Usefulness of ultrasound-guided core biopsy in thyroid nodules with inconclusive fine-needle aspiration biopsy findings

OBJECTIVES

To determine the diagnostic performance of ultrasound-guided core-needle biopsy in thyroid nodules after two inconclusive fine-needle aspiration biopsies. To assess the complications of core-needle biopsy. To analyze the reliability of diagnoses obtained with core-needle biopsy. To measure the economic impact of avoiding lobectomies in patients with benign core-needle biopsy findings.

MATERIAL AND METHODS

This retrospective study reviewed 195 core-needle biopsies in 178 patients. To determine the reliability of the core-needle biopsy findings, we compared the diagnosis from the core-needle specimen versus the histologic findings in the surgical specimens when core-needle biopsy findings indicated malignancy or follicular proliferation and versus the stability of the nodule on ultrasound follow-up for one year when core-biopsy findings indicated benignity.

RESULTS

Core-needle biopsy yielded a diagnosis for 179 (91.7%) nodules, of which 122 (62.5%) were classified as benign, 50 (25.6%) as follicular proliferation, and 7 (3.6%) as malignant. The findings were inconclusive for 16 (8.3%) nodules. Minor complications were observed in 4 (2%) patients; no major complications were observed. The sensitivity of core-needle biopsy for the diagnosis of thyroid cancer was low (42.8%) because the technique was unable to detect capsular or vascular invasion, although the specificity and positive predictive value (PPV) were 100%. However, when we considered histologic findings of malignancy and follicular proliferation positive because both require surgical resection, the sensitivity increased to 97.5% and the PPV decreased to 83.3%. There were 79 nodules with ultrasound follow-up for at least one year; 76 (96.2%) had negative core-needle biopsy findings, and 74 (97.3%) of these remained stable. The negative predictive value (NPV) for malignancy of the benign nodules was 98.6%, although no malignant transformation was observed. Nevertheless, the results of the statistical analysis do not allow us to recommend forgoing ultrasound follow-up in patients with benign core-biopsy findings. The cost savings of avoiding lobectomy in patients with benign nodules and stability of the nodule on ultrasound follow-up for at least one year was about 90%.

CONCLUSIONS

Core-needle biopsy of thyroid nodules is effective because it diagnoses more than 90% of nodules with inconclusive findings after fine-needle aspiration biopsy. It is safe if done by experienced professionals. It is reliable because it yields 100% specificity and 100% PPV for malignant nodule, 97.5% sensitivity for the detection of nodules that require surgery, and 98.6% NPV for benign nodules. It is efficient because it reduces the costs of diagnosis compared to lobectomy in benign nodules.

Usefulness of ultrasound-guided core biopsy in thyroid nodules with inconclusive fine-needle aspiration biopsy findings

OBJECTIVES

To determine the diagnostic performance of ultrasound-guided core-needle biopsy in thyroid nodules after two inconclusive fine-needle aspiration biopsies. To assess the complications of core-needle biopsy. To analyze the reliability of diagnoses obtained with core-needle biopsy. To measure the economic impact of avoiding lobectomies in patients with benign core-needle biopsy findings.

MATERIAL AND METHODS

This retrospective study reviewed 195 core-needle biopsies in 178 patients. To determine the reliability of the core-needle biopsy findings, we compared the diagnosis from the core-needle specimen versus the histologic findings in the surgical specimens when core-needle biopsy findings indicated malignancy or follicular proliferation and versus the stability of the nodule on ultrasound follow-up for one year when core-biopsy findings indicated benignity.

RESULTS

Core-needle biopsy yielded a diagnosis for 179 (91.7%) nodules, of which 122 (62.5%) were classified as benign, 50 (25.6%) as follicular proliferation, and 7 (3.6%) as malignant. The findings were inconclusive for 16 (8.3%) nodules. Minor complications were observed in 4 (2%) patients; no major complications were observed. The sensitivity of core-needle biopsy for the diagnosis of thyroid cancer was low (42.8%) because the technique was unable to detect capsular or vascular invasion, although the specificity and positive predictive value (PPV) were 100%. However, when we considered histologic findings of malignancy and follicular proliferation positive because both require surgical resection, the sensitivity increased to 97.5% and the PPV decreased to 83.3%. There were 79 nodules with ultrasound follow-up for at least one year; 76 (96.2%) had negative core-needle biopsy findings, and 74 (97.3%) of these remained stable. The negative predictive value (NPV) for malignancy of the benign nodules was 98.6%, although no malignant transformation was observed. Nevertheless, the results of the statistical analysis do not allow us to recommend forgoing ultrasound follow-up in patients with benign core-biopsy findings. The cost savings of avoiding lobectomy in patients with benign nodules and stability of the nodule on ultrasound follow-up for at least one year was about 90%.

CONCLUSIONS

Core-needle biopsy of thyroid nodules is effective because it diagnoses more than 90% of nodules with inconclusive findings after fine-needle aspiration biopsy. It is safe if done by experienced professionals. It is reliable because it yields 100% specificity and 100% PPV for malignant nodule, 97.5% sensitivity for the detection of nodules that require surgery, and 98.6% NPV for benign nodules. It is efficient because it reduces the costs of diagnosis compared to lobectomy in benign nodules.

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.