Agata Jodda1, Bartosz Urbański2, Tomasz Piotrowski3, Julian Malicki3. 1. Department of Medical Physics, Greater Poland Cancer Centre, Poznań, Poland. Electronic address: agata.jodda@gmail.com. 2. Department of Electroradiology, Poznań University of Medical Sciences, Poznań, Poland; Gynaecological Radiotherapy Ward, Greater Poland Cancer Centre, Poznań, Poland. 3. Department of Medical Physics, Greater Poland Cancer Centre, Poznań, Poland; Department of Electroradiology, Poznań University of Medical Sciences, Poznań, Poland.
Abstract
PURPOSE: To compare normal tissue complication probability (NTCP) and average doses in the bone marrow (BM), obtained for five different radiotherapy delivery and planning strategies of cervical and endometrial cancer. MATERIAL/ METHODS: 50 patients were taken to analysis. For each case, 3 different dose delivery techniques were used: 4-field, X15MV, 3DCRT; 7-field, X6MV, IMRT; and 2-arc, X6MV, VMAT. Two optimization scenarios were used for the IMRT and VMAT plans generation: with (+) and without (-) the inclusion of the BM as an optimized structure. Average doses and dose-volume histogram parameters for the PTV, BM, bladder, rectum, bowels and femoral heads were compared. In addition, the BM doses were analyzed with respect to the PTV and/or volume of the BM, and NTCP for the BM were computed. RESULTS: The dose in PTV for evaluated plans was similar. The worst doses in organs at risk were obtained for 3DCRT. Using the BM during the optimization of IMRT and VMAT reduces an average dose in BM without increasing the doses in the bladder, rectum and bowels. Differences between doses in BM for IMRT(+) and VMAT(+) plans were similar while NTCP was lower for VMAT(+). A correlation between average dose in BM and the volume ratio of BM and PTV was found for each technique. CONCLUSION: Using the BM during the optimization of the IMRT and VMAT plans effectively reduces the dose in BM without increasing the dose in the bladder, rectum and bowels. The VMAT(+) plans were characterized by the lowest NTCP.
PURPOSE: To compare normal tissue complication probability (NTCP) and average doses in the bone marrow (BM), obtained for five different radiotherapy delivery and planning strategies of cervical and endometrial cancer. MATERIAL/ METHODS: 50 patients were taken to analysis. For each case, 3 different dose delivery techniques were used: 4-field, X15MV, 3DCRT; 7-field, X6MV, IMRT; and 2-arc, X6MV, VMAT. Two optimization scenarios were used for the IMRT and VMAT plans generation: with (+) and without (-) the inclusion of the BM as an optimized structure. Average doses and dose-volume histogram parameters for the PTV, BM, bladder, rectum, bowels and femoral heads were compared. In addition, the BM doses were analyzed with respect to the PTV and/or volume of the BM, and NTCP for the BM were computed. RESULTS: The dose in PTV for evaluated plans was similar. The worst doses in organs at risk were obtained for 3DCRT. Using the BM during the optimization of IMRT and VMAT reduces an average dose in BM without increasing the doses in the bladder, rectum and bowels. Differences between doses in BM for IMRT(+) and VMAT(+) plans were similar while NTCP was lower for VMAT(+). A correlation between average dose in BM and the volume ratio of BM and PTV was found for each technique. CONCLUSION: Using the BM during the optimization of the IMRT and VMAT plans effectively reduces the dose in BM without increasing the dose in the bladder, rectum and bowels. The VMAT(+) plans were characterized by the lowest NTCP.
Authors: T Kumar; A Schernberg; F Busato; M Laurans; I Fumagalli; I Dumas; E Deutsch; C Haie-Meder; C Chargari Journal: Cancer Manag Res Date: 2019-07-08 Impact factor: 3.989