Comparison of CTV-PTV setup margins during IMRT for cervical cancer patients with different body mass index by bladder volume measurement device-assisted CBCT
10.3760/cma.j.issn.1004-4221.2018.04.012
- VernacularTitle:膀胱容积测量仪干预下CBCT观察不同BMI宫颈癌患者CTV至PTV外扩边界差异
- Author:
Shikuo GUAN
1
;
Qing XU
;
Yiran MENG
;
Guihao KE
;
Jun ZHU
;
Xiaohua WU
Author Information
1. 复旦大学附属肿瘤医院放疗科复旦大学上海医学院肿瘤学系
- Keywords:
Cervical neoplasm;
Body mass index;
Clinical target volume;
Planning target volume
- From:
Chinese Journal of Radiation Oncology
2018;27(4):392-395
- CountryChina
- Language:Chinese
-
Abstract:
Objective To investigate the clinical target volume (CTV)-planned target volume (PTV) setup margins during intensity-modulated radiotherapy (IMRT) for cervical cancer patients with different body mass index (BMI),aiming to provide reference for precise individual therapy.Methods Forty patients diagnosed with cervical cancer undergoing IMRT in Cancer Hospital of Fudan University between March and September 2017 were recruited and assigned into the BMI ≤ 18.4,18.5-23.9,24.0-27.9 and ≥ 28 kg/m2 groups according to the BMI classification criteria proposed by National Health and Family Planning Commission (NHFPC) of the People's Republic of China.Assisted with the bladder volume measurement device,9 cycles of kilo-voltage cone beam computed tomography (CBCT) images were subject to online registration and imaging analysis.CTV-PTV setup margins were calculated based on the formula of MPTV =2.5∑+0.7σamong four groups.Single factor variance analysis was performed.LSD test was utilized for two-group comparison.Results Among four groups,the CTV-PTV setup margins in the x,y and z directions were (6.87 mm,6.06 mm,8.49 mm),(3.13 mm,3.02 mm,3.14 mm),(4.70 mm,4.86 mm,5.31 mm) and (7.63 mm,8.28 mm,8.54 mm),respectively (P=0.038,0.048 and 0.004).Conclusions The setup errors in the BMI ≤ 18.4 and ≥28 kg/m2 groups are significantly larger compared with those in the remaining groups Consequently,CTV-PTV setup margins should be enlarged to certain extent for patients with BMI≤ 18.4 and ≥≥28 kg/m2.
