USF-LVHN SELECT
An Analysis of Patients Treated with Stereotactic Body Radiotherapy for Metastatic Urinary Tract Tumors to Identify Predictors of Response.
Publication/Presentation Date
10-1-2023
Abstract
PURPOSE/OBJECTIVE(S): To identify selection criteria linked to outcomes in patients treated with stereotactic body radiotherapy (SBRT) for metastatic tumors of the urinary tract (UT).
MATERIALS/METHODS: Single institution retrospective analysis of SBRT treated patients for oligometastatic/progressive UT tumors from 2006-2022. Charts were queried for M1 status at diagnosis or during disease course, treatment details (surgery, SBRT, systemic therapy), metabolic status (diabetes [DM], BMI) and outcomes. A linear quadratic formula was used to calculate the biologically effective dose (BED) using an α/β of 10 for tumor. Descriptive statistics portrayed the cohort, and analyses were done at patient and site level. Time-to-event analyses, including overall survival (OS) and progression-free survival (PFS) from SBRT, were assessed by the Kaplan-Meier method. Cox regression was used for univariable (UVA) and multivariable analyses (MVA) to identify predictors of outcomes.
RESULTS: A total of 35 patients were treated at 44 metastatic sites, including: bone (25%), node (36.4%), lung (20.5%), soft tissue (13.6%) and liver (4.5%). Most were male (74.3%) with a median age of 70 (range: 51-89), without DM (60%) having a median BMI of 29.8, and ECOG <2 >(97.1%) at time of SBRT. Six (17.1%) patients were M1 at diagnosis. Of the 29 non-M1 patients, 86.2% received definitive local therapy (LT), 58.6% had at least T3/N+ disease, 75.8% received systemic therapy with a median of 2 agents (range: 1-6) prior to SBRT. Sixteen (45.7%) received immunotherapy (IO) with most receiving this before (75%) and after (56.2%) SBRT. Six patients had positive PD-L1 status (n = 10). The median RT dose, fractionation and BED was 40 Gy (range: 14-46), 5 fractions, and 72 (range: 28-132), respectively. At a median follow-up of 34.8, the median OS was 18.4 m (range: 9.3-27.4) with a 2-year OS of 35.9%. At patient level, 62.8% recurred after SBRT. The median PFS after SBRT was 5.3 m (range: 1.8-8.7) with a 2-yr PFS of 29.3%. Patient-level PFS was improved with LT (6.7 vs 1.4 m; p = 0.001) and DM (NR vs 2.9 m; p = 0.015), whereas improved OS was related with LT (18.9 vs 6.6 m; p = 0.03), DM (p = 0.04), ECOG (p = 0.004), and no relapse after SBRT (NR vs 9.8 m; pbone > soft tissue > node > lung. No dosimetric feature was related with recurrence risk. On MVA, both DM (p = 0.02) and LT (p = 0.002) were predictive for PFS. Only recurrence after SBRT predicted for OS on MVA (HR: 6.7, 95% CI: 1.4-31; p = 0.014). In the IO subset, median PFS was 5.3 m and OS was 9.4 m, with no difference seen with IO-SBRT sequence or PDL1 status.
CONCLUSION: Optimized selection criteria for metastasis-directed therapy in patients with UT tumors is unclear, notably with IO. Future studies may benefit by assessing circulating tumor markers prior to SBRT.
Volume
117
Issue
2S
First Page
424
Last Page
424
ISSN
1879-355X
Published In/Presented At
Oh, N., Nakashima, J., Chadha, J. S., Kish, J. A., Manley, B., Pow-Sang, J., Yu, A., Zhang, J., Spiess, P., Chatwal, M. S., Jain, R., Zemp, L. W., Poch, M., Sexton, W. J., Li, R., Gilbert, S. M., Johnstone, P. A. S., Torres-Roca, J. F., Yamoah, K., & Grass, D. (2023). An Analysis of Patients Treated with Stereotactic Body Radiotherapy for Metastatic Urinary Tract Tumors to Identify Predictors of Response. International journal of radiation oncology, biology, physics, 117(2S), e424–e425. https://doi.org/10.1016/j.ijrobp.2023.06.1583
Disciplines
Medical Education | Medicine and Health Sciences
PubMedID
37785392
Department(s)
USF-LVHN SELECT Program, USF-LVHN SELECT Program Students
Document Type
Article