Rectal bleeding, fecal incontinence, and high stool frequency after conformal radiotherapy for prostate cancer: Normal tissue complication probability modeling

Journal Article · Fri Sep 01 04:00:00 EDT 2006 · International Journal of Radiation Oncology, Biology and Physics

DOI:https://doi.org/10.1016/j.ijrobp.2006.03.034· OSTI ID:20850047

Peeters, Stephanie ^[1]; Hoogeman, Mischa S ^[2]; Heemsbergen, Wilma D ^[1]; Hart, Augustinus ^[1]; Koper, Peter C.M. ^[3]; Lebesque, Joos V ^[1]

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1. Department of Radiation Oncology, Netherlands Cancer Institute-Antoni van Leeuwenhoek Hospital, Amsterdam (Netherlands)
2. Department of Radiation Oncology, Erasmus Medical Centre, Rotterdam (Netherlands)
3. Department of Radiation Oncology, Haga Hospital, Den Haag (Netherlands)

Purpose: To analyze whether inclusion of predisposing clinical features in the Lyman-Kutcher-Burman (LKB) normal tissue complication probability (NTCP) model improves the estimation of late gastrointestinal toxicity. Methods and Materials: This study includes 468 prostate cancer patients participating in a randomized trial comparing 68 with 78 Gy. We fitted the probability of developing late toxicity within 3 years (rectal bleeding, high stool frequency, and fecal incontinence) with the original, and a modified LKB model, in which a clinical feature (e.g., history of abdominal surgery) was taken into account by fitting subset specific TD50s. The ratio of these TD50s is the dose-modifying factor for that clinical feature. Dose distributions of anorectal (bleeding and frequency) and anal wall (fecal incontinence) were used. Results: The modified LKB model gave significantly better fits than the original LKB model. Patients with a history of abdominal surgery had a lower tolerance to radiation than did patients without previous surgery, with a dose-modifying factor of 1.1 for bleeding and of 2.5 for fecal incontinence. The dose-response curve for bleeding was approximately two times steeper than that for frequency and three times steeper than that for fecal incontinence. Conclusions: Inclusion of predisposing clinical features significantly improved the estimation of the NTCP. For patients with a history of abdominal surgery, more severe dose constraints should therefore be used during treatment plan optimization.

• OSTI ID: 20850047
• Journal Information: International Journal of Radiation Oncology, Biology and Physics, Journal Name: International Journal of Radiation Oncology, Biology and Physics Journal Issue: 1 Vol. 66; ISSN IOBPD3; ISSN 0360-3016
• Country of Publication: United States
• Language: English

Related Subjects

62 RADIOLOGY AND NUCLEAR MEDICINE
CARCINOMAS
OPTIMIZATION
PATIENTS
PROSTATE
RADIATION DOSE DISTRIBUTIONS
RADIATION DOSES
RADIOTHERAPY
SURGERY
TOXICITY