Comparison Between Thaffium-20 1, Technetium 99m-Sestamibi and Technetium-99m- Teboroxime Planar Myocardial Perfusion Imaging in Detection of Coronary Artery Disease Raymond Taillefer, Raymond Lambert, Richard Essiambre, Denis Carl Phaneuf, and Jean Léveillé From the Department ofNuclear Medicine and Division ofCardiology, HôpitalHôtel-Dieu de Montréal,Universitéde Montréal,Montréal,Canada diagnosis and prognosis of coronary artery disease and Technetium-99m-sestamibi(MIBI) and @Tc-teboroximeevaluatingthehemodynamicsignificanceofdocumented (TEBO) are two new myocardialperfusionimagingagents. coronary stenoses (1—3).Although [201Tl]thallous chloride The purpose of this prospective study was to compare MIBI shows excellent physiologic characteristics for imaging and TEBO to @°1Tlplanar imaging. Eighteen patients with myocardial perfusion and viability, its physical character significant coronary artery disease on coronary angiogram istics are suboptimal for dosimetry and scintillation cam were submitted to three treadmill stress tests performed era imaging. During the last decade, research has focused within 3 mo and were imaged with the three radiopharmaceu on development of myocardial perfusion agents labeled ticals as follows. with 99mTc Different 99mTclabeled agents have been syn 1. TI: 2.2 mCi, immediate and delayed views (4 hr later, 8 mm/view). thesized and have demonstrated interesting myocardial 2. TEBO: 15—20mCi at stress (1 mm/view) and a second uptake and clearance properties. Technetium-99m-labeled injection was repeated 4 hr later at rest (20—25mCi). isonitrile compounds (4) and boronic acid adducts of 3. MIBI:15—18 mCi at stress (8 mm/view) and 1—4days 99mTc dioxime (BATO) compounds (5,6) are two classes later, 15—18mCi at rest. of radiopharmaceuticals that have been more extensively Patients achieved similar levels of exercise. A blinded reading evaluated in humans. Two new 99mTc@labeledmyocardial was performed by three observers. The left ventricle was perfusion imaging agents are now available for clinical use: divided into three segments/view and ischemic/normal wall 99mTc@@mibi (Cardiolite from DuPont) and 99mTc@te@ ratioswerealsodetermined.Segmentalcomparisonshowed boroxime (Cardiotec from Squibb). Many studies compar anagreementin85%(138/162)ofthesegmentsbetweenTI ing 99mTcsestamibi to 201Tl planar and SPE@T imaging and TEBO, in 92% (149/162) between Ti and MIBI and in have been previously reported (7—15).Clinical experience 84% (136/162) between MIBI and TEBO. Abnormal TI, MIBI and TEBO studies were seen in 16 (89%), 16 (89%) and 15 with 99mTcte@roxime and comparison to 201Tl is more (83%) patients, respectively, detecting 77, 75 and 65 abnor limited (16-18). So far, 99mTc@teboroxime has not been mal segments. lschemic-to-normal wall ratios were 0.75 ± directly compared to @mTc@sestamibiand no studies have 0.06, 0.73 ±0.08 and 0.78 ±0.08 for TI, MIBIand TEBO, reported the results of 201Tl, @mTc@sestamibiand 99mTc@ respectively. Inconclusion, although the biologic charactens teboroxime imaging performed in the same patient popu tics of these agents are different, this study showed a good lation. The purpose of this preliminary prospective study correlation between them in detection of significant coronary is to compare planar myocardial perfusion imaging per artery disease (high pretest likelihood population). formed with the three radiopharmaceuticals in patients J NucI Med 1992; 33:000-000 referred for coronary angiography and to evaluate their relative sensitivity and agreement to detect coronary artery disease. uring the past fifteen years, 201T1myocardial perfu METHODS sion imaging has been widely accepted for establishing the PatientPopulation Eighteen patients (16 males, 2 females, ranging in age from 44 Received Oct. 1, 1991; revision accepted Jan. 14, 1992. to 76 yr, mean age, 59 yr) referred for chest pain evaluation and! For reprints contact: Dr. Raymond Taillefer,Départementde Médecine Nucléaire,Hôtel-Dleude Montréal,3840St-UrbainSt., Montreal,Quebec,H2W or coronary angiography were prospectively studied. Within 14 1T8,Canada. wk, all patients underwent coronary angiography and three tread Comparison of 201T1, @“Tc-Sestamibiand @“Tc-Teboroxime•Taillefer et al 1091 mill stress tests with 201T1, @mTc@sestsmibi and 99mTc@teboroxime mm after injection with the same acquisition parameters used in injection for planar myocardial perfusion imaging. The sequence the exercise study. The mean interval between the stress and rest of radiopharmaceuticals injections was randomly assigned. 