Double-phase Tc-99m sestamibi scintimammography to assess angiogenesis and P-glycoprotein expression in patients with untreated breast cancer

Evaluation of morphine effect on tumour angiogenesis in mouse breast tumour model, EATC

Breast cancer is the leading cause of death among women, and morphine is used to relieve the pain of patients with cancer. The data on the effects of morphine on tumour growth and angiogenesis are contradictory. We determined in mouse breast cancer model whether analgesic doses of morphine would affect tumour angiogenesis, and then the correlation between microvessel density (MVD), Doppler sonography (DS) and 99mTc-Tetrofosmin (TF) uptake. Ehrlich ascites tumour cell xenografts, Pgp-negative tumour were divided into two groups: (a) Morphine sulphate [0.714 mg/kg/day (equivalent to 50 mg per day for a 70 kg human)], (b) no-morphine. For the determination of angiogenesis in mice tumour tissue, TF scintigraphy, microvessel density and DS were done. MVD was significantly different between groups (49.4±1.8 vs. 41.8±1.9, morphine and no-morphine groups, respectively, P<0.001). A strong correlation was found between late uptakes of mass at scintigraphy and degree of angiogenesis in histopathologic examination (r=0.52, P<0.01). There was statistically significant inverse correlation between degree of angiogenesis in histopathologic examination and washout ratio of TF (r=0.40, P<0.05). The higher values for angiogenesis are related to higher TF reuptake. There was no statistically significant correlation between DS and TF. A strong correlation was found between MVD and grade of DS (r=0.51, P<0.01). Our preclinical mice study indicates that morphine at clinically relevant doses stimulates angiogenesis, and angiogenesis triggered of morphine is demonstrated with MVD and DS, but not TF. However, uptake and washout of TF are compared with immunohistochemically assessed morphine-stimulated angiogenesis in tumour tissue.

Determination and prediction of P-glycoprotein and multidrug-resistance-related protein expression in breast cancer with double-phase technetium-99m sestamibi scintimammography. Visual and quantitative analyses

PURPOSE

To determine and predict P-glycoprotein (Pgp) and multidrug-resistance-related protein (MRP) expression in untreated breast cancer patients by visual and quantitative indices of double-phase (99m)Tc MIBI scintimammography (DSMM).

PATIENTS AND METHODS

Eighty-two patients with untreated breast cancer received DSMM. Pgp and MRP expression was assessed by immunohistochemical (IHC) staining of surgical specimens. Visual and quantitative analyses were compared with the results of IHC to determine and predict Pgp and MRP.

RESULTS

The early and delayed tumor to normal tissue ratio (T/N) of the Pgp-negative and MRP-negative group had significantly higher values than those of the Pgp-positive and MRP-positive group. However, there were no statistically significant differences in washout rate (WR, in %) according to the expression of Pgp and MRP. The optimal T/N ratios were <or =2.23 for early and < or =1.75 for delayed image for Pgp expression and < or =2.45 for early and < or =1.96 for delayed image for MRP expression. The optimal visual grades of DSMM for the determination of Pgp and MRP expression were < or =3. With logistic regression analysis, potent predictors of DSMM were visual assessment for Pgp expression and early T/N for MRP expression.

CONCLUSION

In conclusion, despite a moderate sensitivity and specificity, visual and quantitative indices of DSMM could be used to determine and predict Pgp and MRP expression in untreated breast cancer. However, these findings need confirmation in a larger patient cohort to enable a better validation of Pgp and MRP expression to determine optimal early and delayed T/Ns and to investigate predictors of Pgp and MRP expression in breast cancer.

