Course book Advanced Treatment Planning 2018

Parameters for clinical outcome: Rectum

Irradiation type (partial organ unless otherwise stated)

Dose (Gy), or dose/volume parameters

Volume segmented Whole organ

Notes on dose/volume parameters

Endpoint

Rate (%)

3D-CRT

V50 <50%

Grade > 2 late rectal toxicity, Grade > 3 late rectal toxicity Grade > 2 late rectal toxicity, Grade > 3 late rectal toxicity Grade > 2 late rectal toxicity, Grade > 3 late rectal toxicity Grade > 2 late rectal toxicity, Grade > 3 late rectal toxicity Grade > 2 late rectal toxicity, Grade > 3 late rectal toxicity

<15 <10 <15 <10 <15 <10 <15 <10 <15 <10

Whole organ

3D-CRT

V60 <35%

Whole organ

3D-CRT

V65 <25%

Prostate cancer treatment

Whole organ

3D-CRT

V70 <20%

Whole organ

3D-CRT

V75 <15%

• Rectal segmentation from above the anal verge to the turn into sigmoid colon • The evaluation of rectal bleeding seems to have an a higher lower than other endpoints (11) • The reduction of V75 from 15% to 10% is more effective than reduction of V50 from 50% to 45% respectively

Michalski JM et al. Radiation Dose-Volume effects in radiation-induced rectal injury. Int. J. Radiation Oncology Biol. Phys., Vol. 76, No. 3, Supplement, pp. S123–S129, 2010.