[Detection of bone marrow involvement in breast cancer and malignant lymphoma using immunoscintigraphy of the hematopoietic bone marrow]

Diagnostic value of MRI in comparison to scintigraphy, PET, MS-CT and PET/CT for the detection of metastases of bone

The initial localization of metastases in the bone in patients with solid tumors has a relatively good prognosis in comparison with visceral metastasization. The early detection of bone marrow metastases allows for a rapid initiation of therapy and a subsequent reduction in the morbidity rate. Modern MRI is superior to the 30-year-old skeletal scintigraphy and bone marrow scintigraphy with respect to sensitivity, specificity, as well as the extent of osteal metastasis. MRI provides substantial, therapy-relevant additional information. MSCT plays an important role in the management of cancer patients in clinical routine and gives an excellent survey of the axial skeleton by demonstrating osteolytic and osteoblastic metastases. Extensive comparative studies of MRI with 18F-FDG-PET and 18F-fluoride-PET have not yet been carried out. Whole body MRI is a very promising new staging method for the oncological diagnosis of solid tumors and the detection of osteal metastases. The adoption of 18F-FDG-PET and 18F-fluoride-PET FDG as well as the side by side PET-CT image fusion and the two in one PET/CT examinations appears to be slightly less sensitive to whole body MRI in the detection of osteal metastases. Larger, prospective multicenter studies are necessary to establish these as new, promising methods for the detection of osteal metastases.

Comparative diagnostic value and therapeutic relevance of magnetic resonance imaging and bone marrow scintigraphy in patients with metastatic solid tumors of the axial skeleton

PURPOSE

To evaluate the comparative impact of magnetic resonance imaging (MRI) and bone marrow scintigraphy (BMS) in bone marrow metastases of solid tumors.

METHODS

In 20 patients with solid tumors MRI of the axial skeleton and whole-body BMS were retrospectively reviewed. Detectability of metastases, extent of disease and therapeutic implications were assessed.

RESULTS

In 15/20 (75%) patients MRI and BMS concordantly revealed bone marrow metastases of the axial skeleton. In nine of these 15 patients (60%) MRI showed more metastases. Local radiotherapy or surgery was performed in seven of these cases (78%). BMS detected additional metastases of the appendicular skeleton in 8/15 (53%) patients. In 4/20 cases (20%) the imaging findings were discordant. In three patients with degenerative changes (n=2) or lipoma (n=1) BMS was false positive. In another patient BMS failed to detect metastases proven by MRI and clinical follow-up resulting in subsequent radiation therapy. One patient had normal bone marrow.

CONCLUSION

MRI appears to be more sensitive and specific in the detection of bone marrow metastases in the axial skeleton and is of clinical importance for subsequent local therapy.

Can pharmacological intervention improve the visualization of the reticuloendothelial system using 99mTc-labeled albumin nanocolloid to that achievable with 111In-labeled granulocytes? Experimental studies in mice

The use of 99mTc-colloids for bone marrow scintigraphy is limited by a high liver uptake, which hampers the evaluation of surrounding skeletal structures. In an experimental mouse system, different measures to increase the bone marrow activity in relation to the liver activity have been tested. A slightly positive, but significant, outcome was achieved by three different measures, namely fasting, pretreatment with a calcium-blocking pharmaceutical (Nimodipine) and pretreatment with large amounts of a gelatine colloid. It is concluded that the possibilities of dramatically improving the bone marrow uptake of a colloid compared to the liver are limited and not comparable to that achievable using radiolabeled granulocytes.

Bone marrow immunoscintigraphy compared with conventional bone scintigraphy for the detection of bone metastases

Immunoscintigraphy of haematopoetic bone marrow was compared to conventional bone scanning in 141 patients with malignant disease. Forty patients had breast cancer, 25 prostatic carcinoma, 14 kidney or bladder cancer, 13 bronchial carcinoma, 39 malignant lymphoma and 10 multiple myeloma. A total of 18,800 skeletal regions were evaluated. Marrow scans showed more metastatic lesions than bone scanning in all patient subgroups. Computerized tomography was concordant with bone marrow scintigraphy in 83.3% of 323 skeletal sites. Bone marrow scans in 30 control patients with fever of unknown origin were abnormal only in 3 patients and in only 7 out of 2,135 skeletal regions examined. In patients with malignant lymphoma, bone marrow histology or aspiration cytology was concordantly positive in 14 and concordantly negative in 17 patients. We conclude that immunoscintigraphy of haematopoetic bone marrow provides a reliable, sensitive and safe novel approach for non-invasive detection of metastatic spread to the skeleton.

Recent advances in bone marrow scanning

Interest in bone marrow scanning has been renewed as the result of the development of radiopharmaceuticals for evaluating specific aspects of bone marrow anatomy, physiology and pathology. This article provides a brief review of bone marrow structure, blood flow and function essential to the understanding of basic principles of bone marrow radionuclide imaging. The prospects and limitations of imaging haematopoietic bone marrow in man using indium 111 chloride, technetium-99m (99mTc)-labelled microcolloid or 99mTc-labelled monoclonal antigranulocytic and antimyelocytic antibodies are discussed in more detail. The technical aspects of bone marrow scintigraphy are presented. Results of more recent studies evaluating bone marrow scanning in circulatory, inflammatory and in systemic haematological disorders are summarized. Special attention is paid to the concept of bone marrow micrometastases and its implications for the follow-up of patients with malignant tumours. Recent results suggest that immunoscintigraphy of bone marrow may provide a novel and sensitive approach for establishing the presence and extent of bone marrow infiltration.