Rein et produits de contraste iodés et gadolinés

A gadofullerene based liver-specific MRI contrast agent for an early diagnosis of orthotopic hepatocellular carcinoma

Hepatocellular carcinoma has become one of the most prevalent cancers, with a high mortality rate. Accurate diagnosis at an earlier stage is regarded as an effective measure to reduce the disease-related mortality of liver cancer. Magnetic resonance imaging (MRI) as a non-invasive checking mode has become a powerful tool in medical diagnosis. However, MRI contrast agents for liver-specific imaging either have some side effects or the imaging effect is not ideal. Thus, development of more efficient and security MRI contrast agents for the early diagnosis of hepatocellular carcinoma is urgent. Herein, a kind of water-soluble gadofullerene nanoparticle (GFNP) with high efficiency and security has been successfully used to achieve in situ liver cancer imaging. By comparing GFNPs with different functional groups, Gd@C82 modified by a hydroxyl group (GF-OH) presents the highest contrast efficiency both in vitro and in vivo. Notably, the smallest tumor with a diameter of only 0.5 mm could be clearly observed by GF-OH using MRI. Moreover, the imaging window of GF-OH is more than 3-6 hours. In addition, GF-OH can be mostly excreted from the living body and causes no serious toxicity. These results demonstrate that GF-OH is a safe, efficient MRI contrast agent for the diagnosis of early orthotopic hepatocellular carcinoma.

[Non-iodinated contrast media nephrotoxicity]

The development of interventional radiology techniques regularly exposes patients to the potential renal toxocity of iodinated contrast media. Faced with this risk of nephrotoxicity, gadolinium-based contrast agents have long been considered as a safe alternative to iodinated contrast media, especially in sensitive or at risk patients. However, these gadolinium-based contrast agents are not devoid of nephrotoxicity and present another risk, a complication related to renal failure, the nephrogenic systemic fibrosis. European and US recommendations from health agencies have recently come closer, defining groups of patients at risk of nephrogenic systemic fibrosis according to their level of renal function and the type of gadolinium-based contrast agent used. What are the real renal risks for these products? How to evaluate the benefit-risk balance of the patient to choose a radiological examination in an informative, effective and safe way? This article focuses on the description of the risks of gadolinium-based contrast agents, reviews existing recommendations and best practices to guide the choice of clinicians.

Emergency gastrointestinal surgery in the elderly

The main problem in management of elderly patients who present to the emergency department with abdominal pain is related to difficulties in establishing a diagnosis, because of frequently impaired communication as well as to unusual clinical and laboratory presentations, resulting in delayed management. Early use of pertinent imaging may reduce this delay. Surgical procedures in the elderly do not differ from those in younger patients, but their associated morbidity is different. Assessing co-morbidities and patient frailty, as well as taking into consideration the diagnosis, patients' wishes and status should help in decision-making. Therapeutic decisions should involve surgeons, anesthesiologists and geriatricians alike, both pre- and postoperatively, with the goal of optimizing patients' rehabilitation and offering good and appropriate care while ensuring the humane, social and financial aspects.

[Renal toxicity of contrast agents in oncologic patients]

Cancer patients frequently undergo imaging examinations to diagnosis but also to evaluate their responses to treatment. These patients are also at high risk of kidney impairment before considering the possible nephrotoxicity of their chemotherapy. In this context, it is overriding to know contrast agents induced risks and what are the good practices to avoid them. Renal function evaluation takes a major part in there. The X-ray radiology using iodinated contrast agent (ICA) exposes patients to acute renal failure. This induced nephropathy is prevented by adequate hydration prior to injection when the glomerular filtration rate (GFR) of the patient is less than 60 ml/min/1.73 m(2). For hardly nephrotoxic, gadolinium-based contrast agents (GBCA) injected in magnetic resonance imaging, were considered for a long as a safe alternative to ICA. Yet they may induce nephrogenic systemic fibrosis (NSF). The recommendations of European and U.S. drugs safety agencies have recently converged defining groups at risk of NSF based on the level of patients GFR and the type of GBCA used. How to assess the risk-benefit balance of the cancer patient for whom you should choose an informative, effective and safe imaging examination?