The role of rhinoscintigraphy in the evaluation of nasal mucociliary clearance function in patients with sinusitis

Nasal mucociliary clearance is one of the homeostatic systems of the respiratory mucosa. Various rhinopathic conditions may involve alterations in nasal mucociliary clearance. The aim of this study was to assess the clinical role of rhinoscintigraphy in the evaluation of nasal mucociliary clearance function of sinusitis patients in comparison with a healthy control group. A single droplet of 99Tcm-labelled macroaggregated albumin (99Tcm-MAA) was deposited on the floor of the nasal meatus about 1 cm behind the mucocutaneous junction, and its course was followed with a gamma camera. The nasal mucociliary clearance was presented as the velocity (mm x min(-1)) of nasal mucociliary transport of the 99Tcm-MAA droplet. A significant difference in nasal mucociliary clearance was observed between the two groups, with a mean of 4.28+/-1.38 mm x min(-1) (4.3+/-1.35 mm x min(-1) in the right nostril, 4.27+/-1.42 mm x min(-1) in the left nostril) for the controls; and 1.8+/-0.64 mm x min(-1) (1.79+/-0.65 mm x min(-1) in the right nostril, 1.82+/-0.63 mm x min(-1) in the left nostril) for the patients with sinusitis. Rhinoscintigraphy is a safe, easy, quick and reliable imaging method for evaluating the ciliary activity of nasal mucosa and the nasal mucociliary clearance function in patients with sinusitis.

Does bowel preparation improve the quality of abdominal gallium scintigraphy?

Physiological accumulation of gallium in the intestine is a major weakness of gallium scintigraphy in evaluating the abdomen. In this study, we used two different cathartics to evaluate the efficacy of bowel cleansing in improving the quality of abdominal gallium imaging. One hundred and fifty patients underwent gallium scintigraphy and were randomly divided into three groups. Group A received no bowel preparation, Group B received 30 ml of castor oil the night before imaging, and Group C received bisacodyl the night before imaging. Gallium activity in the intestine was rated on a three-point scale from 0 to II based on the anterior view of a delayed 48-h gallium image. Our data showed that the incidence of gallium accumulation in the small intestine was low. On the contrary, there was high prevalence of gallium activity in the colon. Forty-eight percent of Group A patients had obvious gallium activity in the colon. The percentage decreased significantly to 28% and 22% in Groups B and C, respectively. No significant difference was noted between Group B and Group C. In conclusion, our data suggest that the application of either castor oil or bisacodyl significantly improves the quality of 48-h abdominal gallium scintigraphy. There were no significant differences in the efficacy of bowel cleansing on gallium activity between these two laxatives.

Histone deacetylase interacts directly with DNA topoisomerase II

Histone deacetylases (HDACs) modify nucleosomal histones, have a key role in the regulation of gene transcription, and may be involved in cell-cycle regulation, differentiation and human cancer. Purified recombinant human HDAC1 protein was used to screen a cDNA expression library, and one of the clones identified encoded DNA topoisomerase II (Topo II), an enzyme known to have a role in transcriptional regulation and chromatin organization. Coimmunoprecipitation experiments indicate that HDAC1 and HDAC2 are associated with Topo II in vivo under normal physiological conditions. Complexes containing Topo II possess HDAC activities, and complexes containing HDAC1 or HDAC2 possess Topo II activities. HDAC and Topo II modify each other's activity in vitro and in vivo. Our results indicate the existence of a functionally coupled complex between these two enzymes and offer insights into the potential mechanisms of action of both enzymes.

