After highlighting limitations in screening for lung cancer, Philippa Cheetham, MD, and Kim L. Sandler, MD, review some of the new technology in development to improve detection.
PUBLISHED November 13, 2017
Philippa Cheetham, MD: Now, we’ve come a long way with imaging. It’s an exciting time to hear about these newer machines, newer interpretation and being able to cut down on radiation. But by the time a tumor is visible to you on CT scan, the tumor is already composed of millions of tumor cells, yes?
Kim L. Sandler, MD: Yes.
Philippa Cheetham, MD: Do you think that in 10, 15, or 20 years, lung cancer specialists will be looking back laughing and saying, “Well, they couldn’t even detect it until they saw a blob of cancer on a CT scan.” We’re still quite advanced in the disease process by the time you actually see a lump of cancer on a CT scan. Is it really as sophisticated as we think?
Kim L. Sandler, MD: I think it is. I certainly hope we get there in 10 or 15 years, where we can take someone’s blood and tell them they have lung cancer without ever having seen an abnormality in their chest. I think when that happens, the advances in imaging will start to change, and we’ll be looking for other things. One of the things that we see often in patients are changes in their lungs as a result of their treatment, and it’s really important to be able to follow those things and to understand what sort of toxicity they may have, where imaging is the only indication of that happening. So, I do think that we are going to become much more sophisticated in early detection of cancer and that the role for imaging will continue to evolve.
Philippa Cheetham, MD: We’re hearing a lot about how we can give patients injections, markers, that will travel through the bloodstream and attach to tumors to make it more obvious to the naked eye when you’re looking at somebody’s CT scan. Do you think there’s any future in patients being given injections that may light up these lesions that are there so that they’re much more obvious for you to see on CT scan? Is that the way this may go?
Kim L. Sandler, MD: I think it will continue to evolve. We’ve been doing FDG [fludeoxyglucose] PET imaging in nuclear medicine, looking for glucose uptake in tumors and how metabolically active the disease is. The problem is it’s very nonspecific, so anything that shows extra activity—like a fungal infection or even if a patient has had a type of trauma, a fracture that’s healing—will show increased metabolic activity. What’s really exciting is that we’re starting to see more specific antigens that can go and detect tumor cells rather than just the metabolic activity itself. And we’ve already seen that in various types of cancers and in some forms of lung cancer. I think that those areas are going to continue to grow.
Philippa Cheetham, MD: Do you have any secrets to share with us from the research world of imaging, where you know what’s coming down the line that’s not yet being used in routine clinical practice that you're excited about that are going to come into our clinical arena just around the corner?
Kim L. Sandler, MD: Oh, absolutely. There’s a whole field of radiomics that people are really excited about, and what that does is allow a computer to actually look at a nodule or an abnormality and evaluate the way that the contours of the nodule interact with the surrounding lung parenchyma. It can use things like machine learning, where you look at tens of thousands of different examples of benign and malignant disease and try to find imaging biomarkers that can tell you whether or not something is cancer without having to watch it grow. So, the idea is that you can have a scan, use this radiomic evaluation, and—based on the morphology of the nodule that’s not visible to the eye, but can be detected with the newer technology—we’ll be able to tell a patient even without a biopsy if it’s cancer.
Philippa Cheetham, MD: Before we talk a bit about the advances in treatment, the CT scan is what you often use to target the needle for biopsy. Has it made your biopsy detection rate more accurate because your imaging is better?
Kim L. Sandler, MD: What’s really great is that some of the newer CT scans that are used primarily for procedures are able to do both CT imaging and fluoroscopic imaging. So, it used to be that we would obtain an image, we would place a needle, we’d have to step outside the room, get another image, go back inside the room, and advance the needle. Now, with a patient having 1 breath hold, we can use the fluoroscopic technology and advance the needle without having to leave the room. That makes us much more accurate and the patient can better tolerate the procedure.
Philippa Cheetham, MD: There are lots of exciting developments in imaging, and it sounds like these are becoming more and more standard of care across the country, not just in centers of excellence, yes?