Ruby Hall Clinic, Pune, Maharashtra, 411001, India.
Department of Physics, Karunya Institute of Technology and Sciences, Coimbatore, 641114, India.
Phys Eng Sci Med. 2021 Dec;44(4):1321-1329. doi: 10.1007/s13246-021-01064-5. Epub 2021 Nov 1.
Quantitative retrospective analysis of the normal lung irradiation due to the variations of the ITV volume based on the techniques used for upper lobe (UL), mid lobe (ML), and lower lobe (LL) lung tumours when used with 2-view, 1-view, 0-view based LOT technique on Cyberknife, AveIP on Helical Tomotherapy, and DIBH on VMAT systems. In the treatment of lung tumours, patients medically inoperable or those who are unwilling to undergo surgery have the option to be treated using radiation therapy. There are many motion control techniques available for the treatment of the moving target, such as movement encompassment, respiratory gating, breath-hold, motion reduction, and tumour monitoring. ITV generation is dependent on technique and hence the volume of the PTVs will differ based on the technique used. This study aimed to determine the influence of these ITVs on the irradiated normal lung volume for UL, ML, and LL lung tumours for 23 patients. The mean difference in the PTV volumes generated with the 0-view technique was significant with that of 2-view and DIBH techniques (p-value < 0.04). The mean difference in the PTV volumes generated by 2-view and DIBH was small for UL, ML, and LL tumours. V of the combined lung with the 0-view method was 5% compared to the 2-view method for UL tumours (p-value = 0.04) and the same was 9.5%, and 16.8% for ML and LL tumours (p-value < 0.04). In contrast to all other techniques, lung volume parameters V, V, V and V for the 0-view technology were consistently higher irrespective of the tumour location in the lung. The observed maximum mean lung dose (MLD) was 6.2 Gy ± 2.7 Gy with the 0-view technique and the minimum was 3.85 Gy ± 1.75 Gy with the DIBH technique. The difference in MLD between DIBH and 2-view was negligible (p-value = 0.67). The MLD increased for LL tumours from 4 Gy to 6.5 Gy from the 2-view to 0-view technique (p-value = 0.009). There was a significant increase in MLD for LL tumours with the 0-view technique compared to AveIP (1.9 Gy, p-value = 0.04) and DIBH (2.0 Gy, p-value = 0.003) technique. For ML and UL tumours, except for 0-view and 1-view, the difference in the MLD between the rest of the methods was not significant (p-value > 0.11). In the treatment of lung tumour patients with SBRT, this study has demonstrated 2-view with Cyberknife and DIBH with VMAT treatment techniques have optimal normal lung tissue sparing. There was a significant increase in the average lung volume receiving 5%,10%, 20%, and 30% dose when comparing the 1-view, 0-view, AveIP, and DIBH techniques to the 2-view technique. However, DIBH with VMAT was dosimetrically advantageous for ML and LL tumours, while providing significantly shorter treatment times than any other technique studied.
基于 2 视图、1 视图、0 视图的 LOT 技术在 Cyberknife、AveIP 螺旋断层放疗和 DIBH 瓦里安调强放疗系统上治疗上叶 (UL)、中叶 (ML) 和下叶 (LL) 肺癌肿瘤时，对正常肺照射量因 ITV 体积变化的定量回顾性分析。对于不能手术或不愿手术的肺部肿瘤患者，可选择放射治疗。有许多运动控制技术可用于治疗移动目标，如运动包围、呼吸门控、屏气、运动减少和肿瘤监测。 ITV 的生成取决于技术，因此基于使用的技术，PTVs 的体积将有所不同。本研究旨在确定这些 ITV 对 23 例 UL、ML 和 LL 肺癌肿瘤照射正常肺体积的影响。0 视图技术生成的 PTV 体积与 2 视图和 DIBH 技术的差异具有统计学意义（p 值<0.04）。2 视图和 DIBH 生成的 PTV 体积之间的差异对于 UL、ML 和 LL 肿瘤较小。0 视图方法的联合肺 V 为 5%，而 2 视图方法为 UL 肿瘤（p 值=0.04），相同的为 9.5%和 16.8%为 ML 和 LL 肿瘤（p 值<0.04）。与所有其他技术相比，0 视图技术的肺体积参数 V、V、V 和 V 无论肿瘤在肺中的位置如何，始终更高。观察到的最大平均肺剂量 (MLD) 为 0 视图技术 6.2 Gy±2.7 Gy，DIBH 技术为 3.85 Gy±1.75 Gy。DIBH 和 2 视图之间的 MLD 差异可以忽略不计（p 值=0.67）。从 2 视图到 0 视图技术，LL 肿瘤的 MLD 从 4 Gy 增加到 6.5 Gy（p 值=0.009）。与 AveIP（1.9 Gy，p 值=0.04）和 DIBH（2.0 Gy，p 值=0.003）技术相比，0 视图技术使 LL 肿瘤的 MLD 显著增加。对于 ML 和 UL 肿瘤，除了 0 视图和 1 视图，其余方法之间的 MLD 差异没有统计学意义（p 值>0.11）。在使用 SBRT 治疗肺部肿瘤患者时，本研究表明，在 Cyberknife 上使用 2 视图和在瓦里安调强放疗系统上使用 DIBH 治疗技术具有最佳的正常肺组织保护。与 2 视图技术相比，1 视图、0 视图、AveIP 和 DIBH 技术使平均肺体积分别接受 5%、10%、20%和 30%剂量的情况明显增加。然而，对于 ML 和 LL 肿瘤，DIBH 与瓦里安调强放疗系统相比具有剂量学优势，同时提供比研究中的任何其他技术都短的治疗时间。