Correlation between 99mTc-MIBI uptake and angiogenesis in MIBI-positive breast lesions

This study was undertaken to assess the correlation between the degree of accumulation and the washout of 99m technetium methoxyisobutylisonitrile ((99m)Tc-MIBI) and angiogenesis in MIBI-positive breast lesions. Twenty-eight patients (mean age, 51+/-11 years) with 31 breast lesions who underwent scintimammography were studied. Anterior, left and right prone lateral images were obtained 20 min and 3 h after the injection of 740 MBq (99m)Tc-MIBI. All breast lesions showed increased (99m)Tc-MIBI uptake. Early and delayed tumor to background activity ratios (T/BG) and washout index (early tumor uptake-delayed tumor uptake divided by early tumor uptake) were calculated. Vascular endothelium was immunohistochemically labeled using a biotinylated monoclonal antibody directed against the factor-VIII-associated antigen using standard biotin-avidin technique. Angiogenesis was evaluated by assessing the vascular surface density (VSD) and the microvessel number (NVES) within 10 randomly chosen areas. All pathological data were compared with early and delayed T/BG activity ratios and washout index of (99m)Tc-MIBI. Statistical analysis was performed using Spearman correlation test. There was no statistically significant correlation between the degree of angiogenesis and early T/BG (r = .287, P > .05 with VSD, r = .351, P > .05 with NVES), delayed T/BG (r = .277, P > .05 with VSD, r = .315, P > .05 with NVES) and the washout index (r = .268, P > .05 with VSD, r = .285, P > .05 with NVES) of (99m)Tc-MIBI in all breast lesions. There was no statistically significant correlation between the degree of angiogenesis and early T/BG (r = .235, P > .05 with VSD, r = .356, P > .05 with NVES), delayed T/BG (r = .181, P > .05 with VSD, r = .285, P > .05 with NVES) and the washout index (r = .158, P > .05 with VSD, r = .187, P > .05 with NVES) of (99m)Tc-MIBI in 24 invasive breast lesions. No statistically significant correlation was found between the degree of angiogenesis and early T/BG (r = -.036, P > .05 with VSD, r = -.107, P > .05 with NVES), delayed T/BG (r = -.500, P > .05 with VSD, r = -.429, P > .05 with NVES), but there was a high correlation between angiogenesis and the washout index (r = .893, P < .05 with VSD, r = .964, P < .05 with NVES) of (99m)Tc-MIBI in seven noninvasive breast lesions. Amount of (99m)Tc-MIBI uptake in breast lesions is dependent on several factors. Our study indicates that early and delayed (99m)Tc-MIBI uptakes in MIBI-positive breast lesions are not related to angiogenesis in both invasive and noninvasive breast lesions. But washout index of (99m)Tc-MIBI in noninvasive breast lesions is highly correlated with angiogenesis. (99m)Tc-MIBI scintigraphy does not seem to be able to indicate angiogenic property of invasive breast lesions.

Nude mice multi-drug resistance model of orthotopic transplantation of liver neoplasm and Tc-99m MIBI SPECT on p-glycoprotein

AIM: To establish a model of drug-resistant neoplasms using a nude mice model, orthotopic transplantation of liver neoplasm and sporadic abdominal chemotherapy.

METHODS: Hepatocellular carcinoma cells HepG2 were cultured and injected subdermally to form the tumor-supplying mice. The orthotopic drug-resistant tumors were formed by implanting the tumor bits under the envelope of the mice liver and induced by abdominal chemotherapy with Pharmorubicin. Physical examination, ultrasonography, spiral CT and visual inspection were used to examine tumor progression. RT-PCR and immunohistochemistry were used to detect expression of mdr1 mRNA and its encoded protein p-glycoprotein (p-gp). Tc-99m sestamibi scintigraphy was performed by obtaining planar abdominal images at 20 min after injection, and the liver/heart ratios were calculated.

RESULTS: Post-implantation mortality was 0% (0/25), tumor implantation success was 90% (22/25), and the rate of implanting successfully for the second time was 100% (3/3). Tumor induction using Pharmorubicin was 80% (16/20). The mdr1 mRNA expression of the induced group was 23 times higher than that of the control group, and p-gp protein expression was 13-fold higher compared to the control group. The liver/heart ratio (as assessed in vivo, using Tc-99m radiography) was decreased significantly in the induced group as compared to the control group.

