Abstract No. 134: Efficacy of ultra low-dose protocol for CT-guided lung biopsies

Abstract

Computed tomography (CT) scans are a significant source of radiation to patients. The purpose of this study was to evaluate the efficacy of CT-guided percutaneous lung biopsy using an “ultra low-dose” (ULD) protocol. 32 consecutive patients (11-81 years old with a mean age of 55.9 years) underwent CT-guided lung biopsies using an ULD protocol. Technical parameters were changed from our standard protocol (140 kVp, automatic dose modulation for initial planning scan, 100 mA for subsequent guiding scans) to an ULD protocol (100 kVp, 15 mA) while keeping all other parameters constant. ULD studies were evaluated subjectively for image quality on a five point scale. Patients' body mass indices (BMI), technical success rates, complication rates, and total estimated radiation doses (DLP-dose length product) were calculated. These results were compared to a group of 32 previous consecutive patients (28-84 years old with a mean age of 60.8 years) who had undergone CT-guided lung biopsies using standard protocol. In the ULD studies, image quality was rated as good or excellent in 100% of cases. Average BMI for ULD and standard dose groups was 24.6 and 26.2, respectively (p = .364). Technical success rate was 93.8% using ULD protocol compared to 96.9% using standard protocol (p = 1.000). Complication rates (pneumothoraces necessitating chest tube placement) in the ULD and standard groups occurred in 9.4% (3 patients) and 0%, respectively (p = .237). Average DLP of ULD protocol was 19.2 mGy-cm, compared to 765.5 mGy-cm for the standard protocol (p < .001). An ultra-low dose CT protocol for lung biopsies reduces patient radiation dose by greater than 95% with acceptable technical success rate and safety profile comparable to a standard protocol.