99Tcm-HMPAO-labelled leucocytes for bone marrow scintigraphy and evaluation of skeletal lesions. Comparison with 99Tcm-HSA colloid results.

Bone marrow scintigrams obtained 2-6 h and/or 20-24 h after injection of 99Tcm-HMPAO-labelled leucocytes (LeuSc) in 16 patients (seven males, nine females, average age 57 years, either with benign or malignant haemopathy, or with benign or metastatic skeletal diseases) have been compared to corresponding pictures obtained 20 min after injection of 99Tcm-labelled human serum albumin nanosized colloids (NanSc, performed within a week thereafter). Overall distribution of the colloids and of the labelled leukocytes at the level of the bone marrow appeared to be the same. Fresh vertebral fractures as well as metastatic lesions of the axial skeleton appeared as cold defects in both investigations. Fractures of the ribs as well as one metastatic lesion involving one trochanter could not be identified. Although all seven lesions involving Th9 to L4 could be clearly investigated with LeuSc, only three could be recognized with NanSc. It is concluded that, in patients with cancerous diseases, LeuSc is better than NanSc in demonstrating lesions in the case of dubious conventional osseous scintigrams as well as in the case of neurological or skeletal symptoms at the level of the lumbar and/or low thoracic regions.