Radiation Oncology/Brachytherapy/General concepts

Manchester system (also called Patterson-Parker) Dose and dose rate: 6000 R - 8000 R in 6-8 days (1000 R/d, 40 R/h) Dose specification criterion: Effective minimum dose is 10% above the minimum dose in treatment plane or volume Dose gradient: Dose in treatment volume or plane varies by no more than 10% from stated dose except for localized hot spots Linear activity: 0.66 and 0.33 mgRaEq/cm HDR Fractionation Amsterdam; 2002 11849810 -- "The optimal fraction size in high-dose-rate brachytherapy: dependency on tissue repair kinetics and low-dose rate." (Sminia P, Int J Radiat Oncol Biol Phys. 2002 Mar 1;52(3):844-9.) Evaluation of optimal fraction size in HDR brachytherapy; assume 20 Gy in either LDR or HDR, repair half-life 1-4 hours and 3x longer than tumor Optimal fractionation: 3 x 6.7 Gy or 4 x 5 Gy For HDR vs LDR BED calculator, see: Radiation_Oncology/Cervix/Brachytherapy#Equivalent_doses Electronic brachytherapy ASTRO; 2010 20206016 -- "American Society for Therapeutic Radiology and Oncology (ASTRO) Emerging Technology Committee report on electronic brachytherapy." (Park CC, Int J Radiat Oncol Biol Phys. 2010 Mar 15;76(4):963-72.) GEC ESTRO Handbook Handbook link