Implementation of ultra-low-dose lung protocols in CT-guided lung biopsies: feasibility and safety in the clinical setting

Optimizing lung biopsy procedures:Comparative analysis of diagnostic efficacy and safety in experimental low-dose, conventional low-dose, and standard-dose CT-guided approaches

PURPOSE

Lung cancer is a major cause of cancer-related deaths, emphasizing the importance of early diagnosis. CT-guided percutaneous lung biopsy(CT-PLB) is a valuable method for diagnosing lung lesions, but multiple scans can elevate radiation exposure. This study aims to compare diagnostic efficacy and safety across different CT-PLB protocols.

METHODS

273 consecutive patients who underwent CT-PLB between June 2018 and February 2021 were enrolled, and were divided into standard-dose, conventional low-dose, and experimental low-dose groups. The study mainly evaluated technical success, diagnostic efficacy, radiation dose, complications, and image quality.

RESULTS

93 patients were assigned to standard-dose group, 85 to conventional low-dose group, and 95 to experimental low-dose group. Technical success rates in these groups were 97.9%, 100%, and 97.9%, respectively. Procedure-related complications rates were similar across the groups(pneumothorax:p=0.71, hemorrhage:p=0.59). Sensitivity, specificity, and overall diagnostic accuracy were comparable among three groups(p=0.59,1.0,0.65), with respective values of 90.5%, 100%, and 93.2% in standard-dose group, 88.1%, 100%, and 90.5% in conventional low-dose group, and 91.9%, 100%, and 93.4% in experimental low-dose group. The effective dose (ED) in the experimental low-dose group was significantly lower compared to both the standard-dose and conventional low-dose CT-PLB groups[ED: 1.49(1.0∼1.97) mSv vs 5.42(3.92∼6.91) mSv vs 3.15(2.52∼4.22) mSv, p<0.001].

CONCLUSIONS

This study has developed a standardized six-step procedure for CT-PLB using experimental low-dose settings. It can achieve comparable diagnostic efficacy to conventional low-dose and standard-dose CT-PLB protocols while substantially reducing radiation exposure. These findings indicate that the experimental low-dose protocol could serve as a safe and effective alternative for CT-PLB.

Safety, feasibility, and effectiveness of a CT-guided transthoracic lung and pleural biopsy - a single-centre experience with own low-dose protocol

Purpose

To assess the efficacy and safety of a low-dose, computed tomography (CT)-guided transthoracic biopsy of lung and pleural lesions.

Material and methods

A total of 135 low-dose, CT-guided transthoracic lung and pleural lesions biopsies were performed. A cutting needle was utilized in 124 cases, and fine needle aspiration biopsy was performed in 14 cases. In all cases, 14- to 22-gauge biopsy needles were used.

Results

Diagnostic material was obtained in 111 (82.2%) patients. In 97 (71.8%) cases neoplastic lesions were found, predominantly adenocarcinoma and non-small cell carcinoma. In 14 (12.6%) cases non atypical cells were reported. Biopsy failed to obtain material suitable for histopathological examination in 24 (17.7%) cases. Complications occurred in 31 patients, including pneumothorax in 28 patients and haematoma in 3 cases.

Conclusions

Based on the obtained results, it can be stated that low-dose, CT-guided transthoracic biopsy of lung and pleural tissues is an accurate and safe procedure. Also, it is linked to a low risk of complications such as a small pneumothorax.

Implementation of Individualized Low-Dose Computed Tomography-Guided Hook Wire Localization of Pulmonary Nodules: Feasibility and Safety in the Clinical Setting

