Johnstone Peter A S, Kerstiens John, Wasserman Stuart, Rosenberg Stephen A
Department of Radiation Oncology, Moffitt Cancer Center, Tampa, FL 33612, USA.
Cancer Care Centers of Brevard, Melbourne, FL 32901, USA.
J Clin Med. 2022 Feb 7;11(3):869. doi: 10.3390/jcm11030869.
Two benefits of MR-guided radiotherapy (MRgRT) are the ability to track target structures while treatment is being delivered and the ability to adapt plans daily for some lesions based on changing anatomy. These unique capacities come at two costs: increased capital for acquisition and greatly decreased workflow. An adaptive gated stereotactic body radiotherapy (MRgART) treatment routinely takes ~90 min to perform and requires the presence of both a physician and a physicist. This may significantly limit daily capacity. We previously described how "simple cases" were necessary for proton facilities to allow for debt management. In this manuscript, we seek to determine the optimal scheduling of different MRgRT plans to recoup capital costs.
MATERIALS/METHODS: We assumed an MR-linac (MRL) was completely scheduled with patients over workdays of varying duration. Treatment times and reimbursement data from our facility for varying complexities of patients were extrapolated for varying numbers treated daily. We then derived the number of adaptive and non-adaptive patients required daily to optimize the schedules. HOPPS data were used to model reimbursement.
A single MRL treating 14 non-gated, non-adaptive IMRT patients over an 8 h workday would take about 4.8 years to cover initial acquisition and installation costs. However, such patients may be more quickly and efficiently treated with a conventional linear accelerator, while MRgART cases may only be treated with an MRL. By treating four of these daily, that same MRL room would cover costs in 2.4 years. Personnel, maintenance costs, and profit further complicate any business case for treating non-adaptive patients or for extending hours.
In our previously published paper discussing proton therapy, we noted that debt is not variable with capacity; this remains true with MRgRT. Different from protons, a clinically optimal case load of adaptive patients provides an optimal business case as well. This requires a large patient cadre to ensure continuing throughput. As improvements in MRgRT are brought to the clinic, shorter adaptive and non-adaptive treatment times will help improve the timeframe to recoup costs but will require even more appropriate patients.
磁共振引导放疗（MRgRT）的两个优势在于，在进行治疗时能够追踪靶结构，以及针对某些病变能够根据解剖结构的变化每天调整治疗计划。这些独特的能力带来了两方面的代价：购置成本增加以及工作流程大幅减慢。自适应门控立体定向体部放疗（MRgART）治疗通常需要约90分钟完成，并且需要一名医生和一名物理学家同时在场。这可能会显著限制每日治疗量。我们之前描述过，对于质子治疗设施而言，“简单病例”对于债务管理是必要的。在本论文中，我们试图确定不同MRgRT计划的最佳排程，以收回资本成本。
材料/方法：我们假设一台磁共振直线加速器（MRL）在不同时长的工作日内完全排满了患者。根据我们机构中不同复杂程度患者的治疗时间和报销数据，推算出每日治疗不同数量患者的情况。然后，我们得出了每日所需的自适应和非自适应患者数量，以优化排程。使用HOPPS数据对报销情况进行建模。
一台MRL在8小时工作日内治疗14名非门控、非自适应的调强放疗（IMRT）患者，大约需要4.8年才能收回初始购置和安装成本。然而，这类患者使用传统直线加速器可能治疗得更快且更高效，而MRgART病例可能只能用MRL治疗。若每天治疗4例此类患者，同一个MRL机房将在2.4年内收回成本。人员、维护成本以及利润使得治疗非自适应患者或延长工作时间的任何商业案例变得更加复杂。
在我们之前发表的讨论质子治疗的论文中，我们指出债务不会随治疗量而变化；MRgRT也是如此。与质子治疗不同，临床上自适应患者的最佳病例负荷也提供了最佳的商业案例。这需要大量的患者群体以确保持续的治疗量。随着MRgRT技术在临床上的改进，更短的自适应和非自适应治疗时间将有助于缩短收回成本的时间框架，但这将需要更合适的患者。
