Low radiation during CT scan can lower cancer chances

New Delhi: Low radiation during computed tomography (CT) scans can reduce the chances of cancer in patients undergoing treatment, doctors here said on Thursday.

They said that up to 10 percent of invasive cancers are related to radiation exposure during CT scan.

"Whenever a person undergoes an imaging test, a quantum of radiation emitted gets deposited and probability of occurrence increases. At the same time, whenever a person receives less radiation, the chances of radiation-induced cancer decreases," said T.B.S. Buxi, chairperson of department of CT and MRI at city-based Sir Ganga Ram Hospital.

He said that people should avoid unnecessary CT scans or other imaging tests as the more people are exposed to radiation, the greater is their lifetime risk of contracting cancer.

He emphasized that instead of undergoing CT scan, the patient should enquire if there is a real need of CT scan or their problem could be managed without it.

Sir Ganga Ram Hospital has come up with a new low dose of iterative reconstruction technique for imaging. It has been found that this scanner leads to significantly reduced radiation doses.

The hospital also conducted a study, as part of which 986 patients' scans were evaluated and an average dose reduction of 33.2 percent in thorax, 32.455 percent in abdomen/pelvis and 49.706 percent in head examinations was achieved.

The doctor said that CT and MRI are used in the diagnosis of cancer and also to follow-up on patients on treatment. Magnetic resonance imaging has no radiation potential.

Samarjit Singh, consultant in the department of CT and MRI at SGRH, said: "The risk of developing cancer after a CT scan is approximately 1 in 2,000 (according to the US Food and Drug Administration) and more so in children, who are more sensitive to radiation."

According to radiologists, a human being should not receive more than 5 millisieverts (measuring unit) of radiation a year. A CT scan, however, expose humans to far more radiation.