Dinges S, Koswig S, Buchali A, Wurm R, Schlenger L, Böhmer D, Budach V
Department of Radiotherapy, University Hospital Charité, Humboldt University of Berlin, Germany.
Strahlenther Onkol. 1998 Oct;174 Suppl 2:28-30.
The exact coverage of the lymph nodes and optimal shielding of the organs at risk are necessary for patients with Hodgkin's disease or malignant lymphoma to guarantee a high cure rate and a low rate of late effects for normal tissue. The purpose of this study was to compare conventional simulation and blocking with virtual simulation in terms of coverage of the target volume and shielding of the organs at risk in this highly curative patient group.
In 10 patients diagnosed with Hodgkin's disease and 5 patients with a Non-Hodgkin lymphoma radiation treatment planning for a mantle field or para-aortic field with inclusion of the spleen was performed in a conventional manner and with virtual simulation. With conventional technique, irradiation portals were defined during fluoroscopy and shielding of the organs at risk was drawn onto the simulation films, based on the information from previous X-ray films, CT or MRI scans. For virtual simulation, contouring of the target volumes and organs at risk (e.g. the kidneys) and the definition of the irradiation portals were performed with the AcQSim software package on a VoxelQ workstation (Picker Inc.) This was done in a beam's eye view environment on a currently driven CT scan in the treatment position. Both irradiation portals were compared in terms of coverage of the target volume and shielding of the organs at risk.
Planning of a mantle field in the conventional way resulted in an incomplete coverage of the right hilus in 4/15 cases and of the left in 1/15 cases, respectively. The spleen and the spleen hilus were not covered completely in 5/15 and 6/15 cases, respectively. The left kidney was adequately shielded in only two thirds (10/15) of the conventionally planned fields. The planning time required for virtual simulation was reduced for the patient, but was increased for the physician because of the more time consuming contouring procedure compared to conventional simulation.
Virtual simulation based on CT scans for radiation treatment planning of malignant lymphoma gives more information about soft tissue structures than conventional treatment planning. Therefore, it allows a more precise coverage of the target volumes and better shielding of the organs at risk. However, the time required for the whole procedure is increased. This is justified because of the often highly curative intention when treating this group of patients.
对于霍奇金病或恶性淋巴瘤患者，精确覆盖淋巴结并对危及器官进行最佳防护，对于保证高治愈率和降低正常组织的晚期效应发生率至关重要。本研究的目的是在这个高治愈率患者群体中，比较传统模拟定位和铅挡块技术与虚拟模拟定位在靶区覆盖和危及器官防护方面的差异。
对10例诊断为霍奇金病的患者和5例非霍奇金淋巴瘤患者，采用传统方法和虚拟模拟定位技术进行包括脾脏的斗篷野或腹主动脉旁野的放射治疗计划设计。采用传统技术时，在透视下确定照射野，并根据先前的X线片、CT或MRI扫描信息，在模拟片上画出危及器官的铅挡块。对于虚拟模拟定位，在VoxelQ工作站（Picker公司）上使用AcQSim软件包对靶区和危及器官（如肾脏）进行轮廓勾画，并在治疗体位的当前CT扫描图像上以射野视角环境确定照射野。比较两种照射野在靶区覆盖和危及器官防护方面的差异。
采用传统方法设计斗篷野时，分别有4/15例右侧肺门和1/15例左侧肺门覆盖不完全。脾脏和脾门分别有5/15例和6/15例未完全覆盖。在传统设计的野中，只有三分之二（10/15）的野能充分保护左肾。虚拟模拟定位所需的计划时间对患者来说减少了，但对医生来说却增加了，因为与传统模拟相比，轮廓勾画过程更耗时。
基于CT扫描的虚拟模拟定位技术在恶性淋巴瘤放射治疗计划设计中，比传统治疗计划能提供更多关于软组织结构的信息。因此，它能更精确地覆盖靶区，并更好地保护危及器官。然而，整个过程所需时间增加了。鉴于治疗这类患者通常有很高的治愈意图，这是合理的。
