Ultrasonic biopsy needle increases tissue yield in pilot study

An ultrasound-enhanced fine-needle aspiration biopsy technique produced higher tissue yield than conventional biopsy methods in a first-in-human pilot study of benign parotid gland tumors.

The study, published in European Radiology Experimental, evaluated ultrasound-enhanced fine-needle aspiration biopsy, or USeFNAB, in 10 adult patients with solid benign parotid gland tumors. Before parotidectomy, each tumor was sampled under ultrasound guidance using 3 techniques: USeFNAB, standard fine-needle aspiration biopsy, and core-needle biopsy.

USeFNAB uses flexural ultrasonic actuation of about 30 kHz at the hypodermic needle tip. The goal is to detach tissue fragments and collect larger samples through a fine needle, potentially combining some of the sample-yield advantages of core-needle biopsy with a less invasive needle approach.

The researchers found that cytology slide quality and histological sample quality were similar across USeFNAB, fine-needle aspiration biopsy, and core-needle biopsy. Sample mass with USeFNAB increased by an average of 1.6 times compared with fine-needle aspiration biopsy and 3.4 times compared with core-needle biopsy. Histological sample area increased by 1.7 and 3.4 times, respectively.

“With the new method we obtain two to three times more tissue than current needle biopsy techniques,” said co-lead author Yohann Le Bourlout of Aalto University.

Fine-needle aspiration biopsy and core-needle biopsy are both widely used to evaluate abnormal tissue masses, but each has limitations. Fine-needle aspiration can produce inadequate samples, while core-needle biopsy uses larger-gauge needles and is more invasive, according to the study.

The technique may be especially relevant as pathology increasingly relies on ancillary testing, including histochemical and molecular diagnostic studies. The authors said USeFNAB could improve diagnostic accuracy and facilitate those additional analyses.

The study protocol was approved by the Finnish Medicines Agency as an investigational device for research purposes, after risk analysis and mitigation. The authors concluded that USeFNAB appeared feasible and safe under in vivo conditions in solid benign parotid gland tumors.

Katri Aro, chief physician at Helsinki University Hospital and a lead author, said accurate diagnosis in the head and neck region can help clinicians plan surgery and counsel patients.

Further research will be needed to test the technique in larger patient groups and other tumor types. Aalto University researchers have indicated interest in exploring applications in thyroid and breast tumors.