The use of thallium-201 in the preoperative detection of breast cancer: an adjunct to mammography and ultrasonography

Generalizable EHR-R-REDCap pipeline for a national multi-institutional rare tumor patient registry

Objective

To develop a clinical informatics pipeline designed to capture large-scale structured Electronic Health Record (EHR) data for a national patient registry.

Materials and Methods

The EHR-R-REDCap pipeline is implemented using R statistical software to remap and import structured EHR data into the Research Electronic Data Capture (REDCap)-based multi-institutional Merkel Cell Carcinoma (MCC) Patient Registry using an adaptable data dictionary.

Results

Clinical laboratory data were extracted from EPIC Clarity across several participating institutions. Laboratory values (Labs) were transformed, remapped, and imported into the MCC registry using the EHR labs abstraction (eLAB) pipeline. Forty-nine clinical tests encompassing 482 450 results were imported into the registry for 1109 enrolled MCC patients. Data-quality assessment revealed highly accurate, valid labs. Univariate modeling was performed for labs at baseline on overall survival (N = 176) using this clinical informatics pipeline.

Conclusion

We demonstrate feasibility of the facile eLAB workflow. EHR data are successfully transformed and bulk-loaded/imported into a REDCap-based national registry to execute real-world data analysis and interoperability.

Healthcare data collected during routine clinical care in patient electronic health records (EHRs) can be curated and organized into disease-focused registries. For example, the Merkel Cell Carcinoma Patient Registry is a multi-institutional national database that utilizes real-world health care data to inform best practices, improve patient outcomes, and test hypotheses that require large data samples. However, many challenges arise when capturing patient-level details/data from the health records especially when this data must be aggregated across multiple institutions. Here, we describe a pipeline that (1)pulls large-scale data from the EHRs, (2)wrangles and remaps the data in a format appropriate for the database using R statistical software, and (3)imports the data in bulk for thousands of patients at a time into Research Electronic Data Capture (REDCap), the electronic data capture system that houses the data. The EHR-R-REDCap pipeline can be utilized to capture many patient data features from the participating institutions. Here, we demonstrate eLAB, the EHR-R-REDCap pipeline utilized by our Merkel Cell Carcinoma Patient Registry to capture thousands of laboratory values from the EHR for thousands of patients. We provide source code, examples, and instructions for adaptability for other clinical research projects that aim to collect large-scale laboratory data from the EHR.

Safety and biodistribution of 111In-amatuximab in patients with mesothelin expressing cancers using single photon emission computed tomography-computed tomography (SPECT-CT) imaging

Amatuximab is a chimeric high-affinity monoclonal IgG1/k antibody targeting mesothelin that is being developed for treatment of mesothelin-expressing cancers. Considering the ongoing clinical development of amatuximab in these cancers, our objective was to characterize the biodistribution, and dosimetry of ¹¹¹Indium (¹¹¹In) radiolabelled amatuximab in mesothelin-expressing cancers. Between October 2011 and February 2013, six patients including four with malignant mesothelioma and two with pancreatic adenocarcinoma underwent Single Photon Emission Computed Tomography-Computed Tomography (SPECT/CT) imaging following administration of ¹¹¹In amatuximab. SPECT/CT images were obtained at 2–4 hours, 24–48 hours and 96–168 hours after radiotracer injection. In all patients, tumor to background ratios (TBR) consistently met or exceeded an uptake of 1.2 (range 1.2–62.0) which is considered the minimum TBR that can be visualized. TBRs were higher in tumors of patients with mesothelioma than pancreatic adenocarcinoma. ¹¹¹In-amatuximab uptake was noted in both primary tumors and metastatic sites. The radiotracer dose was generally well-tolerated and demonstrated physiologic uptake in the heart, liver, kidneys and spleen. This is the first study to show tumor localization of an anti-mesothelin antibody in humans. Our results show that ¹¹¹In-amatuximab was well tolerated with a favorable dosimetry profile. It localizes to mesothelin expressing cancers with a higher uptake in mesothelioma than pancreatic cancer.

