Consensus statement from the International Radiosurgery Oncology Consortium for Kidney for primary renal cell carcinoma

Aim: To provide a multi-institutional consensus document for stereotactic body radiotherapy of primary renal cell carcinoma. Materials & methods: Eight international institutions completed a 65-item survey covering patient selection, planning/treatment aspects and response evaluation. Results: All centers treat patients with pre-existing hypertension and solitary kidneys. Five institutions apply size constraints of 5-8 cm. The total planning target volume expansion is 3-10 mm. All institutions perform pretreatment imaging verification, while seven institutions perform some form of intrafractional monitoring. Number of fractions used are 1-12 to a total dose of 25 Gy-80 GyE. Imaging follow-up for local tumor response includes computed tomography (n = 8), PET-computed tomography (n = 1) and MRI (n = 5). Follow-up frequency is 3-6 months for the first 2 years and 3-12 months for subsequent 3 years. Conclusion: Key methods for safe implementation and practice for stereotactic body radiotherapy kidney have been identified and may aid standardization of treatment delivery.