Sebastia Sabater1, Ignacio Andres2, Marimar Sevillano2, Roberto Berenguer2, Santiago Machin-Hamalainen3, Meritxell Arenas4. 1. Department of Radiation Oncology, Complejo Hospitalario Universitario de Albacete (CHUA), Albacete, Spain. Electronic address: ssabaterm@gmail.com. 2. Department of Radiation Oncology, Complejo Hospitalario Universitario de Albacete (CHUA), Albacete, Spain. 3. C.S. General Ricardos, Area 11, Madrid, Spain. 4. Department of Radiation Oncology, Hospital Universitari Sant Joan, Reus, Spain.
Abstract
PURPOSE: To compare dose summation using a single plan (SP) approach for vaginal cuff brachytherapy (VBT) against dose summation after a rigid or deformable registration for each VBT fraction, in women with early stage endometrial cancer receiving postoperative VBT. METHODS AND MATERIALS: A retrospective analysis of 19 patients who received VBT as the sole adjuvant treatment was undertaken. For the purposes of the study, every VBT fraction was re-segmented and re-planned under the same conditions. CT-planning images were registered, initially following a rigid method and then using deformable registration. The transformation vectors were reused to warp the dose files, followed by the dose summation. Three dose accumulation scenarios were studied: (1) an SP approach, (2) a rigid dose warping summation (RDWS), (3) a deformable dose warping summation (DDWS). Each scenario was analyzed for 3 and 5 fractions to evaluate the effect of fractionation. D0.1cc, D1cc, D2cc, D5cc, D5%, and Dmean values were compared for organs at risk, such as the rectum and bladder. RESULTS: No statistical significances were observed in rectal parameters between SP and RDWS or between SP and DDWS. Significant SP, RDWS and DDWS Dmean, D0.1cc, and D2cc metric differences for the 5 fractions bladder scenario were observed (p = 0.0242, 0.0196, and 0.0242, respectively). CONCLUSIONS: A multi-image planning procedure for a VBT course leads to limited differences between different summation methods. SP is an effective and acceptable surrogate for absorbed doses in organs at risk.
PURPOSE: To compare dose summation using a single plan (SP) approach for vaginal cuff brachytherapy (VBT) against dose summation after a rigid or deformable registration for each VBT fraction, in women with early stage endometrial cancer receiving postoperative VBT. METHODS AND MATERIALS: A retrospective analysis of 19 patients who received VBT as the sole adjuvant treatment was undertaken. For the purposes of the study, every VBT fraction was re-segmented and re-planned under the same conditions. CT-planning images were registered, initially following a rigid method and then using deformable registration. The transformation vectors were reused to warp the dose files, followed by the dose summation. Three dose accumulation scenarios were studied: (1) an SP approach, (2) a rigid dose warping summation (RDWS), (3) a deformable dose warping summation (DDWS). Each scenario was analyzed for 3 and 5 fractions to evaluate the effect of fractionation. D0.1cc, D1cc, D2cc, D5cc, D5%, and Dmean values were compared for organs at risk, such as the rectum and bladder. RESULTS: No statistical significances were observed in rectal parameters between SP and RDWS or between SP and DDWS. Significant SP, RDWS and DDWS Dmean, D0.1cc, and D2cc metric differences for the 5 fractions bladder scenario were observed (p = 0.0242, 0.0196, and 0.0242, respectively). CONCLUSIONS: A multi-image planning procedure for a VBT course leads to limited differences between different summation methods. SP is an effective and acceptable surrogate for absorbed doses in organs at risk.
Authors: Sebastia Sabater; Meritxell Arenas; Roberto Berenguer; Ignacio Andres; Esther Jimenez-Jimenez; Ana Martos; Jesus Fernandez-Lopez; Mar Sevillano; Angeles Rovirosa Journal: Cancer Res Treat Date: 2014-11-24 Impact factor: 4.679
Authors: Ingrid White; Dualta McQuaid; Helen McNair; Alex Dunlop; Steven Court; Naomi Hopkins; Karen Thomas; David Dearnaley; Shree Bhide; Susan Lalondrelle Journal: Phys Imaging Radiat Oncol Date: 2019-04-05