Orio Peter F, Tutar Ismail B, Narayanan Sreeram, Arthurs Sandra, Cho Paul S, Kim Yongmin, Merrick Gregory, Wallner Kent E
Department of Radiation Oncology, University of Washington, Seattle, WA, USA.
Int J Radiat Oncol Biol Phys. 2007 Sep 1;69(1):302-7. doi: 10.1016/j.ijrobp.2007.04.072.
To evaluate a transrectal ultrasound (TRUS)-fluoroscopy fusion-based intraoperative dosimetry system.
Twenty-five patients were treated for prostate cancer with Pd-103 implantation. After the execution of the treatment plan, two sets of TRUS images were collected using the longitudinal and axial transducers of a biplanar probe. Then, three fluoroscopic images were acquired at 0, -15 and +15 degrees . The three-dimensional locations of all implanted seeds were reconstructed from fluoroscopic images. A subset of the implanted seeds was manually identified in TRUS images and used as fiducial markers to perform TRUS-fluoroscopy fusion. To improve the implant quality, additional seeds were placed if adverse isodose patterns were identified during visual inspection. If additional seeds were placed, intraoperative dosimetry was repeated. Day 0 computed tomography-based dosimetry was compared with final intraoperative dosimetry to validate dosimetry achieved in the implant suite.
An average of additional 4.0 seeds was implanted in 16 patients after initial intraoperative dose evaluation. Based on TRUS-fluoroscopy fusion-based dosimetry, the V100 improved from 86% to 93% (p = 0.005), whereas D90 increased from 94% to 109% (p = 0.011) with the guided additional seed implantation. No statistical difference was observed in V200 and V300 values. V100 and D90 values were 95 +/- 4% and 120 +/- 24%, respectively, based on the final intraoperative dosimetry evaluation, compared with 95 +/- 4% and 122 +/- 24%, respectively, based on Day 0 computed tomography-based dosimetry.
Implantation of extra seeds based on TRUS-fluoroscopy fusion-based intraoperative dosimetry can improve the final V100 and D90 values with minimal increase in V200 and V300 values.
评估一种基于经直肠超声（TRUS）-荧光透视融合的术中剂量测定系统。
25例前列腺癌患者接受了钯-103植入治疗。在执行治疗计划后，使用双平面探头的纵向和轴向换能器采集两组TRUS图像。然后，在0°、-15°和+15°获取三张荧光透视图像。从荧光透视图像重建所有植入籽源的三维位置。在TRUS图像中手动识别一部分植入的籽源并用作基准标记以进行TRUS-荧光透视融合。为提高植入质量，在目视检查期间若发现不利的等剂量模式，则放置额外的籽源。若放置了额外的籽源，则重复术中剂量测定。将第0天基于计算机断层扫描的剂量测定与最终术中剂量测定进行比较，以验证在植入室中实现的剂量测定。
在初始术中剂量评估后，16例患者平均额外植入了4.0颗籽源。基于TRUS-荧光透视融合的剂量测定，在引导下额外植入籽源后，V100从86%提高到93%（p = 0.005），而D90从94%增加到109%（p = 0.011）。V200和V300值未观察到统计学差异。基于最终术中剂量测定评估，V100和D90值分别为95±4%和120±24%，相比之下，基于第0天计算机断层扫描的剂量测定，V100和D90值分别为95±4%和122±24%。
基于TRUS-荧光透视融合的术中剂量测定植入额外的籽源可提高最终的V100和D90值，同时V200和V300值的增加最小。
