When do you consider the insertion of nephrostomy tubes for gynecologic malignancies without fistulas?

Indication of nephrostomy for gyn cancer depends on the stage of cancer and renal function. If creatinine is normal range, nephrostomy may not be needed but if abnormal, nephrostomy is indicated. In the early stage of cancer, nephrostomy is more likely indicated than late stage of cancer.

I agree with Professor @Dr. First Last, in addition, bilateral hydronephrosis, cortical thickness intermediate for imminent renal function decline, and treatment (chemoradiation) is planned, nephrostomy tubes can be considered. In some cases, inflammation from radiotherapy (obstructive uropathy) and compromised kidney function from platinum may compromise the seemingly normal creatinine.