CT-guided transthoracic biopsy: histopathologic results and complication rates

Application of a combined radiomics nomogram based on CE-CT in the preoperative prediction of thymomas risk categorization

Objective

This study aimed to establish a combined radiomics nomogram to preoperatively predict the risk categorization of thymomas by using contrast-enhanced computed tomography (CE-CT) images.

Materials and Methods

The clinical, pathological, and CT data of 110 patients with thymoma (50 patients with low-risk thymomas and 60 patients with high-risk thymomas) collected in our Hospital from July 2017 to March 2022 were retrospectively analyzed. The study subjects were randomly divided into the training set (n = 77) and validation set (n = 33) in a 7:3 ratio. Radiomics features were extracted from the CT images, and the least absolute shrinkage and selection operator (LASSO) algorithm was performed to select 13 representative features. Five models, including logistic regression (LR), support vector machine (SVM), random forest (RF), decision tree (DT), and gradient boosting decision tree (GBDT) were constructed to predict thymoma risks based on these features. A combined radiomics nomogram was further established based on the clinical factors and radiomics scores. The performance of the models was evaluated using receiver operating characteristic (ROC) curve, DeLong tests, and decision curve analysis.

Results

Maximum tumor diameter and boundary were selected to build the clinical factors model. Thirteen features were acquired by LASSO algorithm screening as the optimal features for machine learning model construction. The LR model exhibited the highest AUC value (0.819) among the five machine learning models in the validation set. Furthermore, the radiomics nomogram combining the selected clinical variables and radiomics signature predicted the categorization of thymomas at different risks more effectively (the training set, AUC = 0.923; the validation set, AUC = 0.870). Finally, the calibration curve and DCA were utilized to confirm the clinical value of this combined radiomics nomogram.

Conclusion

We demonstrated the clinical diagnostic value of machine learning models based on CT semantic features and the selected clinical variables, providing a non-invasive, appropriate, and accurate method for preoperative prediction of thymomas risk categorization.

Low-dose CT with tin filter combined with iterative metal artefact reduction for guiding lung biopsy

Background

Computed tomography (CT) is currently the imaging modality of choice for guiding pulmonary percutaneous procedures. The use of a tin filter allows low-energy photons to be absorbed which contribute little to image quality but increases the radiation dose that a patient receives. Iterative metal artefact reduction (iMAR) was developed to diminish metal artefacts. This study investigated the impact of using tin filtration combined with an iMAR algorithm on dose reduction and image quality in CT-guided lung biopsy.

Methods

Ninety-nine consecutive patients undergoing CT-guided lung biopsy were randomly assigned to routine-dose CT protocols (groups A and B; without and with iMAR, respectively) or tin filter CT protocols (groups C and D; without or with iMAR, respectively). Subjective image quality was analysed using a 5-point Likert scale. Objective image quality was assessed, and the noise, contrast-to-noise ratio, and figure of merit were compared among the four groups. Metal artefacts were quantified using CT number reduction and metal diameter blurring. The radiation doses, diagnostic performance, and complication rates were also estimated.

Results

The subjective image quality of the two scan types was compared. Images with iMAR reconstruction were superior to those without iMAR reconstruction (group A: 3.49±0.65 vs. group B: 4.63±0.57; P<0.001, and group C: 3.88±0.66 vs. group D: 4.82±0.39; P<0.001). Images taken with a tin filter were found to have a significantly higher figure-of-merit than those taken without a tin filter (group A: 14,041±7,230 vs. group C: 21,866±10,656; P=0.001, and group B: 13,836±6,849 vs. group D: 21,639±9,964; P=0.001). In terms of metal artefact reduction, tin filtration combined with iMAR showed the lowest CT number reduction (116.62±103.48 HU) and metal diameter blurring (0.85±0.30) among the protocols. The effective radiation dose in the tin filter groups was 73.2% lower than that in the routine-dose groups. The complication rate and diagnostic performance (sensitivity, specificity, and overall accuracy) did not differ significantly between the tin filter and routine-dose groups (all P>0.05).

Conclusions

Tin filtration combined with an iMAR algorithm may reduce the radiation dose compared to the routine-dose CT protocol, while maintaining comparable diagnostic accuracy and image quality and producing fewer metal artefacts.

