Table 1 Summary of radiation-planning differences between 3DCRT and IMRT
3DCRT | IMRT | ||
|---|---|---|---|
Planning | slice | 2.5 mm with normal quiet breathing | |
CT | range | upper edge of L3 to at least 7 cm below the bottom of the obturator foramen | |
frequency | once (full bladder) | twice (full bladder and empty bladder) | |
RTP | XiO (Elekta, Stockholm, Sweden) | ||
CTV | regional nodal CTV | common iliac, external iliac, internal iliac and presacral | |
central vaginal CTV | proximal vagina and paravaginal tisusue | ||
PTV | 1.0-cm uniform expansion of CTV | central vaginal CTV fused on both the full bladder and 0.7-cm uniform expansion of CTV | |
Dose | total (Gy) | 50 | 50.4 |
fractions | 25 | 28 | |
prescri ption | center of the PTV | mean dose to the PTV | |
Normal structure | delineate before treatment | - | bladder, rectum, bowel bag and femoral head |
delineate after treatment | bowel bag, small bowel loops, large bowel loop, pelvic bone | small bowel loops |