Optimization of treatment planning parameters used in tomotherapy for prostate cancer patients

摘要: Abstract Background and purpose Tomotherapy treatment planning depends on parameters that are not used conventionally such as: field width (FW), pitch factor (PF) modulation (MF). The aim of this study is to analyze the relationship between these their influence quality plans beam-on time. Material methods Ten prostate cancer patients were included in study. For each patient, two cases irradiation considered depending target volume: PTV1 gland, seminal vesicles, pelvic lymph nodes a 1 cm margin, whereas PTV2 only gland with margin. patient case (PTV1 PTV2) 8 created – all consisted different combination (FW = 1.05, 2.5, 5 cm; PF = 0.107, 0.215, 0.43; MF = 1.5, 3.5). Default values FW = 2.5 cm, PF = 0.215 MF = 2.5. Hence, for FWs, PF MF 0.215 respectively; PFs, FW 2.5 finally MFs, respectively. reference plan was optimized FW = 1.05 cm, PF = 0.107 MF = 3.5, which assumed result best dose distribution longest As result, 160 created. Each analyzed execution Results conclusion : Treatment 5 cm resulted shortest time compromising distribution. Moreover, fall off longitudinal direction sharp. 1.05 cm 0.107 recommended routine due long time, 3 times longer than FW = 5 cm. There no substantial decrease when increased from 0.43 both PTV2); however, slightly compromised. Finally, decreasing 1.5 useless because it did change time; remarkably Nevertheless, increasing up 3.5 could be considered. lowest EUD rectum intestines, observed PF = 0.107. other differences rather small (the almost same). By reducing or 5 1.05 bladder (in case) decreased by 3.13% 2.60%. When volume, 4.54% 3.43% changed 3.5, optimal balance OARs patients, authors would suggest use: FW = 2.5,