不同膀胱状态下局部晚期宫颈癌EBRT联合ICBT放疗融合剂量学分布的比较

发布时间：2018-01-14 17:07

本文关键词：不同膀胱状态下局部晚期宫颈癌EBRT联合ICBT放疗融合剂量学分布的比较　出处：《西南医科大学》2017年硕士论文　论文类型：学位论文

【摘要】：目的:宫颈癌是女性常见恶性肿瘤之一,按FIGO分期,Ⅱa期以前患者可选择手术治疗,Ⅱb期以后患者以放疗为主要治疗。宫颈癌放疗包括外照射(external beam radiotherapy,EBRT)和腔内近距离治疗(intracavitary brachytherapy,ICBT),EBRT联合ICBT是局部晚期宫颈癌(locally advanced cervical cancer,LACC)标准放疗技术,膀胱状态是影响靶区和危及器官(organs at risk,OARs)剂量分布的常见因素。长期以来,LACC EBRT和ICBT放疗靶区和危及器官(organs at risk,OARs)剂量评价分别在相应计划中完成,缺乏综合剂量评价依据。因此,不同膀胱状态下,LACC EBRT联合ICBT放疗的融合剂量分布如何,不清楚。本研究主要目的通过Oncentra治疗计划系统(treatment planning system,TPS)的计划叠加功能,比较不同膀胱状态下,调强放射治疗(intensity modulated radiotherapy,IMRT)与四野盒式照射(BOX-RT)联合ICBT放疗,靶区和OARs几何和融合剂量分布。方法:2015-01-01~2015-07-31西南医科大学附属医院肿瘤科治疗的符合入选标准的LACC患者中,信封法随机选择20例,膀胱充盈及空虚状态下分别行磁共振(magnetic resonance imaging,MRI)和计算机断层成像模拟定位(simulation computed tomography,Sim-CT)扫描,在TPS对应融合MRI/CT图像。在MRI勾画大体肿瘤体积(gross tumor volume,GTV),Sim-CT勾画临床靶体积(clinical target volume,CTV)、计划靶体积(planning target volume,PTV)和OARs(小肠,膀胱,直肠和左右股骨头)。分别设置BOX-RT/ICBT计划及IMRT/ICBT计划,放射源分别为6mv-x射线和192ir。在box-rt/icbt计划及imrt/icbt计划中分别单独计算各自计划中靶区(d95%,d90%,d85%和d80%)和oars(小肠d1cc、2cc,膀胱d5%、10%、30%,直肠d1cc、2cc、5cc,股骨头d1%)剂量,相加为几何剂量。利用tps计划叠加功能,分别叠加box-rt计划与icbt计划形成box-rt/icbt融合计划,叠加imrt计划与icbt计划形成imrt/icbt融合计划,计算靶区和oars剂量为融合剂量。比较不同膀胱状态下,两种外照射技术联合icbt放疗,靶区及oars几何和融合剂量关系,并计算icbt对靶区和oars的剂量贡献。数据符合正态分布采用配对t检验,否则采用符号秩和检验。参数检验的统计量设为t,非参数检验的统计量设为u,检验水准α=0.05。结果:1.box-rt/icbt计划:膀胱空虚时,d95%(ugtv=3.92,tctv=14.59,tptv=14.76)、d90%(ugtv=3.92,tctv=16.51,tptv=16.86)、d85%(ugtv=3.92,tctv=18.24,tptv=19.54)、d80%(ugtv=3.92,tctv=16.04,tptv=17.98),靶区几何剂量低于融合剂量;膀胱充盈时,d95%(ugtv=3.92,tctv=11.88,tptv=12.01),d90%(ugtv=3.92,tctv=13.80,tptv=13.71),d85%(ugtv=3.92,tctv=16.26,tptv=17.06),d80%(tgtv=17.50,tctv=16.68,tptv=18.46),靶区几何剂量低于融合剂量;p值均0.001。gtv,ctv和ptv的几何和融合剂量差异率基本相似,gtv剂量差异率小于5%,ctv和ptv大于5%;oars几何剂量均高于融合剂量,小肠和直肠剂量差异率最明显,均超过5%,膀胱和股骨头剂量差异率相似,均小于5%。膀胱充盈时,oars的融合剂量最小。不同膀胱状态下,icbt对靶区的几何剂量贡献率均低于融合剂量贡献率,差异率均超过3%。icbt对靶区几何和融合剂量贡献率差异基本相似,对gtv的几何及融合剂量贡献率最高,超过49%,对ctv,ptv几何剂量贡献率较小,均小于10%,但融合剂量贡献率高于几何剂量贡献率。膀胱空虚与充盈状态下,icbt对oars的几何剂量贡献率均高于融合剂量贡献率,小肠和直肠剂量贡献差异率最明显,均超过6%,膀胱和股骨头剂量贡献差异率基本相似。与膀胱充盈比较,膀胱空虚时,icbt对oars的几何和融合剂量贡献率均高于膀胱充盈。膀胱充盈时,融合剂量贡献率最小。2.imrt/icbt计划:膀胱空虚时,d95%(ugtv=3.92,tctv=11.28,tptv=10.79)、d90%(ugtv、ctv=3.92,uptv=3.25)、d85%(u=3.92)、d80%(u=3.92),靶区几何剂量低于融合剂量;膀胱充盈时,d95%(ugtv,ptv=3.92,tctv=15.96),d90%(ugtv=3.81,uctv,ptv=3.92),d85%(u=3.92),d80%(ugtv=4.70,uctv,ptv=3.92),靶区几何剂量低于融合剂量;p值均0.001。gtv剂量差异率膀胱充盈低于空虚(分别为0.17%~0.93%和0.32-1.07%),ctv和ptv与膀胱空虚相似(分别为1.10%~2.75%和1.22%~3.40%,0.98%~2.29%和0.94%~3.17%)。膀胱空虚时,oars几何剂量(小肠d1cc,2cc、膀胱d5%,10%,30%、直肠d1cc,2cc,5cc和股骨头d1%)高于融合剂量(u小肠=3.92,t小肠=11.59;u膀胱=3.92,3.92,3.36;u直肠=3.92,t股骨头=4.77和6.06);膀胱充盈时,oars几何剂量高于融合剂量(t小肠=10.27,8.84;t膀胱=10.69,11.77,4.91;u直肠=3.36,3.21,3.25),p值均0.005。