- Title
- Modelling late stool frequency and rectal pain after radical radiotherapy in prostate cancer patients: results from a large pooled population
- Creator
- Cicchetti, A.; Rancati, T.; Avuzzi, B.; Stucchi, C.; Valdagni, R.; Ebert, M.; Fiorino, C.; Palorini, F.; Kennedy, A.; Joseph, D. J.; Denham, J. W.; Vavassori, V.; Fellin, G.
- Relation
- NHMRC.300705, NHMRC. 455521 & NHMRC. 1006447
- Relation
- Physica Medica Vol. 32, Issue 12, p. 1690-1697
- Publisher Link
- http://dx.doi.org/10.1016/j.ejmp.2016.09.018
- Publisher
- Elsevier
- Resource Type
- journal article
- Date
- 2016
- Description
- Aim: To investigate late gastrointestinal toxicity in a large pooled population of prostate cancer patients treated with radical radiotherapy. Normal tissue complication probability models were developed for late stool frequency and late rectal pain. Methods and Materials: Population included 1336 patients, 3-year minimum follow-up, treated with 66-80Gy. Toxicity was scored with LENT-SOMA-scale. Two toxicity endpoints were considered: grade ≥2 rectal pain and mean grade (average score during follow-up) in stool frequency >1. DVHs of anorectum were reduced to equivalent uniform dose (EUD). The best-value of the volume parameter n was determined through numerical optimization. Association between EUD/clinical factors and the endpoints was investigated by logistic analyses. Likelihood, Brier-score and calibration were used to evaluate models. External calibration was also carried out. Results: 4% of patients (45/1122) reported mean stool frequency grade >1; grade ≥2 rectal pain was present in the TROG 03.04 RADAR population only (21/677, 3.1%): for this endpoint, the analysis was limited to this population. Analysis of DVHs highlighted the importance of mid-range doses (30-50Gy) for both endpoints. EUDs calculated with n=1 (OR=1.04) and n=0.35 (OR=1.06) were the most suitable dosimetric descriptors for stool frequency and rectal pain respectively. The final models included EUD and cardiovascular diseases (OR=1.78) for stool frequency and EUD and presence of acute gastrointestinal toxicity (OR=4.2) for rectal pain. Conclusion: Best predictors of stool frequency and rectal pain are consistent with findings previously reported for late faecal incontinence, indicating an important role in optimization of mid-range dose region to minimize these symptoms highly impacting the quality-of-life of long surviving patients.
- Subject
- radiotherapy; prostate cancer; late toxicity; dose-volume models
- Identifier
- http://hdl.handle.net/1959.13/1327883
- Identifier
- uon:25777
- Identifier
- ISSN:1724-191X
- Language
- eng
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