Pilot study of ⁶⁸Ga-Evan’s blue PET/CT for lymphoscintigraphy

Objectives A pilot study was performed to evaluate ⁶⁸Ga-NOTA-Evan’s blue (NEB) as a novel PET tracer in lymphoscintigraphy based on PET/CT technology.

Methods NOTA (1,4,7-triazacyclononane-N,N',N''-triacetic acid)-conjugated truncated Evan’s blue was labeled with ⁶⁸Ga for lymphoscintigraphy. The tracer was injected subcutaneously and the PET/CT scan was performed according to the purpose of examination. A total of 10 patients in suspicion of lymphatic leakage or other disorders were enrolled. The ⁶⁸Ga-NEB PET/CT scan was compared with ^99mTc-sulfur colloid (^99mTc-SC) scintigraphy. All patients are required movement for some time before scan.

Results After subcutaneous injection and urged movement, ⁶⁸Ga-NEB can be clearly observed in the lymphatic vessels and lymph nodes on the PET/CT images of the patients. Neither liver nor spleen had intense uptake of ⁶⁸Ga-NEB. Both ⁶⁸Ga-NEB PET/CT and ^99mTc-SC scintigraphy demonstrated the lymphatic leakage in four patients, whereas ⁶⁸Ga-NEB PET/CT give more accurate location of the lymphatic leakage. In one patient with lymphangiectasis, ⁶⁸Ga-NEB PET/CT confirmed the diagnosis that was uncertain on ^99mTc-SC scintigraphy. ⁶⁸Ga-NEB PET/CT also provided more detailed information in four patients with limb lymphedema and one patient with Chyluria.

Conclusions ⁶⁸Ga-NEB may be a promising tracer for PET/CT imaging of lymphatic system disorder.