Lymphoma: evaluation with Ga-67 SPECT

To determine the value of gallium-67 single photon emission computed tomography (SPECT) in imaging patients with lymphoma, the authors compared Ga-67 planar images and SPECT images in 40 consecutive patients, using radiologic examinations and/or medical records to confirm the presence or absence of disease. Thirty-three patients had Hodgkin disease, and seven had non-Hodgkin lymphoma. Fifty-four examinations were performed. Of 57 sites of lymphoma in the chest, planar imaging depicted 38, while SPECT depicted 55, resulting in sensitivities of 0.66 and 0.96 for planar and SPECT imaging, respectively. In eight sites, both modalities were truly negative, but SPECT was negative in four additional sites that were equivocal on planar imaging, resulting in specificities of 0.66 and 1.00 for planar and SPECT imaging, respectively. In the abdomen, the sensitivities of planar and SPECT imaging were 0.69 and 0.85, and the specificities 0.87 and 1.00, respectively. SPECT was more accurate in depicting foci of gallium-avid lymphoma in the chest and abdomen and in excluding disease when planar imaging was equivocal.