RADIATION ENTERITIS
Table 78.1: Features of Acute and Chronic Radiation Enteritis
| Feature | Acute | Chronic |
|---|---|---|
| Incidence | 75%–80% | 1.2%–15% |
| Timing | 2–4 weeks | 6–24 months |
| Histology | Inflammatory infiltrate, reduced crypt mitosis, crypt microabscesses, ulceration | Obliterative endarteritis, fibrosis, lymphatic dilation, tissue ischemia, necrosis |
| Causes of Symptoms | Malabsorption, bacterial overgrowth | Obstruction (stricture, adhesions), fistula, malabsorption, intestinal failure, neoplasia (recurrent or new) |
Table 78.2: Risk Factors for Radiation Enteritis
- Volume of small bowel in the radiation field
- Radiation dose and fractionation
- Radiation technique
- Concomitant chemotherapy
- Prior intestinal surgery
- Medical comorbidities
Table 78.3: Preventive Methods for Radiation Enteritis
| Therapy Modifications | Medical | Surgical |
|---|---|---|
| Positioning (supine, prone, Trendelenburg) | Glutamine, Triamcinolone, Pectin, Cysteine, Pentoxifylline/tocopherol, Amifostine, L-Carnitine, Prebiotics | Mesh slings, Pelvic expander, Pelvic sling, Reperitonealization, Omental transposition flaps, Abdominopelvic omentopexy, Occlusion of the pelvis with bladder/uterus |
MCQs for Revision
1. All are true about acute radiation enteritis except:
A) More common
B) Occurs within 6-8 months
C) Malabsorption & bacterial overgrowth are the main causes of symptoms
D) Crypt microabscess is found in histology
Correct Answer: B) Occurs within 6-8 months
(Acute radiation enteritis typically occurs 2-4 weeks after exposure, not 6-8 months.)
2. All are histological features of chronic radiation enteritis except:
A) Obliterative endarteritis
B) Fibrosis
C) Ulceration
D) Lymphatic dilation
Correct Answer: C) Ulceration
(Ulceration is more characteristic of acute rather than chronic radiation enteritis.)
3. All are risk factors for radiation enteritis except:
A) Radiation technique
B) Volume of small bowel in the field
C) Type of malignancy
D) Concomitant chemotherapy
Correct Answer: C) Type of malignancy
(The type of malignancy itself is not a risk factor; rather, the location and treatment approach are.)
4. All are considered as preventive methods for radiation enteritis except:
A) Pectin
B) Bladder distension
C) Pelvic sling
D) Peritonectomy
Correct Answer: D) Peritonectomy
(Peritonectomy is not listed as a preventive method for radiation enteritis.)
5. All are radioprotectors except:
A) Glutamine
B) Triamcinolone
C) Phenobarbitone
D) Pentoxifylline
Correct Answer: C) Phenobarbitone
(Phenobarbitone is not known as a radioprotector in the context of radiation enteritis.)
6. Clinically useful biomarker for radiation enteritis is:
A) Plasma Citrulline
B) Fecal fat estimation
C) Procalcitonin
D) C-reactive peptide
Correct Answer: A) Plasma Citrulline
(Plasma Citrulline is a useful biomarker for enterocyte mass and is thus helpful in assessing the severity of radiation enteritis.)