Semi-quantitative evaluation of gallium-67 scintigraphy in lupus nephritis

Within nuclear medicine there is a trend towards quantitative analysis. Gallium renal scan has been reported to be useful in monitoring the disease activity of lupus nephritis. However, only visual interpretation using a four-grade scale has been performed in previous studies, and this method is not sensitive enough for follow-up. In this study, we developed a semi-quantitative method for gallium renal scintigraphy to find a potential parameter for the evaluation of lupus nephritis. Forty-eight patients with lupus nephritis underwent renal biopsy to determine World Health Organization classification, activity index (AI) and chronicity index (CI). A delayed 48-h gallium scan was also performed and interpreted by visual and semi-quantitative methods. For semi-quantitative analysis of the gallium uptake in both kidneys, regions of interest (ROIs) were drawn over both kidneys, the right forearm and the adjacent spine. The uptake ratios between these ROIs were calculated and expressed as the "kidney/spine ratio (K/S ratio)" or the "kidney/arm ratio (K/A ratio)". Spearman's rank correlation test and Mann-Whitney U test were used for statistical analysis. Our data showed a good correlation between the semi-quantitative gallium scan and the results of visual interpretation. K/S ratios showed a better correlation with AI than did K/A ratios. Furthermore, the left K/S ratio displayed a better correlation with AI than did the right K/S ratio. In contrast, CI did not correlate well with the results of semi-quantitative gallium scan. In conclusion, semi-quantitative gallium renal scan is easy to perform and shows a good correlation with the results of visual interpretation and renal biopsy. The left K/S ratio from semi-quantitative renal gallium scintigraphy displays the best correlation with AI and is a useful parameter in evaluating the disease activity in lupus nephritis.

Beta-2-microglobulin (beta 2M) as a tumor marker in nasopharyngeal carcinoma

The purpose of this study was to assess the clinical value of serum beta-2-microglobulin (beta 2M) in patients with nasopharyngeal carcinoma (NPC). beta 2M levels were assayed in 145 Taiwanese patients with untreated NPC, including 100 squamous cell carcinomas (SCC) and 45 undifferentiated carcinomas. The 145 NPC patients were separated into different subgroups based on the International Union Against Cancer (UICC) TNM classification system. In addition, 50 healthy subjects without any evidence of malignancy or other systemic diseases were included as controls. The results showed that (1) the mean serum, beta 2M level of the 145 NPC patients was higher than that of the 50 healthy controls and (2) the mean serum beta 2M levels of NPC patients who were male, older, with SCC, with higher TNM stages, and with a shorter survival time were higher than those patients who were female, younger, with undifferentiated carcinomas, with lower TNM stages, and with a longer survival time. However, none of the differences were significant. In addition, the overall detecting sensitivity of beta 2M for NPC was only 24.1%, and the detecting sensitivities in NPC patients who were male, older, with SCC, with higher TNM stages, and with a shorter survival time were higher than those of patients who were female, younger, with undifferentiated carcinomas, with lower TNM stages, and with a longer survival time. However, these differences also were not significant. In conclusion, our results suggest the beta 2M may have limited clinical potential as a valuable tumor marker for NPC.

Tissue polypeptide specific antigen (TPS) as a tumor marker in nasopharyngeal carcinoma

Tissue polypeptide specific antigen (TPS) is a new tumor marker that indicates tumor proliferative rate rather than tumor burden. The purpose of this study is to assess the clinical value of TPS in patients with nasopharyngeal carcinoma (NPC). Serum levels of TPS were measured in 60 patients with untreated NPC including 36 squamous cell carcinomas (SCC) and 24 undifferentiated carcinomas. NPC patients were separated into different subgroups based on the International Union Against Cancer (UICC) TNM classification system. Forty three healthy subjects without any evidence of malignancy or other systemic diseases were included as controls. The results showed that (1) the mean serum TPS level of the NPC patients was significantly higher than that of the healthy controls, (2) the mean serum TPS level of NPC patients with SCC was significantly higher than patients with undifferentiated carcinomas, (3) the mean serum TPS levels of NPC patients with higher TNM stages were significantly higher than those with lower TNM stages, (4) the overall diagnostic sensitivity of TPS for NPC is 58.3%, and (5) the overall diagnostic sensitivities of TPS in NPC patients with undifferentiated carcinomas and higher TNM stages were significantly higher than those with SCC and lower TNM stages. In conclusion, our results suggest that TPS may have a potential clinical role as a valuable tumor marker for NPC.

