Real-Time Imaging of ¹⁷⁷Lu-Labeled Radiopharmaceutical Infusions with a Portable γ-Camera: Pilot Trial Results

Recently, it was proposed that follow-up imaging for patients treated with ¹⁷⁷Lu-labeled radiopharmaceuticals should be focused on posttherapy SPECT/CT, given the intrinsic γ-photon emitted by ¹⁷⁷Lu, suggesting that real-time imaging of radiopharmaceutical infusions using γ-camera technology may be feasible. In this pilot feasibility study, we used a portable γ-camera situated within our theranostics suite to visualize the infusion of ¹⁷⁷Lu-labeled radiopharmaceuticals in real time. Methods: Patients were consecutively enrolled between June 5, 2025, and July 17, 2025, with any patient receiving a ¹⁷⁷Lu-based radiopharmaceutical infusion at our theranostics center being eligible for inclusion. ¹⁷⁷Lu-based radiopharmaceuticals were administered via syringe method. A portable γ-camera was used for dynamic image acquisition. An open-energy window was used to obtain 120 frames at 30 s per frame for a total of 5 or 30 min (to include the entirety of either a ¹⁷⁷Lu-PSMA-617 or a ¹⁷⁷Lu-DOTATATE infusion, respectively) using a 128 × 128 matrix and a low-energy, high-resolution collimator. Results: Six patients were imaged, and the ¹⁷⁷Lu-labeled radiopharmaceutical was visibly confined to the venous system, with measurable time-activity curves, in all patients. No evidence of immediate complication was seen during the imaging of any of the infusions, and no findings suggest an event such as extravasation occurred. Conclusion: Dynamic, real-time imaging of infusions of ¹⁷⁷Lu-labeled radiopharmaceuticals with a γ-camera is feasible. Although further study is needed, this method may be useful for the early identification of complications from infusions, potentially allowing for the alleviation of toxicities and preservation of expensive radiopharmaceutical doses.