Sabater Sebastia, Arenas Meritxell, Berenguer Roberto, Andres Ignacio, Jimenez-Jimenez Esther, Martos Ana, Fernandez-Lopez Jesus, Sevillano Mar, Rovirosa Angeles
Department of Radiation Oncology, Complejo Hospitalario Universitario de Albacete, Albacete, Spain.
Department of Radiation Oncology, Hospital Universitari Sant Joan, Reus, Spain.
Cancer Res Treat. 2015 Jul;47(3):473-9. doi: 10.4143/crt.2014.115. Epub 2014 Nov 24.
Association between body mass index (BMI) and doses in organs at risk during postoperative vaginal cuff brachytherapy (VCB) treatment has not been evaluated. The aim of this study was to analyse the impact of BMI on the dose delivered to bladder and rectum during high-dose-rate VCB using computed tomography (CT) scans at every fraction.
A retrospective analysis of 220 planning CT sets derived from 59 patients was conducted. Every planning CT was re-segmented and re-planned under the same parameters. Rectum and bladder dose-volume histogram values (D0.1cc, D1cc, and D2cc) were extracted and evaluated. The mean values for all applications per patient were calculated and correlated with BMI, as well as other factors influencing rectal and bladder doses. Multiple regression analysis performed to model organ at risk dose-volume parameters.
According to World Health Organization (WHO), 6.8% of patients were normal, 35.6% were overweight, and 57.6% were class I obese. Median rectal doses were 133.5%, 110.9%, and 99.3% for D0.1cc, D1cc, and D2cc, respectively. The corresponding median bladder doses were 96.2%, 80.6%, and 73.3%, respectively. BMI did not show significant association with rectal doses. However, BMI did show a significant association with evaluated bladder dose metrics (D0.1cc, r=-0.366, p=0.004; D1cc, r=-0.454, p < 0.001; D2cc, r=-0.451, p < 0.001). BMI was retained in the multivariate regression models (D0.1cc, p=0.004; D1cc, p < 0.001; D2cc, p=0.001).
In this group of Mediterranean, overweight, and moderately obese patients, BMI showed association with lower bladder dose values, but not with rectal doses.
尚未评估体重指数（BMI）与术后阴道残端近距离放射治疗（VCB）期间危及器官剂量之间的关联。本研究的目的是使用每次分割时的计算机断层扫描（CT）分析BMI对高剂量率VCB期间膀胱和直肠所接受剂量的影响。
对来自59例患者的220套计划CT进行回顾性分析。每套计划CT在相同参数下重新分割并重新规划。提取并评估直肠和膀胱的剂量体积直方图值（D0.1cc、D1cc和D2cc）。计算每位患者所有应用的平均值，并将其与BMI以及其他影响直肠和膀胱剂量的因素相关联。进行多元回归分析以建立危及器官剂量体积参数模型。
根据世界卫生组织（WHO）的标准，6.8%的患者体重正常，35.6%超重，57.6%为I级肥胖。D0.1cc、D1cc和D2cc的直肠中位剂量分别为133.5%、110.9%和99.3%。相应的膀胱中位剂量分别为96.2%、80.6%和73.3%。BMI与直肠剂量无显著关联。然而，BMI与评估的膀胱剂量指标有显著关联（D0.1cc，r = -0.366，p = 0.004；D1cc，r = -0.454，p < 0.001；D2cc，r = -0.451，p < 0.001）。BMI保留在多变量回归模型中（D0.1cc，p = 0.004；D1cc，p < 0.001；D2cc，p = 0.001）。
在这组地中海地区、超重和中度肥胖患者中，BMI与较低的膀胱剂量值相关，但与直肠剂量无关。
