Tag: low-dose CT

AI Spots Lung Nodules

Posted on by Brian Casey

A new study in Radiology on an AI algorithm for analyzing lung nodules on CT lung cancer screening exams shows that radiologists may be able to have their cake and eat it too: better identification of malignant nodules with lower false-positive rates. 

The rising utilization of low-dose CT screening is great news for clinicians (and eligible patients), but managing suspicious nodules remains a major challenge, as false-positive findings expose patients to unnecessary biopsies and costs.

  • False-positive rates have come down somewhat from the high rates seen in the big lung cancer screening clinical trials like NLST and NELSON, but there is still room for improvement.

Dutch researchers applied AI to the problem, developing a deep learning algorithm trained on 16.1k NLST nodules that produces a score from 0% to 100% based on a nodule’s likelihood of malignancy. 

  • They then tested the algorithm with baseline screening rounds of 4.1k patients from three datasets drawn from different lung cancer screening trials: NELSON, DLSCT in Denmark, and MILD in Italy.

The algorithm’s performance was compared to the Pan-Canadian Early Detection of Lung Cancer model, a widely used clinical guideline that uses patient characteristics like age and family history and nodule characteristics size and location to estimate risk.

Compared to PanCan, the deep learning algorithm…

  • Reduced false-positive findings sharply by classifying more benign cases as low risk (68% vs. 47%) when set at 100% sensitivity for cancers diagnosed within one year.
  • For all nodules, achieved comparable AUCs at one year (0.98 vs. 0.98), two years (0.96 vs. 0.94), and throughout screening (0.94 vs. 0.93).
  • For indeterminate nodules 5-15 mm, significantly outperformed PanCan at one year (0.95 vs. 0.91), two years (0.94 vs. 0.88), and throughout screening (0.91 vs. 0.86).

The model’s performance for indeterminate nodules is particularly intriguing, as these are challenging to manage due to their small size and can lead to unnecessary follow-up procedures.

The Takeaway

Using AI to differentiate malignant from benign nodules promises to make CT lung cancer screening more accurate and easier to perform than manual nodule classification methods – and should add to the exam’s growing momentum.

CT Lung Screening News from WCLC 2025

Posted on by Brian Casey

The World Conference on Lung Cancer wrapped up this week in Barcelona, and CT lung cancer screening was a highlighted topic, as it was at WCLC 2024 in San Diego.

The last year has seen significant global progress toward new population-based lung screening programs, and sessions at WCLC 2025 highlighted the advances being made… 

  • A screening program serving Kentucky and Indiana since 2013 has seen a 30-percentage-point decline in late-stage lung cancer diagnoses – over 3.5X faster than national trends – with far higher uptake than national averages (52% vs. 16%).
  • In the European 4-IN-THE-LUNG-RUN trial, AI had a negative predictive value similar to radiologists (98% vs. 97%) in analyzing 2.2k CT lung screen exams, indicating its potential as a first reader.
  • Another 4-IN-THE-LUNG-RUN study of 2.6k individuals revealed that AI had a 2.5% incidental findings rate, with none having acute consequences after a year.
  • The USPSTF’s 2021 guideline expansion may have reduced the number of at-risk individuals eligible for screening. A California analysis of 11.7k lung cancer patients found 8.8% fewer patients were eligible.
  • Researchers from Illinois found that basing screening eligibility on a 20-year smoking history rather than USPSTF 2021’s 20-pack-year threshold would capture more eligible individuals (70% vs. 65%), especially racial minorities.
  • A screening program at a VA healthcare system in Northern California achieved a 94% adherence rate for 3.9k military veterans, with 67% of cancers diagnosed at early stages.
  • U.S. military veterans had much higher screening rates (50% vs. 29%) in an analysis of 413.6k cancer survivors. Among women, 71% were up to date on mammography screening but only 25% were current for lung screens. 
  • Researchers used Qure.ai’s algorithm to detect malignant pulmonary nodules on 198k routine chest X-rays in a tuberculosis screening program.
  • Asian American women are at higher risk of lung cancer – even if they don’t smoke – and a session explored whether they should be screened.
  • A Stanford University program using electronic alerts to primary care physicians boosted screening compliance after one year (16% vs. 8.9%).
  • Attending lung screening didn’t make people feel they had a “license to smoke” in a U.K. study of 87.8k people.
  • Italian researchers tested Coreline Soft’s AVIEW AI solution as a first reader for screening.

