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

This study reviews the intravesical Bacillus Calmette-Guérin therapy for treatment of non-muscle invasive bladder cancer including mechanism of action, dosing considerations, treatment success and surveillance. A variety of common and uncommon adverse effects are reviewed with a focus on abdominal -pelvic complications stratified into genitourinary and systemic categories. The complications included more common entities such as chemical cystitis, which has been reported to be present in approximately 35% of the patients to more serious but rare complications such as vascular involvement with only a few reported cases in the literature. For each complication, the pertinent imaging findings and available examples are provided. Additionally, it is important to consider the potential for recurrence or progression of bladder cancer in this patient population, with reported rates of 38.2% and 9.8%, respectively. This underscores the necessity of a thorough differential diagnosis when interpreting imaging findings related to these complications.