Some cancer patients would like more information on the health risks of their radiology tests, a new study found.

Most of the 30 patients questioned for the study said they looked online for information about the radiation hazards of tests like computed tomography (CT) scans, since their doctors did not explain the risks.

“Before completing this study, I believed I understood what patients may wish to know and how to provide that information to them,” said Dr. Raymond Thornton, the study’s lead author from Memorial Sloan-Kettering Cancer Center in New York City.

“As we analyzed nine hours of participants’ conversation, however, it became clear that a wide range of personal preference exists regarding what information is desired and the optimal way to transfer that information,” Thornton told Reuters Health by email.

Imaging techniques like X-rays, CT and positron emission tomography (PET) scans expose patients to ionizing radiation, which damages DNA and can lead to cell death or mutations that can increase the risk for later cancers.

The benefits will almost always outweigh the risks when an imaging procedure is performed for an appropriate reason, Thornton said.

In cancer patients, "even negative or normal results add essential information to clinical care,” he said.

For the study, a trained specialist moderated small 90-minute focus groups in 2012, asking open-ended questions.

Altogether, 30 patients with varied types and severities of cancer participated. They were a unique group, 80 percent white and 90 percent with a college degree, the authors write in the journal Radiology.

It may be that among the general population of U.S. cancer patients, knowledge and interest in this topic is different, the authors caution.

Knowledge of which imaging methods involve ionizing radiation and which do not, and how these tests differ from the radiation used for cancer treatment, varied greatly between patients.

The participants were generally grateful for the benefits that the imaging tests provide but were concerned about the cumulative risks of having several scans. They would have liked their doctors to explain in more detail which tests were being ordered when, and their associated risks.

Patients generally preferred to have these discussions with their personal physician and believed that the time constraints of office visits make that difficult.

“Our findings portray a gap between current practice and what patients say they want,” Thornton said.

Creating scripts and educational tools for doctors who aren't radiologists to facilitate discussions is one way to bridge that gap, he said. Written materials, including trusted Internet sources, that address patient concerns is another.

There is no mechanism in schools, government sources, healthcare establishments, or non-government organizations to teach people how to think about health risks or to assess their own risk, said Janet Busey of the radiation department at the University of Washington in Seattle.

“Although the individual radiation risks for diagnostic imaging scans are small, they need to be communicated to patients,” Busey, who wasn’t part of the new study, told Reuters Health by email.

“The 'benefit vs. radiation-risk' issues are generally different in terms of CT scans for patients who are (or were) being treated for cancer, as opposed to CT scans on individuals who do not have cancer,” said David J. Brenner of the radiation oncology department at Columbia University Medical Center in New York City.

“For example, in many situations for cancer patients, long-term follow-up with CT scans is absolutely essential,” said Brenner, who was not part of the new study. “By contrast there are situations among non-cancer patients where there are options as to whether to do a CT scan or to do another type of exam.”

Doctor-patient communication issues in the study are likely common to both cancer and non-cancer patients, he noted.