The Takeaway

Findings from this week’s WCLC 2025 conference show both the challenges and opportunities in CT lung cancer screening. Researchers around the world are demonstrating that with hard work, dedication, and persistence, lung screening can become an effective, life-saving exam.

Are CT Lung Screening Patients Sicker?

Posted on by Brian Casey

Amid the rush of enthusiasm for CT lung cancer screening, a new study published in JAMA Health Forum offers a cautionary note. Researchers found that in the real world, people eligible for lung screening were sicker than those in research studies, and thus may not enjoy screening’s benefits to the same extent. 

Support for CT lung cancer screening is based on randomized controlled trials published in 2011 (NLST) and NELSON (2020) that showed screening reduced lung cancer mortality among high-risk individuals who typically had long smoking histories. 

  • The studies have spurred momentum for large-scale CT lung cancer screening programs, with a number of European and Asian countries starting national initiatives. 

But how generalizable are these results? Researchers noted that people who participated in the NLST study tended to be younger and healthier than individuals who qualify for screening in the real world. 

  • Co-morbidities like COPD, diabetes, and heart disease, as well as age and racial background, can have an impact on survival after treatment for lung cancer, and thus could reduce screening’s risk/benefit calculation. 

In the new Personalized Lung Cancer Screening study, researchers analyzed the comorbidity profiles of 31.8k people who got screened between 2016 and 2021 in California, Florida, and South Carolina. 

  • They noted that their PLuS study cohort was more diverse in terms of age, race, and ethnicity than that used in NLST, and potentially had more comorbid conditions. 

In analyzing their population, PLuS researchers found that compared to NLST participants, people screened in their real-world programs had …

  • Higher rates of COPD (33% vs. 18%).
  • Higher rates of diabetes (25% vs. 9.7%).
  • Higher rates of heart disease (16% vs. 13%).
  • Were more likely to be aged 70 and over (25% vs. 8.8%).
  • Had high scores on various metrics of comorbidity and frailty. 

Older, sicker patients are less likely to have good health outcomes after lung cancer surgery, and might also succumb to conditions like COPD, diabetes, and heart disease before lung cancer, which could also reduce lung screening’s benefits.

The Takeaway

While the new findings aren’t likely to seriously dampen CT lung cancer screening’s growing momentum, they do illustrate a point that should always be kept in mind when looking at research results: in the real world, your mileage may vary. 

CT Lung Screening’s Weak Link

Posted on by Brian Casey

CT lung cancer screening rates in the U.S. remain abysmally low, over a decade after the exam was recommended. Is part of lung screening’s problem its reliance on provider referrals? A new research letter in JAMA Network Open examines this question. 

Unlike breast screening, in which eligible women are able to self-refer themselves for exams, CT lung screening revolves around provider referrals to start the process. 

  • CMS requires a shared decision-making session that results in a written order from a practitioner for a CT lung screening exam in order to pay for screening through Medicare and Medicaid. 

When CMS created the rules in 2015, provider referrals and shared decision-making were seen as ways to get patients involved in their own care by making choices in coordination with their caregivers.

  • But many are starting to see the requirements as a barrier, especially given low CT lung screening rates in the U.S.

In the new article, researchers investigated how easy it would be for an eligible individual to secure a CT lung screening appointment by just calling hospitals – without a provider referral. 

  • They note that one-third of Americans don’t have primary care clinicians, and are often told to call hospitals directly to set up appointments.

So they did just that, placing phone calls to 527 hospitals asking to arrange CT lung screening appointments, finding …

  • 317 calls (60%) failed because the caller did not have a primary care provider’s order.
  • Only 51 hospitals (9.7%) were able to connect callers to any component of a lung cancer screening process. 

The study authors note that the provider referral requirement isn’t the only thing holding CT lung cancer screening back, as even patients with primary care providers aren’t getting screened, and managing nodule follow-up can also be challenging. 

  • But Medicare’s cumbersome reimbursement rules certainly don’t help bring new people into the fold.