CT-Guided Transthoracic Biopsy of Pulmonary Lesions: Diagnostic versus Nondiagnostic Results

(1) Background: Despite the high accuracy of CT-guided transthoracic biopsy for diagnosis of pulmonary lesions, in a certain amount of cases biopsy results may indicate the presence of nonspecific findings or insufficient material. We aimed to investigate the effectiveness of CT-guided transthoracic biopsy of pulmonary lesions in providing a specific diagnosis and to analyze the variables affecting biopsy results. (2) Methods: In this retrospective study, a total of 170 patients undergoing 183 CT-guided transthoracic biopsies of pulmonary lesions were included. The clinical, radiological and pathological data were reviewed to classify biopsy results as diagnostic or nondiagnostic and to identify which variables were associated with the two groups. (3) Results: The biopsy results were diagnostic in 150 cases (82.0%), of which 131 (87.3%) positive for malignancy and 19 (12.7%) with specific benign lesions, and nondiagnostic in 33 cases (18.0%). Twenty-two of the thirty-three (66.7%) nondiagnostic cases were finally determined as malignancies and eleven (33.3%) as benign lesions. In the diagnostic group, all the 131 biopsies positive for malignancy were confirmed to be malignant at final diagnosis (87.3%); of 19 biopsies with specific benign lesions, 13 cases were confirmed to be benign (8.7%), whereas six cases had a final diagnosis of malignancy (4%). Multivariate analysis showed increased risk of nondiagnostic biopsy for lesions ≤ 20 mm (p = 0.006) and lesions with final diagnosis of benignity (p = 0.001). (4) Conclusions: CT-guided transthoracic lung biopsy is an effective technique for the specific diagnosis of pulmonary lesions, with a relatively acceptable proportion of nondiagnostic cases. Small lesion size and final benign diagnosis are risk factors for nondiagnostic biopsy results.

Computed Tomography-guided Lung Biopsy: A Review of Techniques for Reducing the Incidence of Complications

Computed tomography-guided lung biopsy is a well-established method for the histological diagnosis of pulmonary lesions. There is abundant literature regarding the diagnostic yield of and complications associated with computed tomography-guided lung biopsy. Many studies have investigated the risk factors influencing pneumothorax. Conversely, there are a limited number of reports detailing techniques for reducing the incidence of pneumothorax or other complications. This study reviews the indications, diagnostic accuracy, and complications of computed tomography-guided lung biopsy. In addition, techniques for reducing the incidence of these complications were reviewed.

Efficacy and safety of a new disposable percutaneous positioning device invented to facilitate the precision of percutaneous core needle lung biopsies: a prospective, open and randomized controlled study

Background

A new disposable percutaneous positioning device was developed which permits adjustment of the fixing puncture angle while performing a percutaneous core needle lung biopsy (CNLB). The aim of the study was to explore the positioning accuracy and clinical safety of the new device during CT-guided percutaneous CNLB.

Methods

A prospective, open and randomized controlled study with two parallel groups was conducted on 150 patients with pulmonary nodules between July 1, 2018 and June 30, 2019 including 101 males and 49 females who were divided (allocation ratio: 1:1) into a standard CNLB group without the percutaneous positioning device (control, n=75) and a new percutaneous positioning device group combined with CNLB (experimental, n=75). The efficacy was determined by the success rate of reaching the target location on the first percutaneous attempt, the number of CT scans performed and the time required for successful puncture positioning. Safety evaluations included complications related to percutaneous surgery and the new positioning device.

Results

The success rate of reaching the target location on the first percutaneous attempt in the experimental group was significantly higher than in the control group [96.0% (72/75) vs. 42.7% (32/75), P<0.001]. Patients in the experimental group received 3.05±0.28 times CT scans on average for successful percutaneous positioning, which was significantly lower than for the control group (3.95±1.03) (P<0.001). The time required to complete the percutaneous positioning was significantly lower in the experimental group compared to the control group (8.73±3.11 vs. 12.79±4.55 min, P<0.001). There was no significant difference in percutaneous-related complications between the two groups [48.0% (36/75) vs. 61.3% (46/75), P=0.101], except that the bleeding rate in the experimental group was lower than in the control group [26.7% (20/75) vs. 46.7% (35/75), P=0.032].

Conclusions

The use of the optimized percutaneous technology with the new positioning device significantly improved the accuracy and precision of percutaneous lung biopsies.

Trial Registration

ChiCTR-INR-17010322.

Application of a treatment planning system-assisted large-aperture computed tomography simulator to percutaneous biopsy: initial experience of a radiation therapist

Objective

To evaluate the application of treatment planning system (TPS)-assisted large-aperture computed tomography (CT) simulator to percutaneous biopsy.

