Better knowledge of gadolinium retention risks needed for pituitary tumor MRIs
Pituitary tumor management via ongoing MRIs is recommended by most endocrinologists and pituitary neurosurgeons, but there is a need to improve understanding of the safety concerns surrounding gadolinium-based contrast agents, according to findings published in Pituitary.
“Recent studies revealed that gadolinium-based contrast agents administration results in possible brain retention in patients with normal renal function and furthermore even in ones with no intracranial abnormalities. This information has introduced potential concerns among patients, regulatory agencies, as well as the health care, scientific and radiology communities,” Maria Fleseriu, MD, FACE, professor of medicine and neurologic surgery and director of the Pituitary Center at Oregon Health and Science University in Portland, Oregon, told Endocrine Today. “Additionally, timing interval and frequency of pituitary MRI following treatment of pituitary tumors is not well defined in present guidelines.”
Fleseriu and colleagues analyzed responses to a 12-item questionnaire produced by the Pituitary Society Education Committee that assessed practices pertaining to follow-up and surveillance after pituitary surgery. The questionnaire was completed by 43 endocrinologists and one neurosurgeon at the Pituitary Society Membership and Career Development Forum in March 2018 and 14 neurosurgeons at the International Pituitary Neurosurgeons Society conference in February 2018.
Most respondents (69%) preferred waiting 3 to 6 months after pituitary surgery to conduct an initial postoperative MRI. From there, 54% of respondents recommended MRI every 6 months for the first year and then annually. If no tumor recurrence was reported, the most popular option was to increase the time between MRIs to 2 years (38%) compared with 3 years (26%) and 5 years (20%).
There was a noted difference in preferred strategy for follow-up of biochemically uncontrolled pituitary macroadenomas with nonresectable residual tumor. Most respondents from the Pituitary Society forum (64%) made their decisions based on which type of treatment was being used and “proximity to the optic chiasm,” the researchers wrote. Among the neurosurgeon group, 46% preferred an MRI every 6 months and then annually after control was established.
There was a mixed response in terms of strategy for functioning adenomas in remission. During the first year, 32% chose to perform MRI every 6 months and then annually, whereas 35% preferred annual MRI. Another 33% delayed MRI until a patient no longer had biochemical control.
Most respondents (72%) found Ki-67 a “useful index” in determining the best time-range for MRI, and 62% indicated similar feelings about adrenocorticotropic hormone pathology, according to the researchers.
Despite their MRI preferences, 28% of respondents said they were not up to date on gadolinium retention concerns, and 67% indicated no recent change at their affiliated institution in terms of preferred MRI contrast agent.
“Interestingly, based on this survey we found that while most pituitary endocrinologists and neurosurgeons recommend long- term repeated imaging, exact timing varied depending on the specialist group and the specific clinical context of the adenoma,” Fleseriu said. “Pituitary MRI remains a mainstay for follow-up in pituitary disease patients, but further data is needed on the clinical consequences of the contrast agent retention and on the relative toxicities of the different type of agents used. Using non- contrast MRI might be a possibility with the advent of higher-resolution non-contrast MRIs for the follow-up of some pituitary tumors.”– by Phil Neuffer
Disclosures: The authors report no relevant financial disclosures.