What is pre-operative tumour marking?
Pre-operative tumour marking is the placement of special markers like hook wires and coils inside the tumour under image guidance. Tumour marking may also include a colouring agent to aid in visualising the lesion.
Pre-operative tumour marking may be used to assist surgeons in the removal of tumour tissue by clearly marking the margins or location of the tumour. Sometimes tumours are so small that it is difficult to see with the naked eyes or feel. By marking the tumour under image-guidance, the surgeon can see and feel the edges of the tumour better during operation. An imaging technique, such as mammography, ultrasound, CT or magnetic resonance may be used to locate the tumour during the marking procedure.
How does the procedure work?
Pre-operative tumour marking is mainly used for tumours in the breast and lung. There are different types of tumour marking materials. The main purpose of these materials is to make the target lesion easy to find during operation.
The IR will introduce the materials into the lesion of interest with the use of a puncture needle that is placed through the skin under image guidance. The most frequently used method of marking changes in the breast that cannot be seen or felt is the use of special metallic wires that are “anchored” in the selected breast area. Newer device includes tiny metal markers that can be detected by a magnetic probe during operation.
It is possible to use pre-operative coil-marking of tumours in muscles and bones with the use of MR guidance, or marking lung tumours with metallic wires under CT guidance
Why perform it?
Pre-operative marking is widely used for breast cancer patients who are candidates for breast conserving therapy (BCT). More than half of breast cancer in these patients are difficult to see or feel during operation. It is crucial to remove the tumour with a proper margin of healthy tissues which minimises the need for further surgery.
Localisation markers can be applied to virtually all parts of the body. They improve precision of the surgery and reduce operation time as the target can be readily seen or felt.
What are the risks?
These procedures are often very safe. Possible risks include bleeding, bruising, infection and, if the patient has lung lesions, pneumothorax (the abnormal collection of gas or air in the space between the lung and the chest wall). The marker may move out of place between the time of pre-operative marking and surgery.
Bibliography
1. Pereira PL1, Fritz J, Koenig CW, Maurer F, Boehm P, Badke A, Mueller-Schimpfle M, Bitzer M, Claussen CD. Preoperative marking of musculoskeletal tumors guided by magnetic resonance imaging. J Bone Joint Surg Am. 2004 Aug; 86-A(8):1761-7.
2. Masaya Tamura, Makoto Oda, Hideki Fujimori, Yosuke Shimizu, Isao Matsumoto, Go Watanabe. New indication for preoperative marking of small peripheral pulmonary nodules in thoracoscopic surgery Interactive CardioVascular and Thoracic Surgery 11 (2010) 590–593.
3. Beata A, Pawel M. Preoperative localization of nonpalpable breast nodules – which method to choose? Reports of Practical Oncology & Radiotherapy Volume 13, Issue 4, July–August 2008, Pages 202–2.