Post mastectomy linac IMRT irradiation of chest wall and regional nodes: dosimetry data and acute toxicities.
Post mastectomy linac IMRT irradiation of chest wall and regional nodes: dosimetry data and acute toxicities.
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乳房切除术后直线加速器 IMRT 胸壁和区域淋巴结照射：剂量测定数据和急性毒性
DOI：
10.1186/1748-717x-8-81
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发表时间：
2013-04-08
期刊：
影响因子：
--
通讯作者：
Chen J
中科院分区：
文献类型：
--
作者：
Ma J;Li J;Xie J;Chen J;Zhu C;Cai G;Zhang Z;Guo X;Chen J
传统的乳房切除术后放射治疗是通过胸壁的切向场和区域淋巴结的单独场进行的。尽管已经使用RTOG轮廓图谱讨论了胸壁和区域淋巴结的勾画，但将胸壁和区域淋巴结作为整体目标进行治疗的基于CT的计划尚未被广泛接受。我们在此讨论的剂量学特性的直线加速器调强放射治疗技术治疗胸壁和区域节点作为一个整体PTV后，改良根治性乳腺癌切除术，并观察急性毒性照射。适用于PMRT的患者有资格。在计划CT上，将胸壁和锁骨上/锁骨下区域+/−内乳淋巴结作为整体PTV进行轮廓勾画。设计了一种简化的直线加速器调强放射治疗计划，采用整体全射束或两段半射束在锁骨头尾侧边缘分裂。DVH用于评估计划。定期随访急性毒性反应。共入组85例患者。其中，45例左侧病变，35例接受IMN照射。规划设计产生了55个综合计划和30个分段计划，光束的中位数为8（6-12）。整合和分段计划具有相似的一致性（1.41±0.14 vs. 1.47±0.15，p=0.053）和均匀性指数（0.13±0.01 vs. 0.14±0.02，p=0.069）。接受大于110%处方剂量的PTV体积百分比<5%。与分段计划相比，集成计划通常会增加左侧病变患者的同侧肺（p=0.005）和心脏（p=0.001）的V5。同样，整合计划的脊髓Dmax（p=0.009）、同侧肱骨头（p<0.001）和对侧肺Dmean（p=0.019）更高。在随访期间，36例（42%）被确定为≥ 2级放射性皮炎（RD）。其中，35例出现潮湿脱皮。湿性脱屑发生的中位时间为放疗开始后6周（4-7周）。湿性脱屑发生部位以腋前皱襞最多见（32/35），其次为胸壁（12/35）。整合计划和分段计划之间≥ 2级RD发生率的差异无统计学意义（X2=0.35，p=0.55）。仅2例发生2级放射性肺炎。直线加速器调强放射治疗技术应用于胸壁和区域淋巴结作为整体PTV的PMRT在剂量学上是可行的，大多数患者对治疗耐受性良好。
Conventional post-mastectomy radiation therapy is delivered with tangential fields for chest wall and separate fields for regional nodes. Although chest wall and regional nodes delineation has been discussed with RTOG contouring atlas, CT-based planning to treat chest wall and regional nodes as a whole target has not been widely accepted. We herein discuss the dosimetric characteristics of a linac IMRT technique for treating chest wall and regional nodes as a whole PTV after modified radical mastectomy, and observe acute toxicities following irradiation. Patients indicated for PMRT were eligible. Chest wall and supra/infraclavicular region +/−internal mammary nodes were contoured as a whole PTV on planning CT. A simplified linac IMRT plan was designed using either integrated full beams or two segments of half beams split at caudal edge of clavicle head. DVHs were used to evaluate plans. The acute toxicities were followed up regularly. Totally, 85 patients were enrolled. Of these, 45 had left-sided lesions, and 35 received IMN irradiation. Planning designs yielded 55 integrated and 30 segmented plans, with median number of beams of 8 (6–12). The integrated and segmented plans had similar conformity (1.41±0.14 vs. 1.47±0.15, p=0.053) and homogeneity indexes (0.13±0.01 vs. 0.14±0.02, p=0.069). The percent volume of PTV receiving >110% prescription dose was <5%. As compared to segmented plans, integrated plans typically increased V5 of ipsilateral lung (p=0.005), and heart (p=0.001) in patients with left-sided lesions. Similarly, integrated plans had higher spinal cord Dmax (p=0.009), ipsilateral humeral head (p<0.001), and contralateral lung Dmean (p=0.019). During follow-up, 36 (42%) were identified to have ≥ grade 2 radiation dermatitis (RD). Of these, 35 developed moist desquamation. The median time to onset of moist desquamation was 6 (4–7) weeks from start of RT. The sites of moist desquamation were most frequently occurred in anterior axillary fold (32/35), and secondly chest wall (12/35). The difference in occurrence of ≥ grade 2 RD between integrated and segmented plans was statistically insignificant (X2=0.35, p=0.55). Only 2 were found to have grade 2 radiation pneumonitis. The linac IMRT technique applied in PMRT with chest wall and regional nodes as a whole PTV was dosimetrically feasible, and the treatment was proved to be well-tolerated by most patients.