Background: CT-guided hook-wire localization is an essential step in the management of small pulmonary nodules. Few studies, however, have focused on reducing radiation exposure during the procedure. Purpose: This study aims to explore the feasibility of implementing a low-dose computed tomography (CT)-guided hook wire localization using tailored kVp based on patients' body size. Materials and Methods: A total of 151 patients with small pulmonary nodules were prospectively enrolled for CT-guided hook wire localization using individualized low-dose CT (LDCT) vs. standard-dose CT (SDCT) protocols. Radiation dose, image quality, characteristics of target nodules and procedure-related variables were compared. All variables were analyzed using Chi-Square and Student's t-test. Results: The mean CTDIvol was significantly reduced for LDCT (for BMI ≤ 21 kg/m2, 0.56 ± 0.00 mGy and for BMI > 21 kg/m2, 1.48 ± 0.00 mGy) when compared with SDCT (for BMI ≤ 21 kg/m2, 5.24 ± 0.95 mGy and for BMI > 21 kg/m2, 6.69 ± 1.47 mGy). Accordingly, the DLP of LDCT was significantly reduced as compared with that of SDCT (for BMI ≤ 21 kg/m2, 56.86 ± 4.73 vs. 533.58 ± 122.06 mGy.cm, and for BMI > 21 kg/m2, 167.02 ± 38.76 vs. 746.01 ± 230.91 mGy.cm). In comparison with SDCT, the effective dose (ED) of LDCT decreased by an average of 89.42% (for BMI ≤ 21 kg/m2) and 77.68% (for BMI > 21 kg/m2), respectively. Although the images acquired with the LDCT protocol yielded inferior quality to those acquired with the SDCT protocol, they were clinically acceptable for hook wire localization. Conclusions: LDCT-guided localization can provide safety and nodule detection performance comparable to SDCT-guided localization, benefiting radiation dose reduction dramatically, especially for patients with small body mass indexes.

Computed tomography-guided core needle biopsy for lung nodules: low-dose versus standard-dose protocols

Introduction

Computed tomography (CT)-guided core needle biopsy (CNB) is an essential step in the management of lung nodules (LNs). Low-dose CT (LDCT)-guided CNB has been used to decrease the radiation exposure.

Aim

To evaluate the technical success, safety, diagnostic capacity, and radiation exposure to patients between LDCT-guided and standard-dose CT (SDCT)-guided CNB for LNs.

Material and methods

This is a retrospective, single-centre study. Patients who underwent LDCT-guided or SDCT-guided CNB for LNs from January 2015 to December 2017 were included. Data on technical success, diagnostic performance, complications, and radiation exposure were collected and analysed.

Results

A total of 70 and 65 patients underwent LDCT-guided and SDCT-guided CNB procedure, respectively. The technical success rates were 100% in both groups. The diagnostic yield, sensitivity, specificity, and overall diagnostic accuracy in the LDCT and SDCT groups were 71.4% and 67.7% (p = 0.637), 97.8% and 93.2% (p = 0.625), 100%, and 100%, and 98.6% and 95.4% (p = 0.560), respectively. The independent risk factor of diagnostic failure was less sample tissues (p = 0.012; 95% confidence interval: 0.033–0.651). Pneumothorax was found in 9 and 12 patients in the LDCT and SDCT groups, respectively (p = 0.369). Lung haemorrhage was found in 11 and 12 patients in the LDCT and SDCT groups, respectively (p = 0.671). The mean dose-length product was 38.3 ±17.0 mGy · cm and 376.0 ±118.7 mGy · cm in the LDCT and SDCT groups, respectively (p < 0.001).

Conclusions

Compared to SDCT, LDCT-guided CNB can provide comparable safety and diagnostic performance for LNs while reducing exposure to radiation.

Ultralow dose computed tomography protocol for hook-wire localization of solitary pulmonary nodules prior to video-assisted thoracoscopic surgery

BACKGROUND

This study prospectively investigated the efficacy and radiation dose of ultralow dose computed tomography (CT)-guided hook-wire localization (HWL) at 100 kV with tin filtration (100Sn kV) for small solitary pulmonary nodules.

METHODS

All HWL procedures were performed on a third generation dual-source CT system. Eighty-eight consecutive patients undergoing CT-guided HWL were randomly assigned to standard dose CT (Group A: n = 44; reference 110 kV and 50 mA) or ultralow dose CT (Group B: n =44; ¹⁰⁰ Sn kV and 96 mA) protocols. The technical success rate, complications, subjective image quality, and radiation dose were compared between the groups.

RESULTS

The mean volume CT dose index and total dose-length product were significantly lower in Group B compared to Group A (0.32 mGy vs. 3.2 ± 1.1 mGy and 12.1 ± 0.97 mGy-cm vs. 120 ± 40.6 mGy-cm; P < 0.001). The effective dose in Group B was significantly lower than in Group A (0.17 ± 0.01 mSv vs. 1.68 ± 0.57 mSv, -89.8%; P < 0.001). The technical success rates were 100% for both groups. There were no significant differences in complication rates between the protocols (P > 0.05). The image quality of ultralow dose CT met the requirements for HWL procedure.

