Samarium SM-153 lexidronam is a chelated complex of a radioisotope of the element samarium with ethylenediamine tetra(methylene phosphonic acid) (EDTMP). Samarium Sm-153 EDTMP has an affinity for bone and concentrates in areas of bone turnover in association with hydroxyapatite. In clinical studies employing planar imaging techniques, more Samarium (153Sm) lexidronam accumulates in osteoblastic lesions than in normal bone with a lesion-to-normal bone ratio of approximately 5. It is indicated for the relief of pain in patients with confirmed osteoblastic metastatic bone lesions that enhance on radionuclide bone scan. It should not be given concurrently with chemotherapy or external beam radiation therapy unless the benefit outweighs the risks. The most common adverse events are: nausea and vomiting, hemoglobin decrease, myasthenia, paresthesia, thrombocytopenia and abdominal pain.

Samarium SM-153 lexidronam is a chelated complex of a radioisotope of the element samarium with ethylenediamine tetra(methylene phosphonic acid) (EDTMP). Samarium Sm-153 EDTMP has an affinity for bone and concentrates in areas of bone turnover in association with hydroxyapatite. In clinical studies employing planar imaging techniques, more Samarium (153Sm) lexidronam accumulates in osteoblastic lesions than in normal bone with a lesion-to-normal bone ratio of approximately 5. It is indicated for the relief of pain in patients with confirmed osteoblastic metastatic bone lesions that enhance on radionuclide bone scan. It should not be given concurrently with chemotherapy or external beam radiation therapy unless the benefit outweighs the risks. The most common adverse events are: nausea and vomiting, hemoglobin decrease, myasthenia, paresthesia, thrombocytopenia and abdominal pain.

Iobenguane I-131 is a radioactive therapeutic agent. The drug contains radioactive isotope I-131, which decays by electron emission with a half-life of about 8 days. By the chemical structure, iobenguane is similar to the neurotransmitter norepinephrine and is subject to the same uptake and regulation pathways. After intravenous administration, iobenguane I-131 accumulates within pheochromocytoma and paraganglioma cells, and radiation from the radioactive decay causes cell death and tumor necrosis. Iobenguane I-131 was approved by the FDA for the treatment of adult and pediatric patients with iobenguane scan positive, unresectable, locally advanced or metastatic pheochromocytoma or paraganglioma who require systemic anticancer therapy. Iobenguane I-131 is investigated in clinical trials as a treatment of neuroblastoma, ganglioneuroblastoma and other tumors of neuroendocrinal origin.

I-123 radiolabeled ortho-iodohippurate is commonly employed for evaluating effective renal plasma flow (ERPF) by means of either in vivo scintigraphy and/or plasma clearance curves. It has been used to evaluate renal functioning in patients with obstructive uropathy, vesicorenal reflux, hypertensiion due to renal artery stenosis.

IODOHIPPURIC ACID I-131 (ortho-Iodohippuric Acid I-131, [I-123]-OIH) is an iodine-containing compound used in pyelography as a radiopaque medium. Iodine-123 labelled ortho-Iodohippuric acid was used in the early 1970's as a kidney imaging agent or tracer that "lights-up" inside your body when scanned, but over the years its use has declined. [I-123]-OIH is primarily extracted by the renal tubules and has excellent pharmacokinetic properties, with a clearance only slightly less than that of p-aminohippuran, but its use has been compromised by the suboptimal imaging characteristics of the 364-keV photon of 131I and the delivery of relatively high radiation doses to kidneys and thyroid in patients with impaired renal function

P-32 is a radioactive isotope of phosphorus with a half-life of 14.29 days. Radioactive decay of P-32 produces beta-particles (electrons) which are able to penetrate tissue at a range of 3-8 mm. Phosphate ion P-32 has many applications in medicine and biology. P32 sodium phosphate was approved by the FDA for the treatment of polycythemia vera, chronic myelocytic leukemia, and chronic lymphocytic leukemia. P32-phosphate may also be used in the palliative treatment of selected patients with multiple areas of skeletal metastases. As metabolic uptake of phosphorus is selectively increased in malignant tissues, P-32 was also used for cancer diagnostics.

Raclopride is a salicylamide neuroleptic, that acts as a selective antagonist of D2 dopamine receptors both in vitro and in vivo. Tritium-labelled raclopride has properties that demonstrate its usefulness as a radioligand for the labelling of dopamine-D2 receptors : 3H-Raclopride has a high affinity for the rat and human dopamine-D2 receptors, the non-specific binding of 3H-raclopride is very low, not exceeding 5% of the total binding and the distribution of the 3H-raclopride binding sites in the brain closely correlates with the dopaminergic innervation. The binding of 3H-raclopride is blocked by dopamine-D2 agonists and antagonists, while the D1 agonist SKF 38393 and the Dl antagonist SCH 23390 have much less potency. The interaction of dopamine with 3H-raclopride binding results in a shallow competition curve, which suggests that 3H-raclopride, similar to other dopamine-D2 radioligands, labels both high and low agonist affinity states of the dopamine-D2 receptor. The in vivo receptor binding studies performed with 3H-raclopride also demonstrate its favorable properties as a dopamine-D2 receptor marker in vivo In contrast to some other compounds used as radioligands, raclopride enters the brain readily and binds with a low component of non-specific binding in all dopamine-rich brain areas. A saturation curve may be achieved in vivo binding studies since injections of increasing concentrations of 3H-raclopride appears to be saturated at concentrations above 25 mkCi (corresponding to approximately 5 nmol/kg). Raclopride antagonizes apomorphine-induced hyperactivity in the rat at low doses (ED50 = 130 nM/kg i.p.) but induces catalepsy only at much higher doses (ED50 = 27 mkM/kg i.p.). Radiolabelled raclopride has been used as a ligand for in vitro and in vivo autoradiography in rat and primate brains. Raclopride C 11 is used with positron emission tomography (PET) as a clinical research tool to determine dopamine type 2 (D 2) receptor density in the human brain under normal and pathological conditions. For example, raclopride C 11 used in PET studies has served to confirm the age-related decrease in striatal dopamine D2 receptor density, which may be associated with a decline in the motor as well as cognitive functions. In patients with Alzheimer's disease, raclopride C 11 may be used to examine neuroreceptor distribution and quantities, which may help in the analysis of degenerative alterations of neuron populations and neuroreceptor systems in patients with this disease. In Huntington's disease, in which degeneration of neostriatal interneurons occurs (postsynaptic to the dopaminergic input), specific binding of raclopride C 11 to D 2 receptors may serve as one of the parameters in predicting performance in cognitive tasks.

Iodine-124 (124I), a positron emission tomography (PET) radiotracer, can be used in a variety of PET applications, such as protein and antibody iodinations, as well as in the design and synthesis of new PET tracers. I-124 has the potential to improve the current clinical practice in the diagnosis and treatment of differentiated thyroid cancer (DTC). In addition, 124 PET/CT is a sensitive tool to detect some new lesions that are not visualized on the post-treatment I-131 scan. Recently published article has described that in order to I-124 used as a mainstream, this substance should be more commercially available and at a more chipper.