Scintimammography with technetium-99m methoxyisobutylisonitrile: comparison with mammography and magnetic resonance imaging

The aim of the study was to compare the diagnostic accuracy of scintimammography with technetium-99m methoxyisobutylisonitrile (MIBI; SMM) in the detection of primary breast cancer with that of mammography (MM) and magnetic resonance imaging (MRI). Fifty-six patients with suspected lesions detected by palpation or MM were included in the study. Within the 4 weeks preceding excisional biopsy, MM and MRI were performed in all patients. Between 5 and 10 min after the injection of 740 MBq^99mTc-MIBI, SMM in the prone position was performed. In the total group of 56 patients, 43 lesions were palpable, while 13 were non-palpable but were detected by MM. Breast cancer was confirmed by histopathology in 27 of the patients (22 palpable and 5 non-palpable carcinomas). The tumour size ranged from 6 to 80 mm in diameter. For non-palpable lesions, the sensitivity of SMM, MM and MRI was 60%, 60% and 100%, respectively, while the specificity was 75%, 25% and 50%, respectively. For palpable breast lesions, all methods showed high sensitivity (SMM 91%, MM 95%, MRI 91%) but SMM demonstrated significantly higher specificity (SMM 62%, MM 10%, MRI 15%). In two mammographically negative tumours (dense tissue), SMM showed a positive result. In comparison to MRI, one additional carcinoma could be diagnosed by SMM. It may be concluded that for palpable breast lesions, the diagnostic accuracy of SMM is superior to that of MM and MRI. Through the complementary use of SMM it is possible to increase the sensitivity for the detection of breast cancer and multicentric disease. In patients in whom the status of a palpable breast mass remains unclear, SMM may help to reduce the amount of unnecessary biopsies.     

Scintimammography with technetium-99m methoxyisobutylisonitrile: results of a prospective European multicentre trial

The aim of the trial was to determine the diagnostic accuracy of scintimmammography with technetium-99m methoxyisobutylisonitrile (^99mTc-MIBI) in the detection of primary breast cancer and to verify its clinical usefulness. A total of 246 patients with a suspicious breast mass or positive mammogram were included in this prospective European multicentre trial. At 5 min and 60 min (optional) p.i. two lateral prone images were acquired for 10 min each; 30 min p.i. one anterior image was acquired for 10 min. There were 253 lesions (195 palpable and 58 non-palpable), in respect of which histology revealed 165 cancers and 88 benign lesions. Institutional and blinded read results were correlated to core laboratory histopathology results obtained during excisional biopsy. Diagnostic accuracy for the detection of breast cancer was calculated per lesion. The overall sensitivity and specificity of blinded read scintimammography were 71% and 69%, respectively. For palpable lesions, the sensitivity of blinded read and institutional read scintimammography was 83% and 91%, respectively. Sensitivity was not dependent on the density of the breast tissue. Invasive ductal and invasive lobular cancers showed similar sensitivity. The sensitivity and specificity of mammography were 91% and 42%, respectively, and did not depend on the tumour size. In 60% of false-negative mammograms, ^99mTc-MIBI was able to diagnose malignancy (true-positive). High-quality imaging with ^99mTc-MIBI has a high diagnostic accuracy for the detection of primary breast cancer. Used as a complementary method, scintimammography with ^99mTc-MIBI can help to diagnose breast cancer at an earlier stage in patients with dense breasts. Received 11 October and in revised form 12 December 1997     

Optimization of X-ray mammography and technetium-99m methoxyisobutylisonitrile scintimammography in the diagnosis of non-palpable breast lesions

The purpose of this study was to evaluate the contribution of technetium-99m methoxyisobutylisonitrile (MIBI) scintimammography to the early diagnosis of breast cancer in 78 patients with non-palpable breast lesions detected by mammography. In all cases biopsy was indicated and they were classified into three groups according to the mammographic findings: high (28), intermediate (30) and low (20) mammographic probability of malignancy. Histological diagnosis confirmed 37 benign and 41 malignant lesions. In the high-probability group ^99mTc-MIBI scintimammography changed the four false-positives into true negatives at the expense of two false-negatives; in the intermediate group it changed nine of the 17 false-positives into true-negatives at the expense of one false-negative, and in the low-probability group it changed five of the 16 false-positives into true-negatives without false-negatives. Applying scintimammography to patients included in the intermediate and low-probability groups together, 14 of the 33 mammographic false-positives were changed into true-negatives with 1 false-negative; thus, 41% of the unnecessary biopsies would have been avoided. When MIBI scintimammography was applied to the low-probability group, the negative predictive value was 100% and the unnecessary biopsies would have been reduced by 31%. Received 10 November 1997 and in revised form 19 January 1998     