CONCLUSION: We have established an in vivo model of mdr1 in nude mice by orthotopic transplantation of liver neoplasm coupled to chemotherapy. We propose that identification of drug resistance as characterized by decreased 99mTc-ppm radiography due to enhanced clearance by p-gp may be useful in detecting in vivo drug resistance, as well as a useful tool in designing more effective therapies.

Optimization of the accuracy of retention and washout measurements of99mTc-Sestamibi from breast tumours using an anthropomorphic phantom

Quantifying the retention or washout of (99m)Tc-Sestamibi (MIBI) in breast tumours in vivo may provide a basis for predicting the chemotherapy response. The aim of this study is to investigate the variations and limitations of the different methods used to quantify these parameters. A phantom was developed that allowed the modelling of MIBI pharmacokinetics in both the breast tumour and normal breast tissue. Washout and retention were calculated from tumour uptake values based on (1) background corrected counts or (2) total counts in the tumour region of interest (ROI), or (3) tumour to background ratios (TBR), or (4) normalized TBR (nTBR). Method 1 was the most accurate method of quantification whilst method 3 was the most inaccurate. The accuracy of method 1 was independent of the times at which images were acquired, but three sources of error are identified involving incorrect background selection, ROI reproducibility and inconsistent temporal separation of images. In conclusion, background subtracted tumour counts should be used in the calculation of MIBI retention or washout. Accurate results are dependent on selecting the appropriate background, drawing consistent ROIs and using reproducible time intervals between images.

Incremental Diagnostic Value of Quantitative Analysis of Double Phase Tc-99m MIBI Scintimammography for the Detection of Primary Breast Cancer Additive to Visual Analysis

Tc-99m MIBI scintimammography (SMM) is known to be a useful diagnostic tool for primary breast cancer. We conducted this study to establish optimal visual grades for the detection of primary breast cancer and to investigate whether the quantitative indices of double phase SMM could provide incremental diagnostic value additive to visual analysis.

METHODS

Five hundred and twenty highly suspected breast cancer patients (malignant: 370; benign: 150) were included in this study. Double phase Tc-99m MIBI SMM (early: 10 min; delayed: 3 h) was performed after injection of 750 MBq of Tc-99m MIBI. For visual analysis, five scoring method was used. The early and delayed lesion to non-lesion ratios (L/N) and retention index (RI) were calculated. Receiver operating characteristic curve (ROC) analyses was performed to determine the optimal visual grade, to calculate cut-off value of quantitative indices for differentiation malignant and benign diseases and to investigate whether the quantitative indices could provide incremental diagnostic value additive to visual analysis. To investigate the incremental diagnostic value of quantitative index in variable tumor size groups, the patients were subdivided into four groups (group A: size <or= 1 cm, group B: 1 cm < size <or= 3 cm, group C: 3 cm < size <or= 5 cm, group D: size > 5 cm).

RESULTS

When over visual grade 3 was used as the cut-off grade for the diagnosis of breast cancer, the sensitivity and specificity were 75.5, 86.4%, respectively. Early L/N of malignant breast disease was significantly higher than that of benign (2.00 +/- 1.88 vs. 0.60 +/- 0.7; p < 0.01). However, delayed L/N and RI had no significant difference between malignant and benign breast diseases. When early L/N of 1.27 was used as the cut-off value, the sensitivity and specificity of SMM were 77.6, 83.3%, respectively. When the early L/N was added to visual grade, the area under curve (AUC) of visual + quantitative analysis (V + Q) was higher than that of visual analysis (V) alone (AUC 0.893 vs. 0.803; p < 0.01). In group A, the AUC of V + Q was higher than that of V alone (0.843 vs. 0.808; p = 0.029). In group B, the AUC of V + Q was also higher (0.913 vs. 0.781; p < 0.01). However, in groups C and D, the AUCs of V + Q and V were not different (0.926 vs. 0.915; p = 0.144: 0.663 vs. 0.570; p = 0.093). For axillary lymph node involvement, the sensitivity, specificity, and of SMM were 66.9, 70.1, and 68%, respectively.

