Rectum

Late rectal morbidity is principally observed in patients treated with radiotherapy using curative doses for cervical, prostate and rectal cancers.

During radiotherapy, inflammatory changes are prominent and consist in migration of leucocytes through the crypt wall, crypt abscesses, inflammatory cell infiltration in the surface epithelium and lamina propria, and a striking accumulation of eosinophilic granulocytes. These histologic changes are maximal 2 weeks after the beginning of the treatment90. Later radiotherapy induces swelling of the fibroblasts, a subendothelial deposition of hyaline material, an endothelial proliferation with endarteritis of the arterioles. The most marked changes are noted in the submucosa, contrary to the acute radiation injury which is most prominent in the mucosa91. Superficial neovascularization (telangiectasia) can be observed even in asymptomatic patients92. These pathological changes can result in rectal tissue ischemia and fibrosis, leading to bleeding, ulceration, stricture or fistulae93.

Patients with increased acute toxicity during radiotherapy significantly increase the risk of late rectal morbidity94,95. Around 80 % of late rectal complications occur within 30 months after the end of the treatment94,96-99. However the interval can be longer, until several years93. Radiation proctitis can include tenesmus, bleeding, low volume diarrhoea, rectal pain. A stricture results in abdominal pain, constipation. The main symptom of ulceration is pain, increasing with defecation. It can leads to abscess or fistulae93,100,101.

Several classification have been developed102; the RTOG defined proctitis as " being characterised by rectal irritation or urgency (tenesmus), presence of mucous or blood in the stool and in some patients frequent loose bowel actions". More recently the LENT/SOMA scoring has been introduced which lists 6 symptoms for proctitis103. Some authors have utilized their own classification96,99.

0 0

Post a comment