Radiopharmaceuticals inadvertently injected into tissue rather than veins can harm patients and should fall under required national reporting guidelines, researchers urged Monday in Frontiers in Medicine. But the call has drawn criticism from some imaging advocates.
A 1980 policy from the Nuclear Regulatory Commission, which oversees radioactive isotope use in the U.S., currently exempts providers from reporting these medical events, known as extravasations.
But the NRC is currently reviewing a petition filed last year by Lucerno Dynamics—a Cary, North Carolina, company that sells a device used to monitor injection quality—that would require quantification and reporting of certain extravasations.
In this context, authors of the current study reviewed adverse event databases on the topic, pointing to 38 examples listing diagnostic radiopharmaceutical extravasation as a factor in such events, according to Dustin Osborne, with the Radiology Department at the University of Tennessee Graduate School of Medicine, and colleagues.
While some questions remain, they claim their research points to “new hypotheses” related to inadvertent injections.
“Our findings suggest that significant extravasations can or have caused patient harm and can irradiate patients' tissue with doses that exceed medical event reporting limits and deterministic effect thresholds,” they added June 28. “Therefore, diagnostic radiopharmaceutical injections should be monitored, and dosimetry of extravasated tissue should be performed in certain cases where thresholds are thought to have been exceeded.”
Importantly, four of the seven authors are employed by Lucerno Dynamics.
Following last year’s petition, the NRC opened a comment period garnering nearly 400 responses. Many, including the NRC's Advisory Committee on the Medical Uses of Isotopes, supported the claim that there is “no clinical data suggesting radiopharmaceutical extravasation is a patient safety issue.”
A number of medical societies and organizations hold a similar sentiment, including the American College of Radiology.
In a statement sent to Health Imaging on Tuesday, the ACR said NRC’s medical event requirements are a “serious regulatory mechanism,” adding reporting isn’t meant to gather “inconsequential” data.
“Therefore, the ACR is on record—alongside hundreds of medical and scientific stakeholders—as opposed to the company’s (Lucerno Dynamics) petition,” the college said over email. “We support the NRC’s medical advisory committee recommendations that infiltrations reported to NRC as medical events be limited to rare, outlier extravasations that result in actual harm.”
The Society of Nuclear Medicine and Molecular Imaging offered its own comment Tuesday.
“SNMMI firmly believes that extravasation of diagnostic radiopharmaceuticals is not a patient safety issue,” past President Alan Packard, PhD, told Health Imaging over email. “On those rare occasions when a significant extravasation occurs, it is managed under existing procedures under the direction of the authorized user.”
Osborne et al. based their conclusions on information within the U.S. Food and Drug Administration’s Adverse Event Reporting System, which contains voluntarily submitted medication errors, along with two other widely used databases.
They also examined data from nuclear medicine centers at the Carilion Clinic in Roanoke, Virginia, and the aforementioned University of Tennessee Medical Center in Knoxville. Each uses Lucerno’s dosimetry system.
As it stands, misadministration leading to a “dose equivalent to tissue” exceeding 0.5 Sieverts (more than 500-times the dose expected to enter tissue during a proper injection) is thought to indicate a larger systemwide problem and is reportable. But extravasations that result in a tissue dose of 0.5 Sv or higher are not and organizations are not required to notify patients.
The authors say their findings do not support this practice. And while further research into the impact of extravasations on imaging and patient harm is needed, they expect more organizations to join their side.
“We believe that once centers recognize that diagnostic radiopharmaceuticals extravasations can matter to patients and can be more easily characterized, patient care will improve, and inadvertent irradiation and wasteful healthcare spending may be reduced," the authors wrote.
Read the full study here.