Characterization of follicular thyroid nodules at fine needle aspiration biopsy using double phase thallium-201 imaging: comparison of visual and semiquantitative analyses

OBJECTIVE

To compare visual and semiquantitative indices of double phase thallium-201 thyroid scintigraphy (DTS) for differentiation of malignant nodules by indeterminate fine needle aspiration biopsy (FNAB) results.

DESIGN

DTS (early; 15 minutes; delayed, 2 hour) were performed after injection of 37MBq of thallium-201 in 60 patients with indeterminate FNAB.

MAIN OUTCOME

With grade 4 and 5, sensitivity and specificity were 51.4% and 78.3%, respectively. With early lesion to nonlesion ratio (L/N) 1.49, sensitivity and specificity were 97.3% and 39.1%, respectively. With delayed L/N 1.89, sensitivity and specificity were 70.3% and 78.3%, respectively. With wash-out rate (WR) 18.93%, sensitivity and specificity were 89.2% and 82.6%. Early L/N was superior to delayed L/N and WR for the detection of malignant thyroid nodules.

CONCLUSION

Visual assessment had a limited value for differentiation of follicular nodules. The optimal semiquantitative indices were 1.49 for early L/N and 1.89 for delayed L/N. Also, optimal WR was 18.93%. The early L/N was superior to delayed L/N and WR for the detection of malignant thyroid nodular lesions. However, visual assessment and early L/N of DTS showed similar results. Visual analysis and semiquantitative indices of DTS could not differentiate follicular carcinoma and follicular variant of papillary thyroid cancer.

A meta-analysis of scintimammography: an evidence-based approach to its clinical utility

BACKGROUND

Scintimammography using (99m)Tc-labelled isonitriles, sestamibi and tetrofosmin, has become a mature technique in the adjunctive setting for the diagnosis of primary breast cancer. To establish an evidence base for its use, clinically, a meta-analysis was performed on both single-site and multi-centre trials performed since January 1997.

METHODS

Using an on-line literature search all such trials containing 100 or more studies were identified. To prevent double counting of patients only the last published report from any centre was used.

RESULTS

A total of 2424 patients were identified in the single-site trial group, the smallest study having 105 patients and the largest 353 patients. The overall sensitivity was 85% and the specificity was 84%. In the multi-centre trial studies, published data from 3049 patients were included. The overall sensitivity in this group was also 85% and the specificity was 83%.

CONCLUSION

There is evidence that this is a robust imaging technique delivering high sensitivities and specificities in patients studied in both single-centre and multi-centre trials and, as such, can be relied on as an adjunctive method for the investigation of primary breast cancer.

Nuclear medicine and breast cancer: a review of current strategies and novel therapies

While breast cancer is still increasing in frequency, new diagnostic procedures are now available to challenge existing procedures and to make diagnosis of breast cancer more accurate and reliable. Mammography remains the standard investigation to reveal disease in an asymptomatic population: it can also be used to diagnose breast cancer in symptomatic patients (e.g. those with palpable breast lumps) and for guiding fine needle aspiration (FNA). Because the majority of breast lumps are benign, the challenge is to distinguish benign from malignant lesions without the use of invasive methods and this has attracted nuclear medicine physicians and medical oncologists to investigate the role of scintigraphic procedures to identify which patients require FNA. This review attempts to shed light on the various scintigraphic methods available which are of potential practical use in the assessment of malignant breast disease as well as looking at the possible role of nuclear medicine in the treatment of advanced disease.

Usefulness of thallium-201 SPECT scintimammography to differentiate benign from malignant breast masses in mammographically dense breasts

The purpose of this study was to assess the usefulness of thallium-201 (Tl-201) single-photon emission-computed tomography (SPECT) scintimammography to differentiate benign from malignant breast masses in 32 female Taiwanese patients with indeterminate mammographic probability of malignancy because of mammographically dense breasts. All breast masses were removed, and final histopathological diagnoses were obtained in all cases. The results showed that thallium-201 SPECT scintimammography findings were true-positive in 22 cases, false-positive in 1 case, true-negative in 7 cases, and false-negative in 2 cases. The diagnostic sensitivity, specificity, and accuracy were 91.7%, 87.5%, and 90.6%, respectively, for detecting breast cancer in mammographically dense breasts. In conclusion, thallium-201 SPECT scintimammography is a useful tool for differentiating benign from malignant breast masses in patients with indeterminate mammograms because of mammographically dense breasts.

