RESUMO
Objective To evaluate the clinical application of Catalyst system in positioning patients during cervical cancer radiotherapy,and to analyze its correlation with the bladder volume and body mass index (BMI) of patients.Methods A total of 33 patients diagnosed with cervical cancer from July to December 2017 in our hospital were included in the study.All patients were auxiliary positioned by an optical surface imaging system (C-Pad Catalyst) before each treatment.The CBCT imaging was executed twice a week.The setup errors from Catalyst and CBCT in the anterior-posterior (AP),superior-inferior (SI) and leg-fight (LR) directions were recorded.Each patient's bladder volume and BMI were also recorded.Results The setup errors between Catalyst with masks and CBCT had the significant difference in SI (P＜0.05) and LR (P＜0.05).For Catalyst without masks,the setup errors with the bladder volume of 200-300 ml had the significant association in SI (R=-0.316,P＜0.05).For the bladder volume of＞300 ml,the setup errors for Catalyst with masks had the significant association in AP (R=-0.493,P＜0.05),and that without masks had the significant association in SI and LR (R=0.335,P＜0.05,R=-0.348,P＜0.05).For patients of＜25 kg/m2,setup errors for Catalyst with masks had the significant association with the BMI in LR (R=0.197,P＜0.05);for ≥ 25 kg/m2,that with masks had the significant association in AP and SI (R =0.818,P＜0.05;R=-0.498,P＜0.05),that without masks had the significant association in AP and LR (R=0.652,P＜0.05;R=-0.558,P＜0.05).Conclusion Unlike CBCT system,the patient positioning by Catalyst system was easily affected by the bladder volume and BMI of patients.
RESUMO
Objective To evaluate the clinical application of Catalyst system in patient positioning during breast cancer radiotherapy,and to analyze its correlation with age and body mass index (BMI).Methods Twenty-four patients with breast cancer who were admitted to our hospital from May to August,2016 were enrolled as subjects.For all patients,auxiliary positioning was made by the optical surface imaging system (CRad Catalyst) before each treatment.The kV-kV imaging was executed weekly to verify positioning.Age,BMI,and setup errors of the two systems in the anterior-posterior (AP),superior-inferior (SI),and left-fight (LR) directions were recorded and analyzed by independent samples t-test and Pearson correlation analysis.Results The C-Rad Catalyst system had a significantly larger setup error in the AP direction than the kV-kV imaging (0.22±0.17 vs.0.18±0.13 cm,P＜0.05).There were no significant differences in setup errors in the SI or LR direction between the two systems (0.23±0.18 vs.0.19±0.15 cm,P＞0.05;0.28±0.28 vs.0.20±0.15 cm,P＞ 0.05).Age and BMI of patients had significant impacts on the C-Rad Catalyst system but the kV-kV imaging (P＞0.05):there were significant differences in setup errors in the AP and SI directions between patients ≤44 years of age and those 45-59 years of age (all P＜0.05);there were significant differences in setup errors in the AP and LR directions between patients ≤44 years of age and those ≥60 years of age (all P＜0.05);there was a significant difference in setup error in the LR direction between patients 45-59 years of age and those ≥ 60 years of age (P＜0.05);there was a significant difference in setup error in the SI direction between patients with BMIs of＜ 25 and ≥ 25 kg/m2 (P＜ 0.05).For patients ≥ 60 years of age,setup error of the C-Rad Catalyst system in the SI direction was correlated with age (r=-0.496,P＜0.05).For patients with BMI of＜25 kg/m2,setup error of the C-Rad Catalyst system in the AP direction was correlated with BMI (r=-0.445,P＜ 0.05).For patients with a BMI of ≥ 25 kg/m2,setup error of the C-Rad Catalyst system in the SI direction was correlated with BMI (r=-0.252,P＜0.05).Conclusions There is significant difference in setup error in the AP direction between the C-Rad Catalyst system and the kV-kV imaging.Age and BMI have impacts on patient positioning by the C-Rad Catalyst system.