Unexpected Bilateral Lacrimal and Salivary Gland Uptake of 68 Ga-DOTA-Ibandronic Acid on PET/CT.

68 Ga-DOTA-ibandronic acid (IBA) represents a novel positron emission tomography (PET) tracer for bone imaging, primarily employed in the diagnosis of malignant tumor metastases and the guidance of subsequent 177 Lu - DOTA - IBA targeted radionuclide therapy. In a clinical case involving a patient with lung adenocarcinoma and multiple osseous metastases, increased 68 Ga-DOTA-IBA uptake was observed in the metastatic bone lesions. Unexpectedly, increased uptake was also noted in the bilateral lacrimal and salivary glands. This finding underscores the importance of evaluating potential radiation exposure to lacrimal and salivary glands before initiating 177 Lu-DOTA-IBA-based radiopharmaceutical therapy.