Faecal incontinence following radiotherapy for prostate cancer: a systematic review

Faecal incontinence (FI) after radiotherapy is a known phenomenon, but has received little attention to date. This article aimed to review current knowledge on faecal incontinence related to radiotherapy for prostate cancer.

PubMed was searched for English-language articles published from January 1966 to December 2009 using the primary keywords 'faecal incontinence', 'prostate cancer' and 'radiotherapy'. Prospective, retrospective and controlled trials reporting FI as a complication of radiotherapy for prostate cancer were included. The retrieved titles and abstracts were screened permissively and evaluated as to whether they satisfied the predefined inclusion and exclusion criteria.

Nine hundred and ninety four articles were identified from the search. After step-wise review, 213 papers were selected for full article review of which 40 were selected for this review. The incidence of faecal incontinence following radiotherapy for prostate cancer varied from 1.6% to 58%. The mechanism of faecal incontinence was not entirely clear but it is most likely due to injury to the nerve plexus of the rectal muscular layer. Correlation between rectal dose-volume parameters and incidence is equivocal, although some studies suggest parameters confined to the lower rectum and/or anal canal may be of value to predict the extent of the injury and could be used as constraints in the dose planning process.

Interpretation of data is limited due to lack of large cohort studies with data on pre-treatment continence status and because variable instruments have been used to assess the severity of the condition. Well-designed prospective studies are needed to investigate dosimetric parameters focusing on the anal canal and sphincter apparatus. Considering the spatial distribution of radiation to the rectum may identify a more direct linkage between radiation damage and faecal incontinence.