宫颈癌术前自适应调强放疗临床研究

发布时间：2018-06-22 22:48

本文选题：自适应放疗 + 宫颈癌　；参考：《广西医科大学》2014年硕士论文

【摘要】：目的：研究宫颈癌术前自适应调强放疗在靶区与危及器官体积、位移、剂量学的特点,并对自适应放疗在治疗术前宫颈癌近期疗效、毒副作用方面进行初步评价,从而了解自适应放疗技术在宫颈癌放疗方面的优势。材料及方法：对21例IB2-IIIB期(FIGO2009分期)术前放化疗的宫颈癌患者进行每周CT定位,在MIM maestro软件上进行靶区和危及器官的勾画,制定普通调强放疗计划及后续自适应放疗计划,所有计划PGTV靶区处方剂量为53Gy,2.12Gy/次／天,PCTV靶区处方剂量为45Gy,1.8Gy/次／天,5次／周,危及器官勾画参照RTOG盆腔危及器官勾画指南,限量参照QUANTEC标准。收集并统计各周CT靶区及危及器官的体积、位移,通过CBCT在骨性配准及灰度配准模式下对患者治疗期间摆位误差进行统计分析,得出摆位误差并计算外扩边界。初次定位图像通过MM形变融合至新定位图像,初始放疗计划因此得以在新CT上计算实际剂量,将新计划通实际剂量融合得到累加剂量。通过配伍组设计的方差分析研究修改计划前后靶区、危及器官的剂量学改变,根据RECSIT1.1标准及RTOG急性放射损伤标准对自适应放疗近期疗效和毒副作用进行评价。结果：1、肿瘤及危及器官体积情况：肿瘤治疗后平均体积明显缩小,总体积平均缩小37.09%,其中第2周缩小比例较其他周明显(p=0.003),但肿瘤变化情况个体差异较大。肿瘤最大径、治疗前肿瘤体积、治疗前血红蛋白水平、肿瘤分期与肿瘤体积变化比例无相关关系。膀胱初次定位平均体积为(270.93±129.44)cc,直肠初次定位平均体积为39.3cc (14.42-97.7cc),肠袋初次定位平均体积为：948.12cc (473.21-1615.38cc),治疗期间膀胱、直肠、肠袋变化体积绝对值平均为(88.15±74.26) cc、9.12cc (4.12-17.16cc)、101.40cc (35.84-131.32cc),分析初始CT及各周CT危及器官的体积平均值,差异无统计学意义。 2、位移情况：宫颈质心在左右、上下、前后方向位移为(1.8±0.6) mm,(3.1±1.9) mm,(4.9±2.3) mm。膀胱质心在左右、上下、前后方向位移分别为(2.6±1.8) mm、(19.5±8.3)mm、(9.1±3.4)mm。直肠在左右、上下、前后方向位移分别为(3.2±1.5) mm、(6.0±3.3) mm、(9.4±5.8)mm。分析宫颈质心位移同膀胱体积、直肠体积变化关系无统计学意义。宫颈前壁位移同膀胱后壁位移、宫颈后壁位移同直肠前壁位移具有相关性(r=0.282、r=0.481),差异有统计学意义。3、摆位误差与外扩边界：骨性配准模式下的摆位误差在左右、上下、前后方向均值为(0.02±0.248) cm,(0.11±0.989)cm,(-0.06±0.32) cm;灰度配准模式下的摆位误差在左右、上下、前后方向均值为(0.01±0.186) cm,(0.14±0.814)cm,(0.02±0.41) cm。三个方向上不同配准模式得出摆位误差的差异无统计学意义(p值均0.05)。根据Van herk边界公式计算出骨配准模式下CTV-PTV边界分别为：左右方向2.24mm、上下方向9.67mm、前后方向3.74mm。灰度配准模式下CTV-PTV边界分别为：左右方向1.55mm、上下方向9.20mm、前后方向3.37mm。 4、靶区剂量学的变化：如果未修改计划,PGTV的V53、V58.3、V49.29、 D50、CI水平,PCTV的V45、CI水平较原计划水平下降,差异有统计学意义(p值均0.05),修改计划后,PGTV的V53、D50、CI水平、PCTV的V45、CI水平有提高,差异有显著性(p值均0.05)。 5、危及器官剂量学变化：如果未修改计划,膀胱V40、膀胱V50、直肠V40、直肠V50、肠袋V40、肠袋V45绝对体积、肠袋Dmean升高,差异有统计学意义(p均0.05)；修改计划后膀胱V40、膀胱V50、直肠V50、直肠Dmean、肠袋V40、肠袋V45绝对体积下降,差异有统计学意义(p均0.05)。股骨头V50、V30、Dmean,骨髓V10、V20、Dmean剂量学差异在修改计划前后的差异无统计学意义。6、毒副作用及近期疗效：所有患者治疗期间1-2级胃肠道毒性发生率约61.9%,3-4级胃肠道毒性发生率约4.7%；1-2级血液学(白细胞)毒性发生率约52.4%,3-4级血液学(白细胞)毒性发生率约23.8%。所有病例治疗后影像学PR率61.9%,14例患者进行了手术,术后病理CR率42.85%,分析病理CR与影像PR、肿瘤初始体积、最大径、治疗前血红蛋白水平的相关性无统计学意义。结论：1.宫颈癌术前放化疗期间,肿瘤消退在第2周比较显著,但具有较大个体差异性,消退情况同初始肿瘤体积、最大径无明显相关性； 2.即使有一定准备条件,膀胱、直肠体积在放疗期间仍有较大差异,膀胱后壁与宫颈前壁位移弱相关,直肠前壁与宫颈后壁位移中度相关；3.骨性配准及灰度配准模式下测量的摆位误差无明显差异,骨性配准模式下CTV-PTV外扩边界为：左右方向2.24mm、上下方向9.67mm、前后方向3.74mm。灰度配准模式下CTV-PTV外扩边界为：左右方向1.55mm、上下方向9.20mm、前后方向3.37mm。4.宫颈癌术前自适应调强放疗能提高靶区覆盖率及适形度；5.宫颈癌术前自适应调强放疗能在一定剂量水平上降低膀胱、直肠、肠袋的受照剂量。6.宫颈癌术前自适应调强放疗近期疗效确切,毒副反应不高。
