Petersen Peter Meidahl, Rechner Laura Ann, Specht Lena
Dept. of Oncology, Rigshospitalet, University of Copenhagen, Copenhagen, Denmark.
Phys Imaging Radiat Oncol. 2022 May 16;22:137-141. doi: 10.1016/j.phro.2022.05.008. eCollection 2022 Apr.
Radiotherapy (RT) is an important part in the treatment of gastric lymphomas and the prognosis after radiotherapy is very good with a good chance of long-term survival, so prevention of long-term adverse effects is important. In patients with gastric lymphomas cardiac late effects are of most concern. The aim of this study was to assess if the dose to the heart could be reduced with deep inspiration breath-hold (DIBH) without compromising the dose to the target or increasing the risk of other late effects.
Fifteen patients with gastric lymphoma were included. RT plans were made using DIBH and Free breathing (FB) scans. Clinical target volume (CTV) was the stomach plus 1 cm margin. The heart and surrounding organs at risk (OAR) were contoured. Two sets of plan comparisons were made, one with 1 cm CTV to planning target volume (PTV) margin in both DIBH and FB and one set with an additional 5 mm CTV to PTV margin in cranio-caudal direction with FB. Datasets were analysed with Wilcoxon signed rank test for non-parametric paired data.
All patients tolerated the procedures and were treated with volumetric arc therapy technique in DIBH. Target coverage was kept equal between FB and DIBH, while a statistically significant reduction of the estimated does to the heart was seen with DIBH. Median mean heart dose was reduced from 7.1 Gy (5.7-12) to a median of 3.2 Gy (1.2-7.0) and heart V20 from a median of 54 (17-106) cm to 15. (0.0-78) cm. The estimated mean doses to the liver, duodenum, pancreas and spinal cord were at the same level.
This clinical trial of RT with DIBH for gastric lymphomas showed that the heart dose could be reduced without compromising PTV coverage. The doses to abdominal OARs were similar with FB and DIBH.
放射治疗（RT）是胃淋巴瘤治疗的重要组成部分，放疗后的预后非常好，有长期生存的良好机会，因此预防长期不良反应很重要。在胃淋巴瘤患者中，心脏晚期效应最受关注。本研究的目的是评估深吸气屏气（DIBH）是否能在不影响靶区剂量或增加其他晚期效应风险的情况下降低心脏剂量。
纳入15例胃淋巴瘤患者。使用DIBH和自由呼吸（FB）扫描制定放疗计划。临床靶区（CTV）为胃加1 cm边界。勾勒出心脏和周围危及器官（OAR）。进行了两组计划比较，一组在DIBH和FB中CTV至计划靶区（PTV）边界均为1 cm，另一组在FB的头脚方向上CTV至PTV边界额外增加5 mm。采用Wilcoxon符号秩检验对非参数配对数据进行数据集分析。
所有患者均耐受该操作，并在DIBH中采用容积弧形治疗技术进行治疗。FB和DIBH之间的靶区覆盖保持相等，而DIBH显示心脏的估计剂量有统计学意义的降低。心脏平均剂量中位数从7.1 Gy（5.7 - 12）降至3.2 Gy（1.2 - 7.0），心脏V20从中位数54（17 - 106）cm降至15（0.0 - 78）cm。肝脏、十二指肠、胰腺和脊髓的估计平均剂量处于同一水平。
这项针对胃淋巴瘤的DIBH放疗临床试验表明，在不影响PTV覆盖的情况下可以降低心脏剂量。FB和DIBH对腹部OARs的剂量相似。