CONCLUSION

From this study, the optimal visual interpretation grades for diagnosis of breast cancer were grades 4 and 5 and cut-off value of early L/N was 1.27. Also, we found that delayed image was not required for breast cancer detection and quantitative index of early L/N provide incremental diagnostic value additive to visual analysis. Especially, when the tumor is small (size <or= 3 cm), the early L/N should be obtained for the diagnosis of breast cancer.

Identification of angiogenesis in primary breast carcinoma according to the image analysis

Tumor angiogenesis may be an independent prognostic factor for breast cancer survival. However, we can get the angiogenic property of the breast cancer only after the removal of breast tissue. To get this information before surgical resection of the tumor, we evaluated 29 breast carcinoma patients with Tc-99m MIBI scintimammography and power Doppler ultrasound (US) with a microbubble contrast agent preoperatively and compare their results with intratumoral microvessel density (IMD) and reverse transcriptase-polymerase chain reaction (RT-PCR) of VEGF mRNA. IMD was well correlated with VEGF121 (r = 0.220, P = 0.024) and VEGF165 (r = 0.419, P = 0.046) mRNA level of the tumor. Power Doppler US grading of the tumor is well correlated with IMD (r = 0.552, P = 0.033). However, early uptake and washout index calculated from Tc-99m MIBI scintimammography showed no correlation with IMD or VEGF mRNA level, while washout index was inversely correlated with power Doppler US grading (r = -0.945, P = 0.001). In conclusion, the preoperative evaluation of breast cancer with power Doppler US with a microbubble contrast agent could predict tumor angiogenesis. Tc-99m MIBI scintimammography needs further study to use it as an image analysis for angiogenesis.

Nuclear medicine imaging for prediction or early assessment of response to chemotherapy in patients suffering from breast carcinoma

Reliable assays that could assess treatment response more rapidly or even predict responsiveness of breast tumours to chemotherapy would be very valuable as they would allow for adjustment of ineffective treatment and discontinuation of ineffective treatment in an early phase. As with effective cancer therapy, changes in tumour physiology, metabolism and proliferation do often precede volumetric changes routinely measured by morphological imaging modalities, for example, radiography and computerized tomography, assessment of these parameters by means of single photon emission computerized tomography (SPECT) or positron emission tomography may provide more sensitive and earlier markers of tumour cell death or growth inhibition. This paper reviews the available literature on the role of SPECT and PET in the measurement and visualisation of breast tumour metabolism (glucose utilization and protein synthesis rate), apoptosis induction and chemotherapy resistance mechanisms as predictors or early markers of tumour response or non-response to chemotherapeutic options in patients suffering from breast carcinoma.

Comparison of the uptake and clearance of Tc-99m MIBI, Tl-201 and Ga-67 in drug-resistant lymphoma cell lines

