A novel four-dimensional radiotherapy planning strategy from a tumor-tracking beam's eye view

被引:18
作者
Li, Guang [1 ]
Cohen, Patrice [1 ]
Xie, Huchen [2 ]
Low, Daniel [3 ]
Li, Diana [1 ]
Rimner, Andreas [4 ]
机构
[1] Mem Sloan Kettering Canc Ctr, Dept Med Phys, New York, NY 10021 USA
[2] NCI, Radiat Oncol Branch, NIH, Bethesda, MD 20892 USA
[3] Univ Calif Los Angeles, Dept Radiat Oncol, Los Angeles, CA 90024 USA
[4] Mem Sloan Kettering Canc Ctr, Dept Radiat Oncol, New York, NY 10021 USA
关键词
DEFORMABLE IMAGE REGISTRATION; MOVING TARGETS; LUNG-CANCER; MONTE-CARLO; CT SCANS; MOTION; SEGMENTATION; PREDICTION;
D O I
10.1088/0031-9155/57/22/7579
中图分类号
R318 [生物医学工程];
学科分类号
0831 ;
摘要
To investigate the feasibility of four-dimensional radiotherapy (4DRT) planning from a tumor-tracking beam's eye view (ttBEV) with reliable gross tumor volume (GTV) delineation, realistic normal tissue representation, high planning accuracy and low clinical workload, we propose and validate a novel 4D conformal planning strategy based on a synthesized 3.5D computed tomographic (3.5DCT) image with a motion-compensated tumor. To recreate patient anatomy from a ttBEV in the moving tumor coordinate system for 4DRT planning (or 4D planning), the centers of delineated GTVs in all phase CT images of 4DCT were aligned, and then the aligned CTs were averaged to produce a new 3.5DCT image. This GTV-motion-compensated CT contains a motionless target (with motion artifacts minimized) and motion-blurred normal tissues (with a realistic temporal density average). Semi-automatic threshold-based segmentation of the tumor, lung and body was applied, while manual delineation was used for other organs at risk (OARs). To validate this 3.5DCT-based 4D planning strategy, five patients with peripheral lung lesions of small size (<5 cm(3)) and large motion range (1.2-3.5 cm) were retrospectively studied for stereotactic body radiotherapy (SBRT) using 3D conformal radiotherapy planning tools. The 3.5DCT-based 4D plan (3.5DCT plan) with 9-10 conformal beams was compared with the 4DCT-based 4D plan (4DCT plan). The 4DCT plan was derived from multiple 3D plans based on all phase CT images, each of which used the same conformal beam configuration but with an isocenter shift to aim at the moving tumor and a minor beam aperture and weighting adjustment to maintain plan conformality. The dose-volume histogram (DVH) of the 4DCT plan was created with two methods: one is an integrated DVH (iDVH(4D)), which is defined as the temporal average of all 3D-phase-plan DVHs, and the other (DVH4D) is based on the dose distribution in a reference phase CT image by dose warping from all phase plans using the displacement vector field (DVF) from a free-form deformable image registration (DIR). The DVH3.5D (for the 3.5DCT plan) was compared with both iDVH(4D) and DVH4D. To quantify the DVH difference between the 3.5DCT plan and the 4DCT plan, two methods were used: relative difference (%) of the areas underneath the DVH curves and the volumes receiving more than 20% (V20) and 50% (V50) of prescribed dose of these 4D plans. The volume of the delineated GTV from different phase CTs varied dramatically from 24% to 112% among the five patients, whereas the GTV from 3.5DCT deviated from the averaged GTV in 4DCT by only -6% +/- 6%. For planning tumor volume (PTV) coverage, the difference between the DVH3.5D and iDVH(4D) was negligible (<1% area), whereas the DVH3.5D and DVH4D were quite different, due to DIR uncertainty (similar to 2 mm), which propagates to PTV dose coverage with a pronounced uncertainty for small tumors (0.3-4.0 cm(3)) in stereotactic plans with sharp dose falloff around PTV. For OARs, such as the lung, heart, cord and esophagus, the three DVH curves (DVH3.5D, DVH4D and iDVH(4D)) were found to be almost identical for the same patients, especially in high-dose regions. For the tumor-containing lung, the relative difference of the areas underneath the DVH curves was found to be small (5.3% area on average), of which 65% resulted from the low-dose region (D < 20%). The averaged V20 difference between the two 4D plans was 1. 2% +/- 0.8%. For the mean lung dose (MLD), the 3.5DCT plan differed from the 4DCT plan by -1.1% +/- 1.3%. GTV-motion-compensated CT (3.5DCT) produces an accurate and reliable GTV delineation, which is close to the mean GTV from 4DCT. The 3.5DCT plan is equivalent to the 4DCT plan with <1% dose difference to the PTV and negligible dose difference in OARs. The 3.5DCT approach simplifies 4D planning and provides accurate dose calculation without a substantial increase of clinical workload for motion-tracking delivery to treat small peripheral lung tumors with large motion.
