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C H Kao

Publications and source records attributed to C H Kao.

At least 19 recordsLinked to original sources

Usefulness of thallium-201 muscle scan to investigate perfusion reserve in the lower limbs of patients with systemic lupus erythematusus.

Patients with systemic lupus erythematosus (SLE) may develop premature atherosclerosis, notably peripheral vascular disease presenting with intermittent claudication or gangrene. This study evaluates the usefulness of thallium-201 muscle perfusion scan (Tl-201 muscle scan) for investigating perfusion reserve in the lower limbs of 25 asymptomatic, female SLE patients without peripheral ischemia findings. The patients showed no evidence of peripheral arterial disease in history, physical examination, or Doppler ultrasonography. A control group consisted of 24 healthy, age-matched women. Each subject flexed her right foot maximally both dorsally and plantarly 60 times. In the middle of this exercise, 2 mCi of Tl-201 was injected intravenously. Three minutes after the injection, a posterior image of both calves was obtained using a gamma camera. Rectangular regions of interest were symmetrically drawn over both calves. The total count in the resting calf was subtracted from the total count in the exercising calf, and the percentage of increase, termed the perfusion reserve, was determined. A significant difference was found between the perfusion reserves of the SLE patients and control groups (75.3+/-8.9% and 99.6+/-9.0%, respectively, P <0.05). In conclusion, perfusion reserve in the lower limb muscles of SLE patients may be measured by Tl-201 muscle perfusion scan.

Adult↗

Using 99mTc HMPAO brain SPECT to evaluate the effects of anticoagulant therapy on regional cerebral blood flow in primary antiphospholipid antibody syndrome patients with brain involvement-a preliminary report.

Technetium-99m hexamethylpropylene amine oxime ((99m)Tc HMPAO) brain single photon emission computed tomography (SPECT) was used to evaluate the effects of anticoagulant therapy (ACT) on regional cerebral blood flow (rCBF) in patients with primary antiphospholipid antibody syndrome (PAPS). Sixteen female PAPS patients with neuropsychiatric manifestations and hypoperfusion lesions demonstrated on initial (99m)Tc HMPAO brain SPECT images were enrolled in this study. Follow-up (99m)Tc HMPAO brain SPECT images were performed 1 month after ACT. Meanwhile, serum anticardiolipin antibodies (ACA) were measured before and after ACT. Before ACT, 14 (87.5%) patients had positive ACA. After ACT, all 16 PAPS patients showed decreased serologic findings, and their neuropsychiatric manifestations subsided. After ACT, 11 (68.8%) patients showed complete recovery of regional cerebral blood flow (rCBF) and five (31.2%) patients showed partial recovery in the follow-up (99m)Tc HMPAO brain SPECT images. This type of imaging is a logical and objective tool for measuring the effects of ACT in PAPS patients with brain involvement by determining changes in rCBF.

Adult↗

Usefulness of Tc-99m ECD brain SPECT to evaluate the effects of methylprednisolone pulse therapy in lupus erythematosus with brain involvement: a preliminary report.

Methylprednisolone pulse therapy (MPT) was introduced to avoid life-threatening complications in systemic lupus erythematosus (SLE) with brain manifestations. However, its efficacy in SLE patients remains uncertain and needs to be objectively evaluated. In this study, technetium-99m ethyl cysteinate dimer (Tc-99m ECD) brain single photon emission computed tomography (SPECT) was used to detect regional cerebral blood flow (rCBF) in SLE patients with normal brain magnetic resonance imaging (MRI) findings. Twelve female SLE patients with neuropsychiatric symptoms were enrolled in this study. All patients had normal brain MRI and abnormal Tc-99m ECD brain SPECT findings. The Tc-99m ECD brain SPECT studies were performed 2 weeks after MPT. Pre- and post-MPT serum levels of anticardiolipin antibodies (ACA) and antiribosomal P antibodies (anti-P) were also measured. Before MPT, four patients had positive ACA and seven had positive anti-P. After MPT, all 12 patients demonstrated negative serologic findings and no neuropsychiatric symptoms. After MPT, ten patients showed complete recovery and two showed partial recovery of rCBF in the follow-up Tc-99m ECD brain SPECT images. This imaging is a logical and objective tool for measuring the effects of MPT in SLE patients with brain involvement by the determination of rCBF changes.

