The application of volumetric modulated arc therapy in postoperative radiotherapy for cervical cancer
10.11904/j.issn.1002-3070.2014.05.011
- VernacularTitle:容积旋转调强技术在宫颈癌术后放疗中的应用
- Author:
Shiwei LIU
;
Di SUN
;
Baoji XING
;
Linhai WANG
- Publication Type:Journal Article
- Keywords:
Volumetric modulated arc therapy;
Cone-beam tomography;
Cervical neoplasm;
Postopera-tive radiotherapy;
Three dimensional conformal radiotherapy
- From:
Practical Oncology Journal
2014;(5):435-438
- CountryChina
- Language:Chinese
-
Abstract:
Objective To evaluate the value of volumetric modulated arc therapy ( VMAT) in postopera-tive radiotherapy for cervical cancer .Methods Eighty four cases of cervical cancer patients were retrospectively analyzed after surgery .Thirty-nine patients received volumetric modulated arc therapy , while the other forty -five patients received three -dimensional conformal radiation therapy (3DCRT).The images were collected both before and after treatment.We recorded the setup errors including x (lift-right),y(ventral-dorsal),and z(an-terior-posterior)axes in thirty -nine patients with cone beam CT (CBCT).These images were compared with correponding planning images to calculate the position errors .We also analyzed the radiation dosimetry parameters and adverse reactions .Results The setup errors before and after radiation therapy in x ,y,and z axes were (1.07 ±0.91)cm,(0.76 ±1.07)cm,(0.74 ±0.81)cm and(0.11 ±0.04)cm,(0.11 ±0.09)cm,(0.08 ±0.20) cm,respectively.These data showed that the application of CBCT reduced the setup errors of treatment significant -ly.We analyzed the illuminated volume of bladder and rectum with dose volume histogram (DVH),and found there was no difference between VMAT and 3DCRT groups when 20 Gy irradiation dose was adopted .When the ir-radiation dose increased to 30 Gy and 40 Gy, the corresponding illuminated volume of bladder and rectum in VMAT group were 69.45 ±1.13,41.78 ±2.8 and 75.66 ±3.34,30.12 ±9.59,respctively.In the 3DCRT group,the corresponding illuminated volume of bladder and rectum were 93.37 ±6.59,88.32 ±12.13 and 95.26 ±8.95,90.32 ±6.98,respectively.VMAT can obviously decrease the illuminated volume of bladder and rectum when compared to 3DCRT.Conclusion VMAT can not only decrease the setup errors to improve the accuracy of radiotherapy ,but also reduce the reaction of normal tissues effectively in the cervical cancer patients who accepted postoperative radiotherapy .Therefore,the VMAT technology can improve both patients′treatment compliance and their quality of life .
