Murugan Perumal, Manickam Ravikumar, Rajamanickam Tamilarasan, Muthu Sivakumar, Dinesan C, Appunu Karthik, Murali Abishake
Sri Shankara Cancer Hospital and Research Centre, Bengaluru, Karnataka, India.
Department of Radiotherapy, Sri Shankara Cancer Hospital and Research Centre, 1st Cross, Shankarapuram, Basavanagui, Bengaluru, Karnataka, 560004, India.
Radiol Phys Technol. 2025 Aug 23. doi: 10.1007/s12194-025-00954-7.
This study evaluates the dosimetric impact of material and mass density misassignments in Acuros XB dose calculations using phantom simulations and clinical analysis in Eclipse TPS. The phantom study analyzed material and mass density misassignments in Acuros XB using virtual phantoms with a central insert assigned different materials and mass densities to simulate misassignment. A clinical analysis of 270 patient CT scans from three scanners assessed HU variations in sinonasal cavities, bladder, and liver. Dosimetric deviations were examined in 96 radiotherapy patients across these anatomical sites by comparing automatic and manual material assignments, with dose differences assessed using D, D, and D for target volumes and misclassified structures. Material misassignment caused substantial dose differences, particularly in air-lung and cartilage-bone misassignments, with 12.1% and 2.8% deviations, respectively. Mass density misassignments led to dose variations of up to 5.5% for lung-air and 2% for bone. Combined misassignments amplified differences, reaching 18% for air-lung and 5.5% for cartilage-bone. Misassignment of non-biological materials such as biological tissues resulted in dose differences from 1 to 26.5%. Clinical analysis showed HU variations frequently led to material misassignment. Sinonasal air cavities were misclassified as lung, causing dose deviations of 11.8% for D, 8.6% for D, and 2.6% for D. Bladder and liver were predominantly misclassified as muscle and cartilage, respectively, resulting in systematic dose deviations of approximately 1% and 0.5%. Accurate material assignment is critical for precise Acuros XB dose calculations. Material mischaracterization introduces significant dose differences, necessitating manual verification in cases where auto-assignment is prone to misassignment.
本研究使用体模模拟和Eclipse治疗计划系统（TPS）中的临床分析，评估了Acuros XB剂量计算中材料和质量密度误分配的剂量学影响。体模研究使用虚拟体模分析了Acuros XB中的材料和质量密度误分配，该虚拟体模的中心插入物被赋予不同的材料和质量密度以模拟误分配。对来自三台扫描仪的270例患者CT扫描进行临床分析，评估鼻窦腔、膀胱和肝脏中的HU变化。通过比较自动和手动材料分配，检查了96例放疗患者在这些解剖部位的剂量学偏差，并使用D、D和D评估靶区体积和误分类结构的剂量差异。材料误分配导致了显著的剂量差异，尤其是在空气-肺和软骨-骨误分配中，偏差分别为12.1%和2.8%。质量密度误分配导致肺-空气的剂量变化高达5.5%，骨的剂量变化高达2%。组合误分配放大了差异，空气-肺的差异达到18%，软骨-骨的差异达到5.5%。生物组织等非生物材料的误分配导致剂量差异在1%至26.5%之间。临床分析表明，HU变化经常导致材料误分配。鼻窦空气腔被误分类为肺，导致D的剂量偏差为11.8%，D的剂量偏差为8.6%，D的剂量偏差为2.6%。膀胱和肝脏主要分别被误分类为肌肉和软骨，导致系统剂量偏差约为1%和0.5%。准确的材料分配对于精确的Acuros XB剂量计算至关重要。材料错误表征会引入显著的剂量差异，在自动分配容易出现误分配的情况下需要进行人工验证。
