CT-Based Imaging Demonstrates Utility for Early COVID-19 Identification in Lung Cancer

Graham Warren, MD, PhD

Routine computed tomography (CT)-based imaging scans identified abnormal ground-glass opacities and infiltrates indicative of COVID-19 in patients with lung cancer undergoing radiation therapy, enabling earlier diagnosis, treatment, and risk reducing measures, according to a report published in the Journal of Thoracic Oncology.

“If we see the new appearance of patchy infiltrates or areas that look abnormal in the lungs in a patient [who] we’re getting daily or weekly imaging on, in the setting of COVID-19, we may see those imaging changes before patients become symptomatic, which gives us the opportunity to say this is an unexpected change,” said lead study author Graham Warren, MD, PhD. “We may need to test this patient for COVID-19 to see if they have a diagnosis, and that’s a practical utility to trying to identify patients who are at risk for complications from treatment, but it also is a way for us to try and identify patients with the risk of spreading COVID-19 to other patients with cancer.”

In an interview with OncLive®, Warren, a professor in the College of Medicine and Department of Radiation Oncology at the Medical University of South Carolina, discussed the basis for the study and the significance of the findings.

OncLive^®: What was the impetus to evaluate non–cancer related imaging findings of patients with undergoing radiation therapy?

Warren: This came up because COVID-19 really took hold of us internationally, nationally, and certainly in the cancer treatment space. We had a submission come to the Journal of Thoracic Oncology that demonstrated patchy infiltrates on cone beam CT or radiotherapy set-up images. It looked like there was a relationship between seeing these daily images [conducted] for treatment and diagnosis of COVID-19, and this was early in the pandemic.

We made a call for submissions and case reports from centers around the world to see whether there was a relationship between imaging findings and COVID-19 diagnosis in patients undergoing radiation treatment. It’s not something you can design a trial around, but it was certainly something we wanted to find out to see whether there was a way that we could link the 2 to assist with risk identification, mitigation, and identification of COVID-19 in our patients with cancer during treatment.

What was the objective of this research, and what makes the report unique?

The goal behind it was to try and find out if there was consistency between imaging findings and a diagnosis of COVID-19. It certainly seemed like it was a very common thing to see these patchy infiltrates in patients with COVID-19. One of the things we really wanted to see was real-world experience––what radiation oncologists were seeing in cancer treatment with their imaging systems and with their diagnoses. What’s reflected is real-world experience of what happens with patients during cancer treatment, which makes [the report] really kind of unique. It wasn’t set up as a clinical trial with rigorous controls but rather adaptations around COVID-19 and the changes in our cancer care, which really reflects what’s happening right now.

What is the significance of the findings?

Radiation oncologists can see the utility behind this pretty clearly. When a patient is diagnosed with cancer, we want to make sure we hit that target as accurately as possible when we treat with radiation. Imaging is something we use to try and make sure we hit the right target, and CT-based imaging is very common, especially for cancers that are in the chest.

In a real-world setting, this is something we can use with our daily imaging to see if there are changes that suggest a patient is at risk for having COVID-19 and should get tested.

Could this type of surveillance be done for COVID-19 variants or other types of viruses or infections that patients might be at risk for?

With the Delta variant, a lot of the symptoms that we have now are different than what we saw with the original variants, such as more sweats and more body aches, but not as many pulmonary symptoms. As the coronavirus mutates and continues to develop new variants, there could be variants that have more severe or less severe pulmonary symptoms. The utility of this [surveillance], even in the context of COVID-19, could change as variants arise.

In the context of other diseases, certainly, it’s theoretically possible that there could be relationships, but we haven’t had correlations like this before with other traditional viruses. I’m not aware of any studies that have looked at this for things such as the seasonal flu or colds. I don’t know that the utility is there for other viruses and infections. Certainly, we have times where we see opacification or changes on those CT scans that we do daily that can identify pneumonia, for instance; we have seen that. Certainly, oncologists should be aware of that, but these subtle findings with patchy infiltrates are kind of unique, and something that, in the context of COVID-19, may be very helpful.

What is one main insight you’d like to share from this work?

This is something that almost happened by accident. If authors had not submitted original reports showing these patchy infiltrates, this study probably would never have been performed. This is what you could probably call a rapid adaptation for real-world experience in our patients. A lot of things have happened with COVID-19 like that where we’ve had to learn how to adapt to diagnoses and management for most outpatients and inpatients. I anticipate we’re going to continue to have to learn and adapt with COVID-19 as it evolves.

This is a fairly unique study, and one that may be replicated with larger series. It’s a need-based assessment, which really reflects international collaboration and adaptation to what our patients with cancer need, which is a really nice thing to see.

I anticipate that COVID-19 could continue to change and is certainly going to remain in our population. As symptoms continue to change with different variants, we’ll need to be aware of that in the cancer space, and how it affects not only the diagnosis and treatment of our patients, but also how we monitor [patients], adapt to improving patients’ outcomes, and reduce the risk [of contraction] for our other patients with cancer.

Reference

1. Warren GW, Lim VS, Chowdhary M, et al. New pulmonary infiltrates observed on computed tomography-based image guidance for radiotherapy warrant diagnostic workup for coronavirus disease 2019. J Thorac Oncol. 2021;S1556-0864(21)02232-2. doi:10.1016/j.jtho.2021.06.005