Annual screening for lung cancer low-dose CT

This is a major advance as American healthcare evolves from reactive to preventive.

But a key to success in this lung cancer screening program is keeping the radiation dose of each exam as low as possible – certainly well below one mSv. Ideally, a low dose approach would involve model based or some other form of iterative reconstruction. All the other techniques to minimize dose should be employed together. Fortunately, this is an application where very low kVp will work well (70-100).

Next – and possibly even more impactful: coverage for screening CT colonography.

Risk Model Emerges for CT Lung Cancer Screening!

A new risk model for lung cancer was recently highlighted in the August 21 issue of Annals of Internal Medicine. According to the report, the Liverpool Lung Project (LLP) risk model was developed to determine, based on specific and sophisticated assessments, which individuals would benefit most from CT lung screening.

The LLP risk model has a strong ability to predict lung cancer, and, according to principal investigators, does so better than smoking duration or family history. In fact, this data has been confirmed by researchers from the University of Liverpool, as well as several U.K. centers, the U.S. National Cancer Institute, and the Harvard School of Public Health.

Unlike some other major diseases, like breast cancer and heart disease, lung cancer, thus far, has lacked adequate identification tools to determine which patients should be targeted to maximize screening benefits, and minimize its potential harms. Identification of those with the highest risk for lung cancer, a disease which now kills upwards of 1 million annually, will make the best use of the benefit-harm ratio.

Though other risk models have been created, none have been able to successfully apply to all of the world’s population. The LLP could overcome these challenges, though, as it accounts for important risk factors that others skip, including history of pneumonia, non-lung cancer, and asbestos exposure, among family history and smoking history.

The model certainly appears a good way to improve patient selection. As always, the key inscreening exams is to do no harm. Even for those patients deemed appropriate for screening by the LLP, the best approach is with ultra-low dose CT— such as done with model based iterative reconstruction.

To learn more about the LLP, please click here!

Emphysema Found on CT Scans Points to Increased Lung Cancer Risk

That there are strong associations between smoking and emphysema and smoking and lung cancer is well established. Therefore, it’s of little surprise that a report from Lung Cancer finds emphysema that is visible to radiologists from CT scans is correlated with an increased risk of lung cancer.

However, these results were only discovered when the emphysema was read by radiologists— and not by computer interpretation. Researchers point out that radiologists and automated computer software likely detect different types of emphysema- with only doctors appearing to detect the type of emphysema associated with lung cancer. This clearly highlights the “intuition” factor in scan interpretation by experienced radiologists—a factor not yet evident in intelligent computers!

Patients that are found to have emphysema detected by CT scans are already at an increased risk of developing lung cancer and should quit smoking as soon as possible. It is interesting to remember that before cigarette smoking became widespread, both lung cancer and emphysema were exceedingly rare diseases. Those high risk patients should explore the benefits of lung cancer screening and lung cancer screening programs.

For more information on the benefits of lung cancer screening, please see here.

New Research Further Dispels Fear of Over Diagnosis in CT Screening

According to a new study based on the International Early Lung Cancer Action Program (I-ELCAP), lung cancers identified in low-dose CT screening programs are similar to those identified by non- screening means. The research results, which were released on March 27 in Radiology, further alleviate concerns that cancers detected through low- dose CT screening are less aggressive than those found through other means, and therefore demand less attention and resources.  In fact, the frequency of small-cell carcinoma and adenocarcinoma were similar for cancers detected through screening programs and outside the screening setting.

This study is another brick in the wall of evidence building for the value of low radiation dose CT lung cancer screening in high risk asymptomatic smokers. Regardless of whether nodules are solid or “ground glass” (non-solid), growth occurs that is similar in the screened populations and in those detected of having lung cancer due to symptoms.

While it is true we do not yet have a data-based analysis of costs versus quality life years saved, the evidence that screening is worthwhile continues to become stronger. “The CT scanners we have now are really phenomenal,” with resolution that continues to improve as the radiation dose falls, “so that the amount of information you can get out of them for emphysema, for coronary artery risks, and so on, continues to increase,” says Dr. Claudia Henschke, lead author of this study.

She goes on to point out that cancers detected via low dose CT screening “are real cancers that would kill you if they weren’t discovered early, so it kind of underscores again the data that we had shown in ELCAP and that NLST (National Lung Screening Trial) has shown — that screening for lung cancer saves lives.” And that is the key takeaway.

NCCN Confirms Importance of Lung Cancer Screening

Recently, the National Comprehensive Cancer Network has come forward in favor of lung cancer screening with low-dose CT. The NCCN is the first professional organization to perform the comprehensive review and update their recommendations to promote lung cancer screening.

This update further validates the key concept that high risk patients benefit from screening. High risk patients for lung cancer diagnoses are those who are multiple pack year smokers for 25 of more years. For these individuals, low- dose CT screening reduces the number of lung cancer deaths by 20 percent.

While we don’t really know the full cost of a screening program – such as the costs of working up false positive CT findings,  the benefit in lives saved seems to justify considering screening now.

Fortunately, the CT technique for screening is low dose and involves low radiation dosage.

New Data on Lung Cancer Screening Shows Low Dose CT Saves Lives

Earlier this year, I wrote a blog entry about the news surrounding an important study involving CT and lung cancer screening. Now, the same study is making big headlines again as stronger (final) findings have been released. According to CNN, the study found that “low-dose CT screening reduces the number of lung cancer deaths in high risk smokers by 20 percent.”

Here’s another interesting fact coming out of the latest data: In high-risk populations, lung cancer CT screening can save a life for every 300 people screened. That’s more potential lives saved than mammography, colonography and prostate cancer screening COMBINED!

The only hitch: lung cancer CT screening is not covered by most insurance. However, many hospitals and imaging centers are offering this service at attractive rates for those who are willing to pay themselves.

Important Studies on CT Scans and Lung Cancer Make Headlines, Generate Debate

In the last few months I’ve read several stories concerning research about CT screenings for lung cancer.

In mid-November, there was a story making the rounds among the major news outlets about a study that found that CT lung scans can reduce the risk of lung cancer death among former and current heavy smokers. During the excitement of this study, a New York Times piece was published that expressed concern that the study’s findings could easily be taken out of context – and perhaps incite unnecessary fear, as well as drive demand for unnecessary scans.

I’d like to point out the importance of this study: it showed a 20 percent reduction in mortality in patients at very high-risk who were screened with low dose CT compared to patients who were not. Several things to keep in mind about this study – first, it was a study of patients with 30 or more pack-years of smoking history. Second, the technique was a quick and a low dose CT. And third, the costs of false positive findings and their workup have not yet been analyzed.

Now, another study is gaining traction that provides even more support for the findings of the November study. While this data suggests that screening can lower lung cancer mortality substantially in high-risk individuals, what we don’t yet know is the cost of a QUALY – a quality adjusted life-year. Calculating that cost involves knowing how much society had to expend paying for CT exams and the costs of false-positive results in order to capture a saved life-year in an at-risk person. Generally, if you can save a QUALY for $50,000 or less, it’s worth doing. If more, it’s a debate.

Just some things I’ve been thinking about as more and more news agencies report on these findings. I’m interested in learning what you think – what’s your opinion on these studies? Was the New York Times piece correct in its cautionary tone? Or could these findings, in fact, be as revolutionary as some reporters (and researchers) want us to believe?