Development and evaluation of a novel MR-compatible pelvic end-to-end phantom.
Development and evaluation of a novel MR-compatible pelvic end-to-end phantom.
复制标题
DOI：
10.1002/acm2.12455
复制
发表时间：
2019-01
影响因子：
2.1
通讯作者：
Glide-Hurst CK
中科院分区：
文献类型：
--
作者：
Cunningham JM;Barberi EA;Miller J;Kim JP;Glide-Hurst CK
仅 MR 治疗计划和 MR-IGRT 利用 MRI 强大的软组织对比度进行高精度放射治疗。然而，拟人化的 MR 兼容体模目前还很有限。这项工作描述了定制设计、模块化、骨盆端到端 (PETE) MR 兼容体模的开发和评估，以对纯 MR 和 MR-IGRT 工作流程进行基准测试。出于构造方面的考虑，对模型/骨骼几何形状和内脏器官运动学的受试者数据进行了评估，以模拟平均男性骨盆解剖结构。评估了用于骨骼、膀胱和直肠的各种材料在模型中的实用性。构建完成后，PETE 接受了 CT-SIM、MR-Linac 和 MR-SIM 成像，以定性评估器官可见度。对不同膀胱和直肠体积进行扫描，以通过体积和质心差异评估成分相互作用、充盈能力和充盈再现性。 PETE 模拟平均男性骨盆解剖结构，包括一个亚克力椭圆体（高度/宽度 = 23.0/38.1 厘米）和一个铸模聚氨酯骨架，以及模拟膀胱和直肠的硅胶气球、硅胶海绵前列腺和亲水性聚（乙烯醇）泡沫来模拟器官之间的脂肪/组织分离。接入端口可以使用其他插件（包括基于点/胶片的剂量测定选项）对体模进行改造。 CT-SIM 和 MR-Linac 图像可实现可接受的对比度。然而，在 CT-SIM 中很难将膀胱与背景区分开来。 T1 加权和 T2 加权 MR-SIM（分别为暗膀胱和亮膀胱）达到了所需的对比度。直肠和骨骼未显示 MR 信号。输入的体积与描绘的直肠 (CT-SIM) 和膀胱 (MR-SIM) 体积相差 <5 和 <10 mL。膀胱和直肠体积的增加引起器官移位和形状变化。再现体积相差 <4.5 mL，质心位移 <1.4 mm。使用 MR-Linac 中的 MR 兼容离子室进行的点剂量测量在预期的 1.5% 以内。采用合适的材料和特性开发了一种新颖的模块化模型，可以通过多种剂量测定选项准确且可重复地模拟状态变化。未来的工作包括整合更真实的器官模型，以进一步扩大模型的选择。
MR‐only treatment planning and MR‐IGRT leverage MRI's powerful soft tissue contrast for high‐precision radiation therapy. However, anthropomorphic MR‐compatible phantoms are currently limited. This work describes the development and evaluation of a custom‐designed, modular, pelvic end‐to‐end (PETE) MR‐compatible phantom to benchmark MR‐only and MR‐IGRT workflows. For construction considerations, subject data were assessed for phantom/skeletal geometry and internal organ kinematics to simulate average male pelvis anatomy. Various materials for the bone, bladder, and rectum were evaluated for utility within the phantom. Once constructed, PETE underwent CT‐SIM, MR‐Linac, and MR‐SIM imaging to qualitatively assess organ visibility. Scans were acquired with various bladder and rectal volumes to assess component interactions, filling capabilities, and filling reproducibility via volume and centroid differences. PETE simulates average male pelvis anatomy and comprises an acrylic body oval (height/width = 23.0/38.1 cm) and a cast‐mold urethane skeleton, with silicone balloons simulating bladder and rectum, a silicone sponge prostate, and hydrophilic poly(vinyl alcohol) foam to simulate fat/tissue separation between organs. Access ports enable retrofitting the phantom with other inserts including point/film‐based dosimetry options. Acceptable contrast was achievable in CT‐SIM and MR‐Linac images. However, the bladder was challenging to distinguish from background in CT‐SIM. The desired contrast for T1‐weighted and T2‐weighted MR‐SIM (dark and bright bladders, respectively) was achieved. Rectum and bone exhibited no MR signal. Inputted volumes differed by <5 and <10 mL from delineated rectum (CT‐SIM) and bladder (MR‐SIM) volumes. Increasing bladder and rectal volumes induced organ displacements and shape variations. Reproduced volumes differed by <4.5 mL, with centroid displacements <1.4 mm. A point dose measurement with an MR‐compatible ion chamber in an MR‐Linac was within 1.5% of expected. A novel, modular phantom was developed with suitable materials and properties that accurately and reproducibly simulate status changes with multiple dosimetry options. Future work includes integrating more realistic organ models to further expand phantom options.
登录
查看更多内容
影响因子：
3.5
作者：
Schmidt MA;Payne GS
通讯作者：
Payne GS
影响因子：
3.1
作者：
Hentschel, Bettina;Oehler, Wolfgang;Hentschel, Bettina
通讯作者：
Hentschel, Bettina
DOI：
10.1186/s13014-017-0854-4
发表时间：
2017-07-17
期刊：
Radiation oncology (London, England)
影响因子：
--
作者：
Tyagi N;Fontenla S;Zelefsky M;Chong-Ton M;Ostergren K;Shah N;Warner L;Kadbi M;Mechalakos J;Hunt M
通讯作者：
Hunt M
影响因子：
3.8
作者：
Soliman, Abraam S.;Burns, Levi;Chugh, Brige P.
通讯作者：
Chugh, Brige P.
影响因子：
3.8
作者：
Siversson, Carl;Nordstrom, Fredrik;Olsson, Lars E.
通讯作者：
Olsson, Lars E.