Haematuria from radiation cystitis can be very difficult to manage resulting in recurrent hospital admissions, blood transfusions and surgical interventions. RADA16 (Purastat®) is a self-assembling peptide which forms a protein matrix and is used for haemostasis in many surgical specialities. It has an established use in radiation proctitis and has shown promise in causing regression of radiation induced telangiectasia in the bowel. There has been a single case report of its use in radiation cystitis. We describe our initial experience using cystoscopic application of RADA16 for radiation cystitis in patients with refractory haematuria referred to our specialist radiation cystitis service.

Patients referred to our specialist radiation cystitis service with refractory haematuria were offered this novel treatment option. All these patients had already failed standard management requiring hospital admissions, bladder irrigation and/or endoscopic management with diathermy or laser. Patients were taken to operating theatres under general anaesthesia where a standard cystoscopy was performed. Active bleeding was controlled with either diathermy or laser ablation. Fluid was evacuated from the bladder and the bladder insufflated with CO2 to a pressure of 8-15mmH2O to obtain adequate visualisation of the radiation affected regions of the lower urinary tract. RADA16 was then applied to the affected regions via a ureteric catheter. This was left for 5 minutes after which the bladder was emptied. A catheter was left at the discretion of the operating surgeon.

A total of 17 RADA16 peptide treatments were administered to 15 patients between Feb to Oct 2024. Median age was 75 (Range 54-91years) and median time from radiotherapy 7 years (1.5-17). All patients were male and had radiation therapy for prostate cancer (47% primary and 53% adjuvant/salvage treatment). 5 (33%) patients required prior blood transfusions, and 1 patient had 16 units transfused prior to transfer to our centre. 7 (47%) had previous surgical intervention for haematuria. 14 (93%) patients had significant reduction in their haematuria at 6 weeks while 7 (47%) having complete resolution of haematuria. Clavien-Dindo 90-day complications were 1 (7%) - Grade 1 retention, 3 (20%) – Grade 2 blood transfusion, 4 (27%)- Grade 3 Surgical intervention under general anaesthetic. 1 patient required cystodiathermy to bleeding from the prostatic fossa from a concurrent TURP performed at time of RADA16 application. 2 patients required repeat applicaiton of RADA16 and 1 patient required salvage cystectomy for ongoing bleeding. No other patients required readmissions to hospital.

Cystoscopic application of RADA16 (Purastat®) for radiation cystitis is a promising treatment for patients with refractory haematuria. Further study is required to assess its long-term outcomes and whether repetitive applications (which are used for radiation proctitis) can improve durability of these results.