Radiation cystitis is radiation-induced inflammation of the bladder mucosa developing after pelvic radiotherapy (treatment for cervical, prostate, rectal, or bladder cancer). Divided into acute (during or immediately after treatment, reversible) and chronic (months-years later, progressive and irreversible) forms. Clinically significant radiation cystitis develops in 5-15% of patients receiving pelvic radiation. The chronic form results from obliterative endarteritis (small vessel damage) and submucosal fibrosis — leading to mucosal ischemia, telangiectasia, ulceration, hemorrhage, and decreased bladder capacity. Imaging shows diffuse wall thickening, mucosal irregularity, wall calcification, and decreased bladder capacity. Hematuria is the most common symptom; treatment includes hyperbaric oxygen, intravesical therapies, and cystectomy in severe cases.
Age Range
40-85
Peak Age
65
Gender
Equal
Prevalence
Uncommon
Radiation cystitis develops in two phases. Acute phase (0-6 months): ionizing radiation directly damages DNA and triggers apoptosis in rapidly dividing urothelial cells. Mucosal desquamation, edema, and acute inflammation occur. These changes are generally reversible. Chronic phase (6 months-20+ years): obliterative endarteritis (intimal hyperplasia and luminal narrowing of small arteries) leads to submucosal ischemia. Ischemic mucosa develops telangiectasias (dilated, fragile vessels) increasing risk of spontaneous hemorrhage (hematuria). Submucosal fibrosis makes the bladder wall rigid and non-compliant — bladder capacity decreases. On imaging, the chronic phase appears as wall thickening (fibrosis), wall calcification (dystrophic — calcification of ischemic tissue), and small-capacity rigid bladder on CT. On MRI T2, fibrotic wall shows low signal, edema areas high signal. Wall calcification is an important clue for differentiation from infectious cystitis. Distribution limited to the radiation field (e.g., posterior wall emphasis — post-cervical RT) supports the diagnosis.
Calcification in the bladder wall limited to the radiation field — highly suggestive of chronic radiation cystitis. Calcification distribution with posterior wall emphasis after cervical RT, bladder base emphasis after prostate RT correlates with radiation ports. This finding is distinguished from infectious (diffuse), schistosomiasis (tramline), and tumoral (focal) calcification by distribution pattern.
Diffuse bladder wall thickening, wall calcification, and decreased bladder capacity on portal venous phase. Wall thickening is homogeneous or heterogeneous (mixture of fibrosis + edema). Calcification is usually thin, linear, or punctate pattern. Bladder capacity markedly decreased (<100 mL). Perivesical fat stranding is minimal in chronic cases.
Report Sentence
Diffuse bladder wall thickening (___ mm), wall calcification, and decreased bladder capacity are seen, consistent with chronic radiation cystitis; correlation with pelvic radiotherapy history is recommended.
On T2W MRI, fibrotic areas in the bladder wall show low signal, edema areas show high signal. In chronic phase, fibrosis is predominant — diffuse low T2 signal. During active inflammation, edema areas show high signal. Wall calcification appears as signal void on T2. Small-capacity bladder with thickened wall.
Report Sentence
Fibrotic low signal areas and focal edema high signal areas in the bladder wall are seen on T2W MRI, consistent with chronic radiation cystitis.
No focal mass-type diffusion restriction on DWI. Diffuse mild signal increase may be present (edema T2 shine-through). This finding is critical for excluding secondary tumor developing in the radiation field — biopsy is mandatory if focal DWI restriction is present.
Report Sentence
No focal mass-type diffusion restriction is identified in the bladder wall on DWI, with no findings suggesting secondary neoplasia in the radiation field.
Thin linear or punctate calcification in the bladder wall on non-contrast CT. Calcification generally shows distribution limited to the radiation field. Unlike infectious cystitis, no intraluminal gas. Clinical history (pelvic RT vs endemic region) is deterministic for differentiation from schistosomiasis-associated calcification.
