Radiation Oncology/Toxicity/Bladder

Bladder RT Tolerance

Dosimetry

Dutch Dose Escalation Trial; 2010 PMID 20056354 -- "Urinary Obstruction in Prostate Cancer Patients From the Dutch Trial (68 Gy vs. 78 Gy): Relationships with Local Dose, Acute Effects, and Baseline Characteristics." (Heemsbergen WD, Int J Radiat Oncol Biol Phys. 2010 Jan 5. [Epub ahead of print])
- For full trial results, please see the prostate dose escalation page
- Subset analysis. 40 patients with urinary obstruction (19 low dose arm and 21 high dose arm). Dose-difference maps
- Outcome: Early events within 2 years (47%) predicted by baseline complaints and TURP. Late events after 2 years (53%) predicted by bladder surface receiving ≥ 80 Gy and especially with dose to bladder neck in the trigone
- Conclusion: Late urinary obstruction associated with local dose to trigone

MD Anderson, 2007 PMID 17241755 -- "Investigation of bladder dose and volume factors influencing late urinary toxicity after external beam radiotherapy for prostate cancer." (Cheung MR, Int J Radiat Oncol Biol Phys. 2007 Jan 19; [Epub ahead of print])
- Retrospective. 128 patients treated to 78 Gy. Endpoint Grade 1+ late GU toxicity within 2 years of treatment
- Toxicity: Grade 1+ chronic GU toxicity in 15%. No plateau, continued increase with time
- DVH (dose-bladder volume histogram) data fit better than DWH (dose-bladder wall histogram) to toxicity. Recommend using whole-bladder DVH for clinical treatment planning. Urethra (suggested to be important in late GU toxicity) not contoured
- Hotspot model (hottest 3%): if <78 Gy then 8 year toxicity 25%, if >=78 Gy then 50%
- Lyman model: TD50 = 77.6 Gy, n=0.001, m=0.022

1995 PMID 7713787 -- "The response of the urinary bladder, urethra, and ureter to radiation and chemotherapy." (Marks LB, Int J Radiat Oncol Biol Phys. 1995 Mar 30;31(5):1257-80.)
- Comprehensive review. From Late Effects of Normal Tissues (LENT) Consensus Conference.