Stereotactic Ablative Radiotherapy for the Treatment of Upper Urinary Tract Urothelial Carcinoma.

Urothelial carcinomas (UC), also known as transitional cell carcinomas, account for the majority of upper urinary tract tumors. The gold-standard therapy for operable patients with localized disease is radical nephroureterectomy. However, some patients are not surgical candidates. Data on the use of modern radiotherapy (RT) for upper urinary tract UC (UTUC) is scarce. The purpose of this study was to assess the safety and efficacy of stereotactic ablative radiotherapy (SABR) in UTUC.

This retrospective study included all patients with UTUC treated with SABR at one institution. Charts were reviewed to evaluate renal function and development of toxicity using CTCAE v3.0. Tumor response on follow-up imaging with CT- or MRI-scans was assessed using the RECIST 1.1 criteria.

A total of 16 patients, 7 patients with UC at the ureter and 9 at the renal pelvis, were identified as being treated with SABR. Of the 9 patients with renal pelvis UC, 4 had a previous history of bladder cancer. At the time of treatment median age was 85 years (67-95 years). Most patients received 40 Gy in 8 fractions every second day. The median follow-up was 21 months (3-110 months). Most patients maintained a stable renal function, with only 2 patients developing worsening chronic kidney disease, but none requiring dialysis. Acutely, 4 patients developed grade 1 diarrhea, and 1 patient had new grade 1 hematuria. No chronic side effects were observed. One patient did not have follow-up imaging and was thus excluded from tumor response analysis. Two patients had complete response of the treated lesion, 9 had partial response, 2 had stable disease, and 2 had disease progression within the treatment field.

This small case series suggests that SABR for UTUC is safe and well-tolerated, with good radiographic tumor response to ablative doses of RT.

Practical radiation oncology. 2021 Sep 13 [Epub ahead of print]

Julia Khriguian, Horacio Patrocinio, Sero Andonian, Armen Aprikian, Wassim Kassouf, Simon Tanguay, Fabio L Cury

McGill University Health Centre, Department of Radiation Oncology, Montreal, QC, Canada. Electronic address: ., McGill University Health Centre, Department of Medical Physics, Montreal, QC, Canada., McGill University Health Centre, Department of Surgery, Division of Urology, Montreal, QC, Canada., McGill University Health Centre, Department of Radiation Oncology, Montreal, QC, Canada. Electronic address: .