Breast cancer diagnosis by scintimammography: a meta-analysis and review of the literature

Scintimammography is a relatively new, non-invasive diagnostic modality in the evaluation of breast cancer. The purpose of the current study was to review the existing literature on the accuracy of scintimammography in the diagnosis of breast cancer. A search of all articles published between 1st January 1967 and 31st December 1999 was conducted. A total of 64 unique studies were selected. Each scientific paper was reviewed for scientific merit by an epidemiologist, a surgeon and a surgical resident. Assessment of scientific merit was based on a scoring scheme developed for the study. The articles included in this review reported data on a total of 5340 patients assessed for breast cancer with scintimammography. The aggregated summary estimates on these patients were sensitivity: 85.2% and specificity: 86.6%. For patients with a palpable mass the sensitivity and specificity were 87.8 and 87.5%, respectively. For patients without a palpable mass the sensitivity was 66.8% and that for specificity was 86.9%. The results of this review have shown that scintimammography may be used effectively as an adjunct to mammography and physical examination in the diagnosis of breast cancer.

Nuclear medicine in primary breast cancer imaging

The application of nuclear medicine techniques to study patients with breast cancer has recently raised its profile, particularly in the investigation 'indeterminate mammographic lesions'. This review briefly points out some of the difficulties encountered with other more conventional imaging modalities and describes the radionuclide techniques most frequently employed in the investigation of those patients with breast cancer. Both planar and single photon emission tomography methods are discussed including the use of monoclonal antibodies, perfusion ligands, receptor binding hormones and other specific radiotracers, non-specific tumour markers, as well as deoxyglucose and other amino acids labelled with positron emitting radionuclides.

99m-Tc-tetrofosmin scintigraphy for the evaluation of suspicious palpable and non-palpable breast lesions

PURPOSE

To assess the value of 99m-Tc-tetrofosmin (tetrofosmin) scintigraphy in patients with palpable and nonpalpable breast lesions.

PATIENTS AND METHODS

Prospective, blinded trial. One hundred and fifty-nine consecutive patients with 163 breast lesions detected by clinical examination and mammography were included. Tetrofosmin scintigraphy of the breast was performed additionally to the regular diagnostic procedure. Using histologic assessment as the golden standard, sensitivity, specificity, positive and negative predictive value for tetrofosmin scintigraphy of the breast were assessed.

RESULTS

Overall sensitivity and specificity were 82% and 84%. The sensitivity for palpable tumors (65%) was 93% compared to 62% for non-palpable breast lesions. Malignant lesions were nearly twice as big as benign lesions (31.5 mm +/- 2.4 vs. 16.9 mm +/- 2.4). Specificity, positive and negative predictive value (84%, 89%, and 66%) did not differ significantly in palpable versus non-palpable tumors. Of malignant tumors 18% were found false negative by tetrofosmin scintigraphy.

CONCLUSION

The results suggest that tetrofosmin scintigraphy is a valuable tool for the evaluation of palpable breast cancer. In patients with non-palpable tumors, tetrofosmin scintigraphy may not add to the work-up of patients with breast cancer due to a low sensitivity rate.

Somatostatin receptor in breast cancer and axillary nodes: study with scintigraphy, histopathology and receptor autoradiography

We conducted a prospective analysis of somatostatin receptor scintigraphy using (111)In radiolabeled pentetreotide, a somatostatin analog, in patients with breast cancer in the aim to visualize the primary tumor and axillary or parasternal metastatic extension because some malignant breast tumors express somatostatin receptors (SS-R) in 50%, approximately. An analysis of SS-R was performed by autoradiography.

PATIENTS AND METHODS

Thirteen patients with clinically suspected breast tumors (T1, T2), and at least one palpable axillary node (N1) were included. In vivo planar scintigrams were acquired 1, 4, and 24 h after subcutaneous, then after intravenous injections (24 h delay between injections). Improved (111)In-pentetreotide uptake in invaded nodes after subcutaneous injection was hypothesized. Ex vivo scintigrams of surgical specimens were also acquired immediately after tumor resection and axillary dissection. Pathological examination and receptor autoradiography were performed on all surgical specimens.

