leans intently over a form lying on a treatment table. He rests one hand on it lightly while adjusting a handheld controller with the other. A turn of a knob brings a red light beaming from the open eye of the machine arching over him: a new, state-of-the art linear accelerator, one of just a few of its kind in the country.

Guemnie Tafo doesn’t have to remind his patient to stay still. As on many evenings, his subject tonight is “the phantom,” a sophisticated dummy, of sorts, that’s shaped like a human torso and contains an array of radiation sensors.

A postdoctoral researcher training to become a medical physicist, Guemnie Tafo is running a quality control test— essentially, a dry run of a treatment a real patient will receive the following day. A computer printout verifies that the regimen is executed precisely as specified by the treatment plan.

It’s one of many steps in a system designed to ensure the safety of patients undergoing radiation treatment at Fox Chase.


The safety of radiation therapy has come under public scrutiny since recent high-profile media coverage revealed treatment errors that led to patient injuries, and even some deaths. A February New York Times story drew attention to incidents of radiation errors in New York, detailing the harrowing stories of severely overradiated patients. The preceding June, the newspaper had reported on a Philadelphia veterans’ hospital that administered incorrect radiation doses to 97 of 114 veterans with prostate cancer.

Such disturbing cases might prompt some patients to wonder whether they should undergo treatment. Eric Horwitz, chairman of radiation oncology at Fox Chase, has an answer: Yes. “Radiation therapy is safe more than 99.9 percent of the time,” he says, adding that while he applauds the Times articles for bringing attention to lapses in safety, “it would be tragic if they led patients to fear needed therapy.”

Even the Times attests to the rarity of errors: It identified 621 mistakes in the state of New York, which it described as “a leader in monitoring radiotherapy and collecting data about errors,” between 2001 and 2008. According to the American Society for Radiation Oncology, 13.6 million radiation treatments were performed in the state during that period, which means errors occurred just .0046 percent of the time. Moreover, the Times noted that of the errors, “most were minor, causing no immediate injury.”

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Make no mistake: Radiation oncology is a rapidly evolving, highly technical field populated by increasingly powerful, complex equipment. The good news is that those tools deliver more precise treatment, often in a shorter time and with fewer side effects. But it’s imperative, experts say, that they are operated by a properly trained staff, that patients are appropriately monitored, and that treatment facilities have safety checks in place.


A staple in cancer treatment for more than 100 years, radiation therapy consists of high-energy radiation from sources such as X-rays, gamma rays, neutrons, and protons that kills cancer cells by damaging their genetic material. Today, about half of all cancer patients receive radiation therapy, often in combination with chemotherapy or surgery. Three primary types are in use:

  • External beam radiation therapy, the most common form, uses a machine such as a linear accelerator to direct beams at the tumor from outside the body. Methods such as three-dimensional conformal radiation therapy, or 3D-CRT, and intensity-modulated radiation therapy, or IMRT, target tumors precisely with the help of sophisticated computer software.
  • Brachytherapy involves implanting tiny radioactive “seeds” in or near the tumor, where they deliver a continuous dose of radiation. The practice is commonly used to treat cervical, prostate, and skin cancers.
  • Systemic radiation therapy entails the patient swallowing or receiving an injection of a radioactive substance such as iodine. It is typically used to treat or manage thyroid or bone cancer.

While no single agency oversees all aspects of medical radiation, it is nonetheless a highly regulated field, with state and federal agencies setting safety standards for hospitals and physicians. In Pennsylvania, for instance, the Department of Environmental Protection (DEP) requires biannual site inspections and has rigid standards for reporting mistakes.

Problems like those at the veterans’ hospital occur when safety regulations aren’t followed, says W. Robert Lee, a professor of radiation oncology at Duke University School of Medicine, who testified on the matter in July 2009 before the U.S. House of Representatives’ Committee on Veterans’ Affairs.

