Das I J, McGee K P, Fein D A, Milito S J, Shammo G, Curran W J, Coia L R
Department of Radiation Oncology, Fox Chase Cancer Center, Philadelphia, PA 19111, USA.
Radiographics. 1995 Nov;15(6):1483-8. doi: 10.1148/radiographics.15.6.8577971.
A three-dimensional treatment planning system capable of gantry, collimator, and table rotations is required for a noncoplanar conformal therapy. Unfortunately, such a system is not widely available. A method in which multiplanar reformatted radiographic (MPR) and digitally reconstructed radiographic (DRR) images are used is presented for conformal treatment of brain tumors. A head phantom containing a target volume was scanned on a computed tomographic (CT) simulator. The coronal MPR images were digitized on a treatment planning system to create a conformal block of the planned treatment field. The DRR images were generated on the CT simulator with the setup parameters calculated from the treatment planning system. A second set of conformal blocks was generated based on DRR images of the fields. The accuracy of the MPR- and DRR-generated blocks was verified on the vertex field. The differences between the actual planning target volume and the field edges of the MPR and DRR blocks were within +/- 4 mm and +/- 2 mm, respectively. The authors conclude that the MPR and DRR images could be successfully used to generate conformal blocks and for treatment planning of noncoplanar beams in radiation therapy.
非共面适形治疗需要一个能够进行机架、准直器和治疗床旋转的三维治疗计划系统。不幸的是，这样的系统尚未广泛应用。本文提出了一种使用多平面重组射线照相（MPR）和数字重建射线照相（DRR）图像的方法，用于脑肿瘤的适形治疗。在计算机断层扫描（CT）模拟器上扫描包含靶区的头部体模。在治疗计划系统上对冠状位MPR图像进行数字化处理，以创建计划治疗野的适形挡块。利用从治疗计划系统计算出的设置参数，在CT模拟器上生成DRR图像。基于野的DRR图像生成第二组适形挡块。在头顶野验证了MPR和DRR生成挡块的准确性。实际计划靶区与MPR和DRR挡块的野边缘之间的差异分别在±4mm和±2mm以内。作者得出结论，MPR和DRR图像可成功用于生成适形挡块以及放射治疗中非共面射束的治疗计划。
