Radiation dose reduction for CT lung cancer screening using ASIR and MBIR: a phantom study.

The purpose of this study was to reduce the radiation dosage associated with computed tomography (CT) lung cancer screening while maintaining overall diagnostic image quality and definition of ground-glass opacities (GGOs). A lung screening phantom and a multipurpose chest phantom were used to quantitatively assess the performance of two iterative image reconstruction algorithms (adaptive statistical iterative reconstruction (ASIR) and model-based iterative reconstruction (MBIR)) used in conjunction with reduced tube currents relative to a standard clinical lung cancer screening protocol (51 effective mAs (3.9 mGy) and filtered back-projection (FBP) reconstruction). To further assess the algorithms' performances, qualitative image analysis was conducted (in the form of a reader study) using the multipurpose chest phantom, which was implanted with GGOs of two densities. Our quantitative image analysis indicated that tube current, and thus radiation dose, could be reduced by 40% or 80% from ASIR or MBIR, respectively, compared with conventional FBP, while maintaining similar image noise magnitude and contrast-to-noise ratio. The qualitative portion of our study, which assessed reader preference, yielded similar results, indicating that dose could be reduced by 60% (to 20 effective mAs (1.6 mGy)) with either ASIR or MBIR, while maintaining GGO definition. Additionally, the readers' preferences (as indicated by their ratings) regarding overall image quality were equal or better (for a given dose) when using ASIR or MBIR, compared with FBP. In conclusion, combining ASIR or MBIR with reduced tube current may allow for lower doses while maintaining overall diagnostic image quality, as well as GGO definition, during CT lung cancer screening.

Implementing Decision Coaching for Lung Cancer Screening in the Low-Dose Computed Tomography Setting.

PURPOSE: The uptake of shared decision making (SDM) for lung cancer screening (LCS) as required by the Centers for Medicare & Medicaid Services (CMS) is suboptimal. Alternative models for delivering SDM are needed, such as decision coaching in the low-dose computed tomography (LDCT) setting. METHODS AND MATERIALS: The Replicating Effective Programs framework guided our implementation of decision coaching, which included a patient-facilitated component before screening followed by in-person coaching that addressed the required elements for the SDM visit from CMS. We surveyed two LCS patient cohorts (pre-implementation and implementation of decision coaching) about their knowledge of LCS and perception of the SDM process. We conducted time-motion studies to assess the feasibility of implementing decision coaching and audio recorded clinical encounters from the implementation cohort to assess fidelity of the SDM conversation to the CMS requirements. RESULTS: Compared with the pre-implementation cohort (n = 51), the implementation cohort (n = 30) had greater knowledge of LCS (P < .01) and reported a better SDM process (P = .01). Coaching took 7.6 ± 4.1 minutes and did not increase visit time (P = .72). Coaches addressed an average of 6.4 of 7 SDM elements required by CMS. CONCLUSION: Decision coaching in the LDCT setting provides an opportunity for patients to confirm their screening decision by ensuring that patients are truly informed about the potential harms and benefits of LCS. The decision coaching had excellent fidelity in addressing the required SDM elements from CMS and is feasible.