Partial Volume High-Dose Irradiation in Renal Cell Carcinoma for Intra-TUmoural Control ALongside Current Management

Inclusion Criteria: * Histologically confirmed renal cell carcinoma (RCC) (histological confirmation of metastasis not required) or clinically consistent with RCC as per multidisciplinary team (MDT) diagnosis. * Not suitable for surgical resection, metastasectomy or ablative therapy due to tumour or patient factors * All extracranial sites which clinically require radiotherapy (as per clinician discretion) * Age ≥18 years * Karnofsky Performance Status (KPS) ≥50 * Adequate baseline organ function applicable to site-of irradiation * Haemaglobin ≥90g/dl * Platelets ≥50 * Bilirubin \<3x ULN * INR \<1.4 or correctable with vitamin K * AST or ALT \<5x normal range * Creatinine \<200umol/L (or established on dialysis). Note patients on dialysis are unable to have dynamic contrast enhanced MRI. * The use of concurrent systemic therapy is acceptable * Ability of the research subject to understand and the willingness to sign a written informed consent document * Able to undergo all mandated staging and follow-up investigations * Negative pregnancy test (for women of childbearing potential) Exclusion Criteria: * Expected prognosis \<6 months * Uncontrolled intracranial metastases * Previous radiotherapy, such that the delivery of further radiotherapy is not feasible * Unable to have necessary radiotherapy planning, radiotherapy related investigations/fiducials (if required) * Co-morbidities or any psychological, familial, sociological or geographical condition which may preclude ability to undergo/attend investigations, treatment or follow-up * Other active primary cancer * Pregnant or lactating * Requiring ongoing treatment with a concomitant medication, which is contraindicated alongside radiotherapy (e.g. methotrexate)