Detection of axillary lymph node metastases in breast carcinoma by technetium-99m sestamibi breast scintigraphy,ultrasound and conventional mammography

Axillary lymph node status is important in the staging of breast carcinoma. To evaluate the accuracy of technetium-99m sestamibi breast scintigraphy in detecting metastatic axillary lymph nodes as compared with other accepted imaging modalities, we performed^99mTc-sestamibi breast scintigraphy, conventional mammography and ultrasound in 36 patients with primary untreated breast carcinoma. With histopathology as the gold standard,^99mTc-sestamibi breast scintigraphy was found to yield true-positive results in 7 of 11 cases (64%) of axillary lymph node metastases and true-negative results in 18 of 20 cases (90%); it has an accuracy of 81%, a positive predictive value of 77.8% and a negative predictive value of 81.8%.     

Adsorption of technetium-99m tetrofosmin and technetium-99m furifosmin on plastic syringes

Some groups have reported that adsorption of radiopharmaceuticals on disposable plastic syringes can reach levels of almost 50%. This high loss of radioactivity stimulated us to carry out similar studies. Our measurements were done in combination with patient studies. Therefore, we used 2-ml syringes, all of the same brand. The radioactivity in the syringe was measured immediately before and after injection. a total of 500–600 MBq technetium-99m labelled tetrofosmin or technetium-99m furifosmin was administered to 48 patients using four different injection techniques (n = 6 for each technique with each tracer): with needles, 1 min blood incubation at 22°C, 10 or 30 min after preparation of the tracer; with butterflies, 1 min blood incubation at 22°C, 10 or 30 min after preparation of the tracer. Neither in syringes nor in needles or butterflies did more than 7% of the initial radioactivity remain. The entire residual activity in syringe plus needle or syringe plus butterfly together never exceeded the 9% limit. Furthermore, in a pilot study we measured the remaining radioactivity in the vial; here, too, we found no more than 14% of total radioactivity. These findings indicate that total retention of radioactivity during elution and application of ^99mTc-tetrofosmin and ^99mTc-furifosmin with material used in our setting does not approach relevant amounts. Received 6 May and in revised form 19 May 1998     

Technetium-99m tetrofosmin and technetium-99m sestamibi imaging of multiple metastases from differentiated thyroid carcinoma

A 79-year-old male with follicular thyroid carcinoma metastasizing to the lung, bone and lymph nodes was subjected to whole-body scintigraphy using technetium-99m tetrofosmin and^99mTc-sestamibi. Both agents delineated the metastatic lesions and the two image qualities were comparable. We believe that^99mTc-tetrofosmin and^99mTc-sestamibi images may be helpful in localizing metastatic foci and substitute for thallium-201 in the follow-up of patients with differentiated thyroid carcinoma.     

Review of imaging techniques for the diagnosis of breast cancer: a new role of prone scintimammography using technetium-99m sestamibi

Imaging techniques currently used for the diagnosis of breast cancer are reviewed and compared. Besides mammography, magnetic resonance imaging, positron emission tomography, and thallium-201 scintimammography, a new role of technetium-99m sestamibi scintimammography is discussed. It is concluded that while mammography remains the procedure of choice in screening asymptomatic women for breast cancer, other imaging methods play an important role in detecting malignancies in symptomatic patients.^99mTc-sestamibi scintimammography has high sensitivity and improves the specificity of conventional mammography for the detection of breast cancer; with this technique, prone imaging is preferable to supine imaging.^99mTc-sestamibi scintimammography thus deserves further study as a screening technique.     

