Effect of body mass index on inter-fractional setup errors in cone beam CT-guided radiotherapy of cervical cancer(PDF)
《中国医学物理学杂志》[ISSN:1005-202X/CN:44-1351/R]
- Issue:
- 2023年第2期
- Page:
- 144-148
- Research Field:
- 医学放射物理
- Publishing date:
Info
- Title:
- Effect of body mass index on inter-fractional setup errors in cone beam CT-guided radiotherapy of cervical cancer
- Author(s):
- LIANG Li; LI Yong
- Radiotherapy Center, Sichuan Cancer Hospital, Chengdu 610000, China
- Keywords:
- Keywords: body mass index cone beam CT cervical cancer radiotherapy setup error
- PACS:
- R815.6
- DOI:
- DOI:10.3969/j.issn.1005-202X.2023.02.003
- Abstract:
- Abstract: Objective To explore the impact of body mass index (BMI) on inter-fractional setup errors in cervical cancer patients treated with cone beam CT-guided radiotherapy. Methods According to BMI, 90 cervical cancer patients treated in Sichuan Cancer Hospital from September 2020 to September 2021 were divided into underweight group (BMI≤18.4 kg/m2), normal group (18.5 kg/m2≤BMI≤23.9 kg/m2), and overweight group (BMI≥24.0 kg/m2), with 30 cases in each group. Patients in each group were further divided into vacuum pad group (n=15) and thermoplastic film group (n=15). Pelvic CBCT scanning was performed before and after radiotherapy to obtain the setup data, so as to determine the accuracy of radiotherapy localization, formulate a reasonable radiotherapy plan, and analyze the effect of BMI on setup errors in radiotherapy of cervical cancer. Results Without regard to BMI, there was no significant difference in the overall setup error between vacuum pad group and thermoplastic film group (P>0.05) and the cervical cancer patients with bone registration had larger X-axis and Y-axis setup errors, but smaller Z-axis setup errors than those with gray registration (P<0.05). The analysis on the setup errors in underweight group found that the X-axis and Y-axis setup errors in vacuum pad group were smaller than those in thermoplastic film group (P<0.05), but the difference in Z-axis setup errors between two groups was trivial (P>0.05) and the X-axis, Y-axis and Z-axis MPTV of vacuum pad group were significantly lower than those in thermoplastic film group (P<0.05). In normal group, thermoplastic film group has significantly smaller Z-axis setup errors, higher X-axis and Y-axis MPTV, larger X-axis and Y-axis setup errors, and lower Z-axis MPTV than vacuum pad group (P<0.05). In overweight group, compared with vacuum pad group, thermo plastic film group had smaller X-axis and Y-axis setup errors, but larger Z-axis setup errors (P<0.05) and the X-axis, Y-axis and Z-axis MPTV of vacuum pad group were significantly higher than those of thermoplastic film group (P<0.05). Conclusion In radiotherapy of cervical cancer, vacuum pad for patients with low and normal BMI, thermoplastic film for overweight patients, and gray registration in any cases (underweight, normal, and overweight) can reduce setup errors and ensure the successful completion of radiotherapy.
Last Update: 2023-03-03