科研之友
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摘要
Background: Portal-vein stent combined with one iodine-125 (I-125) seed strand has become a new treatment for portal vein tumor thrombosis. However, dosimetric aspects of this irradiation stent have not been reported. Therefore, we aimed to undertake dosimetric analyses comparing portal-vein stents combined with different numbers of I-125 seed strands. @@@ Methods: A water cylinder was created by a treatment-planning system to simulate a portal-vein stent. The stent was combined with one, two, or three I-125 seed strands (Groups I, II, and III, respectively). At different prescribed doses (PDs), 125I seeds of identical activities were loaded on Groups I-III. Conformation number (CN), external volume index, and homogeneity index were calculated. Linear regression analyses were used to evaluate the obtained data. @@@ Results: For identical I-125 seed activity, when the I-125 seed strand increased from one chain to two, D90 (dose delivered to 90% of the target volume) increased by >= 184%; when it increased fiom two chains to three, D90 increased by >= 63%. When the PD was 105 Gy and I-125 seed strands increased from one chain to two, V-100 (percentage of the target volume receiving >= 90% of the PD) increased by 158-249%; when it increased from two chains to three, V-100 increased by 7-175%. CN was correlated positively with (125)J seed activity (B = 0.479, P < 0.001) and number of (125)J seed strands (B = 0.201, P < 0.001) and was independent of PD (B = -0.002, P = 0.078). @@@ Conclusions: Aportal-vein stent combined with a single I-125 seed strand could not meet dosimetry requirements. For a stent combined with two I-125 seed strands, when the PD was 105 Gy and seed activity was 0.7 mCi, the dose distribution could satisfy dosimetry requirements. For a stent combined with three (125)J seed strands, if the PD was 105, 125, or 145 Gy, the recommended seed activities were 0.5, 0.5, and 0.6 mCi, respectively.
- 出版日期2017-9-20
- 单位北京大学
