Stereotactic body radiation therapy (SBRT) using CyberKnife system is a relatively
new radiation therapy that has demonstrated feasibility, safety, and efficacy with
a high local control of various extracranial unresectable primary cancer and oligometastasis.
It involves accurate delivery of very high dose of radiation to the target or tumor
volume with high precision and conformity, while minimizing the radiation exposure
of nontargeted tissue. Radiopaque fiducial markers (FMs) implantation in and around
the tumors is required to track the selected tumor during CyberKnife SBRT, especially
in those organs moving with respiration. They act as internal radiographic landmarks
that maintain a fixed relationship within the tumor and with each other. Although
their implantation can be technically demanding, it can be performed using various
techniques with varying success; however, percutaneous implantation under image guidance
by interventional radiologists is the most common method. Close collaboration between
interventional radiologists and radiation oncologists with understanding of the technical
aspects of CyberKnife SBRT and FMs implantation has important implications for optimal
delivery of therapy and direct impact on the interventional radiology practice in
selected patients proposed for CyberKnife SBRT.
CyberKnife - fiducial marker - stereotactic body radiation therapy