In frail patients with cancer who are to undergo contrast–enhanced CT, the choice of iodated contrast medium can be key to reducing risk for impaired renal function and the development of contrast–induced nephropathy (CIN).

In a head–to–head comparison of two contrast media, iodixanol (Visipaque, GE Healthcare) appeared to have a better safety profile than iopromide (Ultravist, Bayer Healthcare).

The results come from the blinded, randomized COMEDIANS trial, which was conducted in 504 cancer patients at low risk for CIN who underwent chest–abdomen–pelvic CT. The trial was conducted by Maddalena Barba, MD, of the Regina Elena National Cancer Institute in Rome, Italy, and colleagues.

The study was published online August 4 in the Journal of Cellular Physiology.

Although CIN can be minor ? defined by the study investigators as a 25% increase in serum creatinine level ? more severe cases can lead to renal failure, the need for dialysis, or death. Patients with cancer who are weakened by disease or treatment may be particularly vulnerable.

“It is our responsibility to focus on the safety of fragile patients, such as those affected by cancer,” coauthor Irene Terrenato, PhD, of the Regina Elena National Cancer Institute in Rome, said in a statement. “Iodated contrast media is essential, and, unfortunately, we often observe adverse events on renal function due to contrast media use, such as CIN.”

“To understand which contrast medium minimizes the incidence of CIN is fundamental, and this study arises from the need to protect our patients as much as possible,” added Stefano Canitano, MD, who is also at the Regina Elena National Cancer Institute.

The cancer patients taking part in this study were at low risk of developing neuropathy. At baseline, the patients’ estimated glomerular filtration rate (eGFR) was >60 mL/min. The researchers report that CIN developed at 24 hours in seven patients in the iopromide group compared to two patients in the iodixanol group.

The same trend was seen with late–occurrence events, with eight patients in the iopromide group developing CIN at 72 hours compared to two in the iodixanol group.

Overall, 17 patients developed CIN. Among those patients, the event rate was higher in the iopromide arm, although no cases of permanent CIN or significant differences in adverse events or GFR were observed.

“The distribution of CIN events across the study arms seemed to provide a suggestion in support of the use of iodixanol in light of the more favourable toxicity profile,” the study authors say. “However,” they add, “none of these results reached the predefined cut off for statistical significance.” These findings need to be confirmed and the underlying biological mechanisms clarified in larger trials with a similar design, they emphasize.

“Our results can represent a first indication for radiologists who are responsible for performing CT scans on very compromised patients daily,” commented coauthor Antonio Giordano, MD, PhD, from the University of Siena and Istituto Toscano Tumori, in Siena, Italy, who is also the president of the Sbarro Institute for Cancer Research and Molecular Medicine, Temple University, in Philadelphia, Pennsylvania. He emphasized that “further studies are strongly recommended to confirm these results.”