Oncologic outcomes of radical radiotherapy in frail patients with upper tract urothelial carcinoma.

OBJECTIVE

To evaluate oncologic outcomes of high-dose radical radiotherapy (RT) in medically frail patients with upper tract urothelial carcinoma (UTUC).

MATERIALS AND

METHODS

We retrospectively reviewed 63 patients with UTUC who received definitive RT at four major academic hospitals (2014-2021) with significant comorbidities (age-adjusted Charlson Comorbidity Index ≥3). Patients were stratified into high- and low-dose groups using a biologically effective dose (BED10) cutoff of 74.3 Gy (from 63 Gy/35 fractions, assuming α/β ratio = 10). The median BED10 was 64.8 Gy (interquartile range 60.0-72.0) in the low-dose group and 84.0 Gy (interquartile range 78.4-86.4) in the high-dose group. Baseline imbalances were addressed using inverse probability of treatment-weighted (IPTW) in Cox proportional hazard models and Kaplan-Meier analyses.

RESULTS

The median follow-up was 76 months. The pelvic ureter was the most frequently involved site (57%), followed by the renal pelvis (33%) and the abdominal ureter (21%). In the IPTW-adjusted cohort, the disease control rate was significantly higher with high-dose RT (98% vs 62%, P < 0.001). High-dose RT significantly improved IPTW-adjusted locoregional control (3-year LRC: 51% vs 29%, P = 0.041), freedom from distant metastasis (3-year FFDM: 75% vs 39%, P = 0.001), freedom from progression (3-year FFP: 43% vs 25%, P = 0.013), and overall survival (3-year OS: 46% vs 11%, P < 0.001). Multivariate analysis identified higher RT dose as an independent prognosticator of improved FFP (adjusted hazard ratio [aHR] 0.96, P = 0.018) and OS (aHR 0.93, P < 0.001). Furthermore, pre-RT gross haematuria (aHR 2.63, P = 0.002) and age-adjusted Charlson Comorbidity Index >5 (aHR 2.85, P = 0.007) were associated with worse OS.

CONCLUSION

A clear dose-response relationship was observed in UTUC treated with definitive RT. High-dose RT was associated with significantly improved survival and represents a safe alternative for medically frail patients.