Clinical Trial for Patients With a Stage IV Childhood Renal Tumor, Comparing Upfront Vincristine, Actinomycin-D and Doxorubicin (Standard Arm) With Upfront Vincristine, Carboplatin and Etoposide (Experimental Arm)

1 x Vincristin 1,5mg/m² iv bolus day 1 in week 1,2,3,4,5,6

1 x Actinomycin D 45µg/kg iv bolus day 1 in week 1, 3, 5

1 x Doxorubicin 50mg/m² 6h Infusion day 1 in week 1,5

1 x Carboplatin 200 mg/m² 1h infusion day 1,2,3 in week 1,4

1 x Etoposide 100mg/m² 1h infusion day 1,2,3 in week 1,4