Which radiotherapy technique is better for neoadjuvant treatment of rectal cancer: A dosimetric comparison

Authors : Aysegul UCUNCU KEFELI, Aysegul UNAL KARABEY, Umut Efe DOKURLAR, Berna TIRPANCI, Gulsah OZKAN, Aykut Oguz KONUK, Maksut Gorkem AKSU

Pages : 181-186

Doi:10.5472/marumj.1120583

View : 11 | Download : 6

Publication Date : 2022-05-30

Article Type : Research Paper

Abstract :Objective: Our aim was to compare helical tomotherapy insert ignore into journalissuearticles values(HT); and volumetric modulated arc therapy insert ignore into journalissuearticles values(VMAT); plans with 3-dimensional conformal radiotherapy insert ignore into journalissuearticles values(3D-CRT); considering the planning target volume insert ignore into journalissuearticles values(PTV); and organs at risk insert ignore into journalissuearticles values(OARs); in rectal cancer patients treated with neoadjuvant radiotherapy. Patients and Methods: Thirty patients, previously treated with intensity modulated radiotherapy insert ignore into journalissuearticles values(IMRT); or 3D-CRT from January 2014 to February 2020 were selected and 3 plans were generated for each patient using VMAT, HT and 3D-CRT. Dosimetric comparisons were made for each plan regarding PTV and OARs. Integral dose insert ignore into journalissuearticles values(ID); was calculated and beam on times were analyzed. Results: The homogeneity index insert ignore into journalissuearticles values(HI); was significantly better in HT plans compared with VMAT and 3D-CRT plans insert ignore into journalissuearticles values(p<0.001);, conformity index insert ignore into journalissuearticles values(CI); was better in VMAT plans. For small bowel, high doses were higher in 3D-CRT plans insert ignore into journalissuearticles values(p <0.001);. HT produced lower doses for the bladder as compared to VMAT and 3D-CRT insert ignore into journalissuearticles values(p<0.005);. The mean and maximum doses of bilateral femoral heads were higher in 3D-CRT plans. Beam on times were longer and IDs were higher in HT plans insert ignore into journalissuearticles values(p<0.001);. Conclusion: Both VMAT and HT improved target homogeneity and conformity and decreased OAR doses compared to 3D-CRT. Although, VMAT was the best method to decrease ID, HT produced better bladder sparing.
Keywords : Rectum cancer, Volumetric modulated arc therapy, Helical tomotherapy, 3 dimensional conformal radiotherapy, Plan comparison