Comparative myocardial uptake of technetium-99 m sestamibi and technetium-99m tetrofosmin one hour after stress injection

Technetium-99m sestamibi and ^99mTc-tetrofosmin are at present the preferred tracers for simultaneous assessment of myocardial perfusion and function by gated single-photon emission tomography (SPET). The aim of this work was to compare sestamibi and tetrofosmin myocardial uptake 1 h after stress injection. Consecutive unselected patients were studied either with sestamibi or with tetrofosmin on a random basis, until at least 100 patients had been enrolled for each gender and tracer. Stress was obtained by dipyridamole or exercise or combined dipyridamole + exercise; in the latter cases, exercise was sustained for at least 1.5 min after tracer injection. Injected activity was similarly adjusted to body weight. For each patient, imaging began 60–75 min after injection. All SPET projections were summed; due to the acquisition technology (”roving zoom”, i.e. a mobile zoom), the heart always appeared at the centre of the frame in all projections and in the sum image. Thus minimal lung background contamination could be assumed in an elliptic region of interest placed over the heart on the sum image. Three indexes were analysed: total myocardial counts (Sum), mean myocardial pixel (Mean) and maximum myocardial pixel (Max). Four patient groups were analysed: males with sestamibi or tetrofosmin (MS: n = 189 and MT: n = 157), females with sestamibi or tetrofosmin (FS: n = 101 and FT: n = 104). MS and MT groups were comparable for physical variables, maximum heart rate and stress type, as were the FS and FT groups. Sum, Mean and Max were significantly higher with sestamibi (P = 0.0001 by ANOVA). Comparing MS vs MT and FS vs FT, mean values ± SD were as follows: for Sum (kcounts) 750±184 vs 652±166, and 707±202 vs 594±189; for Mean (counts) 4517±1171 vs 4107±898, and 4908±1119 vs 4144±1025; and for Max (counts) 6471±1654 vs 5794±1312, and 7318±1886 vs 6152±1684. The mean gain with sestamibi was +15%, +10% and +12% in males, and +19%, +18% and +19% in females. Similar differences were found within each stress type subgroup. No gender-specific effect was found for Mean, so the overall mean gain was calculated for Mean: +13% for sestamibi vs tetrofosmin. These findings are consistent with other published smaller sample series. Possible differences between tracers with regard to residual activity in syringes were ruled out by an additional experiment. In summary, we found significantly higher myocardial counts with sestamibi than with tetrofosmin, in males as well as in females. Received 10 February and in revised form 27 July 1998     

Parathyroid scintigraphy: comparison of technetium-99m methoxyisobutylisonitrile and technetium-99m tetrofosmin studies

We report the preliminary results of a prospective study demonstrating tetrofosmin uptake in surgically and histologically proven parathyroid adenomas. In ten patients with primary chronic hyperparathyroidism, parathyroid imaging was performed using (1) technetium-99m methoxyisobutylisonitrile (MIBI) and (2)^99mTc-1,2-bis(bis(2-ethoxyethyl)phosphino)ethane (tetrofosmin) within a time interval of 3–5 days. Both tracers correctly identified the parathyroid adenomas by focal prolonged tracer retention. On visual inspection image contrast was generally higher with MIBI than with tetrofosmin in all the patients studied. Tetrofosmin showed a slower elimination from the parathyroid adenomas than MIBI in six of the ten cases. Our preliminary results show that tetrofosmin, like MIBI, as a feasible, sensitive tracer for parathyroid scintigraphy. For routine use, the rapid kit preparation without heating and the lower radiation dose to the patient make tetrofosmin an alternative tracer for parathyroid scintigraphy. Further evaluation is needed to determine which of the two tracers is the more sensitive for the detection of parathyroid adenomas, and which tracer properties better reflect the degree of endocrine activity.[/p]     

Comparison of fluorine-18 fluorodeoxyglucose positron emission tomography and technetium-99m methoxyisobutylisonitrile scintimammography in the detection of breast tumours

