Instituting a Low-dose CT-guided Lung Biopsy Protocol

Abstract

Rationale and objectives: We aimed to evaluate whether implementation of a low-dose computed tomography (CT)-guided lung biopsy protocol, with the support of individual radiologists in the section, would lead to immediate and sustained decreases in radiation dose associated with CT-guided lung biopsies.

Materials and methods: A low-dose CT-guided lung biopsy protocol was developed with modifications of kilovoltage peak, milliamperes, and scan coverage. Out of 413 CT-guided lung biopsies evaluated over a 3-year period beginning in 2009, 175 performed with a standard protocol before the development of a low-dose protocol, and 238 performed with a low-dose protocol. The dose-length product (DLP) was recorded for each lung biopsy and retrospectively compared between the two protocols. Individual radiologist level DLPs were also compared before and after the protocol change.

Results: The mean biopsy dose decreased by 64.4% with the low-dose protocol (113.8 milligray centimeters versus 319.7 milligray centimeters; P < 0.001). This decrease in radiation dose persisted throughout the entire 18 months evaluated following the protocol change. After the protocol change, each attending radiologist demonstrated a decrease in administered radiation dose. The diagnostic outcome rate and complication rate were unchanged over the interval.

Conclusions: Implementation of a low-dose CT-guided lung biopsy protocol resulted in an immediate reduction in patient radiation dose that was seen with all attending radiologists and persisted for at least 18 months. Such an intervention may be considered at other institutions wishing to reduce patient doses.

Keywords: CT-guided lung biopsy; Radiation dose; low-dose.

Figure 1

Representative biopsy images using the standard dose protocol (left, total DLP 568.12) and low dose protocol (right, total DLP 16.33).

Figure 2

Graphical representation of total DLP over 6-month periods surrounding the protocol change. Line represents median DLP with the upper and lower whisker lines representing the interquartile range. Kruskall Wallis test for differences p < 0.001.

Figure 3

Total DLP by attending radiologists before and after the protocol change. Bars represent median DLP, with the upper and lower whisker lines representing the interquartile range. Statistically significant difference at the p=0.05 level is denoted by an asterisk. The attending radiologists are presented in order from the highest to lowest median radiation doses used before the intervention.