Adult↗

Usefulness of technetium-99m methoxyisobutylisonitrile liver single photon emission computed tomography to detect hepatocellular carcinoma.

Technetium-99m methoxyisobutylisonitrile (Tc-99m MIBI) has been shown to be useful in identifying several types of tumors, such as breast, lung and thyroid cancers. The usefulness of Tc-99m MIBI liver imaging in detecting hepatocellular carcinoma (HCC) is still controversial. In this study, 22 patients with HCC performed Tc-99m MIBI liver single photon emission computed tomography (SPECT). Twenty of 22 patients (90.9%) showed negative liver SPECT findings without significant Tc-99m MIBI uptake in HCC, and only 2 patients (9.1%) showed positive liver SPECT findings with significant Tc-99m MIBI uptake in HCC. In addition, no significant correlation between liver SPECT findings with sex, age, alpha feto-protein serum level, HCC differentiation, and virus hepatitis status was found. We concluded that Tc-99m MIBI liver SPECT is not a sensitive tool to detect HCC.

Adult↗

Comparing whole body 18F-2-deoxyglucose positron emission tomography and technetium-99m methylene diphosphate bone scan to detect bone metastases in patients with renal cell carcinomas - a preliminary report.

PURPOSE: Conventional technetium-99m methylene diphosphate whole body bone scan (bone scan) has a high sensitivity but a poor specificity to detect bone metastases. However, positron emission tomography with 18F-2-deoxyglucose (FDG-PET) can offer superior spatial resolution and improved specificity. We have attempted to evaluate the usefulness of FDG-PET for detecting bone metastases in renal cell carcinomas (RCC) and to compare FDG-PET results with bone scan findings. METHODS: Eighteen patients were selected for this study with biopsy-proven RCC. They were suspected of having bone metastases and were undergoing bone scan and FDG-PET to detect bone metastases. The final diagnoses of bone metastases were established by operative, histopathological findings or clinical follow-up longer than 1 year by additional radiographs or following FDG-PET/bone scan findings showing progressive and extensive widespread bone lesions. RESULTS: A total of 52 bone lesions including 40 metastatic and 12 benign bone lesions found on either FDG-PET or bone scan were evaluated. FDG-PET could accurately diagnose all 40 metastatic and 12 benign bone lesions. Bone scan could accurately diagnose only 31 metastatic bone lesions. Diagnostic sensitivity and accuracy of FDG-PET were 100% and 100%, respectively,and bone scan were 77.5% and 59.6%, respectively. CONCLUSIONS: Our data suggest that FDG-PET has a higher sensitivity and a better accuracy than that of bone scan to detect bone metastases in patients with RCC.

Aged↗

Comparing whole body (18)F-2-deoxyglucose positron emission tomography and technetium-99m methylene diphosphonate bone scan to detect bone metastases in patients with breast cancer.

PURPOSE: At present, bone metastases are usually assessed using conventional technetium-99m methylene diphosphonate whole-body bone scan, which has a high sensitivity but a poor specificity. However, positron emission tomography with (18)F-2-deoxyglucose (FDG-PET) can offer superior spatial resolution and improved specificity. We attempted to evaluate the usefulness of FDG-PET for detecting bone metastases in breast cancer and to compare FDG-PET results with bone scan findings. PATIENTS: The study group comprised 48 patients with biopsy-proven breast cancer and suspected of having bone metastases who underwent bone scan and FDG-PET to detect the bone metastases. The final diagnosis of bone metastases was established by operative, histopathological findings or during a clinical follow-up longer than 1 year by additional radiographs or following FDG-PET/bone scan findings showing progressive widespread bone lesions. RESULTS: A total of 127 bone lesions including 105 metastatic and 22 benign bone lesions found by either FDG-PET or bone scan were evaluated. Using FDG-PET, 100 metastatic and 20 benign bone lesions were accurately diagnosed, and using bone scan 98 metastatic and 2 benign bone lesions were accurately diagnosed. The diagnostic sensitivity and accuracy of FDG-PET were 95.2% and 94.5%, and of bone scan were 93.3% and 78.7%, respectively. CONCLUSIONS: Our findings suggest that FDG-PET shows a similar sensitivity and a better accuracy than bone scan for detecting bone metastases in patients with breast cancer.