膀胱d30%和直肠几何平均剂量差均大于融合(分别为1.90gy,1.01gy,0.87gy,0.86gy和1.86gy,0.95gy,0.79gy,0.59gy)。左右股骨头d1%分别为0.76gy、0.41gy和0.26gy、0.73gy。膀胱空虚时,icbt对靶区,d95%(ugtv=3.92,tctv=11.40,tptv=10.84),d90%(ugtv=3.92,uctv=3.29,tptv=6.00),d85%(ugtv=3.92,tctv=17.29,tptv=13.87),d80%(ugtv=3.92,tctv=16.60,tptv=15.41),几何剂量贡献率低于融合剂量贡献率;膀胱充盈时,icbt对靶区,d95%(ugtv=9.87,uctv=15.78,uptv=10.65)、d90%(ugtv=3.81,tctv=20.70,tptv=17.64)、d85%(tgtv=8.31,tctv=23.27,tptv=19.78)、d80%(tgtv=4.68,uctv=3.92,tptv=19.90)几何剂量贡献率低于融合剂量贡献率;p0.005.对gtv剂量贡献率最高,膀胱空虚与充盈几何及融合剂量贡献率分别为51.12%~63.89%、48.10%~60.80%和49.52%~63.35%、46.74%~60.52%;对ctv、ptv几何及融合剂量贡献率10.00%。膀胱空虚时,icbt对oars的几何剂量贡献率高于融合剂量贡献率(u小肠=3.92;u膀胱=3.92,3.92,3.36;u直肠=3.92;t股骨头=4.67和6.16);膀胱充盈时,icbt对oars的几何剂量贡献率高于融合剂量贡献率(t小肠=10.14,8.77;t膀胱=10.74,11.82,4.93;u直肠=3.25,3.21,3.21),p0.005.icbt对直肠几何及融合剂量贡献率膀胱空虚小于充盈(分别为47.77%~59.45%和40.87%~52.40%,47.82%~58.78%和41.61%~52.00%);icbt对膀胱几何及融合剂量贡献率膀胱空虚大于充盈(分别为27.60%~45.17%和26.04%~41.80%,23.36%~43.67%和21.89%~40.22%);小肠空虚大于充盈(分别为30.90%~36.90%和28.85%~34.79%,20.68%~25.13%和18.69%~22.88%);左右股骨头均10%。3.两种融合计划的比较:在膀胱空虚状态,box-rt/icbt计划与imrt/icbt计划在ptv(d95%、d80%)剂量差异值有统计学意义,ptvd95%imrt/icbt融合剂量高于box-rt/icbt融合剂量,剂量差异值为3.26±1.32gy;ptvd80%box-rt/icbt融合剂量高于imrt/icbt融合剂量,剂量差异值为1.52±1.25gy。膀胱充盈状态下,box-rt/icbt融合计划与imrt/icbt融合计划在ctv(d95%、d80%)、ptv(d95%、d80%)剂量差异值有统计学意义,ctvd95%及ptvd95%imrt/icbt融合剂量高于box-rt/icbt融合剂量,剂量差异值分别为1.49±1.02gy、1.51±1.18gy;ctvd80%及ptvd80%box-rt/icbt融合剂量高于imrt/icbt融合剂量,剂量差异值分别为0.95±0.83gy、1.04±0.79gy。不同膀胱状态下,对于小肠和直肠,box-rt/icbt融合剂量值显著高于imrt/icbt融合剂量值,差异有统计学意义(p0.05)。尤其是直肠,box-rt/icbt融合剂量与imrt/icbt融合剂量差异值均5gy.在膀胱充盈状态下,小肠的box-rt/icbt融合剂量均高于IMRT/ICBT融合剂量,差异值均2Gy。无论是膀胱空虚还是充盈,BOX-RT/ICBT融合计划ICBT对靶区剂量贡献率均显著高于IMRT/ICBT融合计划ICBT对靶区剂量贡献率,差异有统计学意义(P0.05),两者对GTV的剂量贡献率的差异率均5%,对CTV、PTV剂量贡献率的差异率均4%。BOX-RT/ICBT融合计划ICBT对OARs剂量贡献率均显著低于IMRT/ICBT融合计划ICBT对OARs剂量贡献率,差异有统计学意义(P0.05),两者对肠道的剂量贡献率的差异率均5%,对直肠剂量贡献率的差异率均7%。结论:1.LACC外照射放疗(BOX-RT和IMRT)联合ICBT放疗的融合剂量学评估优于单纯几何评估,几何与融合剂量评价在直肠的剂量差异率最大,但有待进一步临床观察。2.膀胱状态会影响靶区和OARs剂量,单纯几何计算靶区和OARs剂量,有一定局限性,最好进行融合剂量学分析。3.在宫颈癌的放疗过程中,膀胱充盈有利于OARs的保护,特别是小肠和膀胱,建议ERBT联合ICBT时,膀胱应保持一定容量。虽然膀胱充盈状态下降低了危及器官的受照剂量,但对危及器官相关远期毒性的影响还需要进一步研究。4.与单纯外照射放疗(BOX-RT或IMRT)相比,ICBT有显著优势,尤其是联合BOX-RT照射时,ICBT治疗优势更加明显。与BOX-RT照射技术相比,IMRT在精确提高靶区照射剂量的同时能降低危及器官的受照剂量。
[Abstract]:Objective: cervical cancer is one of the common malignant tumors in women, according to the FIGO staging, stage II A patients before surgical treatment, patients with stage II B after radiotherapy for the treatment of cervical cancer radiotherapy. Including external irradiation (external beam radiotherapy, EBRT) and intracavitary brachytherapy (intracavitary, brachytherapy, ICBT, EBRT and ICBT) is the locally advanced cervical cancer (locally advanced cervical cancer, LACC) standard radiotherapy technology, bladder