Other
Myocardial Imaging: CARDIOLITE®, Kit for the Preparation of Technetium Tc99m Sestamibi for Injection, is a myocardial perfusion agent that is indicated for detecting coronary artery disease by localizing myocardial ischemia (reversible defects) and infarction (non-reversible defects), in evaluating myocardial function and developing information for use in patient management decisions. CARDIOLITE® evaluation of myocardial ischemia can be accomplished with rest and cardiovascular stress techniques (e.g., exercise or pharmacologic stress in accordance with the pharmacologic stress agent's labeling).
It is usually not possible to determine the age of a myocardial infarction or to differentiate a recent myocardial infarction from ischemia.
Breast Imaging: MIRALUMA®, Kit for the Preparation of Technetium Tc99m Sestamibi for Injection, is indicated for planar imaging as a second line diagnostic drug after mammography to assist in the evaluation of breast lesions in patients with an abnormal mammogram or a palpable breast mass.
MIRALUMA® is not indicated for breast cancer screening, to confirm the presence or absence of malignancy, and it is not an alternative to biopsy.
For Myocardial Imaging: The suggested dose range for I.V. administration of CARDIOLITE® in a single dose to be employed in the average patient (70 Kg) is 370 - 1110 MBq (10 - 30 mCi).
For Breast Imaging: The recommended dose range for I.V. administration of MIRALUMA® is a single dose of 740 - 1110 MBq (20 - 30 mCi).
Breast Imaging: It is recommended that images are obtained with a table overlay to separate breast tissue from the myocardium and liver, and to exclude potential activity that may be present in the opposite breast. For lateral images, position the patient prone with the isolateral arm comfortably above the head, shoulders flat against the table, head turned to the side and relaxed, with the breast imaged pendent through an overlay cutout. The breast should not be compressed on the overlay. For anterior images, position the patient supine with both arms behind the head. For either lateral or anterior images, shield the chest and abdominal organs, or remove them from the field of view.
For complete study, sets of images should be obtained five minutes after the injection, and in the following sequence:
Beginning five minutes after the injection of Technetium Tc99m Sestamibi:
- ten-minute lateral image of breast with abnormality
- ten-minute lateral image of contralateral breast
- ten-minute anterior image of both breasts
a. Prior to adding the Sodium Pertechnetate Tc99m Injection to the vial, inspect the vial carefully for the presence of damage, particularly cracks, and do not use the vial if found. Tear off a radiation symbol and attach it to the neck of the vial.b. Waterproof gloves should be worn during the preparation procedure. Remove the plastic disc from the vial and swab the top of the vial closure with alcohol to sanitize the surface.c. Place the vial in a suitable radiation shield with a fitted radiation cap.d. With a sterile shielded syringe, aseptically obtain additive-free, sterile, non-pyrogenic Sodium Pertechnetate Tc99m Injection [925 - 5550 MBq, (25 - 150 mCi)] in approximately 1 to 3 mL.e. Aseptically add the Sodium Pertechnetate Tc99m Injection to the vial in the lead shield. Without withdrawing the needle, remove an equal volume of headspace to maintain atmospheric pressure within the vial.f. Shake vigorously, about 5 to 10 quick upward-downward motions.g. Remove the vial from the lead shield and place upright in an appropriately shielded and contained boiling water bath, such that the vial is suspended above the bottom of the bath, and boil for 10 minutes. Timing for 10 minutes is begun as soon as the water begins to boil again. Do not allow the boiling water to come in contact with the aluminum crimp.h. Remove the vial from the water bath, place in the lead shield and allow to cool for fifteen minutes.c. Place the vial in the thermal cycler radiation shield.d. With a sterile shielded syringe, aseptically obtain additive-free, sterile, non-pyrogenic Sodium Pertechnetate Tc99m Injection [925 - 5550 MBq, (25 - 150 mCi)] in approximately 1 to 3 mL.e. Aseptically add the Sodium Pertechnetate Tc99m Injection to the vial in the lead shield. Without withdrawing the needle, remove an equal volume of headspace to maintain atmospheric pressure within the vial.f. Shake vigorously, about 5 to 10 quick upward-downward motions.g. Place shield on sample block. While slightly pressing downward, give the shield a quarter turn to make certain there is a firm fit between the shield and the sample block.h. Press the proceed button to initiate the program (the thermal cycler automatically heats & cools the vial and contents). Please see the Recon-o-Stat Instruction Manual for further details.i. Using proper shielding, the vial contents should be visually inspected. Use only if the solution is clear and free of particulate matter and discoloration.j. Assay the reaction vial using a suitable radioactivity calibration system. Record the Technetium Tc99m concentration, total volume, assay time and date, expiration time and lot number on the vial shield label and affix the label to the shield.k. Store the reaction vial containing the Technetium Tc99m Sestamibi at 15° to 25°C (59° - 77°F) until use; at such time the product should be aseptically withdrawn. Technetium Tc99m Sestamibi should be used within six hours of preparation. The vial contains no preservative.
