基于 Halcyon™ 环形机架医用直线加速器的容积旋转调强弧形治疗全骨髓照射的临床前验证和治疗。

Preclinical validation and treatment of volumetric modulated arc therapy based total bone marrow irradiation in Halcyon™ ring gantry linear accelerator.

机构信息

Department of Radiation Oncology, Apollo Multispeciality Hospitals, Kolkata, India.

Department of Hemato Oncology, Apollo Multispeciality Hospitals, Kolkata, India.

出版信息

Radiat Oncol. 2022 Aug 19;17(1):145. doi: 10.1186/s13014-022-02109-z.

DOI:10.1186/s13014-022-02109-z

PMID:35986327

原文链接:https://pmc.ncbi.nlm.nih.gov/articles/PMC9389791/

Abstract

AIM

This study aims to report preclinical validation, and the first clinical treatment of total bone marrow irradiation (TMI) and total bone marrow and lymph nodal irradiation (TMLI) using Volumetric modulated arc therapy in Halcyon-E ring gantry linear accelerator. Preclinical validation includes simulation, planning, patient-specific QA, and dry run.

MATERIAL AND METHOD

Four patients, two female and two male, with body weights of 116 kg, 52 kg, 64 kg, and 62 kg; with two with chronic myeloid leukemia, one each with acute lymphoblastic leukemia and acute myeloid leukemia (AML) were simulated and planned for TMI/TMLI. Patients were immobilized with a full-body vacuum bag. Head first supine (HFS) and Feet first supine (FFS) CT scans were acquired from head to knee and knee to toe. Planning target volume (PTV) was created with a uniform margin of 6 mm over the total bone marrow/bone marrow + lymph nodes. HFS and FFS PTVs were optimized independently using 6MV unflatten energy for 12 Gy in 6 fractions. Plans were merged to create the resultant dose distribution using a junction bias dose matching technique. The total number of isocenters was ≤ 10 per CT set, and two to four full arcs were used for each isocenter. A junction dose gradient technique was used for dose feathering between arcs between adjacent isocenters.

RESULT

Only one female patient diagnosed as AML received the TMLI treatment, while the other three patients dropped out due to clinical complications and comorbidities that developed in the time between simulation and treatment. The result presented has been averaged over all four patients. For PTV, 95% dose was normalised to 95% volume, PTV_V107% receiving 3.3 ± 3.1%. Total lung mean and V12Gy were 1048.6 ± 107.1 cGy and 19.5 ± 12.1%. Maximum lens doses were 489.5 ± 35.5 cGy (left: L) and 497 ± 69.2 cGy (right: R). The mean cardiac and bilateral kidney doses were 921.75 ± 89.2 cGy, 917.9 ± 63.2 cGy (L), and 805.9 ± 9.7 cGy (R). Average Monitor Unit was 7738.25 ± 1056.6. The median number of isocenters was 17(HFS+FFS), average MU/Dose (cGy) ratio per isocenter was 2.28 ± 0.3.

CONCLUSION

Halcyon-E ring gantry linear accelerator capable of planning and delivering TMI/TMLI..

摘要

目的

本研究旨在报告使用 Halcyon-E 环机架直线加速器中的容积调强弧形治疗技术对全骨髓照射（TMI）和全骨髓及淋巴结照射（TMLI）进行临床前验证和首次临床治疗。临床前验证包括模拟、计划、患者特异性质量保证和预演。

材料与方法

对 2 例慢性髓系白血病、1 例急性淋巴细胞白血病和 1 例急性髓系白血病患者进行模拟和 TMI/TMLI 计划。患者用全身真空袋固定。行从头至膝关节和膝关节至脚趾的头高脚低仰卧位（HFS）和脚高脚低仰卧位（FFS）CT 扫描。在整个骨髓/骨髓+淋巴结上创建 6mm 的均匀边界以形成计划靶区（PTV）。使用 6MV 非均整能量对 HFS 和 FFS PTV 进行独立优化，6 个分次给予 12Gy。使用连接剂量偏置剂量匹配技术将计划合并以创建最终剂量分布。每个 CT 集的等中心点总数≤10 个，每个等中心点使用 2 到 4 个全弧。在相邻等中心点之间的弧形之间使用连接剂量梯度技术进行剂量渐变。

结果

仅有一名被诊断为 AML 的女性患者接受了 TMLI 治疗，而其他三名患者由于在模拟和治疗之间出现的临床并发症和合并症而退出。结果是所有四名患者的平均值。对于 PTV，95% 的剂量归一化为 95% 的体积，PTV_V107% 接受 3.3±3.1%。总肺平均剂量和 V12Gy 分别为 1048.6±107.1 cGy 和 19.5±12.1%。最大晶状体剂量分别为 489.5±35.5 cGy（左：L）和 497±69.2 cGy（右：R）。心脏和双侧肾脏的平均剂量分别为 921.75±89.2 cGy、917.9±63.2 cGy（L）和 805.9±9.7 cGy（R）。平均监测单位为 7738.25±1056.6。等中心点中位数为 17（HFS+FFS），每个等中心点的平均 MU/剂量（cGy）比为 2.28±0.3。