Adult↗

Detection of recurrent nasopharyngeal carcinomas with positron emission tomography using 18-fluoro-2-deoxyglucose in patients with indeterminate magnetic resonance imaging findings after radiotherapy.

PURPOSE: The aim of this study was to evaluate the effectiveness of positron emission tomography (PET) using 18-fluoro-2-deoxyglucose (FDG) to detect recurrent nasopharyngeal carcinomas (NPC) when magnetic resonance imaging (MRI) findings are indeterminate. PATIENTS AND METHODS: After radiotherapy, 28 NPC patients with indeterminate MRI findings were included. MRI, FDG-PET, and biopsy were performed at least 4 months after radiotherapy and within 1 week. The final results were based on histopathologic findings and a clinical follow-up of at least 6 months. RESULTS: For detecting recurrent NPC in indeterminate MRI findings, the sensitivity, specificity and accuracy of FDG-PET were 100.0%, 92.9% and 96.4%, respectively. CONCLUSIONS: Based on these results, we can recommend FDG-PET for detecting recurrent NPC when MRI findings are indeterminate.

Adult↗

Detection of cervical lymph node metastases in nasopharyngeal carcinomas: comparison between technetium-99m methoxyisobutylisonitrile single photon emission computed tomography and magnetic resonance imaging.

We compared the effectiveness technetium-99m methoxyisobutylisonitrile (Tc-99m MIBI) single photon emission computed tomography (SPECT) and magnetic resonance imaging (MRI) of head and neck in evaluating cervical lymph node (LN) metastasis in nasopharyngeal carcinomas (NPC). Forty NPC patients with cervical LN metastases confirmed histopathologically underwent Te-99m MIBI SPECT and MRI of the head and neck to evaluate cervical LN metastases. For 16 LN lesions with discordant results between Tc-99m MIBI SPECT and MRI, Tc-99m MIBI SPECT could correctly detect 1 metastatic and 10 benign LN lesions as well as MRI could correctly detect 3 metastatic and 2 benign LN lesions. Agreement positive results of Tc-99m MIBI SPECT and MRI could correctly detect all of the remaining 24 metastatic LN lesions. Tc-99m MIBI SPECT has a better specificity but a lower sensitivity for detecting cervical LN metastases in NPC when compared with MRI. The combined use of Tc-99m MIBI SPECT and MRI could increase the accuracy compared with the single use of either Te-99m MIBI SPECT or MRI to detect cervical LN metastases in NPC.

Adult↗

Comparing whole body 18F-2-deoxyglucose positron emission tomography and technetium-99m methylene diophosphate bone scan to detect bone metastases in patients with non-small cell lung cancer.

Despite advances in morphological imaging, some patients with non-small cell lung cancer (NSCLC) are found to have non-resectable disease at surgery or die of recurrence within a year of surgery. At present, metastatic bone involvement is usually assessed using conventional technetium-99m methylene diophosphate (Tc-99m MDP) whole body bone scan (bone scan), which has a high sensitivity but a poor specificity. We have attempted to evaluate the usefulness of whole body positron emission tomography with 18F-2-deoxyglucose (FDG-PET) for the detection of malignant bone metastases of NSCLC, and to compare FDG-PET results with Bone Scan findings. Forty-eight patients with biopsy-proven NSCLC and suspected to have stage IV disease underwent whole body bone scan and FDG-PET to detect bone metastases. The final diagnoses of bone metastases were established by operative, histopathological findings or clinical follow-up longer than 1 year by additional radiographs or following FDG-PET/Tc-99m MDP bone scan findings showing progressively and extensively widespread bone lesions. A total of 138 bone lesions found on either FDG-PET or Tc-99m MDP bone scan were evaluated. Among the 106 metastatic and 32 benign bone lesions, FDG-PET and Tc-99m MDP bone scan could accurately diagnose 99 and 98, as well as 30 and 2 metastatic and benign bone lesions, respectively. Diagnostic sensitivity and accuracy of FDG-PET and Tc-99m MDP bone scan were 93.4% and 92.5%, as well as 93.5% and 72.5%, respectively. In conclusion, our data suggest that FDG-PET with the same sensitivity and a better accuracy than those of Tc-99m MDP bone scan to detect metastatic bone lesions in patients with biopsy-proven NSCLC and suspected to have stage IV disease.