Technetium-99m methoxy-isobutyl-isonitrile chest single photon emission computed tomography to detect mediastinal lymph node metastasis in patients with non-small cell lung cancer: comparison with computed tomography

This study evaluated the clinical role of Tc-99m-methoxyisobtylisonitrile (Tc-MIBI) single photon emission computed tomography (SPECT) of the chest in the detection of mediastinal lymph node (MLN) metastasis in patients with non-small cell lung cancer (NSCLC). Twenty-five patients with proven NSCLC were enrolled in this study. Each of the patients received computed tomography (CT) of the chest and Tc-MIBI SPECT of the chest for presurgical staging. A postsurgical pathologic diagnosis was made and these patients were evaluated for the study of mediastinal lymph nde (MLN) involvement. Meanwhile, 10 volunteers also accepted Tc-MIBI SPECT of the chest for comparison. The results showed that the diagnostic sensitivity, specificity and accuracy of Tc-MIBI chest SPECT were 81.8%, 85.7% and 84% and for chest CT they are 36.3%, 85.7% and 64%, respectively. Our results indicated that Tc-MIBI chest SPECT was more sensitive and accurate than chest CT in the evaluation and detection of MLN involvement in the NSCLC patients.

The role of technetium-99m methoxyisobutylisonitrile scintimammography in diagnosis of breast cancer in patients with mammographically dense breasts

The purpose of this study was to assess the contribution of techentium-99m methoxyisobutylisonitrile (Tc-99m sestamibi) scintimammography in the diagnosis of breast cancer in 32 female patients with indeterminate mammographic probability of malignancy because of mammographically dense breasts. All the breast masses were removed and histopathological diagnoses were obtained in all cases. The results showed that scintimammography with Tc-99m sestamibi was positive in 21 patients (20 true-positive, 4 false-positive) and negative in 11 patients (7 true-negative, 4 false-negative). The diagnostic sensitivity, specificity and accuracy rates were 83%, 88% and 84%, respectively, in the differentiation of malignant from benign breast masses in the patients with mammographically dense breasts. The detection of malignant breast tumors by Tc-99m sestamibi scintimammography was independent of the density of the breast tissue. In conclusion, Tc-99m sestamibi scintimammography appears to be a useful diagnostic method for the detection of breast cancer in patients with non-diagnostic mammograms because of mammographically dense breasts.

Detection of esophageal carcinoma using single photon emission computed tomography with technetium-99m tetrofosmin

Technetium-99m tetrofosmin (Tc-TF) a thallium-201 (Tl-201) and technetium-99m methoxy-isobutyl-isonitrile (Tc-MIBI) competitor, being used as a new radiopharmaceuticalfor myocardial imaging was assessed to understand its value in detecting esophageal carcinoma (Eso-Ca). Forty patients with Eso-Ca underwent Tc-TF single photon emission computed tomography (SPECT) of the chest. Meanwhile 15 controls also accepted Tc-TF SPECT of the chest for comparison. Among the 40 patients Tc-TF chest SPFCT detected Eso-Ca in 33 (82.5%) but not in 7 (17.5%). In contrast all 15 normal controls (100.0%) had negative Tc-TF chest SPECT Detection sensitivities were higher for tumors located in the middle portion of the esophagus for epidermoid ca and for tumors with poor differentiation when compared with tumors in the upper or lower portion for adenocarcinoma and tumors with moderate differentiation. However, the differences were not significant (p values < 0.05). Significantly higher detection sensitivity was found for tumors of larger size than for tumors of smaller size (p value < 0.05). Our results suggest that Tc-TF chest SPECT is a helpful test for detecting Eso-Ca especially larger tumors.

Acute and chronic effects of isosorbide-5-mononitrate administration on effective renal plasma flow and the renin-aldosterone system in cirrhotic patients

BACKGROUND AND AIMS

Isosorbide-5-mononitrate (ISMO) has been shown to be effective in reducing the risk of variceal bleeding in patients with cirrhosis. However, recent studies have suggested that this drug compromises renal function. The present study was conducted to assess the acute and chronic effects of ISMO on effective renal plasma flow (ERPF) and the renin-aldosterone profile in cirrhotic patients.