status is the target and organs at risk (organs at, risk, OARs) common factors of dose distribution. For a long time, LACC EBRT and ICBT radiotherapy and organs (organs at risk, OARs) respectively in dose assessment the corresponding plan, based on the lack of comprehensive dose evaluation. Therefore, different bladder condition, LACC EBRT combined with ICBT radiotherapy dose distribution fusion how unclear. This study mainly by Oncentra treatment plan The system (treatment planning system, TPS) the plan overlay function, comparison of different bladder condition, intensity-modulated radiation therapy (intensity modulated, radiotherapy, IMRT) and four field box (BOX-RT) combined with ICBT radiotherapy, target area and OARs geometry and fusion of dose distribution. Methods: The Affiliated Hospital of Medical College of Southwest oncology treatment with 2015-01-01~2015-07-31 the criteria of LACC patients, 20 cases were randomly selected, and empty bladder filling condition underwent magnetic resonance (magnetic resonance imaging, MRI) and computer tomography (simulation computed simulation tomography, Sim-CT scan, TPS) in the corresponding MRI/CT image fusion. In the delineation of gross tumor volume (MRI gross tumor volume. GTV), Sim-CT (clinical target delineation of clinical target volume, volume, CTV), planning target volume (planning target, volume, PTV) and OARs (small intestine, rectum and bladder. Left and right femoral head). Set BOX-RT/ICBT plan and IMRT/ICBT plan, radioactive sources were 6mv-x and 192ir. in X-ray box-rt/icbt plan and imrt/icbt plan were calculated separately for each plan in the target area (d95%, d90%, d85% and d80%) and oars (d1cc 2cc D5, small intestine, bladder%, 10%, 30%, rectal d1cc. 2cc, 5cc, d1%) dose, the femoral head is added to the geometric dose. Using the TPS program overlay function, respectively superimposed box-rt and ICBT plans to form the box-rt/icbt fusion scheme, superposition of the IMRT and ICBT plans to form the imrt/icbt fusion scheme, calculation of target area and oars dose of fusion dose. Comparison of different bladder condition, two kinds of external irradiation ICBT technology combined with radiotherapy, the target area and oars geometry and fusion dose relationship, and calculate the ICBT of the target area and the dose of oars. The contribution of data to conform to normal distribution using the paired t test, or by Wilcoxon signed rank test. Statistical parametric test The amount is t, nonparametric test statistics for u, a =0.05. level test results: 1.box-rt/icbt plan: to empty the bladder, d95% (ugtv=3.92, tctv=14.59, tptv=14.76), d90% (ugtv=3.92, tctv=16.51, tptv=16.86), d85% (ugtv=3.92, tctv=18.24, tptv= 