Acute effects of therapeutic irradiation for prostatic carcinoma on anorectal function

Abstract

Aim-The incidence of anorectal symptoms after radiotherapy (RTH) for localised pelvic malignant disease is unclear. In addition, the eVects of pelvic irradiation on both anorectal motility and sensory function are poorly defined. A prospective study was therefore performed on 35 patients (55-82 years of age) with localised prostatic carcinoma before and four to six weeks after RTH to assess its eVects on anorectal function. Methods-Anorectal symptoms were assessed by questionnaire. Anorectal pressures at rest and in response to voluntary squeeze, rectal distension, and increases in intra-abdominal pressure were evaluated with perfused sleeve side hole manometry. Rectal sensation was tested during graded balloon distension. Rectal compliance was calculated by the pressure-volume relation obtained during the testing of rectal sensation. Ultrasound was used to determine anal sphincter structure and integrity. Results-RTH had no eVect on anal sphincter morphology. The frequency of defecation increased after RTH (7 (3-21) v 10 (3-56) bowel actions a week; p<0.01). After RTH, 16 patients had faecal urgency and eight faecal incontinence, compared with five and one respectively before RTH (p<0.01 for each). Basal and squeeze sleeve recorded pressures were reduced after RTH (54 (3) v 49 (3) mm Hg (p<0.05) and 111 (8) v 102 (8) mm Hg (p<0.01), before and after RTH respectively; means (SEM)). Rectal compliance was reduced after RTH (1.2 v 1.4 mm Hg/ml, p<0.05). After RTH, threshold volumes for perception of rectal distension were lower in the 16 patients who either experienced faecal urgency for the first time (13 patients) or reported worsening of this symptom (three patients) compared with the remaining patients (34 (4) v 48 (5) ml respectively, p<0.05). Conclusion-Faecal incontinence (23%) is a common problem four to six weeks after RTH for prostatic carcinoma and is associated with minor reductions in anal sphincter pressures. The high prevalence of faecal urgency in patients after RTH may be related to alterations in rectal perception of stool.

Effects of radiation therapy on the structure and function of the pelvic floor muscles of patients with cancer in the pelvic area: a systematic review

“…The effect size for the maximal thickness of the external anal sphincter was in accordance with this result (effect size 0.14), but the effect size for the thickness of the internal anal sphincter suggests a moderate detrimental effect of RT (effect size −0.72). Similar conclusions were drawn from a prospective cohort study conducted by the same author; no differences were found between pre-and postradiation measures of maximal thickness of the external and internal anal sphincters in men treated for prostate cancer in acute [33] and chronic [34] conditions; however, no effect size could be calculated from available data. Another study by Gervaz et al [31] presented an interesting case study with measures until 4 years post-radiation.…”

“…Out of the eight articles studying these aspects, only two had excellent methodological quality [32,34]. The latter study showed no change of the maximal thickness of the external and internal anal sphincters of men irradiated for prostate cancer, which is corroborated in two other studies of good methodological quality [30,33]. The former study showed decreased urethral length and increased fibrosis in the levator ani and urogenital diaphragm muscles of men irradiated for prostate cancer.…”

“…Of the eight articles that studied PFM structure after RT, three compared the irradiated subjects to non-cancer, non-irradiated subjects [28][29][30], another one to a subject with cancer who did not receive radiation [31], and three compared to pre-radiation measures for their cohort study [32][33][34], and the last study had no control group [35]. In these studies, the effects of radiation were observed through evaluation of the changes in the muscle tissue itself, such as its dimension, morphology, or composition (Table 3).…”

“…For the other reviewed articles [35,29,31,30,33], an overall trend toward supporting that radiation affects the PFM structure is presented with a level 4 evidence. The choice of outcome measure was fair: histology was used for one trial, and anal manometry for anal sphincter length's measures in another one.…”

“…Furthermore, the results of a cross-sectional study by Vordermark et al [29] demonstrated a decreased anal resting and maximal squeeze pressure through manometry for the RT group compared to healthy normals. Manometry was also used in the studies by Yeoh et al [30,33,34], where anal resting and maximal squeeze pressure were found decreased in chronic cervical cancer patients [30] 5 to 10 years post-RT compared to healthy volunteers. Strong detrimental effect sizes could be calculated from the data of the first study (between −0.94 and −1.3), except for resting pressure at anal sleeve where only a weak detrimental effect size was calculated (effect size −0.14), The same results were observed in a cohort of men treated for prostate cancer [33], between baseline and 4-6 weeks post-RT.…”