Novel Method to Detect and Characterize ¹⁸F-FDG Infiltration at the Injection Site: A Single-Institution Experience

Abstract

A novel quality control and quality assurance device provides time-activity curves that can identify and characterize PET/CT radiotracer infiltration at the injection site during the uptake phase. The purpose of this study was to compare rates of infiltration detected by the device with rates detected by physicians. We also assessed the value of using the device to improve injection results in our center. 109 subjects consented to the study. All had passive device sensors applied to their skin near the injection site and mirrored on the contralateral arm during the entire uptake period. Nuclear medicine physicians reviewed standard images for the presence of dose infiltration. Sensor-generated time-activity curves were independently examined and then compared with the physician reports. Injection data captured by the software were analyzed, and the results were provided to the technologists. Improvement measures were implemented, and rates were remeasured. Physician review of the initial 40 head-to-toe field-of-view images identified 15 cases (38%) of dose infiltration (9 minor, 5 moderate, and 1 significant). Sensor time-activity curves on these 40 cases independently identified 22 cases (55%) of dose infiltration (16 minor, 5 moderate, and 1 significant). After the time-activity curve results and the contributing factor analysis were shared with technologists, injection techniques were modified and an additional 69 cases were studied. Of these, physician review identified 17 cases (25%) of infiltration (13 minor, 3 moderate, and 1 significant), a 34% decline. Sensor time-activity curves identified 4 cases (6%) of infiltration (2 minor and 2 moderate), an 89% decline. The device provides valuable quality control information for each subject. Time-activity curves can further characterize visible infiltration. Even when the injection site was out of the field of view, the time-activity curves could still detect and characterize infiltration. Our initial experience showed that the quality assurance information obtained from the device helped reduce the rate and severity of infiltration. The device revealed site-specific contributing factors that helped nuclear medicine physicians and technologists customize their quality improvement efforts to these site-specific issues. Reducing infiltration can improve image quality and SUV quantification, as well as the ability to minimize variability in a site's PET/CT results.

Topical Sensor for the Assessment of Injection Quality for 18F-FDG, 68Ga-PSMA and 68Ga-DOTATATE Positron Emission Tomography

“…LARA systems were set up in 3 injection/uptake rooms. In each uptake room, LARA sensors (Lucerno Dynamics) were applied to the subject using adhesive pads 7 cm proximal to the injection site and the same site on the contralateral arm (reference arm) (as previously described; [7]). These sensors were connected to a small recording device which sits in a holder nearby.…”

“…In another study, an analysis of 1367 patient studies, 18% demonstrated extravasation which was quantitated to represent between 1% and 22% of the injected dose [6]. A smaller single-centre analysis reported 38% of patients with extravasated doses [7]. Although an indication of dose extravasation may include pain or swelling at the site of injection, visual evaluation of images post-PET procedure is perhaps the most common approach.…”

“…Williams et al [2], used a topical device (LARA) in FDG PET patients and demonstrated that it helped to detect partial dose extravasation independent of the imaging protocol and provided dynamic data that assisted in characterising the extravasation. Visual detection of extravasated doses identified 38% incidence but the addition of the LARA device demonstrated the true extravasation rate was in fact 55% [7]. Wong et al used the topical device to determine PET extravasation rates across 7 institutions identifying extravasation rates.…”

Technical Note: Characterization of technology to detect residual injection site radioactivity

“…The remaining pulses are then counted to produce a sensor output in counts per second (cps). For this proposed clinical use, the sensor, along with a second sensor placed on the contralateral arm to collect reference data, could identify the presence of excessive residual radiotracer near the injection site . Both sensors would then be removed prior to imaging.…”

“…For this proposed clinical use, the sensor, along with a second sensor placed on the contralateral arm to collect reference data, could identify the presence of excessive residual radiotracer near the injection site. 50,51 Both sensors would then be removed prior to imaging. Based on the sensor design, it may not be possible to provide absolute quantification of the radiotracer near the injection site, but a semi-quantitative assessment would still be valuable.…”