General Procedure:
Boiling Water Bath Procedure:
Recon-o-Stat (thermal cycler) Procedure:
General Procedure (cont.):
| Note: | Adherence to the above product reconstitution instructions is recommended. |
| The potential for cracking and significant contamination exists whenever vials containing radioactive material are heated. | |
| Product should be used within 6 hours after preparation. | |
| Final product with radiochemical purity of at least 90% was used in the clinical trials that established safety and effectiveness. The radiochemical purity was determined by the following method. |
Risk Summary
Limited available data with Technetium Tc99m Sestamibi use in pregnant women have not identified a drug-associated risk of major birth defects, miscarriage, or adverse maternal or fetal outcomes. Animal reproduction and teratogenicity studies have not been conducted with Technetium Tc99m Sestamibi. However, all radiopharmaceuticals have the potential to cause fetal harm depending on the fetal stage of development and the magnitude of the radiation dose. If considering Technetium Tc99m Sestamibi administration to a pregnant woman, inform the patient about the potential for adverse pregnancy outcomes based on the radiation dose from Technetium Tc99m Sestamibi and the gestational timing of exposure.
All pregnancies have a background risk of birth defects, loss, or other adverse outcomes. In the U.S. general population, the estimated background risk of major birth defects and miscarriage in clinically recognized pregnancies is 2-4% and 15-20%, respectively.
Risk Summary
Limited data in the scientific literature on the presence of Technetium Tc99m Sestamibi in human milk, demonstrate that between 0.01% and 0.03% of maternal injected activity of technetium Tc99m Sestamibi was excreted in human milk. Technetium Tc99m Sestamibi accumulates in the lactating breast [see Clinical Considerations]. There are limited data in the scientific literature on effects of Technetium Tc99m Sestamibi on the breastfed infant or on milk production The developmental and health benefits of breastfeeding should be considered along with the mother's clinical need for Technetium Tc99m Sestamibi and any potential adverse effects on the breastfed infant from Technetium Tc99m Sestamibi or from the underlying maternal condition.
Clinical Considerations
Interruption of breastfeeding after exposure to Technetium Tc99m Sestamibi is not necessary because Technetium Tc99m Sestamibi excretion in breast milk is low. However, a lactating woman may restrict close contact with her breast fed infant to a maximum of 5 hours in the 24 hour period after Technetium Tc99m Sestamibi administration in order to minimize radiation exposure.
12.3.1 Metabolism
The agent is excreted without any evidence of metabolism.
12.3.2 Elimination
The major pathway for clearance of Tc99m Sestamibi is the hepatobiliary system. Activity from the gall bladder appears in the intestines within one hour of injection. Twenty-seven percent of the injected dose is excreted in the urine, and approximately thirty-three percent of the injected dose is cleared through the feces in 48 hours.
CLINICAL TRIALS:
MYOCARDIAL IMAGING: In a trial of rest and stress CARDIOLITE® imaging, the relationship of normal or abnormal perfusion scans and long term cardiac events was evaluated in 521 patients (511 men, 10 women) with stable chest pain. There were 73.9% Caucasians, 25.9% Blacks and 0.2% Asians. The mean age was 59.6 years (range: 29 to 84 years). All patients had a baseline rest and exercise CARDIOLITE® scan and were followed for 13.2 ± 4.9 months (range: 1 to 24 months). Images were correlated with the occurrence of a cardiac event (cardiac death or non-fatal myocardial infarction). In this trial as summarized in Table 7.0, 24/521 (4.6%) had a cardiac event.
| Baseline Scan Note: Similar findings were found in two studies with patients who had pharmacologic stress CARDIOLITE® imaging. | Proportion of patients with events by scan results | Proportion of scan result in patients with events; N=24 | Proportion of event-free patients by scan result |
|---|---|---|---|
| Normal | 1/206 (0.5%) | 1/24 (4.2%) | 205/206 (99.5%) |
| Abnormal | 23/315 (7.3%) p<0.01 | 23/24 (95.8%) | 292/315 (92.7%) |
Although patients with normal images had a lower cardiac event rate than those with abnormal images, in all patients with abnormal images it was not possible to predict which patient would be likely to have further cardiac events; i.e., such individuals were not distinguishable from other patients with abnormal images.
The findings were not evaluated for defect location, disease duration, specific vessel involvement or intervening management.
In earlier trials, using a template consisting of the anterior wall, inferior-posterior wall and isolated apex, localization in the anterior or inferior-posterior wall in patients with suspected angina or coronary artery disease was shown. Disease localization isolated to the apex has not been established. In adults, Tc99m Sestamibi has not been studied or evaluated in cardiac disorders other than coronary artery disease.
BREAST IMAGING: MIRALUMA® was evaluated in two multicenter, clinical trials of a total of 673 woman patients. Overall the mean age was 52 (range 23 to 87 years). The racial and ethnic representation was 70% Caucasian, 15% African-American, 14% Hispanic and 1% Asian.