Methods

This retrospective study enrolled patients that underwent TPS-assisted large-aperture CT simulator-guided percutaneous biopsy from November 2018 to December 2019. Retrospective analyses of puncture accuracy were compared using paired t-test and a Wilcoxon rank sum test. The risk factors for puncture accuracy and complications were identified.

Results

A total of 38 patients were included in this study. There were no significant differences between the planned and actual puncture depth and angle. Pulmonary puncture was significantly associated with the accuracy of the puncture angle. The diagnostic rate of malignancy was 76% (29 of 38), of which 20 of 25 patients were in the group initially diagnosed with unconfirmed lesions and nine of 13 patients were in the group of treated patients that needed additional pathological analyses. For patients that underwent a pulmonary biopsy, 12 had minor pneumothorax and three suffered needle track bleeding. No other complications were observed. Regression analyses indicated a significant correlation between puncture angle and the incidence of pneumothorax.

Conclusion

TPS-assisted large-aperture CT simulator may improve the percutaneous biopsy procedure by combining the advantages of radiotherapy specialties with computer targeting.

CT Guided Needle Biopsy of Peripheral Lesions-Lesion Characteristics That May Increase the Diagnostic Yield and Reduce the Complication Rate

Computed tomography-guided needle biopsy (CT-GNB) has a high diagnostic yield for lung cancer but higher complication rates compared to those of other biopsy modalities. We sought to clarify in which thoracic lesions we could achieve a quick pathological diagnosis using CT-GNB, considering the risks and benefits. We retrospectively enrolled 110 patients who underwent CT-GNB and 547 patients who underwent transbronchial biopsy (TBB) for parenchymal lung lesions in clinical practice. The diagnostic rates of CT-GNB and TBB were 87.3% and 75.3%. After failed diagnosis with other biopsy modalities, 92.3% of patients were finally diagnosed using CT-GNB and 65.8% using TBB. In cases with a negative bronchial sign, there was a statistically higher diagnostic rate with CT-GNB than with TBB (p < 0.001: 89.4% vs. 0%). Complication rates were higher with CT-GNB (50.9%) than with TBB (16.3%). However, there were lower rates of complications in cases with inhomogeneous tumors, subpleural lesions, and when more than 15 mm of the punctured needle length was within the target. We conclude that CT-GNB is an effective biopsy modality with a high diagnostic rate that is especially recommended when the bronchus sign is negative. It can be safely performed if risk factors for complications are taken into account.

Exploratory Study of a CT Radiomics Model for the Classification of Small Cell Lung Cancer and Non-small-Cell Lung Cancer

Background: Radiomics can quantify tumor phenotypic characteristics non-invasively by applying feature algorithms to medical imaging data. In this study, we investigated the association between radiomics features and the tumor histological subtypes, and we aimed to establish a nomogram for the classification of small cell lung cancer (SCLC) and non-small-cell lung cancer (NSCLC). Methods: This was a retrospective single center study. In total, 468 cases including 202 patients with SCLC and 266 patients with NSCLC were enrolled in our study, and were randomly divided into a training set (n = 327) and a validation set (n = 141) in a 7:3 ratio. The clinical data of the patients, including age, sex, smoking history, tumor maximum diameter, clinical stage, and serum tumor markers, were collected. All patients underwent enhanced computed tomography (CT) scans, and all lesions were pathologically confirmed. A radiomics signature was generated from the training set using the least absolute shrinkage and selection operator algorithm. Independent risk factors were identified by multivariate logistic regression analysis, and a radiomics nomogram based on the radiomics signature and clinical features was constructed. The capability of the nomogram was evaluated in the training set and validated in the validation set. Results: Fourteen of 396 radiomics parameters were screened as important factors for establishing the radiomics model. The radiomics signature performed well in differentiating SCLC and NSCLC, with an area under the curve (AUC) of 0.86 (95% CI: 0.82-0.90) in the training set and 0.82 (95% CI: 0.75-0.89) in the validation set. The radiomics nomogram had better predictive performance [AUC = 0.94 (95% CI: 0.90-0.98) in the validation set] than the clinical model [AUC = 0.86 (95% CI: 0.80-0.93)] and the radiomics signature [AUC = 0.82 (95% CI: 0.75-0.89)], and the accuracy was 86.2% (95% CI: 0.79-0.92) in the validation set. Conclusion: The enhanced CT radiomics signature performed well in the classification of SCLC and NSCLC. The nomogram based on the radiomics signature and clinical factors has better diagnostic performance for the classification of SCLC and NSCLC than the simple application of the radiomics signature.

