Informace o publikaci

A framework for alignment of on-board imagers of medical linear accelerators

Autoři

TULIK M. KABAT D. KYCIA Radoslaw Antoni TABOR Z. WOSZCZYNA A. LATALA Z.

Rok publikování 2018
Druh Článek v odborném periodiku
Časopis / Zdroj Physica Medica : European Journal of Medical Physics
Fakulta / Pracoviště MU

Přírodovědecká fakulta

Citace
www https://www.sciencedirect.com/science/article/pii/S1120179718300401
Doi http://dx.doi.org/10.1016/j.ejmp.2018.02.017
Klíčová slova QA-quality assurance; OBI-on-board imagers; IGRT-image-guided radiotherapy; Linear accelerator geometry
Popis Purpose: To develop an assumption-free methodology for aligning the geometry of on-board imagers with the geometry of medical linear accelerators applied in image-guided radiotherapy (IGRT). Material: Alignment of the on-board imaging (OBI) system with respect to the accelerator system is achieved using a multi-modular phantom described elsewhere (Tabor et al., 2017), enabling the geometry of the linear accelerator to be specified without any pre-assumptions. Methods: The placement of two isocentres (of the on-board imager and of the therapeutic system) and of three frames of reference (those of the on-board imager, of the therapeutic system, and of the treatment table) is formulated as an optimization problem. It is solved by analysing the images of fiducial points positioned in 3D space in phantom modules attached to the treatment table and to the collimator of the accelerator. Fiducials are projected onto an imaging plane of unknown characteristics from a virtual source of unknown coordinates. Conclusions: An analytical framework exploiting projection images of the proposed multi-modular phantom has been developed, enabling precise alignment of the reference frame related to the on-board imager with the reference frame related to the therapeutic system. Within the proposed framework, the necessary corrections of treatment table positioning prior to patient irradiation, are delivered in the treatment table coordinates.

Používáte starou verzi internetového prohlížeče. Doporučujeme aktualizovat Váš prohlížeč na nejnovější verzi.

Další info