RESULTS

Among 11 pathologically proven malignant tumors (9 ductal and 2 lobular carcinomas), only four were scintigraphically visible although six expressed SS-R receptors in vitro. Among six pathologically proven malignant nodes, four expressed SS-R, including two visualized scintigraphically. Scintigrams acquired after subcutaneous injections were less sensitive than after intravenous injections. There were no false positive. False negatives occurred in cases with small tumors with low-density or heterogeneously distributed SS-R. There was no significant difference by histological type or prognostic factors.

CONCLUSION

Somatostatin receptor scintigraphy does not appear to be sensitive enough to evaluate axillary node extension of breast cancer or even to confirm the presence of tumoral tissue, and this whatever the administration route for (111)In-pentetreotide.

Delayed Tc-99m citrate scintigraphy in the evaluation of palpable breast masses

The aim of this study was to evaluate the potential of Tc-99m citrate as a new tumor-localizing agent in palpable breast masses. Scintimammography was performed in 43 female patients. Of these, 10 women (group A) were considered to be healthy with no palpable breast masses, and the remaining 33 patients (group B) had palpable breast masses. All patients with palpable breast masses underwent fine-needle aspiration cytology and subsequent biopsy within 2 weeks of the study. Nine patients had a primary malignant lesion of the breast, whereas 24 patients had benign disease. The patients with breast cancer underwent surgery, and subsequently a histopathologic diagnosis was made. Sensitivity, specificity, and accuracy values obtained in our study were 87%, 100%, and 90%, respectively. Scintimammograms were performed in these patients up to 24 hours. Initial uptake at 1 and 3 hours was noted in all the breast masses. However, benign masses did not show persistence of tracer uptake at 24 hours, whereas those that were malignant continued to show persistent radionuclide concentration. Thus, the uptake and outflow pattern seemed to differentiate benign breast disease from breast cancer. The study shows the potential of Tc-99m citrate for imaging and evaluating breast masses.

Detection of malignant breast tumours in dense breast tissue: results of 99mTc-tetrofosmin scintimammography related to surgery

AIMS

To assess the contribution of 99mTechnetium tetrofosmin (99mTc-TF) scintimammography for staging of breast lesions in patients with a suspicious or non-diagnostic mammogram to reduce unnecessary surgical procedures in future.

METHODS

Fifty patients with suspicious physical examinations and/or mammography underwent 99mTc-TF breast imaging.

RESULTS

Scintimammography with 99mTc-TF was positive in 37 patients (36 true positive, one false positive) and negative in 13 patients (12 true negative, one false negative). The detection of a malignant tumour by 99mTc-TF was independent of the density of the breast tissue. In 33 patients with a malignant breast tumour 99mTc-TF was diagnostic with respect to axillary status, but in four out of 19 patients with a histologically positive axillary lymph node status, tumour involvement remained undetected by scintigraphy. Moreover, in four patients, scintimammography revealed an additional discrete area of increased 99mTc-TF uptake, which proved to be second primary breast cancers.

CONCLUSIONS

99mTc-TF scintimammography appears to be an accurate diagnostic test in patients with a symptomatic breast lesion and a non-diagnostic mammogram, also in those patients with dense breast tissue. This procedure may also have potential for the detection of second primary breast cancers in an early stage.

The role of 99mTc-sestamibi and other conventional radiopharmaceuticals in breast cancer diagnosis

