Ixabepilone Completed Phase 2 Trials for Recurrent Osteosarcoma / Adult Rhabdomyosarcoma / Recurrent Childhood Rhabdomyosarcoma / Childhood Synovial Sarcoma / Embryonal Childhood Rhabdomyosarcoma / Recurrent Ewing Sarcoma/Peripheral Primitive Neuroectodermal Tumor / Recurrent Neuroblastoma / Recurrent Adult Soft Tissue Sarcoma / Alveolar Childhood Rhabdomyosarcoma / Previously Treated Childhood Rhabdomyosarcoma / Adult Synovial Sarcoma / Recurrent Childhood Soft Tissue Sarcoma / Recurrent Wilms Tumor and Other Childhood Kidney Tumors Treatment