OnGuard Technical Bulletin 

More lung cancers are detected by chest X-rays than by CT scans.¹  Cancer nodules, however, can be small or subtle and difficult to identify through chest X-rays alone.

Researchers at the University of Chicago used Riverain’s OnGuard technology to analyze chest X-rays from patients whose lung cancer was initially missed by radiologists. OnGuard detected 37 percent of the missed cancers, which otherwise would have required more extensive and costly diagnostic testing.²  Researchers at the University of Maryland achieved a similar result in a study that included patients from a local Veteran’s Administration (VA) hospital. Again, OnGuard identified 37 percent of the missed cancers.³   Both studies show that patients could have received an earlier lung cancer diagnosis with the help of OnGuard Chest X-ray CAD.

In one retrospective study, 71 percent of cancers less than 11 mm, 28 percent of cancers 11 - 30 mm and 12 percent of cancers 31 - 40 mm were not detected. The delay in detection resulted in an increase in cancer stage in 43 percent of patients. The authors estimated a 23 percent drop in the five-year patient survival rate because of the delay in diagnosis.⁴

In another study, 15 community-based, board-certified radiologists were asked to detect lung cancer with and without OnGuard Chest X-ray CAD. Relying on chest X-rays alone, 42 percent of nodules sized 9 - 14 mm and 22 percent sized 20 - 27 mm were missed. When using chest X-ray plus OnGuard, 10 of the 15 radiologists improved their detection rates, identifying 10 percent more Stage I cancers between nine and 30 mm and 16 percent more between nine and 15 mm. This study was the basis for the Food and Drug Administration’s approval of OnGuard Chest X-ray CAD technology.⁵

These findings are significant given that early lung cancer diagnosis is key to long-term patient survivability. According to the American Cancer Society, the five-year survival rate for lung cancer patients increases to 49 percent from 16 percent when the cancer is detected in Stage I, when it can be surgically removed. The survival rate of patients who received chemotherapy after successful lung resection was 69 percent in a randomized clinical trial.⁶

 

Sources
¹Altorki N., Kent M. and Pasmantier, M. (2001).  Detection of Early-stage Lung Cancer:  Computed Tomographic Scan or Chest Radiograph?  Journal of Thoracic and Cardiovascular Surgery.  121:  1053-7.

²Li, F., Engelmann, R., Metz, C. & et al (2008). Lung Cancers Missed on Chest Radiographs:  Results Obtained with a Commercial Computer-aided Detection Program.  Radiology.  246:  243-280.

³Chen, J. and White, C. (2008). Use of CAD To Evluate Lung Cancer on Chest Radiography. Journal of Thoracic Imaging. 23, 93-96.

⁴Quekel, L.G., Kessels, A.G., Reginal, G.R. & et al (1999). Miss Rate of Lung Cancer on the Chest Radiograph in Clinical Practice. Chest. 115, 720-724.

⁵Riverain Medical (2001) Clinical Trial for Food and Drug Administration Pre-Market Approval

⁶Winton, T., Livingston, R., Johnson, D. & et al (2005). Vinorelbine Plus Cisplatin vs Observation in Resected Non-Small-Cell Lung Cancer. New England Journal of Medicine. 352, 2589-2597.