To evaluate renal dysfunction after stereotactic ablative body radiotherapy (SABR) for inoperable primary renal cell carcinoma (RCC) using nuclear medicine assessments.
In a prospective clinical trial, patients received single fraction renal SABR (26Gy) for tumours <5cm, or fractionated SABR (3×14Gy) for tumours ⩾5cm.
Global and regional glomerular filtration rate (GFR) was calculated through (51)Cr-EDTA and (99m)Tc-DMSA SPECT/CT, respectively, at baseline and post-treatment (14, 90days and at 1-year). Regional loss in function was correlated to the absolute and biologically effective doses (BED) delivered.
In 21 patients the mean (range) tumour size was 48mm (21-75mm). The mean±SD GFR at baseline was 52±24ml/min. Net change in mean GFR was +0. 6±11. 3, +3. 2±14. 5 and -8. 7±13. 4 ml/min (p=0. 03) at 2weeks, 3months and 1year, respectively. For every 10Gy of physical dose delivered, an exponential decline in affected kidney GFR was observed at 39% for 26Gy/1 fraction and 25% for 42Gy/3 fractions. When normalised to BED3Gy, the dose-response relationship for each treatment prescription was similar with a plateau beyond 100Gy. The R50% conformity index correlated with GFR loss (p=0. 04). No patient required dialysis.
SABR results in clinically acceptable and dose-dependent renal dysfunction at 1-year. Sparing functional kidney from high-dose regions (>50% isodoses) may help reduce risk of functional loss.
Radiotherapy and oncology : journal of the European Society for Therapeutic Radiology and Oncology. 2016 Feb 09 [Epub ahead of print]
Shankar Siva, Price Jackson, Tomas Kron, Mathias Bressel, Eddie Lau, Michael Hofman, Mark Shaw, Sarat Chander, Daniel Pham, Nathan Lawrentschuk, Lih-Ming Wong, Jeremy Goad, Farshad Foroudi
Division of Radiation Oncology and Cancer Imaging, Peter MacCallum Cancer Centre, Australia; Sir Peter MacCallum Department of Oncology, University of Melbourne, Australia. Division of Radiation Oncology and Cancer Imaging, Peter MacCallum Cancer Centre, Australia. , Division of Radiation Oncology and Cancer Imaging, Peter MacCallum Cancer Centre, Australia; Sir Peter MacCallum Department of Oncology, University of Melbourne, Australia. , Department of Biostatistics and Clinical Trials, Peter MacCallum Cancer Centre, Australia. , Division of Radiation Oncology and Cancer Imaging, Peter MacCallum Cancer Centre, Australia; Sir Peter MacCallum Department of Oncology, University of Melbourne, Australia; Department of Radiology, University of Melbourne, Australia. , Division of Radiation Oncology and Cancer Imaging, Peter MacCallum Cancer Centre, Australia; Sir Peter MacCallum Department of Oncology, University of Melbourne, Australia. , Division of Radiation Oncology and Cancer Imaging, Peter MacCallum Cancer Centre, Australia. , Division of Radiation Oncology and Cancer Imaging, Peter MacCallum Cancer Centre, Australia. , Division of Radiation Oncology and Cancer Imaging, Peter MacCallum Cancer Centre, Australia. , Division of Cancer Surgery, Peter MacCallum Cancer Centre, Australia. , Department of Surgery, University of Melbourne, Australia. , Division of Cancer Surgery, Peter MacCallum Cancer Centre, Australia. , Division of Radiation Oncology and Cancer Imaging, Peter MacCallum Cancer Centre, Australia.
PubMed