Predictors of Locoregional Recurrence and Delineation of Adjuvant Radiation Therapy Fields for Patients with Upper Tract Urothelial Carcinoma Receiving Nephroureterectomy.

Abstract

BACKGROUND\nand Purpose: To identify factors predictive of locoregional recurrence (LRR) in upper tract urothelial carcinoma (UTUC) treated with nephroureterectomy (NU) and propose adjuvant radiation therapy (ART) fields.\n\n\nMATERIALS AND METHODS\nClinical and pathologic variables for patients receiving NU for UTUC between 1995 and 2009 were analyzed for associations with outcomes. Sites of LRR from all patients with available imaging (n=39) were contoured on CT image sets of patients with representative anatomy, and ART fields were proposed based on these distributions.\n\n\nRESULTS\nA total of 279 patients with a median follow-up of 13.0 years were analyzed. The 5-year cumulative incidence of LRR was 16.7% (95% CI 12.2-21). Pathologic risk factors (PRF) associated with increased risk of LRR included: tumor in both the renal pelvis and ureter, T-stage≥2, lymph node involvement, grade 3 histology, and positive surgical margins (p<0.05). Patients with an increasing number of PRF had a significantly greater risk of LRR. The 5-year cumulative incidence estimates of LRR were 5.3% (1.8-16.0), 15.6% (9.5-25.7), and 43.9% (31.1-62.1) for those with 1, 2, and ≥3 PRF, respectively. ART fields covering the renal fossa and retroperitoneal lymph nodes from the superior border of L1 through the aortic bifurcation would encompass all sites of LRR for 33 of 46 (72%) patients. Non-LRR bladder and distant failure (DF) occurred in 101 (36.2%) and 73 (26.2%) of patients, respectively. The 5-year cumulative incidence estimate of DF was 22.5% (17.4-27.3).\n\n\nCONCLUSIONS\nIn patients receiving NU for UTUC, LRR is significantly increased in patients with two or more PRF. These data provide clinically valuable insight into the selection of candidates for ART and design of ART fields.