No abstract

Gallium‐67 whole body scintigraphy was included in the diagnostic workup of 44 consecutive patients with biopsy proven malignant melanoma in order to study the uptake of this nuclide by known melanoma tissue and to objectively assess its value in the detection of known and unknown meta‐static disease.

The liver‐spleen scans were reviewed from 108 patients with Hodgkin's disease, including 71 not previously treated. The results were correlated with clinical and pathologic findings in 122 liver biopsies and 50 spleens. Splenomegaly on scan was associated with advancing stage and tumor involvement of the spleen and liver. All 13 spleens measuring over 15 cm on scan and all 7 with filling defects were positive for tumor. In combination with the physical examination and lymphangiogram, the scan enabled accurate prediction of splenic tumor in 43% of the cases. Mean size of the right and left hepatic lobes was greatest in patients with tumor in the liver, but this finding was attributable to the advanced stage of these cases. Filling defects were not a reliable sign of liver involvement. The combination of the lymphangiogram, physical examination, and liver scan proved useful in selecting groups with very high and very low probability of liver involvement.

The relationship between food iron absorption, iron stores, and plasma iron level was studied. On a low iron diet subjects with idiopathic hemochromatosis (IH) during reaccumulation of iron after phlebotomies showed a fall in plasma iron. Fortification of the diet with 22–135 mg of iron/day for 3 days caused little or no change in the plasma iron in subjects with normal iron stores, whereas in subjects with iron deficiency a significant rise in plasma iron occurred with the addition of 45 mg of iron/day. In subjects with IH with normal iron stores, plasma iron increased with the addition of 22.5 mg/day. These studies indicate that iron absorption is an important determinant of the elevated plasma iron in IH and that the plasma iron tolerance test combined with the serum ferritin may be used to detect excessive absorption of iron.

In order to study the use of 67Ga scintigraphy in systemic malignancies, 43 whole body rectilinear scans were performed on 30 patients with acute leukemia. Results of scintigraphy were correlated with bone marrow status and evidence of infection and leukemic masses. The indications for scanning included search for occult infections, documentation of abscesses and tumor infiltrate and evaluation of bone pain. Abnormally high 67Ga activity was found in sites of leukemic involvement in untreated patients and those receiving chemotherapy. Over 80% of the patients with extensive leukemic marrow infiltration had increased bone activity, but only 27% of patients in remission had this pattern. Myeloblastomas were correctly identified in the breast, testes, and nasopharynx. Activity in these lesions also decreased after remission induction. Four patients with proven abscesses and osteomyelitis had strongly positive foci on 67Ga scans. Abscesses decreased in activity after appropriate antibiotics. Abscesses were visualized in patients with white cell counts as low as 200 per cu. mm.