[Abstract]:Objective: To study the characteristics of the volume, displacement and dosimetry of adaptive intensity modulated radiation therapy for cervical cancer in the target area and endanger organs, and to evaluate the short-term effect and side effects of adaptive radiotherapy in the treatment of cervical cancer before treatment, and to understand the advantages of adaptive radiotherapy in the radiotherapy of cervical cancer.
Materials and methods: 21 cases of IB2-IIIB (FIGO2009 staging) preoperative radiotherapy and chemotherapy of cervical cancer patients were given a weekly CT location, the target area and endanger organs were outlined on MIM Maestro software. The general intensity modulated radiation therapy plan and subsequent adaptive radiotherapy plan were made. All the planned PGTV target area prescriptions were 53Gy, 2.12Gy/ times / day, PCTV target area. The prescription dose is 45Gy, 1.8Gy/ times / day, 5 times / week, endanger organs and draw reference to RTOG pelvic organ delineation guide, limited reference to QUANTEC standard. The volume and displacement of CT target area and endanger organ in each week are collected and counted, and the position error of the patients during the treatment of bone registration and gray registration is statistically analyzed by CBCT. The initial positioning image is fused to the new location image through the MM deformation. The initial radiotherapy plan is able to calculate the actual dose on the new CT. The new plan is combined with the actual dose to get the cumulative dose. The target area before and after the modification plan is studied through the variance analysis designed by the compatibility group. The dosimetry of the organs is endangered. According to RECSIT1.1 standard and RTOG acute radiation injury standard, we evaluated the short-term efficacy and side effects of adaptive radiotherapy.
Results: 1, tumor and endanger organ volume: the average volume of the tumor was obviously reduced and the total volume decreased by 37.09%, and the proportion of the second weeks was smaller than that of other Zhou Mingxian (p=0.003), but the individual difference was larger. The maximum diameter of the tumor, the volume of the tumor before treatment, the level of hemoglobin before treatment, the stage of tumor and the tumor body. The average volume of primary location of the bladder was (270.93 + 129.44) CC, the average volume of the primary location of the rectum was 39.3cc (14.42-97.7cc), the average volume of the initial location of the intestinal bag was 948.12cc (473.21-1615.38cc). The mean value of the changes of the volume of the bladder, rectum and intestinal bag was (88.15 + 74.26) CC, 9.12cc (4.12-17.1) during the treatment. 6cc) and 101.40cc (35.84-131.32cc). There was no significant difference in the average volume of CT and CT in each week.
