Giuseppe Iatì1, Antonio Pontoriero2, Stefania Mondello3, Anna Brogna4, Andrea Di Pasquale4, Isidora Ielo4, Antonio Potami1, Giovanna Messina1, Costantino De Renzis5, Stefano Pergolizzi5. 1. Operative Unit of Radiation Oncology, A.O.U. "G. Martino", Messina, Italy. 2. Department of Biomedical Sciences and Morphological and Functional Images, University of Messina, Messina, Italy. Electronic address: apontoriero@unime.it. 3. Department of Neuroscience, University of Messina, Messina, Italy. 4. Operative Unit of Medical Physics, A.O.U. "G. Martino", Messina, Italy. 5. Department of Biomedical Sciences and Morphological and Functional Images, University of Messina, Messina, Italy.
Abstract
PURPOSE: Aim of this study was to evaluate dose distribution within organs at risk (OARs) and planning target volume (PTV) based on three-dimensional treatment planning according to two different setup positions in endometrial carcinoma patients submitted to postoperative brachy-radiotherapy on vaginal vault. METHODS AND MATERIALS: Patients with endometrial cancer necessitating of adjuvant brachytherapy on vaginal vault were enrolled. Pelvic computed tomography studies were prospectively obtained in two different setup positions: extend legs (A position) and gynecological (B position). Contoured OARs were bladder, rectum, and small bowel. The PTV was identified as applicator's surface with an isotropic 5-mm margin expansion. Radiation dose delivered in 1 cc (D1cc) and 2 cc (D2cc) of OAR were calculated. RESULTS: Coverage of PTV and values of D1cc and D2cc obtained for bladder and small bowel were similar in the two positions. For rectum, both D1cc and D2cc had statistically significant lower values in A with respect to B position. CONCLUSIONS: Both in A and B positions, radiation doses delivered do not exceed the dose constraints. However, A setup seems to significantly reduce doses to rectum while obtaining the same PTV coverage. The findings from our study provide evidence supporting the use of A position setup for delivering vaginal vault brachytherapy.
PURPOSE: Aim of this study was to evaluate dose distribution within organs at risk (OARs) and planning target volume (PTV) based on three-dimensional treatment planning according to two different setup positions in endometrial carcinomapatients submitted to postoperative brachy-radiotherapy on vaginal vault. METHODS AND MATERIALS: Patients with endometrial cancer necessitating of adjuvant brachytherapy on vaginal vault were enrolled. Pelvic computed tomography studies were prospectively obtained in two different setup positions: extend legs (A position) and gynecological (B position). Contoured OARs were bladder, rectum, and small bowel. The PTV was identified as applicator's surface with an isotropic 5-mm margin expansion. Radiation dose delivered in 1 cc (D1cc) and 2 cc (D2cc) of OAR were calculated. RESULTS: Coverage of PTV and values of D1cc and D2cc obtained for bladder and small bowel were similar in the two positions. For rectum, both D1cc and D2cc had statistically significant lower values in A with respect to B position. CONCLUSIONS: Both in A and B positions, radiation doses delivered do not exceed the dose constraints. However, A setup seems to significantly reduce doses to rectum while obtaining the same PTV coverage. The findings from our study provide evidence supporting the use of A position setup for delivering vaginal vault brachytherapy.
Authors: Lucas Gomes Sapienza; Antonio Aiza; Maria José Leite Gomes; Michael Jenwei Chen; Antonio Cassio de Assis Pellizzon; David B Mansur; Glauco Baiocchi Journal: J Contemp Brachytherapy Date: 2015-10-13