EXTENSION OF THE NET FRACTIONAL DEPTH DOSE FOR INHOMOGENEITY CORRECTION

对身体组织中不均质性的影响的校正是 在治疗优化中的相当重要的，尤其是 胸部区域的病变，如乳房肿瘤， 食道，或肺。CT的出现使这一点变得有意义。这个 最近描述的NFD已通过合并 场大小和深度参数中的密度比例概念， 在分析形式主义中，因此包含了对 不均质性。此方法现在包括对 二次电子传输是一组重要的条件。进一步 需要做的工作是将电子输运修正纳入近 对于光束边缘和较大场中的小的不均匀性。方法 看起来是准确的、通用的和易于实施的。

The correction for the effect of inhomogeneity in body tissue is of considerable importance in the treatment optimization especially, of lesions in the thoracal region, such as the tumors of the breast, the esophagus, or the lung. The advent of CT has made this meaningful. The recently described NFD has been extended by the incorporation of the density scaling concept in the field size as well as the depth parameter, in the analytical formalism, thus including correction for inhomogeneities. This method now includes correction for the effect of secondary electron transport for a significant set of conditions. Further work needs to be done to incorporate the electron transport correction near the beam edges and for small inhomogeneities in larger fields. The method appears to be accurate, versatile and easy to implement.