The aim of this study was to compare, in breast cancer patients, the diagnostic accuracy of positron emission tomography (PET) using fluorine-18 fluorodeoxyglucose (FDG) and scintimammography (SMM) using technetium-99m methoxyisobutylisonitrile (MIBI). A total of 20 patients (40 breasts with 22 lesions) were evaluated serially with MIBI and, on the following day, with FDG. For SMM, planar and single-photon emission tomography imaging in the prone position was performed starting at 10 min following the injection of MIBI (740 MBq). For PET, scans were acquired 45–60 min after the injection of FDG (370 MBq) and attentuation correction was performed following transmission scans. Results from SMM and PET were subsequently compared with the histopathology results. True-positive results were obtained in 12/13 primary breast cancers (mean diameter=29 mm, range 8–53 mm) with both FDG and MIBI. False-negative results were obtained in two local recurrences (diameter <9 mm) with both FDG and MIBI. In benign disease, FDG and MIBI did not localize three fibrocystic lesions, two fibroadenomas and one inflammatory lesion (true-negative), but both localized one fibroadenoma (false-positive). Collectively, the results demonstrate a sensitivity of 92%, and a specificity of 86%, for primary breast cancer regardless of whether FDG or MIBI was used. In contrast to MIBI scintigraphy, FDG PET scored the axillae correctly as either positive (metastatic disease) or negative (no axillary disease) in all 12 patients. The tumour/non-tumour ratio for MIBI was 1.97 (range 1.43–3.1). The mean standard uptake value (SUV) for FDG uptake was 2.57 (range 0.3–6.2). The diagnostic accuracy of SMM was equivalent to that of FDG PET for the detection of primary breast cancer. For the detection of in situ lymph node metastases of the axilla, FDG seems to be more sensitive than^99mTc-MIBI.     

A head-to-head comparison between technetium-99m-tetrofosmin and technetium-99m-MIBI scintigraphy to evaluate suspicious breast lesions

The aim of this study was to assess the diagnostic value of technetium-99m-tetrofosmin and technetium-99m-MIBI in a head-to-head comparison. Both radiopharmaceuticals are routinely used for detecting breast cancer. In a prospective, open, diagnostic trial, the two radiopharmaceuticals were administered randomly on different days to the same 101 women suffering from 103 breast tumours. Planar images and single photon emission computer tomography (SPET) were performed. After histological examination of the tumours, sensitivity, specificity and positive and negative predictive value were compared. ^99mTc-tetrofosmin and ^99mTc-MIBI showed low sensitivity in planar images (44% vs 46%, respectively). SPET improved sensitivity (70% vs 69%, respectively). Specificity in planar images was 83% and 87%, and it was even lower using SPET (70% vs 78%, respectively). Positive predictive value in planar images was 76% vs 81%, and it was not changed by SPET. Negative predictive value was low in planar images (54% vs 57%, respectively), but it was improved by using SPET (65% vs 67%, respectively). In conclusion, ^99mTc-tetrofosmin and ^99mTc-MIBI scintigraphy show similar diagnostic value in assessing suspicious breast lesions. Received 19 April and in revised form 1 August 1999     

Comparative scanning of thyroid nodules with technetium-99m pertechnetate and technetium-99m methoxyisobutylisonitrile

Thyroid imaging was performed using technetium-99m methoxyisobutylisonitrile and technetium-99m pertechnetate in 58 patients. The ^99mTc-pertechnetate scans showed a total of 77 nodules: 60 cold, 13 hot and 4 of normal activity. There was no ^99mTc-MIBI accumulation in 46.4% of ^99mTc-pertechnetate cold nodules; 27 (45%) of these nodules showed ^99mTc-MIBI uptake with the same intensity as the surrounding normal tissue, and five (8.6%) became hot with ^99mTc-MIBI. Of the ^99mTc-pertechnetate hot nodules 11 (84.6%) could not be differentiated from the normal extranodular tissue on the ^99mTc-MIBI scan. The histopathology of 34 surgically removed nodules proved that increased, normal or decreased ^99mTc-MIBI accumulation is not specific for thyroid malignancy and that the ^99mTc-MIBI uptake depends mainly on the viability of thyroid tissue.Correspondence to: I. Földes     

Predictive value of bone marrow accumulation of Tc-99m tetrofosmin for subsequent development of distant metastases in breast cancer