Adult↗

Usefulness of whole body positron emission tomography (PET) with 18F-fluoro-2-deoxyglucose (FDG) to detect recurrent ovarian cancer based on asymptomatically elevated serum levels of tumor marker.

The aim of this study was to evaluate practice usefulness of whole body positron emission tomography (PET) with 18F-fluoro-2-deoxyglucose (FDG) to detect recurrent ovarian cancer based on asymptomatically elevated tumor marker (CA-125) serum levels. Whole-body FDG-PET was performed in 28 patients with suspected recurrent ovarian cancers and asymptomatically increased serum levels of tumor marker (CA-125 antigen) but negative or equivocal other imaging modality results. All of these 28 asymptomatic patients had serum levels of CA-125 antigen >35 U/ml. The final diagnosis of recurrent ovarian cancer was established by operation/biopsy histopathological findings or clinical follow-up longer than 1 year by additional morphologic imaging techniques. Among the 28 patients, the final diagnoses of recurrent ovarian cancers and benign lesions were established in 20 and 8 patients, respectively. FDG-PET accurately diagnosed recurrent ovarian cancers in 19 patients and benign lesions in 7 patients. When asymptomatically elevated serum levels of CA-125 antigen, the diagnostic sensitivity, specificity, and accuracy of FDG-PET to detect recurrent ovarian cancers were 95.0%, 87.5%, and 92.9%, respectively. FDG-PET is a useful technique to detect recurrent ovarian cancers for patients suspected of recurrent ovarian cancers due to asymptomatically elevated serum levels of CA-125 antigen.

Aged↗

Early predicting recurrent cervical cancer with combination of tissue polypeptide specific antigen (TPS) and squamous cell carcinoma antigen (SCC).

The establishment of new tumor marker combinations including strong lead-time effects in detecting recurrent cervical cancer appears to be warranted. This retrospective study includes 50 patients with recurrent squamous cell cervical cancer after operation or radiotherapy. The serial serum levels of the tumor markers tissue polypeptide specific antigen (TPS) and squamous cell carcinoma antigen (SCC) were determined. Cutoff values of 78.5 U/L for TPS and 1.5 microg/L for SCC were selected according to the 95th percentile of serum concentrations measured in healthy control patients. Comparing with other monitoring modalities, SCC and TPS showed lead-time effective in 27 and 30 cases, respectively. This difference was not statistically significant. The combination of SCC and TPS provided lead-time effects in 42 cases. Our data indicate that combination of TPS and SCC is a valuable tool in the early predicting recurrent cervical cancer.

Adult↗

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.

ATP Binding Cassette Transporter, Subfamily B, Mem↗

Predicting chemotherapy response and comparing with P-glycoprotein expression using technetium-99m tetrofosmin scan in untreated malignant lymphomas.

The purposes of this study were to predict the chemotherapy response of untreated malignant lymphomas (ML) using a technetium-99m tetrofosmin (Tc-TF) scan and to compare Tc-TF results with P-glycoprotein (Pgp) expression. Before undergoing chemotherapy, 25 patients with ML were enrolled in this study. Tc-TF scan was performed 10 min after intravenous injection of Tc-TF. Immunohistochemical analyses were performed on multiple sections of ML specimens to evaluate Pgp expression. The chemotherapy response was evaluated in the first 1-2 years after the completion of treatment. The mean tumor-to-background ratio of the 15 patients with good responses (3.23+/-0.56) was significantly higher than that of the ten patients with poor responses (1.18+/-0.11). All of the 15 patients with good responses had positive Tc-TF scan results, but negative Pgp expression. Among the ten patients with poor responses, all had negative Tc-TF scan results, but six had positive Pgp expression and four had negative Pgp expression. Significant differences in the incidences of good and poor responses were found between patients with positive Tc-TF scan results and patients with negative Tc-TF scan results and between patients with positive Pgp expression and patients with negative Pgp expression. No significant differences in the incidences of good and poor responses were found between Hodgkin's disease patients and non-Hodgkin's lymphoma patients, stage I-II patients and III-IV patients, patients aged >40 and patients aged < or =40 years, and patients with and without B symptoms. Compared with other prognostic factors, Tc-TF scan results and Pgp expression more accurately predict the chemotherapy response in patients with ML.

