Comparing voxel-based absorbed dosimetry methods in tumors, liver, lung, and at the liver-lung interface for (90)Y microsphere selective internal radiation therapy.
Comparing voxel-based absorbed dosimetry methods in tumors, liver, lung, and at the liver-lung interface for (90)Y microsphere selective internal radiation therapy.
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DOI：
10.1186/s40658-015-0119-y
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发表时间：
2015-12
期刊：
影响因子：
4
通讯作者：
Kappadath SC
中科院分区：
文献类型：
--
作者：
Mikell JK;Mahvash A;Siman W;Mourtada F;Kappadath SC
为了评估基于 90Y 轫致辐射 SPECT/CT 的 90Y 微球选择性内放射治疗 (SIRT) 后四种不同的基于体素的剂量测定方法 (VBDM) 之间肿瘤、肝脏和肺吸收剂量的差异，次要目标是估计由于肝肺界面附近器官分割的差异而导致的肝脏和肺吸收剂量的敏感性。研究的 VBDM 包括蒙特卡罗 (MC)、密度校正软组织内核 (SKD)、软组织内核 (SK) 和局部沉积 (LD)。对 17 个 SIRT 案例进行了分析。计算肿瘤、非肿瘤肝脏 (NL) 和右肺 (RL) 的平均吸收剂量 ()。使用各种 SPECT 空间分辨率 (FHWM) 和多个肺分流分数 (LS) 进行的模拟估计了 VBDM 在肝肺界面处的准确性。通过排除靠近界面的部分来评估患者 RL 和 NL 对界面附近分割的敏感性。 SKD、SK 和 LD 的肿瘤和 NL 的 MC 误差在 5% 以内。与 MC 相比，LD 和 SKD 平均分别高估 RL 17 和 20%； SK 平均低估了 RL -60%。模拟（20 mm FWHM，20% LS）表明 SKD、LD 和 MC 与肺部深处真实情况（>39 mm）的误差在 10% 以内； SK 显着低估了肺部深处的吸收剂量约 -70%。所有 VBDM 均位于肝脏深处 (>12 mm) 的真实值的 10% 以内。对于所有 VBDM，排除界面附近 1、2 和 3 cm 的 RL 后，所得 RL 分别改变了 -22、-38 和 -48%。当从界面中排除 3 cm 的 NL 时，NL 的平均变化为 -7%。 当从界面中排除 3 cm NL 时实现。 SKD、SK 和 LD 相当于肿瘤的 MC 和 NL。相对于 MC，SK 低估了 RL，而 LD 和 SKD 则高估了。 RL 受肝肺界面的强烈影响。
To assess differences between four different voxel-based dosimetry methods (VBDM) for tumor, liver, and lung absorbed doses following 90Y microsphere selective internal radiation therapy (SIRT) based on 90Y bremsstrahlung SPECT/CT, a secondary objective was to estimate the sensitivity of liver and lung absorbed doses due to differences in organ segmentation near the liver-lung interface. Investigated VBDM were Monte Carlo (MC), soft-tissue kernel with density correction (SKD), soft-tissue kernel (SK), and local deposition (LD). Seventeen SIRT cases were analyzed. Mean absorbed doses () were calculated for tumor, non-tumoral liver (NL), and right lung (RL). Simulations with various SPECT spatial resolutions (FHWMs) and multiple lung shunt fractions (LSs) estimated the accuracy of VBDM at the liver-lung interface. Sensitivity of patient RL and NL on segmentation near the interface was assessed by excluding portions near the interface. SKD, SK, and LD were within 5 % of MC for tumor and NL . LD and SKD overestimated RL compared to MC on average by 17 and 20 %, respectively; SK underestimated RL on average by −60 %. Simulations (20 mm FWHM, 20 % LS) showed that SKD, LD, and MC were within 10 % of the truth deep (>39 mm) in the lung; SK significantly underestimated the absorbed dose deep in the lung by approximately −70 %. All VBDM were within 10 % of truth deep (>12 mm) in the liver. Excluding 1, 2, and 3 cm of RL near the interface changed the resulting RL by −22, −38, and −48 %, respectively, for all VBDM. An average change of −7 % in the NL was realized when excluding 3 cm of NL from the interface. was realized when excluding 3 cm of NL from the interface. SKD, SK, and LD are equivalent to MC for tumor and NL . SK underestimates RL relative to MC whereas LD and SKD overestimate. RL is strongly influenced by the liver-lung interface.