Deep inspiration breath-hold technique for lung tumors: The potential value of target immobilization and reduced lung density in dose escalation
Deep inspiration breath-hold technique for lung tumors: The potential value of target immobilization and reduced lung density in dose escalation
复制标题
DOI：
10.1016/s0360-3016(99)00154-6
复制
发表时间：
1999-10-01
影响因子：
7
通讯作者：
Kutcher, GJ
中科院分区：
文献类型：
--
作者：
Hanley, J;Debois, MM;Kutcher, GJ
目的/目标：本研究评估了深吸气屏气（DIBH）技术在治疗肺肿瘤中的剂量学益处和可行性。该技术有两个明显的特点深吸气，降低肺密度，屏气，固定肺肿瘤，从而减少边缘。这两个属性可以潜在地减少在高剂量区域的正常肺组织的量，从而降低发病率和提高剂量escalation.Methods和材料的可能性：5例非小细胞肺癌（第IIA-IIIB期）治疗接受计算机断层扫描（CT）扫描下4呼吸条件：自由呼吸，DIBH，浅吸气屏气，浅呼气屏气。自由呼吸和DIBH扫描用于生成三维适形治疗计划以供比较，而浅吸气和呼气扫描确定自由呼吸条件下肿瘤运动的程度。为了获得屏气扫描，使用肺活量测定法使患者达到可再现的呼吸水平，对于DIBH，使用改良的缓慢肺活量操作。自由呼吸计划的计划靶体积（PTV）包括设置误差的裕度（0.75 cm）加上等于呼吸引起的肿瘤运动程度的裕度（1-2 cm）。DIBH计划的计划靶体积包括相同的设置误差裕度，肿瘤位置（0.20.5 cm）的剩余不确定性裕度降低，如重复荧光透视电影所确定。为了模拟呼吸门控治疗的效果并估计单独靶固定的作用（即，没有减少肺密度的好处），第三个计划是从自由呼吸扫描使用PTV与相同的利润率为DIBH plannes.Results：治疗计划比较表明，平均而言，DIBH技术可以减少肺接收量超过25戈伊的30%相比，自由呼吸计划，而呼吸门控可以减少18%的体积。发现DIBH动作具有高度可重复性，根据隔膜位置确定，屏气内可重复性为1.0（+/- 0.9）mm，屏气间可重复性为2.5（+/- 1.6）mm。患者能够进行10-13屏气在一个会话中，舒适的屏气持续时间为12-16秒。结论：患者耐受DIBH演习以及可以执行他们在一个高度可重复的方式。与传统的自由呼吸治疗相比，DIBH技术受益于减少的边缘，由于抑制靶运动，以及降低的肺密度;两者都有助于将正常肺组织移出高剂量区域。由于较少的正常肺组织被照射到高剂量，因此剂量递增的可能性显著提高。(C)1999 Elsevier Science Inc.
Purpose/Objective: This study evaluates the dosimetric benefits and feasibility of a deep inspiration breath-hold (DIBH) technique in the treatment of lung tumors. The technique has two distinct features-deep inspiration, which reduces lung density, and breath-hold, which immobilizes lung tumors, thereby allowing for reduced margins. Both of these properties can potentially reduce the amount of normal lung tissue in the high-dose region, thus reducing morbidity and improving the possibility of dose escalation.Methods and Materials: Five patients treated for non-small cell lung carcinoma (Stage IIA-IIIB) received computed tomography (CT) scans under 4 respiration conditions: free-breathing, DIBH, shallow inspiration breath-hold, and shallow expiration breath-hold. The free-breathing and DIBH scans were used to generate 3-dimensional conformal treatment plans for comparison, while the shallow inspiration and expiration scans determined the extent of tumor motion under free-breathing conditions. To acquire the breath-hold scans, the patients are brought to reproducible respiration levels using spirometry, and for DIBH, modified slow vital capacity maneuvers. Planning target volumes (PTVs) for free-breathing plans included a margin for setup error (0.75 cm) plus a margin equal to the extent of tumor motion due to respiration (1-2 cm). Planning target volumes for DIBH plans included the same margin for setup error, with a reduced margin for residual uncertainty in tumor position (0.20.5 cm) as determined from repeat fluoroscopic movies. To simulate the effects of respiration-gated treatments and estimate the role of target immobilization alone (i.e., without the benefit of reduced lung density), a third plan is generated from the free-breathing scan using a PTV with the same margins as for DIBH plans.Results: The treatment plan comparison suggests that, on average, the DIBH technique can reduce the volume of lung receiving more than 25 Gy by 30% compared to free-breathing plans, while respiration gating can reduce the volume by 18%. The DIBH maneuver was found to be highly reproducible, with intra breath-hold reproducibility of 1.0 (+/- 0.9) mm and inter breath-hold reproducibility of 2.5 (+/- 1.6) mm, as determined from diaphragm position. Patients were able to perform 10-13 breath-holds in one session, with a comfortable breath-hold duration of 12-16 s.Conclusion: Patients tolerate DIBH maneuvers well and can perform them in a highly reproducible fashion. Compared to conventional free-breathing treatment, the DIBH technique benefits from reduced margins, as a result of the suppressed target motion, as well as a decreased lung density; both contribute to moving normal lung tissue out of the high-dose region. Because less normal lung tissue is irradiated to high dose, the possibility for dose escalation is significantly improved. (C) 1999 Elsevier Science Inc.