External beam radiation therapy followed by interstitial radiotherapy with iridium-192 for solitary bladder tumours: results of 111 treated patients

BACKGROUND: Evaluation of bladder-preserving treatment protocol.

OBJECTIVE: To evaluate the long-term results of iridium-192 brachytherapy-based bladder-sparing treatment strategy in patients with solitary invasive bladder tumours.

DESIGN, SETTING, AND PARTICIPANTS: We performed a retrospective analysis of 111 patients with solitary T1G3-T2Gall bladder tumours (< or = 5 cm), who were treated with iridium-afterloading brachytherapy between February 1988 and May 2007.

INTERVENTION: After transurethral tumour resection, external beam radiotherapy (28 Gy; 12 fractions) was given, followed by brachytherapy (Iridium-192; 40 Gy). Partial cystectomy was part of the treatment strategy in nine patients. In five of those patients a T3 tumour was found, and they were included in the analysis.

MEASUREMENTS: The 5-, 10- and 15-yr overall survival rate (OS); disease-specific survival rate (DSS); and disease-free survival rate (DFS) estimates were determined using the Kaplan-Meier method.

RESULTS AND LIMITATIONS: Mean follow-up period was 6.2 yr (range: 0.2-16.3 yr). At the last follow-up 75 patients were alive without evidence of disease, whereas 17 patients had died without evidence of disease. Nineteen patients died of bladder cancer after a mean follow-up period of 2.9 yr (range: 0.5-9.0). OS rates at 5 yr, 10 yr, and 15 yr were 70%, 55%, and 51%, respectively. DSS rates at 5 yr, 10 yr, and 15 yr were 82%, 73% and 73%, respectively. DFS rates at 5 yr, 10 yr, and 15 yr were 60%, 47%, and 23%, respectively. Higher tumour stage (T3 vs T1) was negatively associated with DSS (hazard ratio [HR]:19.8; p=0.01) and DFS (HR: 4.67; p=0.02). No prognostic factor was found for OS. Local recurrence occurred in 27% of patients and salvage cystectomy was performed in 9% of patients. Bladder function was able to be preserved in 99 of 111 patients (89%).

CONCLUSIONS: In patients with solitary stage T1-T2 bladder cancer (< or = 5 cm) who refuse radical cystectomy or who are poor candidates for major surgical procedures, this modality is a valuable treatment alternative.