The dosimetric study of multiple planned computed tomography image guided high-dose-rate 192Ir brachytherapy in cervical cancer
AN Ju-sheng, HUANG Man-ni, XU Ying-jie, ZHANG Gong-yi, WU Ling-ying, LI Xiao-guang, ZHANG Rong, DAI Jian-rong.
Department of Gynecologic Oncology, Cancer Hospital (Institute), Chinese Academy of Medical Science, Peking Union Medical College, Beijing 100021, China
Objective To evaluate the reproducity of planning and impact of organ at risk in CT image guided three-dimensional high dose rate 192Ir brachytherapy in cervical cancer by dosimetric analysis. Methods Ten patients with FIGO stage Ⅱb or Ⅲb of cervical cancer were selected who were treated with CT image guided three-dimensioned high-dose-rate 192Ir brachytherapy. Patients underwent a CT scan in each fraction of brachytherapy and treatment plans were made. Prescription dose to point A with 7 Gy per fraction and graphical optimized with organs at risk (OAR) dose limitations of D2 cm3≤5 Gy in rectum and sigmoid and D2 cm3≤5.5 Gy in bladder. The optimized plan for the first fraction in each patients as the standard planning based on which the optimization planning for the following fractions. The dose volume histogram ((high risk clinical target volume (HRCTV) D90, bladder D2 cm3, rectum D2 cm3 and sigmoid D2 cm3) were evaluated and compared between the two groups of planning. Planning comparison analysis used independent samples t-test and OAR parameters with Pearson correlation analysis. Results HRCTV D90 were not statistically significant difference between the optimization and standard planning (t=-0.03—-1.61,P=0.978—0.128). D2 cm3 of bladder, rectum and sigmoid were statistically higher in the standard plans (t=-2.27—-3.35,P=0.049—0.004). D2 cm3 of bladder, rectum and sigmoid correlated positively with the absolute volume respectively (r=0.314,0.407,0.539,P=0.026,0.003,0.000). Conclusions It′s necessary for the multiple planning for CT image guided brachytherapy in cervical cancer. The bigger volume of OAR, the higher D2 cm3.
. The dosimetric study of multiple planned computed tomography image guided high-dose-rate 192Ir brachytherapy in cervical cancer[J]. Chinese Journal of Radiation Oncology, 2013, 22(3): 243-246.
[1] P tter R, Georg P, Dimopoulos JC, et al. Clinical outcome of protocol based image (MRI) guided adaptive brachytherapy combined with 3D conformal radiotherapy with or without chemotherapy in patients with locally advanced cervical cancer. Radiother Oncol,2011,100:116-123. [2] Haie-Meder C, P tter R, Van Limbergen E, et al. Recommendations from gnaecological (GYN) GEC-ESTRO working group (Ⅰ):concepts and terms in 3D image based 3D treatment planning in cervix cancer brachytherapy with emphasis on MRI assessment of GTV and CTV. Radiother Oncol,2005,74:235-245. [3] P tter R, Haie-Meder C, Van Limbergen E, et al. Recommendations from gynaecological (GYN) GEC ESTRO working group (Ⅱ):concepts and terms in 3D image-based treatment planning in cervix cancer brachytherapy-3D dose volume parameters and aspects of 3D image-based anatomy, radiation physics, radiobiology. Radiother Oncol,2006,78:67-77. [4] Nag S, Cardenes H, Chang S, et al. Proposed guidelines for image-based intracavitary brachytherapy for cervical carcinoma:report from image-guided brachytherapy working group. Int J Radiat Oncol Biol Phys,2004,60:1160-1172. [5] Van de Kamer JB, De Leeuw AA, Moerland MA, et al. Determining DVH parameters for combined external beam and brachytherapy treatment:3D biological dose adding for patients with cervical cancer. Radiother Oncol,2010,94:248-253. [6] Kerkhof EM, Raaymakers BW, van der Heide UA, et al. Online MRI guidance for healthy tissue sparing in patients with cervical cancer:an IMRT planning study. Radiother Oncol,2008,88:241-249. [7] van de Bunt L, Jürgenliemk-Schulz IM, de Kort GA, et al. Motion and deformation of the target volumes during IMRT for cervical cancer:what margins do we need? Radiother Oncol,2008,88:233-240. [8] Lim K, Kelly V, Stewart J, et al. Pelvic radiotherapy for cancer of the cervix:is what you plan actually what you deliver? Int J Radiat Oncol Biol Phys,2009,74:304-312. [9] Kim RY, Shen S, Lin HY, et al. Effects of bladder distension on organs at risk in 3D image-based planning of intracavitary brachytherapy for cervical cancer. Int J Radiat Oncol Biol Phys,2010,76:485-489. [10] Sun LM, Huang HY, Huang EY, et al. A prospective study to assess the bladder distension effects on dosimetry in intracavitary brachytherapy of cervical cancer via computed tomography-assisted techniques. Radiother Oncol,2005,77:77-82.