Background: The low-dose computed tomography (CT) technique has been widely used because it decreases the potential risk of radiation exposure, as well as enabling low-dose CT-guided lung lesion biopsy. However, uncertainties remain regarding diagnostic accuracy, radiation dose, complication rate, and image quality.
Purpose: To compare the diagnostic accuracy, radiation dose, complication rate, and image quality of lung lesion biopsy between conventional CT-guided and low-dose CT-guided techniques.
Material and methods: A total of 90 patients were prospectively enrolled and randomized into two groups (group A: 120 kv; 200 mA; thickness, 2.0 mm; pitch, 16 mm/rot; n = 44; group B: 120 kv;10 mA; thickness, 2.0 mm; pitch, 23 mm/rot; n = 46). Sensitivity, specificity, accuracy, positive predictive value (PPV), negative predictive value (NPV), radiation dose, image quality, and complication rate were compared. All variables between the two groups were analyzed using chi-square and Student's t tests. A P value of < 0.05 was considered statistically significant.
Results: The sensitivity, specificity, accuracy, positive predictive value (PPV), and negative predictive value (NPV) for diagnosing lung lesions were 96.88%, 100%, 97.5%, 100%, and 88.89% in group A, respectively. In group B, the values were 96.67%, 100%, 97.5%, 100%, and 90.91%, respectively (P > 0.05). The mean weighted CT dose index (CTDIw) and dose-length product (DLP) were 29.29 ± 3.93 mGy and 211.74 ± 37.89 mGy*cm in group A and 1.55 ± 0.15 mGy and 10.98 ± 1.56 mGy*cm in group B (P < 0.001). Image quality satisfied the need for a coaxial biopsy. Complications in group A and group B were observed in 27.28% and 23.91% of the patients, respectively (P > 0.05).
Conclusion: Compared to conventional CT-guided biopsies, lung lesion biopsies guided by the low-dose CT biopsy protocol showed dramatically lower CTDIw and DLP levels. In contrast, the diagnostic yield of the procedures did not differ significantly, which is a recommended technique in certain populations.
Keywords: Low-dose CT; coaxial biopsy; lung; radiation dose.