Dosimetric comparison of various optimization techniques for high dose rate brachytherapy of interstitial cervix implants

摘要: HDR brachytherapy treatment planning often involves optimization methods to calculate the dwell times and positions of radioactive source along specified afterloading catheters. The purpose this study is compare dose distribution obtained with geometric (GO) volume (VO) combined isodose reshaping. This a retrospective 10 cervix interstitial implants planned using treated 6 Gy per fraction. Four plans were compared: (GO), (VO), followed by reshape (GO_IsoR), (VO_IsoR). Dose histogram (DVH) was analyzed four evaluated based on dosimetric parameters: target coverage (V 100 ), conformal index (COIN), homogeneity (HI), nonuniformity ratio (DNR) natural (NDR). Good prescription achieved GO_ IsoR (mean V 88.11%), 150% 200% receiving 32.0% 10.4% dose, respectively. Slightly lower VO_IsoR 86.11%) significant reduction in tumor high 150 28.29% mean 200 7.3%). Conformity good VO_ COIN = 0.75 HI 0.58) as compared other techniques. are supe­rior sparing normal structures while also providing better conformity target. Clinically acceptable can be reshaping provided lines dragged carefully.