- 作者：Eric T. Shinohara ; M.D. ; M.S.C.I.&lowast ; ; eric.t.shinohara@vanderbilt.edu ; Alireza Kassaee ; Ph.D.&dagger ; ; Nandita Mitra ; Ph.D.&Dagger ; ; Neha Vapiwala ; M.D.&dagger ; ; John P. Plastaras ; M.D. ; Ph.D.&dagger ; ; Jeff Drebin ; M.D. ; Ph.D.§ ; ; Fei Wan ; M.S.&Dagger ; ; James M. Metz ; M.D.&dagger ;
- 关键词：Radiation ; Pancreatic neoplasms ; Calypso ; Organ motion
- 刊名：International Journal of Radiation Oncology*Biology*Physics
- 出版年：2012
- 期刊代码：136_03603016
- 类别：med
- 出版时间：1 June, 2012
- 卷：83
- 期：2
- 页码：566-573
- 文件大小：399 K
Purpose
The primary objective of this study was to determine the feasibility of electromagnetic transponder implantation in patients with locally advanced unresectable pancreatic cancer. Secondarily, the use of transponders to monitor inter- and intrafractional motion, and the efficacy of breath holding for limiting target motion, were examined.Methods and Materials
During routine screening laparoscopy, 5 patients without metastatic disease were implanted with transponders peri-tumorally. The Calypso System鈥檚 localization and tracking modes were used to monitor inter- and intrafractional motion, respectively. Intrafractional motion, with and without breath holding, was also examined using Calypso tracking mode.
Results
Transponder implantation was well tolerated in all patients, with minimal migration, aside from 1 patient who expulsed a single transponder. Interfractional motion based on mean shifts from setup using tattoos/orthogonal imaging to transponder based localization from 164 treatments was significant in all dimensions. Mean shift (in millimeters), followed by the standard deviation and p value, were as follows: X-axis: 4.5 mm (1.0, p = 0.01); Y axis: 6.4 mm (1.9, p = 0.03); and Z-axis 3.9 mm (0.6, p = 0.002). Mean intrafractional motion was also found to be significant in all directions: superior, 7.2 mm (0.9, p = 0.01); inferior, 11.9 mm (0.9, p < 0.01); anterior: 4.9 mm (0.5, p = 0.01); posterior, 2.9 mm (0.5, p = 0.02); left, 2.2 mm (0.4, p = 0.02); and right, 3.1 mm (0.6, p = 0.04). Breath holding during treatment significantly decreased tumor motion in all directions.
Conclusions
Electromagnetic transponder implantation appears to be safe and effective for monitoring inter- and intrafractional motion. Based on these results a larger clinical trial is underway.