“I agree with the federal investigators who concluded that quality management practices were ‘deficient,’” he says. “In short, the ‘culture of safety’ that we in radiation treatment strive for was not accomplished. My hope is that patients…will recognize that the situation at the Philadelphia VAMC is an isolated incident.”

In contrast, Horwitz says, some institutions go “above and beyond what’s required when it comes to assuring patient safety.” He places Fox Chase—home to one of the largest academic radiation therapy departments in the country— firmly in that category.

So does Fox Chase radiation safety officer Karen Sheehan, who characterizes the Center’s safety record as “stellar— among the cancer treatment community’s best.”

“We’re wholly committed to maintaining patient safety,” Sheehan says.

Fox Chase has been recognized as one of the top NCI centers in the country for radiation therapy and safety standards, and Horwitz and his colleagues consult on safety issues at other institutions.

The Center’s recipe for success? A culture of vigilant, proactive monitoring, and multiple layers of safety checks.

Take the phantom. Whenever a patient is to undergo intensity-modulated radiation therapy, an advanced and highly precise form of external beam therapy, a phantom serves as test subject. While most hospitals employ the practice only when first using a new machine, Horwitz says, Fox Chase is dedicated to the practice. “Fox Chase has done it for every single one of our 5,000 IMRT patients for the past 11 years,” he says, “and we will continue to do so.”

The department also voluntarily developed its own internal tracking and reporting system to identify errors, catching any small mistakes—the kind that have no impact on the patient—before they can develop into anything serious. The department uses the system, which has earned praise from the DEP, as an educational tool, revisiting any missteps to ensure they don’t occur again.

In addition, multiple radiation therapists must be present at all times during treatments. “We never have people treating patients by themselves,” says Robert A. Price Jr., chief clinical physicist, who oversees the technical aspects of treatment planning and delivery. “One person could think ‘4’ and enter ‘8’ that day; the other person is there to guard against that type of human error.”

And while Fox Chase is a longtime leader in the advancement and use of leading-edge radiation technology, Price says, it is also committed to adopting those technologies carefully and sensibly. He recalls a recent case in which the Center obtained a new machine that promised faster, more precise treatment. Despite urging by the manufacturer to begin using it immediately, the department waited until several months of testing and dry runs had proven the equipment sufficiently reliable and efficient for use with patients.


Radiation therapy is, on the whole, a safe practice. As Lee puts it, “Your odds of beating cancer with the help of treatments like radiation therapy are significantly greater than being harmed by a mistake.”

“Your odds of beating cancer with the help of treatments like radiation therapy are significantly greater than being harmed by a mistake.”

Nonetheless, it’s worth paying attention to safety. Analysis of the tragic cases detailed in The New York Times reveal they did not happen purely by chance, just as Fox Chase’s safety record is no accident. Patients can do more than cross their fingers and hope they’re not among the unlucky; Horwitz suggests they use a critical eye when selecting a treatment provider.

“The key is for patients to select an institution with multiple checks and balances, adequate staffing, and technical staff onsite to assure the equipment is functioning correctly,” he says.

He suggests patients ask questions such as:

  • Does the radiation therapy team radiate a test “phantom” before administering treatment?
  • How are implanted brachytherapy seeds monitored to ensure proper placement and delivery of therapy?
  • Do multiple radiation therapists attend the machines so that no one is treating the patient alone?
  • Are there full-time physicists, engineers, and information technology staff onsite to ensure that equipment functions properly?

And with a radiation oncology department, as in other areas of medicine, staff experience, patient volume, and department size are also relevant.

Once they’re comfortable that they’re in an environment committed to safety, patients should be confident in their radiation therapy and be able to focus on the matter at hand: becoming well.


For more information on radiation therapy:

Fox Chase Radiation Oncology www.fccc.edu/physicians/radiation • 1-888-FOX CHASE (1-888-369-2427)

American Society for Radiation Oncology

www.rtanswers.org • 703-502-1550 National Cancer Institute

www.cancer.gov • 1-800-4-CANCER (1-800-422-6237)


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