Pencil Beam Scanning in Patients With Renal Tumors

Inclusion Criteria: * Less than 30 years of age * Diagnosis a. Any patient with Wilms tumor or clear cell sarcoma of the kidney who would require radiation therapy as standard of care including 1. Any patient with favorable histology (FH), stage III disease 2. Any patient with focal or diffuse anaplasia 3. Any patient with CCSK * The patient is a candidate for external beam radiotherapy based on standard of care for treatment of Wilms tumor or CCSK Exclusion Criteria: * Prior radiotherapy to the region of the study cancer * Chemotherapy administered for diagnosis of Wilms tumor or CCSK * Pregnant or breastfeeding