Fig. 1.

Single-fraction SBRT for a biopsy-confirmed RCC in a 64-year-old patient. A papillary T1b (4.2 × 3.8 × 3.5 cm) RCC was treated with single-fraction SBRT delivering 26 Gy at the 80% isodose in February 2013. The 64-year-old patient had a good performance status (ECOG 0) but suffered from some cardiac comorbidities such as cardiomyopathy and atrial fibrillation requiring warfarin. Furthermore, he exhibited a moderate chronic kidney disease with a GFR of 47 ml/min/1.73 m² prior to SBRT. (A) CT image in January 2013 showing an RCC in the right kidney. (B) Treatment plan demonstrating the dose distribution. By using a 4D-CT, an ITV concept was used with an ITV-PTV-expansion of 5 mm. (C) Coronal CT image with some organs at risk (liver, contralateral kidney, stomach) and different isodoses for the SBRT. A cone beam CT was performed before, during and after SBRT. Immobilization was ensured using Elekta BodyFix® with a vacuum drape. (D) CT image at the 6-year follow-up (February 2019) showing tumor size reduction (2.8 × 2.3 cm) and central necrosis with no signs of recurrence. Blood tests revealed mild deterioration in kidney function (GFR of 39 ml/min/1.73 m²).