Report Sentence
Thin linear calcification is seen in the ___ wall of the bladder on non-contrast CT, showing distribution consistent with the radiation field.
Diffuse wall thickening and decreased bladder capacity on US. Wall echogenicity may be increased (fibrosis). Calcification areas appear as echogenic foci + shadowing. Post-void residual volume may be increased (bladder non-compliance). US is suitable for initial evaluation before cystoscopy.
Report Sentence
Diffuse wall thickening, decreased capacity, and increased wall echogenicity are seen on US, suggesting chronic radiation changes.
Increased mucosal enhancement on contrast MRI (active inflammation/telangiectasia). Decreased enhancement in chronic fibrotic areas (avascular scar tissue). In advanced cases, vesicovaginal or vesicorrectal fistula can be demonstrated on contrast sequences and T2. Fistula tract should be evaluated for differentiation between tumor recurrence and radiation necrosis.
Report Sentence
Heterogeneous mucosal enhancement (focally increased — telangiectasia, focally decreased — fibrosis) is seen on contrast MRI, consistent with chronic radiation cystitis; fistula ___ (not identified/identified).
Criteria
Form developing during or immediately after radiotherapy (0-6 months). Mucosal edema and acute inflammation predominant.
Distinct Features
Generally reversible. Diffuse wall thickening and edema on CT/MRI, no calcification. Symptoms improve within 4-6 weeks after RT. Anti-inflammatory and hydration treatment.
Criteria
Progressive, irreversible form developing 6 months-20+ years after RT. Obliterative endarteritis and fibrosis predominant.
Distinct Features
Wall fibrosis + calcification + decreased capacity + telangiectasia → hematuria. Irreversible. Hyperbaric oxygen, intravesical therapy, cystectomy in severe cases.
Criteria
Severe variant of chronic form — characterized by significant and treatment-refractory hematuria. Massive bleeding from telangiectatic vessels.
Distinct Features
Blood clot in bladder lumen (CT: hyperdense, MRI: T1 high), risk of bladder tamponade during acute bleeding. Treatment: cystoscopic coagulation, hyperbaric oxygen, intravesical formalin or alum, embolization or cystectomy in refractory cases.
Distinguishing Feature
Infectious cystitis does not show wall calcification (except emphysematous — gas present). More prominent perivesical stranding. No radiation history. Improves with antibiotherapy.
Distinguishing Feature
Urothelial carcinoma shows focal mass + focal DWI restriction. Radiation cystitis shows diffuse changes + no focal mass. However, secondary carcinoma may develop in radiation field — biopsy mandatory if focal DWI restriction is present.
Distinguishing Feature
SCC shows focal mass + heterogeneous enhancement + calcification. Radiation cystitis shows diffuse changes. Calcification in SCC is intratumoral, in radiation cystitis wall calcification is diffuse.
Distinguishing Feature
Neurogenic bladder shows trabeculation and wall thickening but calcification is rare and no radiation history. Underlying neurological pathology is present.
Urgency
routineManagement
medicalBiopsy
Not NeededFollow-up
6-monthTreatment depends on severity. Mild: anti-inflammatory, hydration. Hemorrhagic: cystoscopic coagulation, hyperbaric oxygen (40-60 sessions, 60-80% response), intravesical alum or formalin. Refractory: arterial embolization, urinary diversion, or cystectomy. Secondary tumor development in radiation field (1-3% risk) should be screened by cystoscopy + biopsy — biopsy mandatory if focal DWI restriction is present.
Radiation cystitis occurs in 5-10% of patients receiving pelvic radiotherapy. The hemorrhagic form is the most serious complication and can be life-threatening with massive bleeding. Treatment can be conservative (hyperbaric oxygen, intravesical instillation), endoscopic (coagulation), or surgical (cystectomy). The risk of bladder carcinoma development is increased in chronic radiation cystitis (2-5%). Differentiation from tumor recurrence is important — biopsy is needed if focal mass or prominent diffusion restriction is present.