99mTc@tsmibi injections was 2 days (1—4days). A written, informed consent approved by the ethics committee of our institution was obtained from each patient. Patients with Technetium99m-TeboroximeMyocardialImaging unstable angina, severe arrhythmias, recent myocardial infarction A same-day stress-rest injection protocol was used for @mTc@ (less than 6 wk), overt congestive heart failure, significant valvular teboroxime imaging. Patients were submitted to a stress test heart disease or patients unable to achieve an adequate level of similar to the two previous with 201T1and 99mTc@sestamibiimag exercise or with known left main disease were excluded from the ing. A dose of 15—20mCi of 99mTc@teboroximewas injected 30— study. 60 secbeforethe end of exercise.Planarimagingwasstarted Preparation of the patients was identical for the 201'fl,99mTc approximately 90—120sec after injection with the same gamma sestamibi and 99mTcteberoxjme studies. Patients were instructed camera and collimator used in the 20Tl study. The first two to fast after midnight and, whenever possible, cardiovascular planar images (supine anterior and 45°LAO views)were acquired drugs were discontinued 24—48hr prior to the study. The exercise for 60 sec/view and the last view (left lateral, patient sitting with protocol (standard Bruce protocol) was similar for each patient his left side close to the camera) lasted 90 sec. Approximately 4 who exercised to the same level (heart rate and blood pressure) hr later (215 ±60 mm), a second injection of 20—25mCi of for each of the three stress tests. An intravenous line with NaCl 99mTcteboroxime was given at rest. Two minutes later, planar 0.9% solution was installed with a no. 20 gauge plastic cannula imaging was repeated in the same three standard views according in an antecubital vein before the stress test and radionuclide to acquisition parameters used in the stress study. injection. Patients were exercised on the treadmill until they reached 85% ofthe age-predicted maximal heart rate or developed CardiacCatheterization angina, shortness of breath, hypotension or arrhythmias. Thirty All patients underwent coronary angiography and left ventric to 60 sec before the end ofthe stress test, the radiopharmaceutical ulography using the Judkin's technique with multiple views of was injected as a compact bolus. the right and left coronary arteries. Coronary angiograms were Radiochemical purity was assessed by thin-layer chromatog interpreted by two independent observers without knowledge of raphy for both 99mTc@@tsmibiand @mTc@teboroximebefore each the 201Tl,99mTcsestamibi or 99mTcteboroxime study results. Sig injection. A labeling efficiency of more than 90% was necessary nificant coronary artery stenosis was defined as a 70% or greater for the intravenous injection of the radiopharmaceuticals. reduction in luminal diameter of one or more major coronary arteries. Thallium-201MyocardialImaging A standard stress-redistribution 201T1imaging protocol was Data Analysis used. One minute before the end of exercise, 2.2—2.5 mCi of All myocardial scintigraphic studies were analyzed by three 201T1wereinjectedintothecannulaandimmediatelyflushed experienced observers without prior knowledge of the patient's with 10 ml of normal saline solution. Myocardial planar imaging history, results of the stress electrocardiograms or coronary anat was started 5 mm after 20―flinjection with a small field of view omy. Disagreements in interpretation were resolved by consensus. scintillation camera using a low-energy, all-purpose, parallel-hole The reading of201T1,99mTcsestamibi and 99mTc.teboroximestud collimator. The gamma camera was interfaced to a computer. ies was performed independently. Digital images were recorded using a 128 x 128 matrix. The first Interpretation of the three myocardial scans was based pri image acquired was a 45°left anterior oblique (LAO) view (best manly on analog and digital displays using a semiquantitative septal view) followed by the anterior and a left lateral view using analysis with segmental activity profiles of opposing myocardial an acquisition time of 8 mm for each view with the photopeak walls for each view on digital images (images with a 10% standard set at 80 keV with a 20% symmetrical window. In all cases, uniform background subtraction were also available for the three redistribution images were obtained 3—5hr later. The same studies). This display was used for both stress and rest (or redis imaging parameters were used for the redistribution phase. tribution) studies. A semiquantitative analysis was also used to assess the relative severity of ischemia. Ischemic-to-normal wall Technetium99m-SestamibiMyocardialImaging ratios were determined for the three studies. Three regions of At least three days after the 201Tlor @mTc@teboroximestudy, interest were chosen for each patient with ischemic defects (on patients were submitted to another exercise