Injection activity

Table 8. Percentage of injected activity recovered (8 hamsters per group)...

In the years after World War II (1946 to 1950), repeated injections of radium-224 were given to adults and children in Germany for treatment of tuberculosis, ankylosing spondylitis, and other diseases. Out of about 2,000 persons who received this treatment, 816 of these cases are currently being followed (Spiess et al. 1978). Of the 816, 204 were injected as juveniles (ages 1 to 20 years) and 612 as adults. The average total injected activity was 18 pCi/kg (666 kBq/kg) (Mays et al. 

A second study of persons injected with radium-224 in Germany from 1948 to 1975 included 1,473 ankylosing spondylitis patients who were also treated with repeated intravenous injections of radium, but at lower levels. They typically received a series of 10 to 12 injections at weekly intervals, each containing 28 pCi (1,037 kBq). Some patients received two or three such series, and one patient received four. The average total injected activity was 4.8 pCi/kg (178 kBq/kg) (Wick and Gossner 1983, 1989). 

Athymic mice with induced tumours were used to study biodistribution. For these studies, 11 MBq (30 gCi) of Tc-BN 1, Lu-DOTA-MG or Lu-DOTATATE in 0.04 mL was injected into the tail vein. The mice (n = 3- per time point) were sacrificed at 5,15 and 30 min, and 1.5,3 and 4 h post-injection, or, in the case of Tc-BN, at 2 h post-injection. The heart, spleen and kidneys, and samples of lung, liver, blood, stomach, intestines, muscle and bone were rinsed with saline, blotted with paper and placed into preweighed plastic test tubes. The activity was determined in a well type scintillation detector (Canberra) along with six 0.5 mL ahquots of the diluted standard representing 100% of the injected activity. The mean activity was used to obtain the percentage of injected dose per gram of tissue (% ID/g). 

WITH INDUCED PCS TUMOURS, 2 H POSTADMINISTRATION OF Tc-EDDA/HYNIC-[Lys ]BN (expressed as percentage of injected activity per gram of tissue (% ID/g) mean SD a = 4)... 

The monovalent anion pertechnetate is actively transported into the thyroid in a manner similar to iodide however, it is not metabolized and is released from the thyroid unchanged. It has been demonstrated that the active transport of iodide and pertechnetate share the same carrier mechanism (Wolff and Maurey 1962). Uptake in the thyroid gland is between 1.5 and 2% of the injected activity within 20 min (Andros et al. 1965). 

A major difference between the kinetics of pertechnetate and iodide in humans is the excretion pattern only pertechnetate is excreted in the feces (Andros et al. 1965 Hays and Berman 1977). Renal excretion by glomerular filtration is observed in the first 24 h after administration 25-30% of the injected activity is recovered in the urine. During the following 48-72 h, fecal excretion predominates and may amount to 35% of the injected radioactivity. A total of approximately 60% of the administered radioactivity is recovered in urine and feces in 72 h approximately 40% is retained in the body, mainly in the digestive tract. The whole-body biological half-time is estimated to be 53 h (Andros et al. 1965). Tubular reabsorption of pertechnetate was determined as 86.5% of the filtered amount. Tc-pertechnetate is excreted unchanged (Dayton et al. 1969). 

Subtraction Previously injected activity in thyroid gland is subtracted from the total neck image ( Tc-sestamibi -I- 1- or " Tc-thyroid image) (Wei et al. 1992). 

After intravenous injection of a bolus of activity, Tc-l,l-ECD is distributed in the normal brain proportional to regional blood flow (Friberg et al. 1994). The Upophilic complex crosses the blood-brain barrier (BBB) cerebral uptake at 5 min postinjection is approximately 6.5% of the injected radioactivity (Holman et al. 1989 Leveille et al. 1989 Vallabhajosula et al. 1989). Within 4 h after injection, activity in the brain decreased to 3.7 0.3% injection dose (ID). 

Uptake of Tc-PYP in acute myocardial infarction was detected with higher sensitivity than were the known Tc-diphosphonate complexes (Kelly et al. 1979). Using a rat model, the percentage of injected activity per gram of infarct was approximately 2.4 times higher than with Tc-MDP (Davis et al. 1976). Visualization of the infarct can be effected from 24 h-7 days after the onset of symptoms and with maximum sensitivity (96%) between 48 and 72 h (Kelly et al. 1979). 

Stannous medronate has an affinity for RBC. It has been shown that stannous ion binds to the j5-chain of hemoglobin. When Tc-Na-pertechnetate is injected 20-30 min after the intravenous injection of the reducing solution, high labeling of the preloaded erythrocytes is obtained (Callahan et al. 1982). Approximately 15% of the injected activity is excreted in the urine during the first day (Porter et al. 1983). 

A fraction of the injected activity is retained in the kidneys, indicating proximal tu-hular reabsorption, as has been observed with "ln-(DTPA)octreotide (Vallabhajosula et al. 1996). 

The uptake of [ "Tc (MIBI)(, (Fig. 6.9.B) in the human heart is about 1.5 % of the injected activity, and decreases to 1 % after 4 h. The background activity in the blood, lungs, liver, and spleen is sufficiently low 92. The presence of the methoxy groups on the periphery of the cation provides for optimal lipophilicity and allows for in vivo hydrolysis of the ethers to the respective alcohols which may increase the clearance rates from blood and liver [5]. The complex cation seems not to be taken up in the myocardium by the Na /K-ATPasc pump but is retained in cellular membranes including mitochondrial membranes [93,94]. As for - T1, the distribution of (MIBI) ] reflects the myocardial blood flow, but unlike 20171 there is no evidence of... 

During the periods 0 00-6 00, 6 00-12 00, and 12 00-24 00 hr. after the administration of the radioactive morphine to HE, 2.39%, 0.62%, and 0.36% of the injected activity were recovered from the expired air in the same intervals 55.96%, 8.72%, and 11.02% were recovered in the urine. Initially 23 times as much radioactivity appeared in the urine as in the expired air, while from 6 (X)-12 00 only 12 times as much, and in the final period 30 times as much radioactivity was obtained in the urine. 

Concentrations of Radioactivity Drug Addict FA. The urine delivered had concentrations of 32, 29, 66, 20, and 30 times the radioactivity present on the average in the rest of the body. During the first 48 hr. the average concentration of radioactivity per milliliter of urine was 2.0 X 10 S and per gram of feces was 0.03 X 10, of the injected activity. Only a negligible fraction of the radioactivity appears in the feces as compared with the urine. 

AquaMephyton solution for s.c.fi.m. injection Active substance Solubilizer Preservative To adjust isotonicity Solvent phytomenadione poiyoxyethylated fatty acid derivative benzyl alcohol dextrose water in 1 ml 2 or 10 mg 70 mg 0.9% 37.5 mg to volume... 

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