McCarroll Rachel, Youssef Bassem, Beadle Beth, Bojador Maureen, Cardan Rex, Famiglietti Robin, Followill David, Ibbott Geoffrey, Jhingran Anuja, Trauernicht Christoph, Balter Peter, Court Laurence
, , , , , , , and , The University of Texas MD Anderson Cancer Center; The University of Texas Graduate School of Biomedical Sciences at Houston, Houston, TX; , Benavides Cancer Institute, University of Santo Tomas Hospital, Manila, Philippines; , University of Alabama Birmingham, Birmingham, AL; , American University of Beirut Medical Center, Beirut, Lebanon; and , Groote Schuur Hospital, Cape Town, South Africa.
J Glob Oncol. 2017 Jan 11;3(5):563-571. doi: 10.1200/JGO.2016.005306. eCollection 2017 Oct.
More than 6,500 megavoltage teletherapy units are needed worldwide, many in low-resource settings. Cobalt-60 units or linear accelerators (linacs) can fill this need. We have evaluated machine performance on the basis of patient throughput to provide insight into machine viability under various conditions in such a way that conclusions can be generalized to a vast array of clinical scenarios.
Data from patient treatment plans, peer-reviewed studies, and international organizations were combined to assess the relative patient throughput of linacs and cobalt-60 units that deliver radiotherapy with standard techniques under various power and maintenance support conditions. Data concerning the frequency and duration of power outages and downtime characteristics of the machines were used to model teletherapy operation in low-resource settings.
Modeled average daily throughput was decreased for linacs because of lack of power infrastructure and for cobalt-60 units because of limited and decaying source strength. For conformal radiotherapy delivered with multileaf collimators, average daily patient throughput over 8 years of operation was equal for cobalt-60 units and linacs when an average of 1.83 hours of power outage occurred per 10-hour working day. Relative to conformal treatments delivered with multileaf collimators on the respective machines, the use of advanced techniques on linacs decreased throughput between 20% and 32% and, for cobalt machines, the need to manually place blocks reduced throughput up to 37%.
Our patient throughput data indicate that cobalt-60 units are generally best suited for implementation when machine operation might be 70% or less of total operable time because of power outages or mechanical repair. However, each implementation scenario is unique and requires consideration of all variables affecting implementation.
全球需要超过6500台兆伏远距离治疗设备，其中许多位于资源匮乏地区。钴 - 60设备或直线加速器（直线加速器）可以满足这一需求。我们根据患者吞吐量评估了机器性能，以便深入了解在各种条件下机器的可行性，从而使结论能够推广到大量临床场景。
结合患者治疗计划、同行评审研究和国际组织的数据，评估在各种功率和维护支持条件下采用标准技术进行放射治疗的直线加速器和钴 - 60设备的相对患者吞吐量。有关停电频率和持续时间以及机器停机时间特征的数据用于模拟资源匮乏地区的远距离治疗操作。
由于缺乏电力基础设施，直线加速器的模拟平均每日吞吐量下降；而钴 - 60设备则由于源强度有限和衰减而下降。对于使用多叶准直器进行的适形放疗，当每10小时工作日平均停电1.83小时时，钴 - 60设备和直线加速器在8年运行期间的平均每日患者吞吐量相等。相对于在各自机器上使用多叶准直器进行的适形治疗，直线加速器上使用先进技术使吞吐量降低了20%至32%，而对于钴设备，手动放置挡块的需求使吞吐量降低了37%。
我们的患者吞吐量数据表明，由于停电或机械维修，当机器运行时间可能占总可运行时间的70%或更少时，钴 - 60设备通常最适合实施。然而，每个实施场景都是独特的，需要考虑所有影响实施的变量。