The wide availability and the extensive use of screening mammography have resulted in an earlier diagnosis of breast cancer and in a significant reduction in the relative risk of dying from this disease. Despite technical improvements and major advantages associated with the use of mammography (and breast ultrasound), this procedure has some limitations in clinical practice, especially in women with dense breast tissue, implants, severe dysplastic disease, or significant architectural distortion following breast surgery or radiation therapy. Different noninvasive imaging techniques have been evaluated to overcome these limitations. Nuclear medicine also has been actively involved in the detection of breast cancer, using various types of radiopharmaceuticals. Currently, there are three radiotracers commonly used for breast imaging or scintimammography in either clinical practice or research: 99mTc-sestamibi and 99mTc-tetrofosmin (two agents used for myocardial perfusion imaging) and 99mTc-MDP (methylene diphosphonate, used for bone scintigraphy). 99mTc-sestamibi was the first radiopharmaceutical to be approved by the FDA for scintimammography. Several prospective studies have shown that the overall sensitivity of 99mTc-sestamibi scintimammography in detection of breast cancer was 85%, the specificity was 89%, and the positive and negative predictive values were 89% and 84% respectively. Similar numbers have been demonstrated for 99mTc-tetrofosmin and 99mTc-MDP scintimammography. Although not indicated as a screening procedure for the detection of breast cancer, scintimammography may play a useful and significant role in various specific clinical indications such as nondiagnostic or difficult mammography, and evaluation of high-risk patients, tumor response to chemotherapy, and axillary lymph node metastatic involvement.

Gamma emission imaging in the management of breast disorders

Breast cancer is the commonest malignancy to affect women. The malignant process may present clinicians with problems in establishing the diagnosis expeditiously, accurately staging the disease and assessing tumour response to primary systemic chemotherapy. Considerable recent interest has focused on the application of imaging techniques that utilize tumour-specific gamma-ray-emitting radiopharmaceuticals to resolve these problems. The wide availability of gamma camera systems makes single photon-imaging techniques, using radiopharmaceuticals incorporating conventional isotopes, attractive options. However, results concerning the detection of the primary breast cancer and the staging of axillary lymph nodes suggest that these techniques would appear to offer no significant advantages, when compared with those obtained using standard diagnostic methods. Dual gamma-ray-emission imaging by positron emission tomography (PET) may offer an alternative solution. Studies performed show that PET can accurately detect primary breast cancers, stage locoregional lymph nodes and visualize distant tumour metastases. Furthermore, PET may be able to monitor early tumour response to chemotherapy agents. It would appear, therefore, that dual gamma emission might have an important role to play in the management of patients with breast cancer.

Dynamic imaging: scintimammography

Although mammography remains the technique of choice for the early detection of breast cancer, new emerging breast imaging techniques such as ultrasound, magnetic resonance and radionuclide scanning have been investigated and included in many diagnostic protocols. This overview discusses the current problems related to radionuclide breast imaging trying to define its role in the management of women with suspicious breast lesions at mammography. A number of tumor-imaging agents have been recently used for the differential diagnosis of malignant and benign lesions in radiographically dense breasts and breasts with architectural distortions from prior biopsy or surgery or following radiation therapy. 99mTc-MIBI is the most used tracer which has become the paradigm of this new class of compounds suitable for breast imaging. The current sensitivity and specificity rates for breast scintigraphy with 99mTc-MIBI depend on a number of factors including lesion size and site. Sensitivity and specificity rates and positive and negative predictive values of 92, 89, 81 and 96%, respectively, have been reported in a large series of patients with palpable breast lesions, which figures have been confirmed in many other series. On the contrary, lower sensitivity has been reported for nonpalpable breast abnormalities or for lesions smaller than 1 cm. This observation, confirmed by many authors, implies that a new nonpalpable lesion that is suspicious for malignancy at mammography needs a histologic diagnosis. We also report the results of our recent studies on functional imaging with 99mTc-MIBI of the multidrug resistance phenotype in breast cancer patients. These studies followed an observation that this tracer is a suitable transport substrate for the P-glycoprotein (P-gp) which is commonly associated with the development of a multidrug resistance phenotype. We examined 30 patients with histologically confirmed breast carcinoma who had received no previous chemotherapy or preoperative local irradiation. We found a positive and significant correlation between the efflux rates of 99mTc-MIBI determined by in vivo kinetic analysis and the P-gp levels measured in vitro by quantitative autoradiography in the same tumors (r = 0.62; p < 0.001). More recently, we tested whether tumor clearance of 99mTc-MIBI can predict the response to neoadjuvant chemotherapy in patients with locally advanced breast cancer. Thirty-nine patients with stage III disease underwent 99mTc-MIBI scanning before neoadjuvant chemotherapy and the time to half-clearance of the tracer was calculated. The patients then received epirubicin and underwent mastectomy after completing chemotherapy. This study showed that a rapid tumor clearance of 99mTc-MIBI (< or = 204 min) can predict the lack of tumor response to neoadjuvant chemotherapy with drugs affected by multidrug resistance phenotype in advanced breast carcinoma patients. However, slower tracer clearance (> or = 204 min) did not guarantee an objective tumor response to chemotherapy in all patients, in agreement with the existence of several P-gp-independent mechanisms of drug resistance. We conclude that the preliminary study of this phenotype would allow to predict the response to (neo)adjuvant chemotherapy and select the appropriate treatment regimen for each patient. Finally, radionuclide breast scanning may be helpful in the differential diagnosis of malignant and benign breast lesions as a guide to subsequent chemotherapy.