ATP Binding Cassette Transporter, Subfamily B, Mem↗

To predict chemotherapy response using technetium-99m tetrofosmin and compare with p-glycoprotein and multidrug resistance related protein-1 expression in patients with untreated small cell lung cancer.

The aim of this study was to investigate the relationships among technetium-99m tetrofosmin (Tc-TF) accumulation in untreated small cell lung cancer (SCLC), the expression of P-glycoprotein (Pgp) and multidrug resistance related protein-1 (MRP1), and the response to chemotherapy in patients with untreated SCLC. Thirty patients with SCLC were studied with chest scintigraphy 15 to 30 min after intravenous injection of Tc-TF before chemotherapeutic induction. Tc-TF chest scans were interpreted both visually and quantitatively. The response to chemotherapy was evaluated upon completion of chemotherapy. Immunohistochemical analyses were performed on multiple non-consecutive sections of biopsy specimens to detect Pgp and MRP1 expression. Fifteen patients with good response to chemotherapy had a significantly higher incidence (100.0%) of positive Tc-TF chest single photon emission computed tomography (SPECT) findings and negative Pgp or MPR expression than 15 patients with poor response (20%) (P<0.05). The tumor/background (T/B) ratios were 1.8+/-0.3 and 1.2+/-0.3 for patients with good response and poor response, respectively (P<0.05). However, other prognostic factors (performance status, tumor size and stage) were not significantly related to Tc-TF chest scan findings and response to chemotherapy. Tc-TF chest scintigraphy correlated well with Pgp or MRP1 expression and accurately predicted the response to chemotherapy in patients with SCLC.

ATP Binding Cassette Transporter, Subfamily B, Mem↗

Changes in the levels of nitric oxide synthase and protein kinase C gamma following kainic acid receptor activation in the rat spinal cord.

In this study, we evaluated the levels of nitric oxide synthase, both neuronal and induced (nNOS and iNOS, respectively), cyclooxygenase-1 and 2 (COX-1 and COX-2) and protein kinase C gamma (PKCgamma) and correlated these with algogenic behavior following spinal kainic acid (KA) receptor activation in rats. Thirty adult male Sprague-Dawley rats were randomly assigned into six groups (n=5). Groups A, B, and C received 0.5 g kainic acid intrathecally and were analyzed at 3, 6, 24 h after injection, respectively. Groups D, E, and F received saline and were analyzed at 3, 6, 24 h after injection, respectively. We observed for behavioral changes in the rats following intrathecal KA injection and analyzed the protein levels of NOS, COX and PKCgamma by Western blotting techniques. Importantly, we clarified the potential roles of PKCgamma in the regulation of nNOS and COX-2 following intrathecal injection with KA in the rat spinal cord. COX-2 protein was detected but not significantly changed in the lumbosacral spinal cord at 3, 6, and 24 h following intrathecal KA injection (P>0.05). In contrast, nNOS protein was detected at higher levels in comparison with normal spinal cord at 6 and 24 h after intrathecal administration of KA (P<0.05). PKCgamma also increased significantly at 3, 6, and 24 h after intrathecal KA injection when compared with the baseline level (P<0.05). On the other hand, COX-1 and iNOS were not detected in either normal or KA treated spinal cords. These results provide strong in vivo evidence to support the idea that nNOS but not COX-2, plays an important role in spinal KA receptor activation. Furthermore, up-regulation of PKCgamma is involved in KA induced algogenic behavior in rats.

Animals↗

Evaluation of chemotherapy response using technetium-99M-sestamibi scintigraphy in untreated adult malignant lymphomas and comparison with other prognosis factors: a preliminary report.

