• 作者：M. Benchalal^a ; ^{m.benchalal@wanadoo.fr} ; G. Cazoulat^b ; ^c ; J. Bellec^d ; J. Leseur^a ; E. Chajon^a ; P. Haigron^b ; ^c ; H. L&eacute ; na^e ; R. de Crevoisier^a ; ^b ; ^c ; A. Simon^b ; ^c
• 关键词：Volume cible interne ; Position moyenne du cycle respiratoire ; Dosim&eacute ; trie quadridimensionnelle ; Recalage &eacute ; lastique
• 刊名：Cancer Radiotherapie
• 出版年：2012
• 期刊代码：45_12783218
• 类别：med
• 出版时间：April, 2012
• 卷：16
• 期：2
• 页码：91-99
• 文件大小：1143 K

Purpose

The dose distribution for lung tumour is estimated using a 3D-CT scan, and since a person breathes while the images are captured, the dose distribution doesn鈥檛 reflect the reality. A 4D-CT scan integrates the motion of the tumour during breathing and, therefore, provides us with important information regarding tumour's motion in all directions, the motion volume (ITV) and the time-weighted average position (MVP).

Patient and methods

Based on these two concepts, we have estimated, for a lung carcinoma case a 3D dose distribution from a 3D-CT scan, and a 4D dose distribution from a 4-D CT scan. To this, we have applied a non-rigid registration to estimate the cumulative dose.

Results

Our study shows that the 4D dose estimation of the GTV is almost the same when made using MVP and ITV concepts, but sparring of the healthy lung is better done using the MPV model (MVP), as compared to the ITV model. This improvement of the therapeutic index allows, from a projection on the theoretical maximal dose to PTV (strictly restricted to doses for the lungs and the spinal cord), for an increase of about 11%on the total dose (maximal dose of 86 Gy for the ITV and 96 Gy for the MVP).

Conclusion

Further studies with more patients are needed to confirm our data.