CONCLUSION

Ultralow dose CT-guided HWL of solitary pulmonary nodules performed at ¹⁰⁰ Sn kVp spectral shaping significantly reduced the radiation dose compared to standard dose CT, with high technical success and acceptable patient safety.

Intermittent CT fluoroscopic guided lung biopsy - Retrospective analysis of success rate, radiation exposure, complications and duration of procedure

OBJECTIVE

Intermittent CT fluoroscopic biopsy is a new technology, but has not been studied widely. This study aims to investigate correlation between the radiation dose and fluoroscopic CT exposure factors to establish the low dose parameters for performing percutaneous lung biopsies, as well as the relationship of the mean diameter and depth of lesions with radiation dose, procedure time, success and complication rates.

MATERIALS AND METHODS

This is a retrospective study to analyse lung biopsies performed using intermittent CT fluoroscopic technique with 18 G semi-automated coaxial gun on 256 slice scanner. A total of 50 patients were included in the study. Biopsy was done in three mAs and KVp settings (30 and 70, 10 and 120, 30 and 120, respectively). The statistical data analysis was performed using SPSS Statistics software.

RESULTS

Pneumothorax occurred in 22 % of cases. Sampling rate was 98% but histopathological diagnosis was made in 94% cases. Mean procedure time was 30.5±11.1 minutes. Low dose protocol (30 mAs and 70 KVp) had least radiation exposure during biopsy procedure (p < 0.001) with similar success rate, complications and procedure time (p > 0.05) in comparison with high dose protocol (10 and 120, 30 and 120 mAs and KVp, respectively). Mean diameter of lesions didn't correlate with radiation dose, success rate, complications and duration of procedure (p > 0.05) while significant association was found when depth was correlated with radiation exposure during fluoroscopic biopsy, duration of procedure and complication rates (p < 0.05) while no association was found with success rates.

CONCLUSION

On third generation dual energy source CT scanner, reducing mAs and KVp to 30 and 70 during fluoroscopy biopsy can produce images whose complications and success rates are comparable to high dose CT. In general, intermittent CT fluoroscopy guided lung biopsy has good success rates with acceptable complications, while utilising less radiation dose and procedure time.

Reinforcing the Importance and Feasibility of Implementing a Low-dose Protocol for CT-guided Biopsies

RATIONALE AND OBJECTIVES

This study sought to more definitely illustrate the impact and feasibility of implementing a low-dose protocol for computed tomography (CT)-guided biopsies using size-specific dose estimates and multivariate analyses.

MATERIALS AND METHODS

Fifty consecutive CT-guided lung and extrapulmonary biopsies were reviewed before and after implementation of a low-dose protocol (200 patients total, mean age 61 ± 15 years, 128 women). Analyses of variance with Bonferroni correction were used to compare standard and low-dose protocols in terms of patient demographics, physician experience, target lesion size, total dose-length product, total acquisitions, size-specific dose estimate, signal-to-noise ratio, contrast-to-noise ratio, and lesion conspicuity ratings. All procedures were performed on the same 16-slice CT scanner.

RESULTS

Voluntary protocol adherence was 100% (lung) and 89% (extrapulmonary). The low-dose protocol achieved significantly lower total average dose-length product [(lung) 735.6 ± 599.4 mGy × cm to 252.1 ± 101.9 mGy × cm, P < .001; (extrapulmonary) 724.7 ± 545.0 mGy × cm to 392.9 ± 239.5 mGy × cm, P < .001] and size-specific dose estimate [(lung) 5.2 ± 0.8 mGy × cm to 4.3 ± 1.5 mGy, P < .001; (extrapulmonary) 10.1 ± 6.7 mGy to 6.5 ± 2.7 mGy, P < .001]. Only the change in protocol was independently associated with lower size-specific dose estimates when controlling for the other variables (P < .0001). This was achieved with no significant differences in signal-to-noise ratio, contrast-to-noise ratio, or lesion conspicuity.

CONCLUSIONS

Implementation of a low-dose protocol for CT-guided biopsies resulted in 21% and 36% of size-specific dose estimate reduction for lung and extrapulmonary biopsies, respectively, with excellent adherence. Interventional and body radiologists should implement low dose CT-guidance protocols aiming to improve patient safety.