19.54), d80% (ugtv=3.92, tctv=16.04, tptv=17.98). The target geometry dose less than fusion dose; bladder filling, d95% (ugtv=3.92, tctv=11.88, tptv=12.01), d90% (ugtv=3.92, tctv=13.80, tptv=13.71), d85% (ugtv=3.92, tctv=16.26, tptv=17.06), d80% (tgtv=17.50, tctv=16.68, tptv=18.46), the target dose is lower than the geometric fusion dose; P values were 0.001.gtv, CTV and geometry PTV and fusion dose difference was similar, GTV dose difference rate is less than 5%, CTV and PTV is greater than 5%; oars dose was higher than that of geometric fusion agent, small intestine and rectum dose rate of the most obvious differences, more than 5%, bladder and femoral head difference dose rate Like, are less than 5%. of bladder filling, oars fusion dose minimum. Different bladder condition, geometric dose to the target area of the ICBT contribution rate was lower than the fusion dose contribution rate, the difference rate of more than 3%.icbt of different target geometry and fusion dose contribution rate similar to GTV geometry and fusion dose contribution rate the highest, more than 49% of CTV, the smaller the contribution rate of PTV geometric dose was less than 10%, but the fusion rate is higher than the dose contribution of geometric dose contribution rate. Bladder empty and filled, geometric dose of oars ICBT contribution rate were higher than the fusion dose contribution rate, small intestine and rectum dose contribution rate difference was more than 6%, bladder and femoral head dose contribution difference was similar. Compared with the filling of bladder, bladder empty, geometric ICBT on oars and fusion rate were higher than the dose contribution of bladder filling. The filling of bladder, fusion dose the minimum contribution rate of.2.im Rt/icbt plan: to empty the bladder, d95% (ugtv=3.92, tctv=11.28, tptv=10.79), d90% (ugtv, ctv=3.92, uptv=3.25), d85% (u=3.92), d80% (u=3.92), the target dose is lower than the geometric fusion dose; bladder filling, d95% (ugtv, ptv=3.92, tctv=15.96), d90% (ugtv=3.81, uctv, ptv=3.92) d85%, (u=3.92), d80% (ugtv=4.70, uctv, ptv=3.92), the target dose is lower than the geometric fusion dose; P values were 0.001.gtv dose difference rate is lower than the bladder filling empty (0.17%~0.93% and 0.32-1.07%), CTV and PTV with bladder empty similar (respectively 1.10%~2.75% and 1.22%~3.40%, 0.98%~2.29% and 0.94%~3.17%) to empty the bladder. When oars dose (geometric intestinal d1cc, 2cc, d5% 10%, 30% bladder, rectum, d1cc, 2cc, 5cc and d1% was higher than that of the femoral head (U) fusion dose of =3.92 in the small intestine, the small intestine t =11.59; u =3.92,3.92,3.36 u =3.92 rectal bladder; femoral head, t =4.77 and 6.06); bladder filling, oars geometric dose above the melting The