引用
收藏
页码:7579 / 7598
页数:20
相关论文
共 37 条
[1]   Feasibility of a novel deformable image registration technique to facilitate classification, targeting, and monitoring of tumor and normal tissue [J].
Brock, KK ;
Dawson, LA ;
Sharpe, MB ;
Moseley, DJ ;
Jaffray, DA .
INTERNATIONAL JOURNAL OF RADIATION ONCOLOGY BIOLOGY PHYSICS, 2006, 64 (04) :1245-1254
[2]   Treatment of early non-small cell lung cancer, stage IA, by image-guided robotic stereotactic radioablation- CyberKnife [J].
Brown, William T. ;
Wu, Xiaodong ;
Amendola, Beatriz ;
Perman, Mark ;
Han, Hoke ;
Fayad, Fahed ;
Garcia, Silvio ;
Lewin, Alan ;
Abitbol, Andre ;
de la Zerda, Alberto ;
Schwade, James G. .
CANCER JOURNAL, 2007, 13 (02) :87-94
[3]   Improving Radiation Conformality in the Treatment of Non-Small-Cell Lung Cancer [J].
Chang, Joe Y. ;
Cox, James D. .
SEMINARS IN RADIATION ONCOLOGY, 2010, 20 (03) :171-177
[4]   A simple fixed-point approach to invert a deformation field [J].
Chen, Mingli ;
Lu, Weiguo ;
Chen, Quan ;
Ruchala, Kenneth J. ;
Olivera, Gustavo H. .
MEDICAL PHYSICS, 2008, 35 (01) :81-88
[5]   Real-time intra-fraction-motion tracking using the treatment couch: a feasibility study [J].
D'Souza, WD ;
Naqvi, SA ;
Yu, CX .
PHYSICS IN MEDICINE AND BIOLOGY, 2005, 50 (17) :4021-4033
[6]   Geometric accuracy of a novel gimbals based radiation therapy tumor tracking system [J].
Depuydt, Tom ;
Verellen, Dirk ;
Haas, Olivier ;
Gevaert, Thierry ;
Linthout, Nadine ;
Duchateau, Michael ;
Tournel, Koen ;
Reynders, Truus ;
Leysen, Katrien ;
Hoogeman, Mischa ;
Storme, Guy ;
De Ridder, Mark .
RADIOTHERAPY AND ONCOLOGY, 2011, 98 (03) :365-372
[7]   Four-dimensional proton treatment planning for lung tumors [J].
Engelsman, M ;
Rietzel, E ;
Kooy, HM .
INTERNATIONAL JOURNAL OF RADIATION ONCOLOGY BIOLOGY PHYSICS, 2006, 64 (05) :1589-1595
[8]  
Giraud P, 2006, Cancer Radiother, V10, P269, DOI 10.1016/j.canrad.2006.05.009
[9]   A simplified method of four-dimensional dose accumulation using the mean patient density representation [J].
Glide-Hurst, Carri K. ;
Hugo, Geoffrey D. ;
Liang, Jian ;
Yan, Di .
MEDICAL PHYSICS, 2008, 35 (12) :5269-5277
[10]   Four-dimensional dosimetry validation and study in lung radiotherapy using deformable image registration and Monte Carlo techniques [J].
Huang, Tzung-Chi ;
Liang, Ji-An ;
Dilling, Thomas ;
Wu, Tung-Hsin ;
Zhang, Geoffrey .
RADIATION ONCOLOGY, 2010, 5