Enable dosimetric of the Stereotactic Body Frame from Elekta in treatment planning systems for Radiotherapy

The purpose of this study is to evaluate the commissioning of a stereotactic body frame (SBF®, Elekta) professional treatment planning systems (TPS) model Elekta's PrecisePlan® and ERGO++®, for highly foxused delivery of megavoltage photon beams intended for treating tumors located in the thorax and abdominal region. For this purpose we applicated a dedicate stereotactic body frame (SBF®, Elekta) intended for high precision radiotherapy in extra-cranial located tumors was studied. Issues associated with their implementation in the TPSs were evaluated comparing the dose calculations in two studies of CT under different conditions. an anthropomorphic thorax phantom, model CIRS Thorax IMRT®, was used in designing several test cases. Ion chamber measurement was permormed in selected points in the phantom, for comparison purposes with dose calculated by the treatment planning systems. The commissioning of the stereotactic body frame (SBF®, Elekta) and the stereotactic localization was verified, including the dose calculation verification in presence the SBF. The attenuation factors measured for the SBF were obtained and corrected in the TPS PrecisePlan®, the biggest discrepancies obtained were ∼5% for the oblique sectors (inferior corners), because the minimum permissible value for the software is 0.95 while the real value measured was 0.898. It was studied the SBF, their components and their interference in depth with the photon beams and their implementation in the TPS. The introduction of the correction factors demonstrated to be effective to reduce the eventual errors of dose calculation in the TPS . (Author)