Intravesical BCG therapy: implications for radiologists in abdominal imaging follow-up

Area of Science:

• Urology
• Oncology
• Radiology

Background:

• Non-muscle invasive bladder cancer (NMIBC) requires effective treatment.
• Intravesical Bacillus Calmette-Guérin (BCG) is a standard therapy for NMIBC.
• Understanding BCG's complications and imaging findings is crucial for patient management.

Purpose of the Study:

• To review intravesical BCG therapy for NMIBC.
• To detail the mechanism of action, dosing, success, and surveillance of BCG therapy.
• To comprehensively review BCG-associated adverse effects, focusing on abdominal-pelvic complications and their imaging features.

Main Methods:

• Literature review of intravesical BCG therapy for NMIBC.
• Analysis of common and uncommon adverse events, including genitourinary and systemic complications.
• Correlation of imaging findings with specific BCG complications.
• Review of bladder cancer recurrence and progression rates post-BCG therapy.

Main Results:

• BCG therapy involves intravesical administration for NMIBC.
• Adverse effects range from chemical cystitis (approx. 35%) to rare vascular complications.
• Imaging findings are provided for various complications.
• Bladder cancer recurrence and progression rates are reported as 38.2% and 9.8%, respectively.

Conclusions:

• Intravesical BCG is a key treatment for NMIBC, necessitating careful monitoring for side effects.
• Radiological assessment is vital for diagnosing BCG-induced complications.
• A broad differential diagnosis is essential when interpreting imaging in patients treated with BCG, considering potential cancer recurrence or progression.