Both clinical studies evaluated women who were referred for further evaluation for either: 1) a mammographically detected (with varying degrees of malignant likelihood) but not palpable breast lesion (study A, n=387, mean age = 54 years), or 2) a palpable breast lesion (study B, n=286, mean age = 50 years). In both studies all patients were scheduled for biopsy.
MIRALUMA® (20 - 30 mCi) was injected intravenously in a vein that was contralateral to the breast lesion in question. Planar imaging was completed with a high resolution collimator with a 10% window centered at 140 KeV, and 128 × 128 matrix. An initial marker image, that was not used in the data analysis, was obtained using a cobalt Co57 point source as a marker of a palpable mass. Images were obtained 5 minutes after injection as follows: lateral image of the affected breast for 10 minutes, lateral image of the contralateral breast for 10 minutes, and an anterior image of both breasts for 10 minutes. For the lateral image the patients were positioned in a prone position. For the anterior image, the patients were supine. The MIRALUMA® scintigraphic images were read in a randomized method by two groups of three blinded readers. MIRALUMA® uptake was scored as: normal (no uptake), equivocal, low, moderate, or high uptake. The results of MIRALUMA® images and mammography were analyzed in comparison to histopathologic findings of malignant or non-malignant disease.
As shown in Table 8.0 for the 483 evaluable patients, the sensitivity and specificity of any degree of MIRALUMA® uptake appear to vary with the presence or absence of palpable mass.
| STATISTIC | Study A Non-Palpable Mass and an Abnormal Mammogram | Study B Palpable Mass |
|---|---|---|
| Number of Patients and Lesions | N=277 Patients with 300 Lesions | N=206 Patients with 240 Lesions |
| Sensitivity | 52(42,62) Median and approximated 95% Confidence Interval | 76(67,83) |
| Specificity | 94(89,96) | 85(77,91) |
| PPV PPV= Positive Predict Value; NPV= Negative Predict Value | 79(67,88) | 83(74,89) |
| NPV | 80(74,85) | 78(69,84) |
| Agreement | 80(75,85) | 80(75,85) |
| Prevalence | 32(27,37) | 49(43,56) |
In a separate retrospective subset analyses of 259 patients with dense (heterogeneously/extremely dense) and 275 patients with fatty (almost entirely fat/numerous vague densities) breast tissue, the MIRALUMA® results were similar. Overall, the studies were not designed to compare the performance of MIRALUMA® with the performance of mammography in patients with breast densities or other coexistent breast tissue disorders.
In general the histology seems to correlate with the degree of MIRALUMA® uptake. As shown in Tables 9.0 and 10.0, the majority of the normal MIRALUMA® images are associated with non-malignant tissue (78-81%) and the majority of low, moderate or high uptake MIRALUMA® images are associated with malignant disease (79-83%). In an individual patient, however, the intensity of MIRALUMA® uptake can not be used to confirm the presence or absence of malignancy. Equivocal results do not have a correlation with histology.
| Normal Uptake N = 249 lesions | Equivocal Uptake N = 25 lesions | Low, Moderate or High Uptake N = 66 lesions | |
|---|---|---|---|
| Non-malignant Includes benign tissue, fibroadenoma, benign intramammary nodes, radial scar. | 201 (81%) | 14 (56%) | 14 (21%) |
| Malignant | 48 (19%) | 11 (44%) | 52 (79%) |
| Normal Uptake N = 129 lesions | Equivocal Uptake N = 32 lesions | Low, Moderate or High Uptake N = 115 lesions | |
|---|---|---|---|
| Non-malignant Includes benign tissue, fibroadenoma, benign intramammary nodes, radial scar. | 100 (78%) | 19 (59%) | 20 (17%) |
| Malignant | 29 (22%) | 13 (41%) | 95 (83%) |
An estimate of the likelihood of malignancy based on the MIRALUMA® uptake score in combination with the mammographic score has not been studied.
In these two studies approximately 150 additional, non-biopsied lesions were found to be positive after MIRALUMA® imaging. These lesions were identified in sites that did not physically correlate with identified entry criteria mammographic lesions and these lesions were not palpable. These lesions were not biopsied. Whether these lesions were benign or malignant is not known. MIRALUMA® uptake can occur in both benign and malignant disease. THE CLINICAL USEFULNESS OF A POSITIVE MIRALUMA® IMAGE IN THE ABSENCE OF AN ABNORMAL MAMMOGRAM OR A PALPABLE LESION IS NOT KNOWN.
Lactation: Interruption of breastfeeding after exposure to Technetium Tc99m Sestamibi is not necessary, however, a lactating woman should be advised to consider restricting close contact with her breast fed infant to a maximum of 5 hours in the 24 hour period after Technetium Tc99m Sestamibi administration in order to minimize radiation exposure [see Use in Specific Populations (8.2)].