Biomaterial Database

Technetium-99m labeled agents for skeletal imaging. 1976

J H Thrall

Technetium-99m labeled radiopharmaceuticals are the currently accepted agents of choice for skeletal imaging. Their introduction in 1971 literally initiated a new era in clinical bone scanning. The development of techniques for reducing Tc(VII) with Sn(II) provided the means for complexing this useful radionuclide with various phosphorus-containing compounds which were already known to be avid bone seekers. Long chain polyphosphates were widely used at first, but have been superceded by pyrophosphate and its organic analogs, the diphosphonates. Pyrophosphate is characterized chemically by P--O--P bonds, and the diphosphonates by P--C--P bonds. The chemical forms of their complexes with tin and technetium are not known, but they behave in many respects as weak chelates. Labeling efficiencies for 99mTc of 95% or better are routinely obtainable with both "in house" preparations and commercial kits. Proper molar concentrations and ratios of phosphorus-compound to tin are necessary for both for good labeling and to achieve optimum tissue distribution. Unreacted TcO4- and reduced unbound 99mTc are both potential contaminants in these preparations and must be considered in radiochemical quality control. In vivo tissue distribution and kinetics of the 99mTc-Sn-phosphorus compounds differ with details of preparation, category of agent, and clinical status of the patient. Blood clearance is multi-exponential, with skeletal uptake and urinary clearance accounting for most of the activity. Scanning may be started in 2 1/2 to 4 hr, at which time skeletal activity is on the order of 40 to 50% of the injected dose. The primary indication for bone scanning remains the detection of metastases from extraskeletal malignancies, and the 99mTc labeled agents are more sensitive than either radiographs or Fluorine-18 for demonstrating active lesions. In addition, many new applications in evaluating benign bone disease have widened the clinical scope of skeletal imaging which is rapidly becoming one of the most important studies in nuclear medicine.

UI	MeSH Term	Description	Entries
D006957	Hyperostosis Frontalis Interna	Thickening of the inner table of the frontal bone, which may be associated with hypertrichosis and obesity. It most commonly affects women near menopause.	Leontiasis Ossium,Morgagni-Stewart-Morel Syndrome,Morgagni Stewart Morel Syndrome,Syndrome, Morgagni-Stewart-Morel
D008175	Lung Neoplasms	Tumors or cancer of the LUNG.	Cancer of Lung,Lung Cancer,Pulmonary Cancer,Pulmonary Neoplasms,Cancer of the Lung,Neoplasms, Lung,Neoplasms, Pulmonary,Cancer, Lung,Cancer, Pulmonary,Cancers, Lung,Cancers, Pulmonary,Lung Cancers,Lung Neoplasm,Neoplasm, Lung,Neoplasm, Pulmonary,Pulmonary Cancers,Pulmonary Neoplasm
D008297	Male		Males
D009221	Myositis Ossificans	A disease characterized by bony deposits or the ossification of muscle tissue.	Fibrodysplasia Ossificans Progressiva,Myositis Ossificans Progressiva,Progressive Myositis Ossificans,Progressive Ossifying Myositis
D009362	Neoplasm Metastasis	The transfer of a neoplasm from one organ or part of the body to another remote from the primary site.	Metastase,Metastasis,Metastases, Neoplasm,Metastasis, Neoplasm,Neoplasm Metastases,Metastases
D010001	Osteitis Deformans	A disease marked by repeated episodes of increased bone resorption followed by excessive attempts at repair, resulting in weakened, deformed bones of increased mass. The resultant architecture of the bone assumes a mosaic pattern in which the fibers take on a haphazard pattern instead of the normal parallel symmetry.	Paget's Disease of Bone,Osseous Paget's Disease,Paget Disease of Bone,Paget Disease, Bone,Pagets Disease, Bone
D010017	Osteoma, Osteoid	A benign osteoblastic tumor with central vascularized nidus surrounded by normal reactive bone. It occurs especially in second decade of life most commonly in the femoral neck but can occur in any bone and any site within a bone.	Osteoid Osteoma,Osteoid Osteomas,Osteomas, Osteoid
D010020	Osteonecrosis	Death of a bone or part of a bone, either atraumatic or posttraumatic.	Aseptic Necrosis of Bone,Avascular Necrosis of Bone,Kienbock Disease,Necrosis, Aseptic, of Bone,Necrosis, Avascular, of Bone,Bone Necrosis,Kienbock's Disease,Kienboeck Disease,Kienboeck's Disease,Bone Aseptic Necrosis,Bone Avascular Necrosis,Bone Necroses,Kienboecks Disease,Necroses, Bone,Necrosis, Bone,Osteonecroses
D010710	Phosphates	Inorganic salts of phosphoric acid.	Inorganic Phosphate,Phosphates, Inorganic,Inorganic Phosphates,Orthophosphate,Phosphate,Phosphate, Inorganic
D011471	Prostatic Neoplasms	Tumors or cancer of the PROSTATE.	Cancer of Prostate,Prostate Cancer,Cancer of the Prostate,Neoplasms, Prostate,Neoplasms, Prostatic,Prostate Neoplasms,Prostatic Cancer,Cancer, Prostate,Cancer, Prostatic,Cancers, Prostate,Cancers, Prostatic,Neoplasm, Prostate,Neoplasm, Prostatic,Prostate Cancers,Prostate Neoplasm,Prostatic Cancers,Prostatic Neoplasm