Comparison of indium-111 octreotide and thallium-201 scintigraphy in patients mammographically suspected of having breast cancer: preliminary results

Indium-111 octreotide and thallium-201 scintigraphic studies were compared in 21 patients (16 with palpable and five with non-palpable lesions) suspected of having breast malignancies on the basis of mammography. Early (15 min) and late (3 h) 201Tl (111 MBq) and 4-h and 24-h 111In-octreotide (111-148 MBq) static planar anterior images (matrix 256 x 256) were obtained on separate days. Images were evaluated both visually and quantitatively. Biopsy was performed following the imaging studies. Histopathology revealed 17 breast carcinomas (15 cases of invasive ductal carcinoma, one mucinous adenocarcinoma and one intraductal carcinoma) and four benign breast lesions (two fibroadenomas, one abscess and one case of fat necrosis). The means histopathological tumour size (mean largest diameter) was 3.38 +/- 1.9 cm. 111In-octreotide detected 16 of the 17 breast cancers (94%) while 201Tl detected 13 of them (76%). Both 111In-octreotide and 201Tl missed one non-palpable carcinoma showing only an isolated cluster of microcalcifications on mammography. The smallest tumour size detected by both agents 1.5 x 1.5 cm. Of the four benign lesions, only the breast abscess revealed both 201Tl and 111In-octreotide uptake. 111In-octreotide scan also showed tracer uptake in five of the six patients with histologically proven axillary metastases, while four of these six patients showed 201Tl uptake. The tumour/background (T/B) ratios of late 111In-octreotide and 201Tl images were 1.71 +/- 0.38 and 1.46 +/- 0.30 respectively (P = 0.039). In this preliminary study, 111In-octreotide yielded more favourable results than 201Tl in the detection of breast carcinomas. However, the diagnostic efficacy of 111In-octreotide imaging needs to be investigated in larger patient series.

Tl-201 scintigraphy, mammography and ultrasonography in the evaluation of palpable and nonpalpable breast lesions: a correlative study

PURPOSE

To determine the feasibility of Tl-201 as a tumor localizing agent in palpable and nonpalpable breast lesions, in comparison with mammography and ultrasonography (US), and to evaluate the contribution of these modalities to each other in obviating biopsy.

MATERIALS AND METHODS

Seventy-two palpable and nonpalpable breast lesions were prospectively classified as benign, indeterminate, or malignant according to the sonographic and mammographic criteria and were further analyzed with Tl-201 scanning. These classifications were compared with biopsy results. The sensitivity, specificity, accuracy, false positive and false negative rates (FPR, FNR), negative and positive predictive values (npv, ppv) were calculated for each individual modality and combination of modalities to evaluate the contribution of these three techniques to each other.

RESULTS

Of 72 lesions 52 were histologically malignant and 20 were benign. Overall, mammography was the most sensitive (92%) and Tl-201 was the most specific (75%) of the three modalities. Mammography + Tl combination was the most specific (90%) and accurate (97%) of dual combinations. In mammographically or sonographically indeterminate cases, Tl-201 was much more specific (75% versus 37% for mammography and US) and more accurate (82% versus 36% for mammography and 54% for US) than the other two modalities, and mammography + Tl combination was significantly superior to other dual combinations (87% specific and 91% accurate). Use of Tl-201 scanning as an adjunct to mammography + US combination increased the specificity, ppv, and accuracy rates overall, particularly in mammographically or sonographically indeterminate cases.

