Radiation cystitis is in general rarely occurring, which makes it very difficult to study in a large group of clinical trials. Most available data about radiation cystitis treatment come from a small number of descriptive studies or from expert opinions. As clinical data are considered to have low quality then physicians, who are still facing patients with a disease hugely influencing quality of life, mostly base on their own experience. We thus want to test fuzzy decision-making model, regarded as a valuable tool, to help in selecting a patient-tailored treatment in radiation cystitis. Theoretical fuzzy decision-making models, possessing the utility matrix filled with distinct utilities of pairs (decision, object-state), give rise to own trials of successfully accomplished applications concerning the item of medication. After interpreting pairs (decision, object-state) as (therapy, symptom), we intend to prove decision-making based on the Choquet integral to extract the optimal treatment in radiation cystitis.