PURPOSE: CyberKnife Frameless Image-Guided Radiosurgery with the SynchronyTM Motion Tracking Module is now available for the treatment of thoracic malignancies. Gold fiducial markers are required for the treatment planning and tracking of the tumor during each treatment. Fiducials have traditionally been placed under CT-guidance. We describe our center's experience placing fiducials using flexible bronchoscopy with a transbronchial aspiration needle (TBNA).
METHODS: All patients referred for CyberKnife stereotactic radiosurgery at Georgetown University Hospital for treatment of thoracic malignancies were reviewed by a multidisciplinary thoracic oncology team. Patients with centrally located or larger peripheral tumors were selected for fiducial placement via flexible bronchoscopy. Gold fiducials were loaded into the tip of the 19-gauge needle of a 19/21-gauge transbronchial needle. At the desired location, the 19-gauge needle was advanced. The 21-gauge needle was extended and the fiducial deployed under fluoroscopic guidance. Data collected included patient demographics, number and location of fiducials placed, and complications associated with their placement.
RESULTS: Between July 2004 and March 2005 a total of twenty-eight patients underwent fiducial placement via flexible bronchoscopy. The main diagnosis was non-small cell lung cancer (58% of the patients) and the main reason for choosing CyberKnife therapy was previous radiotherapy to the chest. A total of 110 fiducials were inserted (average of 3.8 fiducials per target lesion). 61 were placed in mediastinal, 9 hilar and 40 parenchymal. Three fiducials embolized during insertion via the pulmonary artery without adverse clinical consequence and 1 patient developed bronchospasm requiring mechanical ventilation for 48 hours. A single fiducial was expectorated prior to treatment. There was no incidence of pneumothorax or significant bleeding.
CONCLUSION: Flexible bronchoscopy using a TBNA needle for fiducial placement appears to be safe. At our institution, flexible bronchoscopy is the preferred method for insertion of fiducials in mediastinal, hilar and larger peripheral tumors. CT-guidance is recommended for smaller peripheral nodules.
CLINICAL IMPLICATIONS: Gold fiducials may be placed for CyberKnife stereotactic radiosurgery safely via flexible bronchoscopy.
DISCLOSURE: Eric Anderson, Consultant fee, speaker bureau, advisory committee, etc. I have received honoraria from Accuray for lectures given in 2006.