METHODS

Fifteen cirrhotic patients were included in the present study. The mean arterial pressure (MAP), heart rate (HR), serum renin concentration (SR), ERPF and plasma aldosterone concentration (PA) were checked before ISMO treatment (baseline study), after a single oral dose of 20 mg ISMO (acute effect study) and after 3 weeks of ISMO treatment (chronic effect study).

RESULTS

Our data showed that the oral administration of a single dose (20 mg) of ISMO to cirrhotic patients was associated with significant decreases in ERPF (from 405.18 to 369.06 mL/min) and MAP (from 93.26 to 86.40 mmHg), and increases in HR (from 65.53 to 70.06 beats/min), SR (from 24.15 to 54.41 pg/mL), and PA (from 105.1 to 148.7 pg/mL). However, no significant changes were observed in HR, MAP, PA, SR, or ERPF after 3 weeks of ISMO treatment when compared with the baseline study.

CONCLUSIONS

The administration of ISMO causes a decrease in ERPF in cirrhotic patients and its use in patients with renal impairment should be considered cautiously.

Transient increase in alveolar epithelial permeability induced by volatile anesthesia with isoflurane

Fifteen patients undergoing surgery and receiving volatile anesthesia with isoflurane were enrolled as the study group. At the same time, 15 patients undergoing surgery with intravenous anesthesia drugs were included as a control group to compare each other. Before surgery, 1 h after surgery, and 1 week after surgery, we investigated these two groups of patients with technetium-99m-labeled diethylene triamine pentaacetic acid radioaerosol inhalation lung scan (DTPA lung scan), a test to evaluate lung ventilation (LV), which was evaluated by the first and equilibrium lung ventilation image and alveolar epithelial permeability (AP) which was evaluated by the half time (T1/2, minutes) of Tc-99m DTPA radioaerosol lung clearance. No significant change and abnormality of LV before surgery, 1 h after surgery, or 1 week after surgery was found in either group of patients. In addition, no significant change in AP before surgery (T1/2 = 64.0 +/- 17.3 min), 1 h after surgery (64.5 +/- 19.6 min), or 1 week after surgery (63.6 +/- 17.6 min) was found among the control group patients (p values > 0.05). However, a significant transient increase in AP was found in the study group 1 h after surgery (71.7 +/- 17.5 versus 51.2 +/- 16.4 min), but it recovered 1 week after surgery (51.2 +/- 16.4 versus 70.9 +/- 16.0 min) (p values < 0.05). We conclude that volatile anesthesia with isoflurane can induce transient increase of AP.

Radionuclide esophageal transit test to detect esophageal disorders in patients with mitral valve prolapse

AIM

The origin of chest discomfort in patients with mitral valve prolapse (MVP) is controversial. Our aim was to prospectively determine the incidence of esophageal disorders in MVP patients with or without chest pain.

METHODS

Twenty-five MVP patients with chest pain (group A) and 25 MVP patients without chest pain (group B) underwent evaluation of esophageal motility. None of the total of 50 MVP patients had significant coronary artery disease on cardiac catheterization. Esophageal motility including esophageal mean transit time (MTT), residual fraction (RF), and retrograde index (RI) was analyzed by the radionuclide esophageal transit test (RETT).

RESULTS

In comparison with 25 age and sex-matched healthy volunteers, the results showed that: (1) 19 patients in group A (76%) had abnormal RETT findings (48% of cases with prolonged MTT, 44% of cases with higher RF, and 60% of cases with higher RI); (2) 3 patients in group B (12%) had abnormal RETT findings (8% of cases with prolonged MTT, 4% of cases with higher RF, and 8% of cases with higher RI). In addition, mean values of MTT, RF, and RI in group A patients were significantly higher than in group B patients and healthy volunteers.

CONCLUSION

We found that the chest pain in some MVP patients may be related to abnormal esophageal motility, based on the evidence from a simple and noninvasive RETT.

