SCIENTISTS have warned that multiple Computerised Tomography (CT) scans in childhood can triple the risk of developing brain cancer or leukaemia. The warning is contained in a new study published in The Lancet yesterday.
An earlier study published in the medical journal Radiology showed that people who undergo numerous CT scans over their lifetime might be at a significantly increased risk of cancer.
In Nigeria, there are also concerns about the cost of the procedure, which requires at least four exposures to get a good result, and the rate at which most hospitals in Nigeria are procuring the high-tech equipment.
The Guardian learnt that in Nigeria, one CT scan session costs N40,000 in government hospitals and over N80,000 in some private hospitals that have it.
However, researchers suggest physicians should review a patient’s CT imaging history and cumulative radiation dose when considering whether to perform another CT exam.
Meanwhile, Prof. Francoise Barre-Sinoussi who won a Nobel Prize for her work in first identifying Human Immuno-deficiency Virus (HIV) told the British Broadcasting Corporation (BBC) she at last believes finding a cure for the virus, which causes Acquired Immune Deficiency Syndrome (AIDS), might be possible.
Barre-Sinoussi said she could not put a timescale on when it might be found but scientists were developing promising new tools.
Over 30 million people have died from HIV/AIDS since it was first identified in 1981.
CT scan is an X-ray procedure that combines many X-ray images with the aid of a computer to generate cross-sectional views and, if needed, three-dimensional images of the internal organs and structures of the body.
A CT scan is used to define normal and abnormal structures in the body and/or assist in procedures by helping to accurately guide the placement of instruments or treatments.
The authors of the study in the The Lancet emphasised that the benefits of the scans usually outweigh the risks. They said the study underlined the fact the scans should only be used when necessary and that ways of cutting their radiation should be pursued.
During a CT scan, an X-ray tube rotates around the patient’s body to produce detailed images of internal organs and other parts of the body.
In the first long-term study of its kind, the researchers looked at the records of patients aged under 21 who had CT scans at a range of British hospitals between 1985 and 2002.
Because radiation-related cancer takes time to develop, they examined data on cancer cases and mortality up until 2009.
“The important thing is that parents can be reassured that if a doctor in the UK suggests a child should have a CT scan, the radiation and cancer risks will have been taken into account,” the study said.
The study estimated that the increased risk translated into one extra case of leukaemia and one extra brain tumour among 10,000 CT head scans of children under 10 years. CT scans are useful for children because anaesthesia and sedation are not required.
This type of check is often ordered after serious accidents, to look for internal injuries, and for finding out more about possible lung disease.
On why CT scan is being used more frequently, a public health physician and Chief Medical Director of Lagos University Teaching Hospital (LUTH), Idi-Araba, Prof. Akin Osibogun, told The Guardian: “A skull X-ray, a CT scan and a Magnetic Resonance Image (MRI) of the skull give extremely different diagnostic accuracy. While the X-Ray costs about N10,000 and the CT some N40,000, the MRI costs about N90,000.
“The experts have convinced me that a single CT scan or MRI may not conclude the diagnosis! There was this young man who was involved in an accident. A CT scan of the skull had shown no skull fracture or any obvious damage to the brain but he got progressively worse over the next 24 hours and thereby compelled a repeat CT scan. Lo and behold, a massive sub-dural haemorrhage was discovered. A small vascular damage was thus not detected by the first scan and gradual but definite bleeding into the sub-dural space had continued and became massive enough to compress brain tissue.”
Osibogun added: “Neurosurgeons have now informed me that repeated CT scan is required in head-injury patients if we are to make prompt diagnosis and early treatment. A total of about four scans within 24 hours can help physicians monitor a patient reasonably well to pick up any incipient bleeding into the brain. The average Nigerian patient pays out of pocket directly for health care services and most of the time, either does so grudgingly or simply cannot afford the costs. Agreed, N160,000 for only four CT scans is no small money for an individual to pay within any economy but certainly, it cannot be the responsibility of the doctor to pay for the patient.”