Gallium citrate Ga-67

Gallium Citrate Ga 67 Injection has held FDA approval since the 1970s (NDA 017478) for demonstrating the presence and extent of Hodgkin's disease, other lymphomas and bronchogenic carcinoma, and as an aid in detecting some acute inflammatory lesions; it is currently labelled and marketed by Curium. The adult dose is 74-185 MBq (2-5 mCi) IV, with optimal images typically obtained 48 hours post-injection, though acceptable images can be acquired anywhere from 6 to 120 hours afterward given considerable inter-patient biological variability.

The label itself flags the tracer's major limitation: up to 40% false-negative rates in some pathological conditions, an inability to distinguish tumour from acute inflammation without additional studies, and poor performance in lymphocytic lymphoma specifically, which the label states is not recommended for gallium imaging. FDG-PET has substantially displaced Ga-67 citrate for lymphoma staging and for fever-of-unknown-origin workups because it offers same-day imaging, higher spatial resolution and better sensitivity; gallium scintigraphy's most durable remaining niche is spinal and musculoskeletal infection imaging (often as SPECT/CT) in settings where FDG-PET is unavailable.