The Takeaway

Given CT lung cancer screening’s undisputed life-saving value, there’s no reason to put unnecessary barriers in its way. The provider referral and shared decision-making requirements are lung screening’s weak link to securing greater adoption, and CMS should rescind them to put CT lung cancer screening on the path to greater adoption.

More Backing for CT Lung Screening

Posted on by Brian Casey

Yet another study is showing support for CT lung cancer screening. In a real-world study in Cancer, researchers tracked screening’s impact on military veterans, finding that it contributed to more early-stage diagnoses as well as lower all-cause mortality. 

It’s no secret that uptake of CT lung screening has been disappointing since the USPSTF in 2013 endorsed the test for high-risk people – mostly those with smoking histories. 

  • Uptake rates have been estimated to be under 10% by some studies, although recent research has shown that targeted interventions can improve that figure.

In the new study, researchers described results from the Veterans Health Administration’s effort to provide low-dose CT lung cancer screening to veterans from 2011 to 2018.

  • The researchers noted that smoking rates are higher among veterans, resulting in lung cancer incidence rates that are 76% higher than the general population. 

Researchers tracked outcomes retrospectively for 2.2k veterans who got screening before a lung cancer diagnosis and compared them to those with lung cancer who weren’t screened, finding that screening led to…

  • Higher rates of stage I diagnosis (52% vs. 27%)
  • Lower rates of stage IV diagnosis (11% vs. 32%)
  • Lower rates of cancer mortality (41% vs. 70%)
  • Lower rates of all-cause mortality (50% vs. 72%)

The sharp reduction in all-cause mortality is particularly striking. 

  • As we’ve discussed in the past, most population-based cancer screening tests have been shown to reduce cancer-specific deaths, but it’s been harder to show a decline in deaths from all causes. 

The study also illustrates the advantage of providing lung screening within a large, integrated healthcare system, where it’s easier to track at-risk individuals and direct them to screening if necessary.

The Takeaway

Of all the positive studies published so far this year on CT lung cancer screening, this one is the most exciting. The findings show that even in an environment of low lung screening uptake, dramatic benefits can be realized with the right approach.

CT Detects Early Lung Cancer

Posted on by Brian Casey

A massive CT lung cancer screening program launched in Taiwan has been effective in detecting early lung cancer. Research presented at this week’s World Conference on Lung Cancer (WCLC) in Singapore offers more support for lung screening, which has seen the lowest uptake of the major population-based screening programs. 

Previous randomized clinical trials like the National Lung Screening Trial and the NELSON study have shown that LDCT lung cancer screening can reduce lung cancer mortality by at least 20%. But screening adherence rates remain low, ranging from the upper single digits to as high as 21% in a recent US study. 

Meanwhile, lung cancer remains the leading cause of cancer death worldwide. To reduce this burden, Taiwan in July 2022 launched the Lung Cancer Early Detection Program, which offers biennial screening nationwide to people at high risk of lung cancer.

The Taiwan program differs from screening programs in the US and South Korea by including family history of lung cancer in the eligibility criteria, rather than just focusing on people who smoke. 

Researchers at WCLC 2023 presented the first preliminary results from the program, covering almost 50k individuals screened from July 2022 to June 2023; 29k had a family history of lung cancer and 19k were people who smoked heavily. Researchers found …

  • 4.4k individuals receive a positive screening result for a positive rate of 9.2%
  • 531 people were diagnosed with lung cancer for a detection rate of 1.1%
  • 85% of cancers were diagnosed at an early stage, either stage 0 or stage 1

This last finding is perhaps the most significant, as part of the reason for lung cancer’s high mortality rate is that it’s often discovered at a late stage, when it’s far more difficult to treat. As such, lung cancer’s five-year survival rate is about 25% – far lower than breast cancer at 91%.

The Takeaway

Taiwan is setting an example to other countries for how to conduct a nationwide LDCT lung cancer screening program, even as some critics take aim at population-based screening. Taiwan’s approach is broader and more proactive than that of the US, for example, which has erected screening barriers like shared decision-making.

Although it’s still early days for the Taiwan program, future results will be examined closely to determine screening’s impact on lung cancer mortality – and respond to screening’s critics.

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