2, displacement situation: the cervical center of mass was left and right, up and down, the displacement of the anterior and posterior direction was (1.8 + 0.6) mm, (3.1 + 1.9) mm, and (4.9 + 2.3) mm. of the bladder center of mass, and up and down, the displacement was (2.6 + 1.8) mm, (19.5 + 8.3) mm and (9.1 + 3.4) mm. rectum in left and right, up and down, respectively mm, mm, mm. The relationship between the displacement of the cervix and the volume of the bladder and the volume of the rectum was not statistically significant. The displacement of the anterior wall of the cervix with the displacement of the posterior wall of the bladder, the displacement of the posterior wall of the cervix and the displacement of the anterior wall of the rectum (r=0.282, r=0.481) were statistically significant, and the difference was statistically significant, and the pendulum error and the exodiffused boundary were left and right in the pattern of bone registration. Up and down, the mean value of the front and rear directions is (0.02 + 0.248) cm, (0.11 + 0.989) cm and (-0.06 + 0.32) cm, and the pendulum position error in gray registration mode is about, up and down, the mean value of the direction is (0.01 + 0.186) cm, (0.14 + 0.814) cm, (0.02 + 0.41) cm., and the difference of the pendulum error is not statistically significant (P value 0.05) according to the different registration modes. The Van herk boundary formula calculates that the CTV-PTV boundary in the bone registration mode is respectively: the left and right 2.24mm, the upper and lower direction 9.67mm, and the 3.74mm. gray registration mode in the front and back direction 3.74mm., respectively, the left and right 1.55mm, the upper and lower 9.20mm, and the back and back 3.37mm..
4, the change in dosimetry in the target area: if the plan is not modified, PGTV's V53, V58.3, V49.29, D50, CI level, PCTV V45, CI level is lower than the original plan level, and the difference is statistically significant (P value is 0.05).
5, endanger the changes in dosimetry: bladder V40, bladder V50, rectal V40, rectal V50, intestinal bag V40, intestinal bag V45 absolute volume, intestinal bag Dmean increased, the difference was statistically significant (P 0.05), and modified planned bladder V40, bladder V50, rectum V50, rectal Dmean, intestinal bag, intestinal bag absolute volume decreased, the difference was statistically significant Meaning (P 0.05). The difference between V50, V30, Dmean, bone marrow V10, V20, Dmean was not statistically significant.6, side effects, and short-term efficacy before and after the modification plan: the incidence of gastrointestinal toxicity at level 1-2 was about 61.9% during the treatment of all patients, and the incidence of grade 3-4 gastrointestinal toxicity was about 4.7%; the incidence of grade 1-2 Hematology (leukocyte) toxicity was about 4.7% 52.4%, the incidence of grade 3-4 Hematology (leukocyte) toxicity was about 23.8%. in all cases, the rate of PR was 61.9%, and 14 patients underwent surgery. The postoperative pathological CR rate was 42.85%. The pathological CR and image PR were analyzed. The initial volume, the maximum diameter of the tumor, and the correlation of the hemoglobin level before treatment were not statistically significant.
Conclusion: 1. during the preoperative and postoperative radiotherapy and chemotherapy of cervical cancer, the tumor regression was significant in second weeks, but there was a larger individual difference. The regression was not significantly correlated with the initial tumor volume and the maximum diameter.
2. even with certain preparation conditions, the volume of the bladder and rectum still vary considerably during the radiotherapy. The posterior wall of the bladder is weakly related to the displacement of the anterior wall of the cervix, the anterior wall of the rectum is moderately related to the displacement of the posterior wall of the cervix, and there is no obvious difference in the displacement error measured in 3. bone registration and gray registration mode, and the CTV-PTV external expansion boundary under the bone registration mode is left: left The right direction 2.24mm, the upper and lower direction 9.67mm, the front and back direction 3.74mm. gray registration mode, the CTV-PTV external expansion boundary is: the left and right 1.55mm, the upper and lower direction 9.20mm, the anterior and back direction 3.37mm.4. cervical cancer preoperative adaptive intensity modulated radiotherapy can improve the target area coverage and conformal degree; 5. the preoperative adaptive intensity modulated radiation therapy of cervical cancer can be at a certain dose level Reducing the dose of bladder, rectum and intestinal pouch.6. the effect of preoperative intensity modulated radiation therapy on cervical cancer is definite and the toxic side effects are not high.
【学位授予单位】：广西医科大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：R737.33

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