amount of mixture (t t =10.69,11.77,4.91 =10.27,8.84 in the small intestine; bladder; rectal u =3.36,3.21,3.25), P values were the average dose of 0.005. d30% bladder and rectum geometric difference fusion (respectively 1.90gy, 1.01gy, 0.87gy, 0.86gy and 1.86gy, 0.95gy, 0.79gy, 0.59gy). The left and right femur head d1% were 0.76gy, 0.41gy and 0.26gy, 0.73gy. empty bladder, ICBT in the target area, d95% (ugtv=3.92, tctv=11.40, tptv=10.84), d90% (ugtv=3.92, uctv=3.29, tptv=6.00), d85% (ugtv=3.92, tctv=17.29, tptv=13.87), d80% (ugtv=3.92, tctv=16.60, tptv=15.41), geometric dose contribution rate is lower than the fusion dose contribution rate; bladder filling, ICBT of the target area, d95% (ugtv=9.87, uctv=15.78, uptv=10.65), d90% (ugtv=3.81, tctv=20.70, tptv=17.64), d85% (tgtv=8.31, tctv=23.27, tptv=19.78), d80% (tgtv=4.68, uctv=3.92, tptv=19.90) geometric dose contribution rate is lower than the fusion dose contribution rate; the dose of GTV p0.005. The highest contribution rate, and the filling bladder empty geometry and fusion dose contribution rates were 51.12%~63.89%, 48.10%~60.80% and 49.52%~63.35%, 46.74%~60.52%; on CTV, PTV geometry and fusion dose contribution of 10.00%. to empty the bladder, ICBT geometric dose contribution to oars ratio is higher than the amount of the contribution rate of fusion agents (u u =3.92,3.92,3.36 =3.92 in the small intestine; bladder rectum; u =3.92; t =4.67; 6.16) femoral head and bladder filling, ICBT geometric dose contribution to oars ratio is higher than the fusion dose contribution rate (t t =10.74,11.82,4.93 =10.14,8.77 in the small intestine; bladder rectum; u = 3.25,3.21,3.21), p0.005.icbt of rectum geometry and fusion dose contribution rate of bladder filling is less than the empty (respectively 47.77%~59.45% and 40.87%~52.40%, and 47.82%~58.78% 41.61%~52.00%; ICBT) on bladder geometry and fusion dose contribution rate to empty the bladder filling is greater than (respectively 27.60%~45.17% and 26.04%~41.80%, 23.36%~43.67% and 2 1.89%~40.22%); void filling is greater than the small intestine (respectively 30.90%~36.90% and 28.85%~34.79%, 20.68%~25.13% and 18.69%~22.88%); more left femoral head were 10%.3. two fusion schemes: in bladder empty state, box-rt/icbt and imrt/icbt plans in PTV (d95%, d80%) dose difference was statistically significant, ptvd95%imrt/icbt fusion doses higher than box-rt/icbt fusion dose, dose the difference value was 3.26 + 1.32gy; ptvd80%box-rt/icbt fusion fusion dose more than imrt/icbt dose, dose difference value was 1.52 + 1.25gy. of bladder filling, box-rt/ ICBT fusion and imrt/icbt fusion plan plan in CTV (d95%, d80%), PTV (d95%, d80%) dose difference was statistically significant, ctvd95% dose is higher than that