RESUMO
OBJECTIVE: To determine whether the intravesical use of hyaluronic acid (HA) reduces acute and late vesical toxicity induced by radiotherapy. METHODS: Single-centre retrospective study of patients diagnosed with cervical and endometrial cancer treated with brachytherapy (BT) with or without intravesical instillation of HA. Patients were assigned consecutively to the two treatment groups. Forty milligrams of HA was instilled intravesically for approximately 30 min prior to each BT session. Rates of acute and late vesical toxicity were recorded using the RTOG criteria. RESULTS: Ninety-five clinical histories were reviewed (48 with HA instillation and 47 without). Surgery had been performed in 85.3% of cases, external radiotherapy in 76.8% and chemotherapy in 25.3%. There were no significant differences between groups with regard to the total number of BT sessions, dose per session, total dose or biological equivalent dose. In all the sessions the percentage of patients presenting acute vesical toxicity was lower in the HA group, the differences being statistically significant (p<0.05) after the 2nd (20.8% vs. 40.4%) and 4th sessions (10.9% vs. 31.9%). No patients in the HA group presented vesical toxicity after six months of follow-up. Over the whole study period, the percentage of patients presenting vesical toxicity of degree 2 or more was significantly lower in the HA group (2.08% vs. 12.8%; p<0.05). CONCLUSION: Vesical instillations of HA decrease the incidence and the degree of acute vesical toxicity induced by high-dose BT, and reduce the percentage of patients that develop toxicity of degree 2 or more.
