Commentary: Finding a needle in a haystack—technology and innovation for precise intraoperative localization of deep-seated pulmonary nodules

Finding a needle in a haystack. Image courtesy strung together (strungt), Montreal, Canada.

Central Message.

Intraoperative localization of small, deep pulmonary nodules can be technically challenging. The use of a radiofrequency identification system may be a promising option to localize deep lesions.

See Article page 301 in the December 2020 issue.

Video-assisted thoracoscopic surgery without adjunctive localization techniques is best used for medium- to large-sized nodules located superficially or close to the pleural surface, because of the ability to visually inspect or palpate these lesions.¹ For deeper nodules, accurate localization can be challenging, and various techniques have been used preoperatively, including the use of hook wires, fiducial markers, micro-coils, injected dyes, and fluoroscopy.1, 2, 3 The choice of technique depends on its availability, safety, operator experience, hospital resource availability, and cost- and time-effectiveness.

We read with great interest and congratulate Sato and colleagues⁴ on their article on clinical application of a radiofrequency identification (RFID) marking system. The authors propose a novel technique to precisely locate small pulmonary nodules intraoperatively based on RFID technology. In their technique, a radiofrequency tag is inserted under virtual bronchoscopy and fluoroscopic guidance in proximity to the target lesion, the position of which is then confirmed with cone beam computed tomography. This tag communicates with an antenna to aid localization of the nodule intraoperatively and allow successful wedge resection with clear margins.

The authors have indeed made an important contribution, given that there is no gold standard for precisely locating small pulmonary nodules before surgical resection. Accurate localization of the target lesion is of high importance, since adequate wedge resection with clear margins may reduce the risk of disease recurrence.⁵ This technology has several positive attributes, including its potential relative simplicity, accuracy, and low risk in terms of complications. However, some key clinical aspects need to be taken into consideration before further clinical extrapolation of this novel technique for intraoperative localization of small lung nodules. First, the entire procedure including setup can be time-consuming, which could limit the number of procedures that can be performed and prolong the waiting period for critical surgeries, especially in high- volume centers. Second, the authors describe only a single case; widespread application will require larger series of cases with evaluation of accuracy, risk, marker displacement, and reproducibility. Furthermore, if a tissue diagnosis is obtained before surgery, it would be interesting to see whether the tag can be inserted during the same procedure to save cost and time. Other important limitations to widespread application of this technique is the requirement for both a virtual bronchoscopic system, cone beam computed tomography availability in the operating room, and the training, experience, and skill set required to accurately use these systems.

As we enter the era of increased ground glass opacity detection, lung cancer screening with resulting small nodules and an increased incidence of benign nodules and surgery for patients with limited pulmonary function with intraoperative localization techniques is becoming increasingly important. RFID marking may be an important adjunct to intraoperative localization to help us find that “needle in a haystack.”