Collection and Handling of Thoracic Small Biopsy and Cytology Specimens for Ancillary Studies: Guideline From the College of American Pathologists in Collaboration With the American College of Chest Physicians, Association for Molecular Pathology, American Society of Cytopathology, American Thoracic Society, Pulmonary Pathology Society, Papanicolaou Society of Cytopathology, Society of Interventional Radiology, and Society of Thoracic Radiology

CONTEXT.—

The need for appropriate specimen use for ancillary testing has become more commonplace in the practice of pathology. This, coupled with improvements in technology, often provides less invasive methods of testing, but presents new challenges to appropriate specimen collection and handling of these small specimens, including thoracic small biopsy and cytology samples.

OBJECTIVE.—

To develop a clinical practice guideline including recommendations on how to obtain, handle, and process thoracic small biopsy and cytology tissue specimens for diagnostic testing and ancillary studies.

METHODS.—

The College of American Pathologists convened an expert panel to perform a systematic review of the literature and develop recommendations. Core needle biopsy, touch preparation, fine-needle aspiration, and effusion specimens with thoracic diseases including malignancy, granulomatous process/sarcoidosis, and infection (eg, tuberculosis) were deemed within scope. Ancillary studies included immunohistochemistry and immunocytochemistry, fluorescence in situ hybridization, mutational analysis, flow cytometry, cytogenetics, and microbiologic studies routinely performed in the clinical pathology laboratory. The use of rapid on-site evaluation was also covered.

RESULTS.—

Sixteen guideline statements were developed to assist clinicians and pathologists in collecting and processing thoracic small biopsy and cytology tissue samples.

CONCLUSIONS.—

Based on the systematic review and expert panel consensus, thoracic small specimens can be handled and processed to perform downstream testing (eg, molecular markers, immunohistochemical biomarkers), core needle and fine-needle techniques can provide appropriate cytologic and histologic specimens for ancillary studies, and rapid on-site cytologic evaluation remains helpful in appropriate triage, handling, and processing of specimens.

CT-guided Core-Needle Biopsy of the Lung Is Safe and More Effective than Fine-Needle Aspiration Biopsy in Patients with Hematologic Malignancies

Purpose

To evaluate the safety and diagnostic yield of CT-guided core-needle biopsy (CNB) versus fine-needle aspiration biopsy (FNAB) of lung nodules and masses in patients with hematologic malignancies (HMs).

Materials and Methods

With institutional review board approval, 166 patients were retrospectively reviewed between 2007 and 2017 who were diagnosed with leukemia, lymphoma, or myelodysplastic syndromes (with or without hematopoietic stem cell transplant) and who underwent CT-guided FNAB and/or CNB of the lung. Patient medical records, pathologic reports, and interventional biopsy reports were reviewed.

Results

In the study period, 166 patients underwent percutaneous CT-guided lung biopsy; 36% (60 of 166) of the procedures included CNB (CNB + FNAB and CNB only), whereas 64% (106 of 166) were FNAB only. In the CNB group, FNAB was also performed for 92% (55 of 60) of the patients before CNB; 13% (eight of 60) of patients in the CNB group were nondiagnostic versus 45% (48 of 106) of FNAB only (P < .0001). There was no statistically significant difference in the pulmonary complication rates, with 1.7% of CNB and 1.9% of FNAB only requiring chest tube placement (P = .7), 5% of CNB and 2.8% of FNAB only developing hemoptysis (P = .4), and 5% of CNB and 2% of FNAB only developing hemothorax (P = .3). A change in clinical management was observed in 51% of patients with diagnostic biopsies compared with 21% of patients with nondiagnostic biopsies (P = .0002).

Conclusion

CT-guided CNB is an effective technique for performing lung biopsy in patients with HMs with higher diagnostic yield compared with FNAB, and a higher, although not a statistically significant, increased risk of bleeding complications and pneumothorax.© RSNA, 2019See also the commentary by Elicker in this issue.

