Chest CT scans: Are they being used indiscriminately and should you worry about the radiations?

The second wave saw an overwhelming number of people rushing for chest scans, many of them not even prescribed by doctors but recommended by family and friends who believed chest CT scan can more accurately determine the damage caused by COVID. AIIMS director Dr Randeep Guleria had warned people earlier this month about this indiscrimate use of CT scans. He said, “There is a lot of misuse of CT scans and biomarkers. A lot of people are doing CTs the moment they test positive. There is no point in doing it for mild positive cases. Even asymptomatic people will have some patches and they go away without treatment. If you have a mild illness and oxygen saturation is good, there is no point in doing a CT scan."
Many even used their CT scans to prove their COVID positive status in absence of a positive RT-PCR report. Talking about the importance of CT scans, Dr. S.P Rai- consultant, Pulmonary Medicine and Sleep Medicine at Kokilaben Dhirubhai Ambani Hospital said, “Chest CT scans play a very important role in diagnosis and management of COVID-19, but it should not be used indiscriminately. Chest CT scan is not indicated as a routine screening modality due to the poor sensitivity and specificity.”

When should you get a chest CT scan

According to Dr Rai, chest CT scan should be done in the following cases
(a) COVID-19 suspects who have got significant respiratory symptoms but swab is negative for RT-PCR and have normal / indeterminate chest X ray.
(b) COVID-19 positive patients who show sudden AND / OR unexplained clinical deterioration
(c) Patients with suspicion of pulmonary embolism, pneumomediastinum or pneumothorax.
(d) Patients with suspicion of other concurrent lung disease requiring change in treatment.
(e) Patients who are at risk of disease progression such as age>65 yrs, associated comorbidities like Diabetes, chronic lung disease, hypertension, immuno - compromised state..
(f) Post COVID patients having low SpO2 and decreased lung capacity; to evaluate and manage lung fibrosis.

Use and misuse

Dr Rai adds, “When done in the above mentioned scenarios, it is useful in decision making and treatment, however they constitute only a small proportion of patients. CT scan as a routine screening in COVID-19 is not recommended because if it is done early, 15%-50% patients with COVID-19 may have normal chest CT, leading to incorrect interpretation, including inappropriate isolation, disease management and quarantine recommendations. There is no point in doing a CT scan early in the course of COVID-19 with mild severity, as such patients can have ground glass opacities in the lung, which do not merit specific treatment and will resolve on their own.”

Will the radiations have worrying after effects?

With patients undergoing 2-3 chest CT scans during the course of their COVID treatment, should one be worried about the after effects of the radiation exposure of the scan? “Indiscriminate and multiple CT scans expose individuals to unnecessary radiation, which could be harmful in the long run. It can increase the risk of cancer, later on in life. When required, CT scan should be performed with a low dose, single phase protocol using fast scanning techniques to decrease the radiation hazards.”

Dr. Lancelot Pinto, Consultant Pulmonologist and Epidemiologist, P.D Hinduja Hospital shared, “The other day, a woman came to me for a second opinion. She was breastfeeding a nine month old baby. Now, when you're breastfeeding, your breasts are hypertrophied, they're grown in size and that is supposed to be a fertile ground for radiation causing damage to the body. Worldwide there are clear guidelines about how lactating women should not have CT scans, unless needed. And this woman had two scans already and the doctor asked her to get the third scan.”

CT scans should be used judiciously. “We should not overplay the effects of radiation if the scan is going to help us diagnose something of importance. The problem is that many people are now using it indiscriminately and one shouldn’t be exposed to radiation with no gain. That’s unacceptable,” Dr Pinto concluded.