Ferreira I H, Richter J, Dutreix A, Bridier A, Chavaudra J, Svensson H
ESTRO-EQUAL Measuring Laboratory, Service de Physique, Institut Gustave-Roussy, Villejuif, France.
Strahlenther Onkol. 2001 Aug;177(8):383-93. doi: 10.1007/s00066-001-0864-9.
In 1998 an ESTRO Quality Assurance Network for radiotherapy (EQUAL) has been set up for 25 European countries for photon and electron beams in reference and non-reference conditions.
Measurements are done using LiF powder (DTL937-Philitech, France) that is processed with the PCL3 automatic reader (Fimel-PTW). The participating centers irradiate the TLDs with an absorbed dose of 2 Gy according to the clinical routine.
Until September 2000 EQUAL has checked 135 photon beams (including the beams rechecked) from 51 radiotherapy centers in Germany out of 86 accepted centers. The results show that 2% of the beam outputs in reference conditions and 3% of the percentage depth doses are outside the tolerance level (deviation > +/- 5%). 6% of the beam output variations and of the wedge transmission factors show deviations > +/- 5%. The global analysis of results shows deviations > +/- 5% in at least one parameter for 18 beams out of the 135 beams checked. Five rechecked beams present one "real dosimetric" problem in one or more parameters, corresponding to 4% of the 114 beams for which the deviations cannot be attributed to set-up errors.--The EQUAL network has checked 89 electron beams in Germany. The results show that all beam outputs checked are within the tolerance level. The standard deviation for the beam output in reference conditions is 2.0% and 2.2% for the beam output for the others field sizes. The percentage of deviations > 3% and < or = 5% for the reference beam output is higher for electron beams than for photon beam checks. Therefore the electron beam calibration and the TPS algorithms should be improved to increase the accuracy of the patient dosimetry for radiotherapy.
EQUAL program demonstrates a consistency in radiotherapy dosimetry for photon and electron beams resulting in a satisfying accuracy of the dosimetry in Germany.
1998年，为25个欧洲国家建立了一个放射治疗ESTRO质量保证网络（EQUAL），用于参考条件和非参考条件下的光子和电子束。
使用LiF粉末（法国Philitech公司的DTL937）进行测量，并通过PCL3自动读数器（Fimel-PTW）进行处理。参与中心按照临床常规用2 Gy的吸收剂量照射热释光剂量计。
截至2000年9月，EQUAL已检查了德国86个被接受中心中51个放射治疗中心的135束光子束（包括重新检查的束）。结果显示，参考条件下2%的射束输出和3%的百分深度剂量超出公差水平（偏差>±5%）。6%的射束输出变化和楔形滤过器传输因子显示偏差>±5%。对结果的整体分析表明，在检查的135束射束中，有18束至少有一个参数的偏差>±5%。五束重新检查的射束在一个或多个参数中存在一个“实际剂量学”问题，占114束偏差不能归因于设置误差的射束的4%。——EQUAL网络已检查了德国的89束电子束。结果显示，所有检查的射束输出均在公差水平内。参考条件下射束输出的标准偏差为2.0%，其他野尺寸射束输出的标准偏差为2.2%。电子束参考射束输出偏差>3%且≤5%的百分比高于光子束检查。因此，应改进电子束校准和治疗计划系统算法，以提高放射治疗患者剂量测定的准确性。
EQUAL计划证明了光子束和电子束放射治疗剂量测定的一致性，在德国产生了令人满意的剂量测定准确性。
