While the last decade has seen a number of advances in surgical, radiotherapeutic, and chemotherapeutic methods of treatment, lung cancer remains one of the most serious and difficult to treat diseases we face. In the UK, recorded statistics show that there are around 46,700 new lung cancer cases every year, making it the third most common cancer in the country. The sharp rise in smoking prevention and cessation programmes may be decreasing mortality rates, but it’s clear that there remains a large at-risk population, says Fairford Medical’s Michael Bradfield
As with many other types of cancer, however, the earlier a patient is diagnosed, the easier and quicker it is to treat and the greater the patient’s chance of survival. Since it is able to detect even very small nodules in the lungs, the use of Low Dose Computed Tomography (LDCT) using the very latest dose optimisation CT technology in screening examinations can be highly beneficial in identifying early-stage tumours before symptoms have begun.
In light of the positive correlation that was discovered in the National Lung Screening Trial in the early 2000s, the U.S. Preventive Services Task Force (USPSTF) issued a recommendation in favour of annual screening for lung cancer with LDCT for individuals at high risk of lung cancer due to their age and smoking history. The results showed a 20 per cent reduction in the number of lung cancer deaths in the group monitored with the low dose CT scans compared to the X-rays.
Note that it is not just the “high risk” individuals who would benefit from regular Lung Cancer CT Screening, as nodules are often found in those who never smoked or gave up smoking decades earlier. These are generally detected at a late stage only when the cancer has spread elsewhere in the body.
Given the ultra-low X-Ray dosage of the very latest (and more affordable) CT systems, there is a good case for widening the selection parameters for regular Lung Cancer CT Screening.
The increasing benefits of CT lung screening over time were highlighted in the latest results from the Multicentric Italian Lung Detection (MILD) trial, which found a 39% reduction in lung cancer mortality risk for eligible smokers at 10 years. The study sought to evaluate the advantages of annual or biennial lung cancer screening for eligible smokers or former smokers who were at risk of, but not yet diagnosed with, lung cancer.
Between 2005-2018, researchers from the Istituto di Ricovero e Cura a Carattere Scientifico (IRCCS) National Cancer Institute of Milan assessed the benefits of CT lung screening over time – starting after year five – in 4,099 eligible smokers between 2005 and 2018. The results suggested that a well-structured Lung Cancer CT screening program could lead to a 39 per cent reduction in lung cancer mortality, compared with no screening, exceeding the 20 per cent reduction reported in the National Lung Screening Trial.
Unfortunately, when lung cancer is diagnosed, 55 per cent of patients will already have metastatic disease – meaning the cancer has spread beyond the lung to other parts of the body. It is for this reason that the survival rate remains low despite developments in curative therapies. Further patient and referring physician education is required before low dose lung cancer screening through CT becomes widespread, but a new large-scale trial in Japan has shone fresh light on the clear benefits of this approach.
Between 1998 and 2012, a team of researchers led by Dr Takeshi Nawa from Hitachi General Hospital in Japan investigated the effect on mortality rates of a citywide lung cancer screening program that used both CT and X-ray in the city of Hitachi. Their report concluded that screening high-risk individuals for lung cancer reduced mortality by a whopping 51 per cent compared to X-ray.
Despite many positives, Low-dose Lung Cancer CT scanning of patients is not without drawbacks. For one, a screening can result in invasive biopsies for people who turn out not to have cancer, as well as missing some early stage tumours. Improving the follow-up and analysis of a positive CT scan (such as repeating the scan 3 months later and/or use of a PET/CT scan) will be essential in mitigating the risk of false positive diagnosis.
According to researchers at Northwestern University in Illinois and Google, cutting-edge AI (or more correctly ‘Deep Learning’) technology could hold the key to boosting the effectiveness of lung cancer screening. Their study involved training computer software to analyse 42,290 CT lung scans from nearly 15,000 patients.
The only information the researchers provided the AI was which patients had gone on to develop cancer and which hadn’t. Tested against a team of six radiologists, the AI proved more effective when investigating a single CT scan. The results, in Nature Medicine, showed the AI could boost cancer detection by 5 per cent while also cutting false-positives (people falsely diagnosed with cancer) by 11 per cent.
Meanwhile, Harvard researchers have successfully developed an artificial intelligence algorithm capable of analysing routine CT scans to predict the response a patient will have to treatment and their likelihood of survival. Their deep learning model was applied to the CT scans of 179 patients with stage 3 non-small cell lung cancer who had already received chemotherapy. The researchers then tested the AI model on a dataset of 178 CT scans from 89 NSCLC patients who had undergone chemoradiation as well as surgery.
The results of the research were ground-breaking, with the AI model successfully predicting the patients’ two-year survival. The deep learning algorithm was further able to establish that the patients it categorised as having a low mortality risk were six times more likely to survive than the high-risk patients.
It may take a while for AI to become widely available for clinical use, but such studies show significant promise for the future. While the use of AI will NOT replace experienced radiologists reporting on scans, it will allow them to work more efficiently and accurately in reporting on the scan results.
On the basis of the evidence found through these studies, the need for high-risk individuals to undergo a Low Dose CT screening is clear. Scanning high-risk current and former smokers on a regular basis has been shown to identify early-stage tumours and reduce lung cancer mortality.
If the benefits of an early diagnosis are to be felt throughout the population, the regular Low Dose Lung Cancer CT screening must be made more widely available on the NHS. The NHS has recently issued tenders for ten such screening programs throughout the UK. Manchester and Leeds are now up and running with the rest before the end of 2019. Hopefully, the results will show improved patient outcomes, lower mortality and a lifetime saving to the NHS by detecting Lung Cancer at a much earlier stage.
Fairford Medical provides medical diagnostic imaging solutions, not just products. Our motivation is to make MRI and CT diagnostic imaging more widely available to the public at an affordable cost to improve overall patient outcomes. We work with customers to better understand their operational problems and financial constraints to come up with creative and personalised solutions. The company has a fleet of mobile, relocatable and static CT and MRI systems for interim, medium and long-term rental or lease, together with all the supporting services and logistics required, including the new CT Scanbox which is highly affordable. Its self-contained and relocatable CT Scanbox system comes fitted with the latest technology scanners: all the advantages of a mobile but in a 4-metre-wide relocatable format which can be easily delivered and set-up on-site at minimal cost.
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