Latest CT Technologies in Lung Cancer Screening

Protocols and Radiation Dose Reduction

Marleen Vonder; Monique D. Dorrius; Rozemarijn Vliegenthart


Transl Lung Cancer Res. 2021;10(2):1154-1164. 

In This Article


In the past two decades, CT lung cancer screening protocols have evolved from prefixed settings for tube voltage and tube current towards automatic tube current modulation and tube voltage selection. Current clinical guidelines provide detailed information on reconstruction settings and encourage the use of thin slices, MPR and MIP for nodule detection and quantification. Based on the guidelines, the CT protocol should result in radiation dose of <3 mGy for standard size patient. Although cautiously, radiation dose may be further decreased in ultra-low dose CT protocols with the use of IR and tin-filter to 0.3 mGy. Performance of new ultra-low dose protocols should be evaluated thoroughly. The sensitivity in relation to nodule size, density and composition should be determined. In addition, impact on volume measurement and reproducibility, as well as performance of CAD and radiomic features should be evaluated. For the latter, re-training and re-evaluation may be required for optimal use of these techniques in ultra-low dose protocols for lung cancer CT screening. Deep learning denoising techniques are promising to increase the image quality and to apply ultra-low dose CT protocols in a wider range of screening participants, and help to optimize the accuracy and precision of lung nodule quantification and management. With the expected large-scale implementation of lung cancer screening, further standardization of (ultra) low-dose CT techniques, including acquisition, post-processing and reporting, will be required.