A new device (electromagnetic tracking) to locate hard-to-see targets during biopsy and ablation

This study will evaluate the accuracy and effectiveness of an experimental tracking device for locating abnormalities during invasive procedures, such as biopsy or ablation, that cannot easily be visualized by usual imaging techniques, such as computed tomography (CT) scans or ultrasound. Some lesions, such as certain liver or kidney tumors, small endocrine abnormalities, and others, may be hard to find or only visible for a few seconds. The new method uses a needle with a miniature tracking device buried inside the metal that tells where the tip of the needle is located, somewhat like a mini GPS, or global positioning system. It uses a very weak magnet to localize the device like a miniature satellite system. This study will explore whether this system can be used in the future to more accurately place the needle in or near the desired location or abnormality.

Patients 18 years of age and older who have a lesion that needs to be biopsied or an ablation procedure that requires CT guidance may be eligible for this study. Candidates are screened with a medical history and review of medical records, including imaging studies.

Participants undergo the biopsy or ablation procedure as they normally would, with the following exceptions: some stickers are placed on the skin before the procedure and a very weak magnet is placed nearby. The needles used are similar to the ones that would normally be used except that they contain a metal coil or spring buried deep within the needle metal. The procedure involves the following steps:

1. Small 1-cm plastic donuts are place on the skin with tape. 2. A planning CT scan is done. 3. The CT scan is sent to the computer and matched to the patient's body location with the help of a very weak magnet. 4. The needle used for the procedure is placed towards the target tissue or abnormality and the "smart needle" location lights up on the old CT scan. 5. A repeat CT is done as it normally is to look for the location of the needle. 6. After the procedure the CT scans are examined to determine how well the new tool located the needle in the old scan.