Lutetium Lu 177 dotatate binds to somatostatin receptors with highest affinity for subtype 2 receptors (SSRT2). Upon binding to somatostatin receptor expressing cells, including malignant somatostatin receptor-positive tumors, the compound is internalized. The beta emission from Lu 177 induces cellular damage by formation of free radicals in somatostatin receptor-positive cells and in neighboring cells. LUTATHERA® (lutetium Lu 177 dotatate) is indicated for the treatment of somatostatin receptor-positive gastroenteropancreatic neuroendocrine tumors (GEP-NETs), including foregut, midgut, and hindgut neuroendocrine tumors in adults.

Strontium SR-89 is a radioactive isotope of strontium. Strontium-89 decays by beta emission with a half-life of 50.5 days. Beta-particles produced by radioactive decay penetrate tissues at a range of approximately 8 mm. Strontium SR-89 is used in medicine for the relief of bone pain in patients with painful skeletal metastases. Following intravenous injection, soluble strontium compounds behave like their calcium analogs, clearing rapidly from the blood and selectively localizing in bone mineral. Uptake of strontium by bone occurs preferentially in sites of active osteogenesis; thus primary bone tumors and areas of metastatic involvement (blastic lesions) can accumulate significantly greater concentrations of strontium than surrounding normal bone.

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.

The therapeutic use of radioactive colloidal gold Gold Au-198 (Au198) was first described by Sheppard et al., who reported on intravenous use in 1947. Its possibilities for the treatment of various malignant processes have been explored in great variation. Gold Au-198 is an antineoplastic, diagnostic aid (liver imaging) and radioactive agent. Thus, intracavitary instillation of colloidal radioactive gold Au-198 was used for treatment of patients with multiple papillomata of the bladder. Approximately 300 mc. of gold was instilled into the bladder for four to six hours to deliver a dose of about 4,000 to 5,000 r to the bladder epithelium. The treatment had no harmful side-effects locally or on the general condition of the patient. It was also used to estimate the hepatic blood flow in children with active or progressive chronic hepatitis. Gold Au-198 was used in the combination therapy of rectal cancer.

Erbium-169 citrate is anti-inflammatory and antirheumatic radiopharmaceutical agent. Erbium-169 decays with half-life 9.4 days by the emission of beta particle and very low energy gamma radiation. The average radiation penetration is 0.3 mm in the soft tissues and 0.2 mm in the cartilage. Colloid Er-169 is used in radiosynovectomy on rheumatoid arthritis patients whose condition is resistant to standard methods of treatment. During this procedure, colloid erbium-169 citrate is directly injected into the synovial cavity of the affected joint. The data indicate that after intra-articular injection, radioactive colloid particles are picked up by superficial synovial cells. Under the effect of irradiation, necrosis of the superficial synovial layer takes place, followed by phagocytosis of the necrotic tissue and delineated inflammatory flare. This temporarily halts synovitis and improves synovial joint function.

YTTRIUM Y-90 (YTRACIS®, YTTRIGA®) is a radioactive form of the chemical element yttrium. It is used for radiolabelling other medicines. An example of its use is the treatment of some type of tumors, where the radiolabelled medicine carries the radioactivity to the site of a tumor to destroy the tumor cells.