宫颈癌移位卵巢的位点选择及其放疗防护的研究

发布时间：2018-10-11 11:05

【摘要】：目的：本课题旨在探讨需行术后放疗的宫颈癌患者的最佳卵巢移位点以及移位卵巢在盆腔盒式放疗中的防护措施。方法：在仿真体模上模拟宫颈癌盒式放疗，选取体模3个高度层面、每一层面上5个“卵巢移位点”，每一位点上分别以垂直及平行皮缘的方式平面布放LiF热释光剂量计，并在中间层面选择4个位点，采用与横截面垂直向下的方式竖直布放剂量计，分别测定每一剂量计在体模接受单次盒式放疗（四野均等给量）后的吸收剂量；在放疗计划系统中对体模6个层面、每个层面上的5个“移位卵巢”进行勾画并评估剂量；选取6例宫颈癌患者，分别勾画出2个层面、每个层面上5个“移位卵巢”，制定四野均等与非均等给量的盒式放疗计划并评估剂量。分别使用2mmPb铅皮、0.35mmPb铅衣，自制为宽度10cm、5cm的“铅皮条”，，对仿真体模进行环绕式全覆盖防护，其下界为髂嵴平面，测定髂嵴上3cm层面垂直向下布放的4粒剂量计在各种防护条件下的吸收剂量。结果： 1、体模每一层面的同一位点，剂量计平行及垂直皮缘放置的所测数据相近；同一位点上的剂量计测量值与计划系统的评估值较为一致。 2、体模上“移位卵巢”的实测剂量随高度的增加而显著降低。髂嵴上3cm层面“移位卵巢”的剂量为2.7-3.7Gy（单次剂量乘25所得）。 3、在各测量方式中的每一高度层面上，靠近后方的2个“移位卵巢”比侧方的2个“移位卵巢”在盒式放疗中的吸收剂量少；在宫颈癌患者放疗计划中的2个层面上有统计学意义（P＜0.05）。 4、铅当量2mm，宽度5cm、10cm的“铅皮条”对“移位卵巢”的剂量减少为：13.07%、20.63%；铅当量0.35mm，宽度5cm、10cm的“铅皮条”的剂量减少：12.95%、-2.93%。结论： 1对于接受盒式放疗的宫颈癌患者，建议在允许范围内将卵巢至少移至髂嵴上3~4.5cm。 2宫颈癌盆腔盒式放疗中，卵巢移位于结肠旁沟后方较侧方的吸收剂量小。 3“铅皮条”覆盖于仿真体模能在一定程度上减少吸收剂量，可能与铅当量与宽度有关。
[Abstract]:Objective: to investigate the optimal ovarian translocation and the protective measures of ovarian translocation in patients with cervical cancer undergoing postoperative radiotherapy. Methods: cervical cancer boxed radiotherapy was simulated on simulated phantom. Three height layers of phantom were selected, 5 "ovarian translocation points" were selected on each level, and LiF thermoluminescence metering was arranged in vertical and parallel skin margin respectively. At the middle level, four sites were selected and vertical dosimeter was used to measure the absorbed dose of each dosimeter after a single dose box radiotherapy (equal dose in four fields) was given to each dosimeter. In the radiotherapy planning system, the six levels of phantom, the five "translocation ovaries" at each level and the dose were evaluated, and six patients with cervical cancer were selected to draw two layers, five ovaries on each level. Develop four-field equal and unequal dose boxed radiotherapy plan and evaluate dose. The 2mmPb lead coat and the 0.35mmPb lead coat were used respectively, and the "lead strip" with a width of 10 cm or 5 cm was made by ourselves. The simulated phantom was completely covered with circumferential cover. The lower boundary was the iliac crest plane. The absorption dose of 4 grains placed vertically downwards on the 3cm layer of iliac crest under various protective conditions was measured. Results: 1. The data of the same site in each plane of the phantom were similar to those of the parallel and vertical skin margin placed by the dosimeter. The dosimeter measured at the same site was in good agreement with the evaluation value of the planning system. 2. The measured dose of "translocation of ovary" on the phantom decreased significantly with the increase of height. The dose of "ovarian translocation" at the 3cm level on the iliac crest was 2.7-3.7Gy (single dose multiplied by 25). The amount of absorbents in the two "translocated ovaries" near the rear side was less than that in the lateral ones. There was significant difference in the two levels of radiotherapy plan for patients with cervical cancer (P < 0.05). The dose of "lead strip" with lead equivalent of 2 mm and width of 5 cm / 10 cm was reduced to 13.07% 20.63 cm. The lead equivalent of 0.35 mm and the width of 5 cm / 10 cm "lead lice" decreased: 12.95% -2.93%. Conclusion: 1 for patients with cervical cancer receiving box radiotherapy, it is recommended that the ovary be moved to the upper iliac crest at least 34.5 cm 路2 to the extent permitted. The absorption dose of ovarian translocation to the posterior side of the paracolonic sulcus was lower. 3 the "lead lice" covered in the phantom could reduce the absorbed dose to a certain extent, which might be related to the lead equivalent and width.
【学位授予单位】：川北医学院
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：R737.33

【参考文献】