of box-rt/icbt and ptvd95%imrt/icbt fusion fusion dose, dose difference values were 1.49 + 1.02gy, 1.51 + 1.18gy; ctvd80% and ptvd80%box-rt/icbt fusion dose higher than IMR T/icbt fusion dose, dose difference values were 0.95 + 0.83gy, 1.04 + 0.79gy. different bladder condition for small intestine and rectum, box-rt/icbt fusion dose value was significantly higher than that of imrt/icbt fusion dose value, the difference was statistically significant (P0.05). Especially the rectum, box-rt/icbt fusion agent content and imrt/icbt values were 5gy. fusion dose differences in bladder filling under the condition of small bowel box-rt/icbt fusion dose was higher than that of IMRT/ICBT fusion 2Gy. dose, the differences were either empty or bladder filling, BOX-RT/ICBT fusion ICBT plan on target dose contribution rate was significantly higher than that of IMRT/ICBT fusion ICBT plan contribution rate on target dose, the difference was statistically significant (P0.05), the difference of GTV dose contribution the rate of rate was 5%, the difference between PTV CTV, the contribution rate of dose rate was 4%.BOX-RT/ICBT ICBT of the OARs integration plan dose contribution rate was significantly lower than that of IMRT/ICBT fusion project ICBT of OARs dose contribution rate, the difference was statistically significant (P0.05), the difference of the intestinal dose contribution rate was 5%, 7%. conclusion differences in rectal dose contribution rate: 1.LACC external irradiation (BOX-RT and IMRT) and ICBT combined with radiotherapy dosimetry fusion evaluation on simple geometric evaluation, and geometry the fusion rate maximum dose assessment dose differences in the rectum, but further clinical observation of.2. bladder can affect the target area and the dose of OARs, calculation of target volume and OARs dose of simple geometry, there are some limitations, the best fusion dose analysis.3. in radiotherapy of cervical cancer, bladder filling is conducive to the protection of OARs. Especially in the small intestine and bladder, suggest that ERBT combined with ICBT, the bladder should maintain a certain capacity. Although the bladder filling was reduced dose of the organs at risk, but also need to influence the long-term toxicity of the relevant organs The further study of.4. and simple external irradiation (BOX-RT or IMRT) compared to ICBT has significant advantages, especially when combined with BOX-RT irradiation, the advantage of ICBT treatment is more obvious. Compared with the BOX-RT irradiation technology, IMRT can improve accuracy in lower doses to organs and target doses.

【学位授予单位】：西南医科大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：R737.33

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