Evaluation of bone-marrow scanning with technetium-99m sulfur colloid in pediatric oncology.

Eighty-six technetium-99m sulfur colloid (Tc-SC) bone-marrow scans in 56 pediatric oncology patients were reviewed. The distribution of the sulfur colloid was similar to that in adult bone marrow in normal children older than 10 yr, and involved progressively more marrow of the extremities in normal children under 10 years of age. After irradiation or chemotherapy there was an extension of the Tc-SC to peripheral marrow sites. There was also diminished uptake of the tracer in sites corresponding to irradiated areas. In most patients there was recovery of these defects by 6 mo after completion of therapy. Tumor replacement of the marrow was reflected in the scans, and the extent of the scan defect paralleled the course of the disease. In four patients, despite normal bone scans and radiographs, marrow-scan abnormalities due to tumor replacement were present and confirmed by needle aspiration and/or biopsy. In two other patients, the marrow-scan abnormality preceded radiographic and histologic evidence of tumor metastasis. Two patients who responded clinically showed persistent defects; biopsy in one revealed fibrosis. Technetium-99m sulfur colloid bone-marrow scanning appears to be a sensitive monitor of marrow alteration caused by metastases, irradiation damage, or tissue fibrosis in children receiving treatment for cancer.