title: Body Mass Index and Doses at Organs at Risk in a Mediterranean Population Treated with Postoperative Vaginal Cuff Brachytherapy.
abstract: OBJECTIVE
  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.
  
  
  METHODS
  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.
  
  
  RESULTS
  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).
  
  
  CONCLUSIONS
  In this group of Mediterranean, overweight, and moderately obese patients, BMI showed association with lower bladder dose values, but not with rectal doses.
authors: Department of Radiation Oncology, Complejo Hospitalario Universitario de Albacete, Albacete, Spain.
authors: Sebastia
authors: S
authors: Sabater
authors: Department of Radiation Oncology, Hospital Universitari Sant Joan, Reus, Spain.
authors: Meritxell
authors: M
authors: Arenas
authors: Department of Radiation Oncology, Complejo Hospitalario Universitario de Albacete, Albacete, Spain.
authors: Roberto
authors: R
authors: Berenguer
authors: Department of Radiation Oncology, Complejo Hospitalario Universitario de Albacete, Albacete, Spain.
authors: Ignacio
authors: I
authors: Andres
authors: Department of Radiation Oncology, Hospital Son Espases, Palma de Mallorca, Spain.
authors: Esther
authors: E
authors: Jimenez-Jimenez
authors: Department of Radiation Oncology, Hospital Central, Oviedo, Spain.
authors: Ana
authors: A
authors: Martos
authors: Department of Radiation Oncology, Complejo Hospitalario Universitario de Albacete, Albacete, Spain.
authors: Jesus
authors: J
authors: Fernandez-Lopez
authors: Department of Radiation Oncology, Complejo Hospitalario Universitario de Albacete, Albacete, Spain.
authors: Mar
authors: M
authors: Sevillano
authors: Gynecological Cancer Unit, Radiation Oncology Department, ICMHO, Hospital Clinic, University of Barcelona, IDIBAPS, Barcelona, Spain.
authors: Angeles
authors: A
authors: Rovirosa
keywords: Body mass index; Brachytherapy; Obesity; Rectum; Urinary bladder