[Three-dimensional conformal radiotherapy for extracranial tumors using a stereotactic body frame]

This paper was reviewed to evaluate the feasibility of three-dimensional (3-D) conformal radiotherapy for extracranial tumors, especially for solitary lung tumors using a stereotactic body frame. To extend the technique of stereotactic irradiation for intracranial tumors, accurate body fixation and regulation of internal target motion are essential. In our study, a stereotactic body frame was used, and daily setup accuracy was verified. As a result, its setup accuracy was maintained within 0-8.5 mm (Ave=2.5mm). In our initial clinical experiences for thirty-two patients with 6-10 non-coplanar static beams, forty or 48 Gy was irradiated. During the follow-up of 4-27 (Average=11) months, twenty-nine (94%) tumors were locally controlled without any symptomatic complications. Recently, respiratory-gated irradiation systems, CT-linac systems, a real-time tumor tracking system, Cyber-knife, and C-arm linac were developed. With all these techniques, stereotactic irradiation for extracranial tumors are future direction of three-dimensional conformal radiotherapy.