Department of Radiation Oncology, Bangalore Institute of Oncology, 44-45/2, II Cross, RRMR Extension, Bangalore 560027, India.
Phys Med. 2011 Jan;27(1):21-9. doi: 10.1016/j.ejmp.2010.01.006. Epub 2010 Feb 20.
In radiation therapy, the monitor units (MU) needed to deliver a treatment plan are calculated by treatment planning systems (TPS). The essential part of quality assurance is to verify the MU with independent monitor unit calculation to correct any potential errors prior to the start of treatment. In this study, we have compared the MU calculated by TPS and by independent MU verification software. The MU verification software was commissioned and tested for the data integrity to ensure that the correct beam data was considered for MU calculations. The accuracy of the calculations was tested by creating a series of test plans and comparing them with ion chamber measurements. The results show that there is good agreement between the two. The MU difference (MUdiff) between the monitor unit calculations of TPS and independent MU verification system was calculated for 623 fields from 245 patients and was analyzed by treatment site for head & neck, thorax, breast, abdomen and pelvis. The mean MUdiff of -0.838% with a standard deviation of 3.04% was observed for all 623 fields. The site specific standard deviation of MUdiff was as follows: abdomen and pelvis (<1.75%), head & neck (2.5%), thorax (2.32%) and breast (6.01%). The disparities were analyzed and different correction methods were used to reduce the disparity.
在放射治疗中，治疗计划系统（TPS）计算出完成治疗计划所需的监测单位（MU）。质量保证的重要部分是通过独立的监测单位计算来验证 MU，以在治疗开始前纠正任何潜在的错误。在这项研究中，我们比较了 TPS 和独立 MU 验证软件计算出的 MU。MU 验证软件经过委托和测试，以确保数据完整性，从而确保在 MU 计算中考虑了正确的射束数据。通过创建一系列测试计划并将其与电离室测量值进行比较，测试了计算的准确性。结果表明，两者之间具有良好的一致性。为 245 名患者的 623 个射野计算了 TPS 和独立 MU 验证系统的监测单位计算之间的 MU 差异（MUdiff），并按头颈部、胸部、乳房、腹部和骨盆进行了治疗部位分析。所有 623 个射野的 MUdiff 平均值为-0.838%，标准差为 3.04%。MUdiff 的特定部位标准差如下：腹部和骨盆（<1.75%）、头颈部（2.5%）、胸部（2.32%）和乳房（6.01%）。对差异进行了分析，并使用不同的校正方法来减少差异。