OBJECTIVE: We evaluated the predictive value of bone marrow accumulation of technetium (Tc)-99m tetrofosmin in patients with breast cancer for distant metastases in comparison with conventional prognostic factors such as clinical stage, tumor size, axillary lymph node (Node) status, and estrogen receptor (ER) status. METHODS: Bone marrow scans with Tc-99m tetrofosmin were performed on 64 patients with breast cancer who had no clinical evidence of distant metastases. Accumulation in the femoral marrow was classified into four patterns, no detectable, lower, higher, and intensively higher. Higher or intensively higher pattern was interpreted as abnormal. Thirty-six patients with abnormal accumulation (marrow-positive group) and 28 patients without abnormal accumulation (marrow-negative group) were enrolled in the follow-up study. The mean length of observation after scans was approximately 3 years. The predictive value of femoral marrow status and conventional prognostic factors for distant metastases was evaluated by statistical analysis. RESULTS: Univariate analysis showed a significantly higher incidence of subsequent bone metastases (36%>4%; P<0.005), and distant metastases (69%>18%; P<0.001) in the marrow-positive group when compared with the marrow-negative group. Conventional prognostic factors except tumor size were also significantly associated with the development of distant metastases; 77% in clinical stage 3>39% in clinical stages 1, 2, P<0.05; 64% in Node-positive>29% in Node-negative, P<0.01; and 70% in ER negative>27% in ER positive, P<0.005. These conventional factors were not significantly associated with bone metastases. The Cox proportional hazard ratio for bone metastases was markedly higher in femoral marrow status (hazard ratio=11.07). The distant metastases-free survival was significantly reduced in ER negative (P<0.0005), Node-positive (P=0.0215), and clinical stage 3 patients (P=0.0163). On the other hand, a more marked difference was observed in the femoral marrow status (P<0.0001). The hazard ratio for distant metastases was 2.44 in clinical stage, 2.74 in tumor size, 2.74 in Node, and 3.68 in ER, which were each independent prognostic factors associated with distant metastases. However, femoral marrow status was markedly associated with distant metastases (hazard ratio=5.27). CONCLUSIONS: Bone marrow accumulation of Tc-99m tetrofosmin can be a promising prognostic factor independent of conventional prognostic factors for predicting development of not only bone metastases but also distant metastases in breast cancer.     

First experiences with technetium-99m furifosmin as tumour-seeking agent in breast cancer and recurrent ovarian cancer

Recent in vitro studies suggest that technetium-99m furifosmin may have tumour-seeking properties. We analysed the diagnostic value of^99mTc-furifosmin scintigraphy in nine patients with documented carcinoma of the breast and in eight patients with continued recurrent ovarian cancer. In the breast,^99mTc-furifosmin failed to visualize the primary malignant tumour and the associated malignant lymph nodes in all patients. In contrast, multiple sites of increased tracer uptake were demonstrated in one patient with acute benign inflammatory breast disease. In four of eight patients with recurrent ovarian cancer,^99mTc-furifosmin scintigraphy demonstrated early (5 min p.i.) localized increased uptake corresponding to adhesions to the bowel as diagnosed by computed tomography, but failed to reveal further abnormalities in all patients. The present study demonstrates that furifosmin is of no value in the imaging of breast cancer and recurrent ovarian cancer. These results do not continue the pattern observed in cell culture studies and are quite in contrast to the findings of mammoscintigraphy using^99mTc-methoxyisobutylisonitrile and^99mTc-tetrofosmin.     

Technetium-99m tetrofosmin imaging in patients with subacute thyroiditis

We studied the significance of technetium-99m tetrofosmin scintigraphy in patients with subacute thyroiditis (SAT). Six patients with SAT, who had painful goitre with thyrotoxicosis, underwent ^99mTc-pertechnetate scintigraphy and ^99mTc-tetrofosmin imaging during the acute and recovery stages of SAT. The thyroid uptake ratio of tetrofosmin was compared with the clinical parameters associated with SAT. ^99mTc-pertechnetate scintigraphy showed markedly reduced uptake in the thyroid during the acute stage of SAT, suggesting that the appropriate metabolic pathway is not functioning. Conversely, ^99mTc-tetrofosmin images showed diffuse increased uptake in the thyroid region on early and delayed imaging. Tetrofosmin images in the acute stage and in the recovery stage of SAT showed different clearance curves for tetrofosmin uptake. The uptake ratio assessed as thyroid uptake/background (T/B) correlated with the serum C-reactive protein concentration. In conclusion, ^99mTc-tetrofosmin uptake may reflect the inflammatory process associated with SAT, and thus this tracer may have potential as a marker of disease activity and severity. Received 20 May and in revised form 10 July 1998     

