The presentation of clinical results of radiolabelling of ^99mTc-MIBI complex using ultrasound technique for myocardial perfusion SPECT scanning

Background. - The aim of this study was to introduce a new clinical procedure (ultrasound irradiation technique) as an alternative method for the preparation of sestamibi kits as opposed to the boiling water bath technique. The main proposal of this study was to evaluate the clinical application of ultrasound method, preparation of ^99mTc-MIBI complex and biodistribution of the heart in comparison with ^99mTc- MIBI complex, which was prepared using the boiling water technique. Materials and methods. - Forty MIBI kits were supplied for twenty patient volunteers. 740-3700 MBq (20-100 mCi) freshly eluted solution of Na+^99mTcO4- was added to freeze-dry MIBI Kits (The first day up to 20 kits and the second day another 20 kits with the same amount was used). Moreover, twenty kits were labeled applying the ultrasound radiation method as an alternative approach (The vials were sonicated in thermo noted bath (Elma, P = 50 W, Germany) at 65 ± 0.5 C and for 60 ± 1 seconds), and another twenty kits were provided applying boiling water bath method as a standard approach. Twenty patient volunteers (8 men and 12 women; age range 30-72, median 52.45 years) took part in this research. These volunteers had originally been referred to the hospital for myocardial perfusion imaging. The twenty volunteer patients were divided into two groups (each group contained ten people): group A (consisted of 3 men and 7 women with an age range from 36 to 67 years and a mean age of 51.7 years), and group B (involving 5 men and 5 women with an age range from 30 to 72 years and an average age of 50.3 years). The ^99mTc-MIBI complex samples provided by ultrasound method were injected into group A subjects intravenously and group B received ^99mTc-MIBI vials provided by boiling water bath approach (intravenous injection). In this research, the myocardial perfusion-SPECT was performed applying a rest-stress protocol which is carried-out between two isolated days for all volunteer patients. Results. - The results obtained in this research applying radio-HPLC and ITLC, suggest that radiolabeling of MIBI vial with ^99mTc can be achieved with high efficacy and appropriate acceptance applying the ultrasound method as a novel approach. The imaging research applying SPECT indicated that the ^99mTc- MIBI complex samples that were prepared applying an ultrasound irradiation approach indicate very similar biodistribution in the heart, thyroid, lung, liver, gallbladder, kidneys, stomach, GI and bladder of the volunteer patients. Non-habitual aggregation of ^99mTc-MIBI samples were not observed in our approach. Conclusions. - The results of this research suggest that the sonication approach can be proposed for preparation of ^99mTc-MIBI radio-complex samples. The reaction time to provide radio-complex can be considerably decreased compared to the boiling water bath approach. This main development could decrease the potential risk to the patient to inhibit any delay in emergency situations i.e. acute therapy, especially for myocardial infarction patients in clinical practice. (authors)