Carboplatin vs. Taxol as maintenance chemotherapy

My mother, a 45 years old patient, case of CA ovary stage IIIC completed successfuly her first line chemotherapy(Taxol:300mg, Carboplatin:550mg). The CT scan for chest, abdomen and pelvis was free of disease, her CA125 was 6. Her dr decided to give her maintenance chemotherapy (6 additional cycles)and he wants to give her carboplatin.

I want to know if carboplatin is superior to taxol or not as maintenance chemotherapy.