A comparative study of technetium-99m sestamibi and technetium-99m tetrofosmin single-photon tomography in the detection of nasopharyngeal carcinoma

The intention of this prospective study was to compare the diagnostic potential of technetium-99m sestamibi (MIBI) and a novel radiotracer,^99mTc-Tetrofosmin (Tetro), for the assessment of primary nasopharyngeal carcinoma (NPC) and the differentiation of residual disease from post-therapy changes. A total of 38 patients underwent MIBI and Tetro single-photon emission tomography (SPET) imaging at initial presentation (n=22) or following therapy (n=16). The findings were correlated with computed tomography or magnetic resonance imaging (MRI) on a site-by-site basis. Tumour/background (Tm/Bkg) ratios were obtained on coronal sections. Biopsy (nine patients) and/or 12- to 24-month clinical follow-up data were available in the post-therapy group. All primary disease sites were accurately detected by both imaging studies. Although there was no statistical difference between the two imaging techniques in the detection of primary disease, MIBI was superior to Tetro in the detection of regional lymph node metastases (sensitivity: 95% vs 79%). Tetro and MIBI SPET were true-positive in all patients (n=7) with proven residual/recurrent diseuse. In nine patients who had no evidence of residual/recurrent tumour, MRI was false-positive in five while Tetro and MIBI SPET were false-positive in two and three patients, respectively. Tm/Bkg ratios were 1.7 in all false-positive cases except one. Tetro, MIBI and MRI had specificities of 78%, 67% and 44%, and accuracies of 87.5%, 81% and 69%, respectively. The results of Tetro and of MIBI SPET were rot statistically different from one another with regard to the prediction of residual/recurrent or metastatic NPC.     

Scintimammography with 99mTc-MIBI and magnetic resonance imaging in the evaluation of breast cancer

This study was performed to evaluate the sensitivity and specificity of technetium-99m methoxyisobutylisonitrile (^99mTc-MIBI) scintimammography (SMM) and contrast-enhanced magnetic resonance imaging (MRI) in patients with breast masses, using the histological findings as the gold standard. Forty-five consecutive patients with a breast lesion, detected by self-examination, physical examination or screening mammography, underwent SMM and MRI. In 38 cases (84.5%), the histopathology was malignant; the breast cancers ranged from 3 to 100 mm in diameter (mean 22 mm). In the overall patient group, MRI showed a slightly higher sensitivity than SMM (92% vs 84%), but SMM showed a better specificity: 71% vs 42%. The accuracy was 82% and 84% for SMM and MRI respectively. To evaluate the influence of lesion size on the results, patients with lesions 20 mm and 15 mm were examined. In patients with lesions 20 mm, the sensitivity of SMM and MRI decreased to 64% and 82% respectively, while SMM again displayed considerably better specificity: 83% vs 50% for MRI. The accuracy of SMM and MRI was 64% and 82% respectively. In patients with lesions 15 mm, SMM again showed better specificity (75% vs 50%), while MRI displayed better sensitivity and accuracy (sensitivity, 81% vs 62%; accuracy, 75% vs 65%). In this study the specificity of SMM in patients with breast lesions was thus superior to that of MRI. The combination of SMM and MRI may be used in those patients with equivocal findings at mammography and ultrasound to reduce the number of unnecessary surgical biopsies.     

