Radionuclide bone scanning in giant cell tumor.

Radionuclide bone scan findings are described and correlated with pathology in 23 patients with giant cell tumor (GCT) of the bone. The degree of radionuclide activity was markedly increased in 20 (87%), minimally increased in three (13%), and decreased in none of the patients. Of the 23 patients with increased radioactivity, the pattern was diffuse in 11 (48%) and doughnut in 12 (52%). Extended patterns of radioactivity were present in 19 of 22 patients; however, none were associated with true tumor extension. Bone scanning did not aid in the detection of GCT, was nonspecific, and did not differentiate benign from malignant GCT. Although radioactivity extended beyond the radiographic abnormality in the majority of patients, this was most likely secondary to other bony abnormalities or local and/or regional hyperemia, and caution should be taken in ascribing this extension to either tumor or metastasis.

The spectrum of gallium-67 renal activity in patients with no evidence of renal disease.

Thirty-seven gallium-67 images were reviewed retrospectively to determine relative renal gallium activity ( RGA ) in patients with no evidence of renal disease. Twenty-four patients were classified as having no evidence of renal disease (NRD). RGA was identified in 50.0% (12/24) of patients in the NRD group. We conclude that the presence of RGA neither suggests nor rules out renal disease. Altered nonrenal biological factors (such as saturation of iron-binding capacity) may decrease soft-tissue gallium accumulation while activity in the kidney remains unchanged. The latter provides renal images with better signal-to-noise ratio. Current imaging equipment may allow renal visualization in these patients.

Value of selective spleen scintigraphy when liver/spleen image shows equivocal spleen defects: concise communication.

A retrospective review was performed to determine the utility of selective spleen scintigraphy (SSS) in the evaluation of equivocal defects on liver/spleen (LS) image. Six of seven questionable features on LS image were classified on SSS to be definite defects in three, and normal in three. Three of seven patients had defects on SSS that were not seen on LS image. The inability of the LS image to exclude or delineate an abnormality in the spleen was attributed to an overlying left lobe of the liver in five, and to technique in one. The SSS is a valuable diagnostic tool in the further evaluation of equivocal spleen defects on LS image, and SSS may demonstrate abnormalities not demonstrated on LS image.

Solitary abnormalities in bone scans of patients with extraosseous malignancies.

The incidence and significance of solitary bone scan abnormalities were assessed in a study of 1,129 consecutive patients with extraskeletal primary malignancies. Solitary abnormalities were encountered in 172 cases (15%). The etiology of the scan abnormality was established in 90 of the 172 cases; 58 (64%) were due to metastatic disease, and 32 (36%) were secondary to a benign process. A significant percentage of solitary scan abnormalities is due to benign disease processes, even in patients with proved extraosseous malignancies.