Georgetown University Hospital.
J Appl Clin Med Phys. 2014 Mar 6;15(2):4547. doi: 10.1120/jacmp.v15i2.4547.
Treatment planning for breast cancer has been traditionally based on clinical landmarks. The Radiation Therapy Oncology Group (RTOG) published consensus guidelines on contouring target volumes (TV) for the breast/chest wall and draining lymphatics. The effect of these guidelines on dosimetric parameters in surrounding organs at risk (OAR) and TVs is unknown. Fourteen patients treated with clinically derived plans from 2007-2011 (Group I) and fourteen patients treated with target volume-based plans from 2011-2012 were selected for comparison (Group II). Treatment plans were constructed based on clinical landmarks (Group I) or TVs (Group II) to a median dose of 50.4 Gy to the breast/chest wall, axilla (Ax), supraclavicular (SCV), and internal mammary (IMN) lymph nodes. The RTOG TVs were then contoured in Group I patients by a single investigator blinded to the dose distributions. Dose-volume histograms (DVH) were computed for the RTOG TVs and OARs in both groups, and DVH parameters were compared. In Group II, coverage improved for the SCV (V90 = 78.0% versus 93.6%, p = 0.02) and intact breast (V95 = 95.6% versus 99.3%, p = 0.007). The dose to the cord, the lung (V20Gy and V30Gy), and contralateral breast (V5Gy) were the same. Finally, the low dose to the heart and lung was decreased in Group II (heart V5Gy= 48.7% versus 27.3%, p= 0.02, heart V10Gy = 33.5% vs. 17.5%, p = 0.01, and ipsilateral lung V5Gy = 84.5% vs. 69.3%, p = 0.001). Overall, our study supports that treatment planning using the RTOG consensus guidelines can improve coverage to certain target volumes compared to treatments based solely on clinical landmarks. Additionally, treatment planning using these target volumes does not increase dose to the contralateral breast, cord, heart, or lungs. Longer follow-up is needed to determine if using these target volumes will affect clinical outcomes.
乳腺癌的治疗计划传统上基于临床标志。放射治疗肿瘤学组（RTOG）发布了有关乳房/胸壁和引流淋巴结靶区（TV）勾画的共识指南。这些指南对周围危及器官（OAR）和 TV 中的剂量学参数的影响尚不清楚。选择了 2007-2011 年基于临床衍生计划治疗的 14 例患者（I 组）和 2011-2012 年基于靶区计划治疗的 14 例患者（II 组）进行比较。根据临床标志（I 组）或 TV（II 组）构建治疗计划，使乳房/胸壁、腋窝（Ax）、锁骨上（SCV）和内乳（IMN）淋巴结的中位数剂量达到 50.4Gy。然后由一位单独的研究者在不知道剂量分布的情况下对 I 组患者进行 RTOG TV 勾画。在两组中计算了 RTOG TV 和 OAR 的剂量-体积直方图（DVH），并比较了 DVH 参数。在 II 组中，SCV（V90=78.0%对 93.6%，p=0.02）和完整乳房（V95=95.6%对 99.3%，p=0.007）的覆盖范围得到改善。脊髓、肺（V20Gy 和 V30Gy）和对侧乳房（V5Gy）的剂量相同。最后，II 组中心脏和肺的低剂量减少（心脏 V5Gy=48.7%对 27.3%，p=0.02，心脏 V10Gy=33.5%对 17.5%，p=0.01，同侧肺 V5Gy=84.5%对 69.3%，p=0.001）。总的来说，我们的研究支持与仅基于临床标志的治疗相比，使用 RTOG 共识指南进行治疗计划可以改善某些靶区的覆盖范围。此外，使用这些靶区进行治疗计划不会增加对对侧乳房、脊髓、心脏或肺部的剂量。需要更长时间的随访来确定使用这些靶区是否会影响临床结果。
