Le Roux P L, Shackleton D, Wulff A
Br J Radiol. 1980 Dec;53(636):1177-81. doi: 10.1259/0007-1285-53-636-1177.
It has long been suspected that the depth-dose characteristics of modern 60Co teletherapy units are no longer well represented by the traditional data of The British Journal of Radiology Supplement 11. Extensive measurements have been undertaken on three modern 60Co units in an attempt to clarify this position. Three different values of source-to-skin distance were studied, namely 50, 80 and 100 cm. Systematic deviations from the traditional data are unambiguous, amounting to up to 3% at 80 cm SSD and as much as 7% at 50 cm SSD. Comparison with calibration results at a large number of institutions lends confidence that the present results are representative of modern treatment units.
长期以来，人们一直怀疑现代钴 - 60远距离治疗机的深度剂量特性已不能很好地由《英国放射学杂志增刊11》的传统数据来体现。为了澄清这一情况，已对三台现代钴 - 60治疗机进行了大量测量。研究了三种不同的源皮距，即50厘米、80厘米和100厘米。与传统数据的系统性偏差是明确的，在源皮距80厘米时偏差高达3%，在源皮距50厘米时偏差高达7%。与大量机构的校准结果进行比较，使人们相信目前的结果代表了现代治疗设备的情况。