Ultra-Low Radiation Dose CT Fluoroscopy for Percutaneous Interventions: A Porcine Feasibility Study

Purpose To determine the feasibility of ultra-low-dose (ULD) CT fluoroscopy for performing percutaneous CT-guided interventions in an in vivo porcine model and to compare radiation dose, spatial accuracy, and metal artifact for conventional CT versus CT fluoroscopy. Materials and Methods An in vivo swine model was used (n = 4, ∼50 kg) for 20 procedures guided by 246 incremental conventional CT scans (mean, 12.5 scans per procedure). The procedures were approved by the Institutional Animal Care and Use Committee and performed by two experienced radiologists from September 7, 2017, to August 8, 2018. ULD CT fluoroscopic acquisitions were simulated by using only two of 984 conventional CT projections to locate and reconstruct the needle, which was superimposed on a previously acquired and motion-compensated CT scan. The authors (medical physicists) compared the ULD CT fluoroscopy results to those of conventional CT for needle location, radiation dose, and metal artifacts using Deming regression and generalized mixed models. Results The average distance between the needle tip reconstructed using conventional CT and ULD CT fluoroscopy was 1.06 mm. Compared with CT fluoroscopy, the estimated dose for a percutaneous procedure, including planning acquisitions, was 0.99 mSv (21% reduction) for patients (effective dose) and 0.015 µGy (97% reduction) for physicians (scattered dose in air). Metal artifacts were statistically significantly reduced (P < .001, bootstrapping), and the average registration error of the motion compensation was within 1-3 mm. Conclusion Ultra-low-dose CT fluoroscopy has the potential to reduce radiation exposure for intraprocedural scans to patients and staff by a factor of approximately 500 times compared with conventional CT acquisition, while maintaining image quality without metal artifacts. © RSNA, 2019.

Cost-effectiveness of hydrogel plugs in CT-guided lung biopsies

OBJECTIVE

Using a hydrogel plug decreases the number of cases of pneumothorax and reduces the need for pleural drainage tubes in CT-guided lung biopsies. We aimed to analyze the cost-effectiveness of using hydrogel plugs.

MATERIAL AND METHODS

We analyzed 171 lung biopsies divided into three groups: Group 1 (n=22): fine-needle aspiration cytology (FNAC) without hydrogel plugs; Group 2 (n=89): FNAC with hydrogel plugs; and Group 3 (n=60): FNAC plus core-needle biopsy (CNB) with hydrogel plugs. We calculated the total costs (direct and indirect) in the three groups. We analyzed the percentage of correct diagnoses, the average and incremental rations, and the most cost-effective option.

RESULTS

Total costs: Group 1 = 1,261.28 + 52.65 = € 1,313.93; Group 2 = 1,201.36 + 67.25 = € 1,268.61; Group 3 = 1,220.22 + 47.20 = € 1,267.42. Percentage of correct diagnoses: Group 1 = 77.3%, Group 2 = 85.4%, and Group 3 = 95% (p = 0.04). Average cost-effectiveness ratio: Group 1 = 16.99; Group 2 = 14.85; and Group 3 = 13.34.

CONCLUSIONS

Group 3 was the best option, with the lowest average cost-effectiveness ratio; therefore, the most cost-effective approach is to do FNAC and CNB using a dehydrated hydrogel plug at the end of the procedure.

Efficacy of a Dehydrated Hydrogel Plug to Reduce Complications Associated With Computed Tomography-guided Percutaneous Transthoracic Needle Biopsy

PURPOSE

The aim of the study was to determine whether a hydrogel plug, when placed in the needle tract after a computed tomography-guided percutaneous transthoracic needle lung biopsy, reduces the rate of complications.

MATERIALS AND METHODS

This retrospective analysis included biopsies of lung lesions from 200 consecutive patients. The first 100 consecutive biopsies made up the control group, in which no plug intervention was used. The next 100 consecutive biopsies made up the treatment group, in which a hydrogel plug was deployed through a 19-G coaxial needle system after 20-G core samples were obtained.

RESULTS

The overall mean age was 64.92 years. No statistically significant differences in patient characteristics and procedure parameters were found between the control and treatment groups except for age (mean age, 62.92 vs. 66.92 y, P=0.022) and procedure duration (mean minutes, 7.81 vs. 6.47 min, P=0.021). The rate of pneumothorax in the control versus treatment group was 31% vs. 29% (P=0.498) and the rate of hemoptysis was 6% vs. 3% (P=0.354). The rate of chest tube insertion after pneumothorax was significantly higher in the control group than in the treatment group (10% vs. 2%, P=0.032) and the average length of hospital stay was longer in the control group (0.44 vs. 0.07 d, P=0.041). The difference was still statistically significant for the chest tube insertion rate (P=0.030) and close to statistically significant for the length of hospital stay (P=0.063), after adjusting for the confounding effect of age and procedure duration.

CONCLUSION

These data show that the deployment of a hydrogel plug after a computed tomography-guided lung biopsy significantly reduced the rate of chest tube insertion along with a reduced length of hospital stay.