CONCLUSIONS

In mammographically and sonographically indeterminate breast lesions thallium scanning may be offered as a third step of investigation to obviate biopsy.

Scintigraphic imaging of breast tumors

Technetium-99m-sestamibi scintigraphy has recently emerged as a new procedure for the imaging of malignant breast tumors. A large clinical experience has now been collected and this article reviews the main published results. The major drawback of the procedure appears to be its low sensitivity in detecting lesions smaller than 1 cm. The biological background underlying the tracer accumulation is also described. The stimulating potent applications of this functional imaging technique to non-invasively explore the development, and possibly the reversal, of a multidrug resistance under chemotherapy are discussed. The data related to the use of the positron emitter fluor-18-labeled fluorodeoxyglucose (FDG), a very promising agent for imaging breast as well as other solid tumors, are also reviewed. This situation of specific agents, still under development and such as labeled receptor ligands, is examined.

Scintimammography with technetium-99m tetrofosmin in the diagnosis of breast cancer and lymph node metastases

The aim of the study was to evaluate the possible role of scintimammography (SMM) with technetium-99m tetrofosmin in breast cancer. Thirty-three patients with breast disease and ten normal controls were included in the study. Planar scintigraphic images in supine anterior, prone lateral and lateral views, with the patient lying in lateral recumbency, were acquired. A qualitative analysis evaluating both breasts and lymph nodes was performed. All breast lesions were verified after surgery and/or by fine-needle aspiration. In 8 of the 33 patients, mammography was inconclusive because of mastectomy or dense breasts. For mammography, a sensitivity of 95.6%, a specificity of 66.7% and an accuracy of 89.6% were obtained. At SMM, 26 out of 28 malignant lesions (average size 2.8 cm, range 0. 4-12 cm), including two recurrences, were detected with a 92.8% sensitivity, a 100% specificity and a 95.1% accuracy. The smallest detectable carcinoma measured 0.6 cm. Two false-negative results on SMM were found in a 0.4-cm intraductal carcinoma and in the only mucinous papillary carcinoma in our series. With regard to lymph node analysis, 11 out of 12 axillary metastases (sensitivity=91.6%) were detected. A false-positive result, yielding a specificity of 92. 3% was also obtained. A metastatic involvement of the internal mammary chain was observed. No uptake was seen in 11 benign mammary lesions or at the level of the breast and axilla when neoplastic involvement was absent. In conclusion, SMM with 99mTc-tetrofosmin is an effective technique for the evaluation of primary breast carcinomas, recurrences and lymph node metastases.

Primary breast cancer imaging with technetium-99m sestamibi and its relation with P-glycoprotein overexpression

The aim of this preliminary study was to evaluate retrospectively sestamibi scintigraphy in relation to the presence of the 170-kDa P-glycoprotein (Pgp), which represents an expression of multidrug resistance in patients with primary breast cancer. Fifteen women (age range 37-76 years) were referred for technetium-99m sestamibi scintigraphy because of suspicious breast lesions detected by mammography and ultrasonography, and subsequently assessed by fine-needle aspiration. Scintigraphy was performed 30 min following the injection of 500 MBq 99mTc-sestamibi. Three planar anterior and oblique images were obtained with the patient in the supine position. Excised tumours were assessed for cytosolic CA 15.3, oestrogen (OR) and progesterone (PR) receptors and c-erb B2 neu oncogene. Pathology revealed that only 13 of the 15 patients had malignant tumours. The two benign tumours were sestamibi-negative and Pgp-positive. Sestamibi scintigraphy was positive in 10 of the 13 malignant lesions (including nine of ten infiltrating ductal carcinomas). Two of the three lesions with false-negative scintigraphy were Pgp-negative; in one of these cases histology revealed an invasive lobular carcinoma and in the other, mucinous adenocarcinoma. The third false-negative lesion was a Pgp-positive infiltrating ductal carcinoma which was c-erb B2 neu-negative but CA 15.3-, OR- and PR-positive. This preliminary study confirms that the resistance to chemotherapy which may occur in patients with primary breast cancer can be a cause of negative sestamibi scintigraphy.