Affiliations: Baylor Health Care System, Dallas, TX, USA | Department of Radiology, University of Kentucky,
Lexington, KY, USA
Note: [] Corresponding author: Victor J. Weir, Texas Licensed Medical
Physicist (Diagnostic Radiological Physics), Medical Physics & Radiation
Safety, Baylor Health Care System, 4005 Crutcher Street, Suite 330, Dallas, TX
75246, USA. Tel.: +1 214 820 8516; E-mail: victor.weir@baylorhealth.edu
Abstract: PURPOSE: Patient radiation dose during Computed Tomography (CT)
guided biopsy procedures is determined by both acquisition technical parameters
and physician practice. The potential effect of the physician practice is of
concern. This study is to investigate the effects of those intangibles on
patient radiation dose. METHODS: Patient radiation dose from 252 patients who underwent CT
guided biopsy from 2009 to 2010 were retrospectively studied. Ten physicians
who used conventional intermittent shots, low mA dose saving feature, or both
were included in the study. The patient dose reports were retrieved and the
total dose length products (DLPs) were analyzed. Linear regression analysis
performed between various variables and reported dose. Patient detriment index
(PDI) was developed, which sets threshold (standard of practice) for comparing
physician practice with their peers. Odds ratio was calculated to determine
odds of a group of patients receiving dose above threshold when compared to
another group. RESULTS: Median DLP among ten physicians was 1194 mGy-cm. There was
a significant difference (p< 0.01) between reported DLPs doses when
physicians used dose saving feature vs. when feature not used (539.8 ±
169.4 mGy-cm vs. 1269.7 ± 659.0 mGy-cm). In general, physicians who used
dose saving feature had lower relative PDIs (< 1) compared to the PDIs (>
1) without the dose feature. Odds ratio estimate of 7.7 at 95% confidence level
indicates that the odds of a group receiving a high dose depends on
practitioner. CONCLUSION: Adjustments of practice habits, use of dose saving
features or both may be needed to improve patient care for CT biopsy.
