Stereotactic body radiation therapy for medically inoperable, clinically localized, urothelial carcinoma of the renal pelvis: A case report

Upper urinary tract urothelial carcinoma (UUTUC) is rare. Current estimates claim that urothelial (transitional) cell malignancies within the renal pelvis account for less than 10% of all renal tumors. Although related, ureteric lesions are far less prevalent than their renal pelvis counterpart, with renal pelvis-to-ureter ratios exceeding 3:1. The Memorial Sloan Kettering Cancer Center reported a large longitudinal series consisting of primary urothelial carcinoma (UC) cases, of which 88% were bladder, 7% urethra, 3% renal pelvis, and 2% ureter. Other studies have corroborated the low prevalence of UC in the upper urinary tract. Consequent to the rarity of UUTUC, the literature is largely limited to retrospective analyses and case reports. For UUTUC, prognosis is strongly linked to age at diagnosis, T-category, histology grade, and lymphatic involvement. The standard treatment for a UUTUC includes radical nephroureterectomy (RNU) with removal of the bladder cuff. There are alternative kidney-sparing techniques, but patient selection is crucial when opting for less invasive approaches because the risk of disease recurrence is high. With limited data on UUTUC and no prospective randomized trials, the exact role of nonoperative therapies, including chemotherapy, immunotherapy, and radiation therapy, is currently unclear. Unfortunately, there is no standard treatment for patients with UUTUC who are not candidates for surgery as a result of poor functional status, overwhelming disease burden, or refusal of surgical intervention. Novel, noninvasive treatments are needed for this clinical scenario and stereotactic body radiation therapy (SBRT) may be an option, as presented in this report.