Tc-99m sestamibi (MIBI) has been used as a tumor-seeking agent. However, its role in detecting lymphomas has not been widely investigated. The aim of the present study was to determine the uptake and clearance characteristics of Tc-99m MIBI in vincristine-resistant lymphoma cell lines. In addition, thallium-201 (Tl-201) and gallium-67 (Ga-67) uptake and clearance characteristics were evaluated for comparison with Tc-99m MIBI. Drug-resistant lymphoma cell lines (monocyte-like, histiocytic lymphoma, human; B-lymphoma cell line, American Burkitt lymphoma, lymphoblastoid, human; Hodgkin's disease, lymphoid, human) were selected by multistep vincristine treatment up to 50 nM. After incubation of the radiotracers, Tc-99m MIBI, Tl-201 and Ga-67, in medium for 0, 10, 20, 30, 60 or 120 min, the uptake and clearance of each radiotracer were measured in the drug-resistant lymphoma cell lines. In addition, P-glycoprotein expression was determined by immunohistochemical study. In a comparison of the three radiotracers, the uptake of Tc-99m MIBI was the greatest in the studied wild-type lymphoma cell lines. Tc-99m MIBI uptake was much lower in drug-resistant tumor cell lines than in non-resistant cell lines. On the other hand, the uptake characteristics of Tl-201 did not differ between drug-resistant and non-resistant cells. Immunohistochemistry analyses of Ab-1 or JSB indicated that tumor cells expressed MDR-1 protein in all three cell lines. Tc-99m MIBI is a good radiotracer for detecting drug resistance in lymphoma cell lines.

Scintigraphic evolution of a breast cancer with Tc-99m MIBI scintimammography

Early detection and prompt treatment of breast cancer are the main tools to decrease mortality rates. Several diagnostic techniques such as mammography, magnetic resonance imaging, and ultrasound are used, but none of these are conclusive. The authors describe a 56-year-old woman who was suspected of having breast cancer on mammography. Tc-99m MIBI scintimammography showed a small mass with elevated radiotracer uptake located near the pectoral muscle of the patient's left breast. The possible tumor was confirmed with fine-needle aspiration biopsy. After the diagnosis was established, the patient did not allow any treatment. Eighteen months later, a second scintimammography was performed, showing a large mammary tumor with a high radiotracer uptake, a new small lesion located in the left upper quadrant, and axillary lymph node involvement. Chemotherapy treatment was instituted and after treatment, Tc-99m MIBI scintimammography was normal. This case report provides further evidence for Tc-99m MIBI scintimammography for the detection of breast cancer as well as to evaluate the response to chemotherapy.

Comparison of Tc-99m sestamibi, serum neuron-specific enolase and lactate dehydrogenase as predictors of response to chemotherapy in small cell lung cancer

Neuron-specific enolase (NSE) and lactate dehydrogenase (LDH) are tumor markers of small cell lung cancer (SCLC) which were reported to predict outcome of patients with SCLC. We previously reported that dipyridamole-modulated Tc-99m sestamibi (dipyridamole-MIBI) single photon emission computed tomography (SPECT) could predict the response to chemotherapy in SCLC patients. The purpose of this study was to compare dipyridamole-MIBI and pretreatment serum levels of NSE and LDH for the prediction of response to chemotherapy in SCLC. Twenty-eight SCLC patients underwent dipyridamole-MIBI SPECT 3 to 7 days before starting chemotherapy (80 mg/m2 etoposide and 80 mg/m2 cisplatin every 3 or 4 weeks for at lease two cycles). Serum levels of NSE and LDH were also measured at the same day of the imaging. Tomographic images before and after 0.84 mg/kg dipyridamole infusion were acquired 1 hour after injection of 370 (10 mCi) and 1,110 (30 mCi) MBq MIBI, respectively. The response to chemotherapy was grouped as specified as complete (CR), partial response (PR), no change (NC), and progressive disease (PD), according to the change in tumor size on chest roentgenography and CT. Patients showing CR and PR were classified as responders, and those who showed NC and PD were considered nonresponders. Among the 28 patients, 15 were responders (2 CR, 13 PR) and 13 were nonresponders (11 NC, 2 PD). The change of tumor-to-normal lung ratio (T:NL) after infusion of dipyridamole was significantly higher in responders as compared with nonresponders (0.38 +/- 0.64 vs. -0.38 +/- 0.50, respectively, p = 0.002). However, pretreatment serum NSE and LDH levels did not correlate with the response to chemotherapy. Increase of T:NL after dipyridamole infusion was a strong negative predictor of chemotherapeutic response in SCLC patients, while NSE and LDH could not predict it.