乳腺肿块~(99m) Tc-MIBI双时相显像与X线钼靶对照研究

目的：探讨~(９９ｍ)ＴＣ－ＭＩＢＩ双时相乳腺显像和乳腺钼靶的联合应用对提高患者术前诊断准确性的价值。材料和方法：对疑为乳腺癌的 ３４名患者术前行钼靶检查和~(９９ｍ)Ｔｃ－ ＭＩＢＩ双时相乳腺显像。乳腺钼靶：双乳分别行轴位（头足位）和侧位摄片。乳腺双时相核素显像采用平面显像行正位、双侧斜位、俯卧位时双侧乳腺侧位。所有病例均于两项检查后两星期内行手术获得病理诊断。结果：~(９９ｍ)Ｔｃ－ ＭＩＢＩ乳腺双时相显像示：乳腺的早期和延迟显像一致。恶性病变早期和延迟相的平均Ｔ／Ｎ值分别为１８０±０．６８、１．６４±０．４２,两者Ｐ＞０．０５。~(９９ｍ)Ｔｃ－ＭＩＢＩ乳腺双时相显像敏感性为８８％,特异性为７６％,准确性为８２％。钼靶检查：良性病变诊断的８例中,一例为恶性病变（浸润性导管癌）;病变性质无法确定的１４例中,６例为恶性病变（浸润性导管癌３例,浸润性腺癌２例,鳞癌１例）;恶性病变诊断的１２例中２例为良性病变。钼靶检查病变性质无法确定的１４例中,乳腺双时相显像诊断正确为１２例。结论：~(９９ｍ) Ｔｃ－ＭＩＢＩ乳腺双时相显像和钼靶检查对乳腺肿块的诊断和鉴别诊断中有各自的特点。在临床实践中合理的诊断程序有助于提高诊断准确率,减少不     

Complexes of technetium-99m with tetrapeptides containing one alanyl and three glycyl moieties

Recently, we have shown that tetrapeptides can be efficiently labelled with technetium-99m by direct labelling at alkaline pH. Tetrapeptides can be considered derivatives of mercaptoacetyltriglycine (MAG3) in which the mercaptoacetyl moiety is replaced by an amino acid residue. In view of the interesting biological properties of some C-methyl substituted derivatives of^99mTc-MAG3, we have now synthesised and evaluated the complexes of^99mTc with tetrapeptides containing three glycyl (G) moieties and oned- orl-alanyl (A) moiety. In mice,^99mTc-l-GAGG,^99mTc-d-GGAG and^99mTc-l-GGAG showed a rapid and high renal excretion, comparable to that of^99mTc-MAG3. Renal handling was somewhat reduced for isomersd andl of^99mTc-AGGG and^99mTc-d-GAGG and markedly inferior for^99mTc-l-GGGA and^99mTc-d-GGGA. In the baboon,^99mTc-l-AGGG,^99mTc-d-AGGG and^99mTc-l-GAGG showed a comparable or even higher 1-h plasma clearance than^99mTc-MAG3.^99mTc-d-GAGG,^99mTc-l-GGAG and^99mTc-d-GGAG were characterised by a lower plasma clearance and the clearance of^99mTc-l-GGGA and^99mTc-d-GGGA was remarkably low. The three^99mTc-labelled tetrapeptides with the highest plasma clearance in a baboon were compared with^99mTc-MAG3 in a human volunteer.^99mTc-l-AGGG and^99mTc-l-GAGG had a roughly similar plasma clearance as^99mTc-MAG3. The clearance of^99mTc-d-AGGG was significantly lower and liver uptake was clearly visible with this compound. Left kidney renograms of^99mTc-l-AGGG and^99mTc-d-AGGG indicated moderate kidney accumulation. On the other hand, the renogram obtained after injection of^99mTc-l-GAGG had an excellent shape and the maximum kidney concentration was slightly higher than for^99mTc-MAG3. These results show the importance of the position of the methyl substituent on the^99mTc-tetrapeptide with respect to its biological behaviour.     

Breast cancer staging using technetium-99m sestamibi and indium-111 pentetreotide single-photon emission tomography

We evaluated the clinical usefulness of single-photon emission tomography (SPET) with technetium-99m sestamibi and indium-111 pentetreotide in breast cancer staging. Fifteen patients with clinical and/or mammographic findings suggesting T1-2N0-1 breast cancer were studied. SPET images were acquired 20 min after^99mTc-sestamibi injection and 4 and 24 h after¹¹¹In-pentetreotide injection. Patients underwent surgery the day after the later¹¹¹In-pentetreotide acquisition. Pathological examination showed 16 tumours in the 15 patients, with one bilateral carcinoma. The mean tumour diameter was 18.7 mm. Metastatic axillary involvement was found in 6/16 tumours, with a mean of five metastatic nodes per axilla. Both tracers correctly identified 15/16 primary tumours and five of the six cases of metastatic axillary node involvement. No difference between the tracers was observed in breast cancer staging.^99mTc-sestamibi seems to be the better tracer in terms of physical characteristics, execution time and cost-effectiveness. Our data suggest the future possibility of using nuclear medicine imaging to avoid axillary dissection in patients with T1 breast cancer.