Suntharalingam N, Steben J D
Med Phys. 1977 Mar-Apr;4(2):134-40. doi: 10.1118/1.594391.
Central-axis percentage depth doses and tissue-maximum ratios (TMR) for 45-MV photon beams from a betatron have been measured in water. Also the influence of field size and collimator scatter on the dose in the buildup region have been investigated. The maximum dose for TMR has been shown to occur at a point about 2 cm deeper than the maximum dose for percentage depth dose. This difference is significant in the characterization of the photon beam at this high energy. The measured physical data have been computerized for use in routine treatment planning. Computer-gererated beams have been found to be in close agreement with measured isodose curves. Computer-generated isodose distributions for typical clinical irradiation techniques have been verified using RP/V film in an Alderson phantom.
已在水中测量了来自电子感应加速器的45兆伏光子束的中心轴百分深度剂量和组织最大剂量比（TMR）。还研究了射野大小和准直器散射对建成区剂量的影响。已表明TMR的最大剂量出现在比百分深度剂量的最大剂量深约2厘米处。在这种高能情况下，这种差异对光子束的特性描述具有重要意义。已将测量的物理数据进行计算机处理，以用于常规治疗计划。已发现计算机生成的射束与测量的等剂量曲线非常吻合。已使用Alderson体模中的RP/V胶片验证了典型临床照射技术的计算机生成等剂量分布。
