The radiocolloid bone marrow scan in malignant disease

The radiocolloid bone marrow scans in 107 patients with malignant disease were reviewed. The observed scan patterns were classified into five groups: normal (type 1), moderately expanded (type 2), greatly expanded (type 3), peripheral expansion with central depression (type 4), and greatly reduced to absent intramedullary marrow (type 5). Correlation was made between scan pattern and clinical status of the patient for each disease category. In polycythemia vera, there was progressive expansion of the marrow organ that correlated well with the patient's course but not duration of disease. Type 3 or 4 marrow scans were associated with failure of effective marrow function. In myelofibrosis, regardless of associated cause, the scan pattern was predominantly type 4 or 5. Among the 42 patients with leukemia, 41 had abnormal scans. Type 4 was the characteristic scan pattern in untreated acute leukemia, and the scan became more normal with favorable treatment response. Patients with chronic myelogenous leukemia, either with myelofibrosis or blast crisis, had a type 4 or 5 marrow pattern. Scan patterns in the 30 patients with Hodgkin's disease were influenced by stage of disease and prior therapy. In untreated patients of stage I‐II, the scan pattern was always normal. Among the 17 stage III or IV patients, scan patterns of type 4 or 5 were frequently observed regardless of previous therapy. Focal defects were common in this group and were of two types: (1) a small irregular defect due to infiltration of tumor (two cases), and (2) a sharply circumscribed defect due to radiation therapy (seven cases). Patients with metastatic malignancy and lymphosarcoma involving bone marrow had abnormal scans showing peripheral expansion or focal defects. Some of the clinical applications for radiocolloid marrow scanning that were suggested for these observations include determining optimal bone marrow biopsy site, aiding staging and the evaluation of treatment response for hematologic malignancies, screening patients for metastatic involvement of bone as an adjunct to the strontium‐85 bone scan, and evaluating extent of bone marrow injury following radiation therapy. It is concluded that the radiocolloid scan of the bone marrow organ can be an important aid in management of patients with malignant disease.