5 Radiobiology of LDR, HDR, PDR and VLDR Brachytherapy

Radiobiology of LDR, HDR, PDR and VLDR Brachytherapy

10

THE GEC ESTROHANDBOOKOF BRACHYTHERAPY | Part I: The Basics of Brachytherapy Version 1 - 22/10/2015

Fig 5.11: Volume Biological Effect of 4 different PDR schedules, compared to CLDR 50 Gy/h. 70 Gy/h in function of pulse size (4 diagrams) and different half lines of repair. When pulse doses exceed 1 Gy isoeffect to CLDR is only present when half line of repair is slower than 30 minutes. After Fowler and Van Limbergen (Fowler 1997)

Fig 5.12 A: Double plane breast implant with 9 source tracks and 7 mean central dose points(a to g). B: Dose rate in central dose point c during a pulse with the stepping source travelling through the nine source channels. Note that the dose in c is delivered by a few dwell positions close to the central dose point c. (with thanks to Barbara Geelen, Delft, The Netherlands)