OPTIMIZATION OF DOSE DISTRIBUTIONS FROM INTRAOPERATIVE APPLICATORS

由于术中使用的单次剂量较高， 在放射治疗中，重要的是尽量减少高剂量的区域。这些领域 由于光子准直器之间的散射关系而产生， 施用器系统。它们可能是不对称的， 不对称的施用器设计，或施用器的制造公差， 涂抹器系统导致涂抹器的中心略微 不同于加速器的中心射线。这些剂量分布 可以通过使用最佳字段将其优化到预定标准 用于施加器和电子能量每种组合的尺寸。使用 不对称准直器可以进一步校正剂量的不均匀性 由于不对称设计、施用器斜角或 施用器未对准。

Due to the high single fraction doses employed in intraoperative radiotherapy, it is important to minimize areas of high dose. These areas arise due to the scattering relationship between the photon collimators and the applicator system. They may be non-symmetric due to either an asymmetric applicator design, or to manufacturing tolerances of the applicator system resulting in the center of the applicator to be slightly different than the central ray of the accelerator. These dose distributions can be optimized to predetermined criteria by the use of an optimum field size for each combination of applicator and electron energy. The use of asymmetric collimators can further correct for nonuniformity in the dose distribution due to asymmetric design, applicator bevel angle, or applicator mis-alignment.