Renal atrophy following gated delivery of stereotactic ablative radiotherapy to adrenal metastases.

John R Van Sörnsen De Koste,Claire C Van Vliet,Miguel A Palacios,Berend J Slotman,Famke L Schneiders,Suresh Senan,Anna M.E Bruynzeel

doi:10.1016/j.phro.2021.09.001

John R Van Sörnsen De Koste, Claire C Van Vliet + Show 5 more

Open Access

https://doi.org/10.1016/j.phro.2021.09.001

Copy DOI

Abstract

Stereotactic ablative radiotherapy (SABR) planning for adrenal metastases aims to minimize doses to the adjacent kidney. Renal dose constraints for SABR delivery are not well defined. In 20 patients who underwent MR-guided breath-hold SABR in five daily fractions of 8–10 Gy, ipsilateral renal volumes receiving ≥20 Gy best correlated with loss of renal volumes, with median renal volume reduction being 6% (range: 3%-11%, 10th-90th percentiles). Organ function did not deteriorate in 18 patients, who had post treatment renal function tests available. This suggests that the ipsilateral renal volume receiving 20 Gy can be used as partial organ dose constraint for SABR to targets in the upper abdomen.

Highlights

The use of stereotactic ablative radiotherapy (SABR) is increasing in patients with oligometastatic disease, based on data emerging from both randomised phase II clinical trials and prospective registries [1]
The preferred dose for adrenal SABR in patients with oligometastatic disease is a BED10Gy of at least 100 Gy, as this correlates with long-term tumor control [11,12]
Despite the close proximity of the kidneys and adrenals, this study revealed only limited IRVref atrophy after delivery of high-dose breath-hold SABR to adrenal metastases

Summary

Introduction

The use of stereotactic ablative radiotherapy (SABR) is increasing in patients with oligometastatic disease, based on data emerging from both randomised phase II clinical trials and prospective registries [1]. It is important to minimize doses to organs at risk (OAR’s) during SABR delivery in order to avoid serious complications [2]. Recently has renal function data emerged from patients treated using SABR [7,8]. After SABR to primary renal tumors to a dose of 42 Gy in three fractions, each 10 Gy increase in physical dose led to an exponential decline of 25% in glomerular filtration rates (GFR) [7]. SABR delivery during free breathing may lead to less accurate estimates of doses to a mobile OAR.

Objectives

Methods

Results

Conclusion