The purpose of this study was to predict chemotherapy response using technetium-99m methoxyisobutylisonitrile (Tc-MIBI) scintigraphy in untreated adult malignant lymphomas (ML) and compare the response with other prognosis factors. Before chemotherapy, 25 adult patients with ML were enrolled in this study. Tc-MIBI scintigraphy was performed 10 min after intravenous injection of Tc-MIBI to calculate tumor-to-background (T/B) uptake ratio and interpret the results visually. Chemotherapy response was evaluated in the first 1 to 2 years after completion of treatment by clinical and radiological methods. The mean T/B uptake ratio of the 15 patients with good response (3.3 +/- 0.6) was significantly higher than that of the 10 patients with poor response (1.2 +/- 0.1). All of the 15 patients with good response had positive Tc-MIBI scintigraphic results. All of the 10 patients with poor response had negative Tc-MIBI scintigraphic results. However, there were no significant differences in the incidences of good and poor responses for other prognosis factors. In our preliminary study, when compared with other prognosis factors, Tc-MIBI scintigraphy was the best tool to predict chemotherapy response in adult patients with ML.

Adult↗

Comparing 18-fluoro-2-deoxyglucose positron emission tomography with a combination of technetium 99m tetrofosmin single photon emission computed tomography and computed tomography to detect recurrent or persistent nasopharyngeal carcinomas after radiotherapy.

BACKGROUND: The diagnostic accuracy of combined computed tomography (CT) and technetium 99m tetrofosmin (Tc-TF) single photon emission computed tomography (SPECT) of head and neck to differentiate recurrent or residual nasopharyngeal carcinomas (NPCs) from benign lesions after radiotherapy was evaluated and compared with positron emission tomography (PET) with 18-fluoro-2-deoxyglucose (FDG). METHODS: Four months after radiotherapy, 36 patients with NPC underwent Tc-TF SPECT and CT of head and neck to differentiate recurrent or residual NPC from benign lesions. Histopathologic examinations were performed on nasopharyngeal biopsies of all 36 patients. RESULTS: Based on the biopsy results, the sensitivity, specificity, and accuracy of Tc-TF SPECT were 64%, 96%, and 86%, respectively, for differentiation of recurrent or persistent NPC from benign lesions. For CT and FDG-PET, the sensitivity, specificity, and accuracy were 73%, 88%, and 83% and 100%, 96%, 97%, respectively. For the 27 patients with NPC whose Tc-TF SPECT and CT results were congruent, the combination of Tc-TF SPECT and CT had the same sensitivity, specificity, and accuracy (100%, 96%, and 96%) as FDG-PET. For the nine patients with NPC with incongruent Tc-TF SPECT and CT results, FDG-PET correctly differentiated two benign lesions from seven recurrent/residual NPCs. CONCLUSIONS: Although, FDG-PET is the best tool for detecting recurrent or residual NPC, combined congruent Tc-TF SPECT and CT results achieved the same accuracy as FDG-PET. Therefore, we concluded that FDG-PET could be considered only when Tc-TF SPECT and CT give incongruent results.

Adolescent↗

P-Glycoprotein and multidrug resistance-related protein expressions in relation to technetium-99m methoxyisobutylisonitrile scintimammography findings.

The purpose of this study was to retrospectively study 48 patients with infiltrating ductal breast cancer to evaluate the relationship between the degree of accumulation of technetium-99m methoxyisobutylisonitrile (Tc-MIBI) and P-glycoprotein (Pgp) or multidrug resistance-related protein (MRP) expression in breast cancer tissues. Before surgery or biopsy, all 48 patients underwent scintimammography started 10 min after the injection of Tc-MIBI. Tumor:background (T:B) ratios were calculated from the Tc-MIBI scintimammography. Immunohistochemical analysis was performed on the pathological specimens of the 48 breast tumors to determine Pgp and MRP expression. According to the results of immunohistochemical analysis, the 48 breast cancers were separated into four groups: (a) group 1, 12 cancers with both positive Pgp expression and positive MRP expression; (b) group 2, 12 cancers with positive Pgp expression and negative MRP expression; (c) group 3, 12 cancers with negative Pgp expression and positive MRP expression; and (d) group 4, 12 cancers with both negative Pgp expression and negative MRP expression. Among the four groups, the T:B ratio was lowest in group 1 (1.13+/-0.10) and highest in group 4 (2.17+/-0.14), respectively (P < 0.05). The T:B ratios of groups 2 (1.30+/-0.25) and 3 (1.32+/-0.26) were between those of groups 1 and 4. Our data confirmed that Tc-MIBI scintimammography is useful for determining Pgp and MRP expression in patients with breast cancers.

ATP Binding Cassette Transporter, Subfamily B, Mem↗