Radionuclide Localization > Old Techniques

Old Techniques

Some Previously Described Localization Techniques and Their Limiting Features

Several techniques for easier localization of a nodule immediately prior to its thoracoscopic excisional biopsy have been described. These techniques include:

 

Methylene Blue:

Methylene blue injection of the pleura overlying a nodule using CT guidance followed by direct visualization of the stained area at thoracoscopy has been used by some surgeons.

Limitation: The dye frequently dissipates over a large area by the time the surgical procedure is performed. In addition, the dye does not clearly identify the depth of the lesion and therefore offers no guide to the required depth of the excisional biopsy for lesions greater than 1 cm below the pleural surface.

 

Kopans Needles or Other Hooked Devices:

Kopans needles and other hooked devices have been placed transthoracically using CT guidance with the surgeon subsequently cutting down upon and following these devices to the nodule at thoracoscopy.

Limitation: These devices are unreliable due to their frequent failure to stay in the region of the nodule. They are associated with a relatively high rate of pneumothorax. The surgeon's view of the lung is often from a different angle than that of the radiologist placing the needle. Therefore, tracking the wire down to the lesion may be difficult if it is not oriented in the exact thoracoscopic viewing plane. The wire may cross a fissure en route to the nodule making thoracoscopic resection more difficult.

 

Barium Markers:

Bronchoscopic placement of a barium marker near a nodule has been used with subsequent use of intraoperative fluoroscopy for localization of this radiopaque material in or near the nodule.

Limitation: The bronchoscopic skill required is not readily available at most institutions. Requirement of fluoroscopy in the operating room and the limited viewing angles available with a patient in the lateral decubitus position make this technique cumbersome. Fluoroscopic time and associated radiation exposure to the patient and operators can become significant in difficult cases.

 

Cyanoacrylate Material:

Cyanoacrylate material has been placed transthoracically using CT guidance followed by intraoperative fluoroscopic localization of this radiopaque material in or near the nodule.

Limitation: Hard consistency of this material makes sectioning for pathologic examination difficult. There is also concern about possible embolization of this material into the systemic circulation.

 

Lipiodol:

Lipiodol has been injected into or near a nodule using CT guidance with the subsequent use of intraoperative fluorocoscopy for localization of this radiopaque material.

Limitation: Possible systemic embolization of the marking solution and intraoperative need for fluoroscopy limit this technique's usefulness.

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