Monitoring the effect of anticoagulants on left atrial thrombi in patients with rheumatic heart disease: assessment with 111In-oxine-labelled platelet heart scintigraphy and transoesophageal echocardiography

111In-oxine-labelled platelet heart scintigraphy (In-plt) was used to evaluate the activity of left atrial thrombi detected by transoesophageal echocardiography (TEE) in 16 cases of rheumatic heart disease. The effect of anticoagulants on the therapeutic intervention of these patients was evaluated by In-plt and TEE. In-plt was performed in all patients in serial pre- and post-anticoagulant therapy studies with anterior, 45 degrees left anterior oblique and left lateral views taken daily from the second to sixth day after injection of labelled platelets. After discontinuing anticoagulants for at least 1 week, only nine cases of left atrial thrombi were detected among the 16 cases by initial In-plt. After anticoagulants were again used for at least 3 weeks, all nine positive cases became negative on repeat In-plt. These results suggest that the diagnostic sensitivity of In-plt is lower than that of TEE. However, In-plt is more suitable and useful for evaluating the activity of left atrial thrombi after antithrombotic agent therapy and for monitoring the effect of anticoagulant therapy on left atrial thrombi in patients with rheumatic heart disease.

A simple method for preparing radioactive capsules in colon transit study

Colon transit study is currently performed by delivering technetium-99m or indium-111 labelled activated charcoal to the colon in a methacrylate-coated capsule (coated capsule). However, the coating procedure is complicated and methacrylate has not been approved by the Food and Drug Administration. Therefore, a simpler method is needed for the clinical routine use of colon transit study. In this study, we used a commercial empty enteric capsule and a coated capsule for the measurement of colon transit time. We compared the in vitro stability and in vivo scintigraphy of 99mTc-labelled activated charcoal in the coated capsule and the enteric capsule to evaluate the possibility of clinical usage of the enteric capsule for colon transit time study. Activated charcoal powder was mixed with 49mTc-diethylene triamine pentaacetic acid (DTPA) and vaporized to dryness. The dry 99mTc-DTPA activated charcoal was loaded into the coated capsule and the enteric capsule. In vitro stability study was performed by immersing these capsules in a colourless buffer of variable pH which mimicked the conditions in the stomach and the small bowel. Capsule disruption was determined. Colon transit scintigraphy with 99mTc-DTPA charcoal was performed in five normal volunteers using these two capsules. The in vitro stability of these two types of capsule was similar and the colon transit scintigraphy findings were almost identical. Most capsules dissolved in the ascending colon and very few in the terminal ileum. It is concluded that enteric capsule is a suitable alternative to coated capsule for measurement of colon transit.

Cytokeratin fragment 19 and squamous cell carcinoma antigen for early prediction of recurrence of squamous cell lung carcinoma

Sixty patients with squamous cell carcinoma (SCC) of the lung, including 25 cases with recurrence and 35 cases without recurrence 1 year after operation, were enrolled in this study. The serial serum levels of cytokeratin fragment 19 (CYFRA 21-1) and SCC antigen were measured before operation and 1 week, 1 month, 3 months, 6 months, 9 months, and 12 months after operation for early detection of recurrence. The results revealed that 1) mean serum values of CYFRA 21-1 were significantly higher at early and any times after operation in 25 patients with recurrent SCC when compared with 35 patients without recurrent SCC; and 2) mean serum values of SCC antigen were significantly higher until 9 and 12 months after operation, in 25 patients with recurrent SCC when compared with 35 patients without recurrent SCC. We conclude that CYFRA 21-1 is a better marker than SCC antigen for early prediction of SCC recurrence in the lung.

Expression of mediated P-glycoprotein multidrug resistance related to Tc-99m MIBI scintimammography results

We prospectively studied a total of 24 patients with breast cancer to evaluate the relationship between the degree of accumulation of technetium-99m sestamibi (Tc-99m MIBI) and p-glycoprotein (Pgp) expression in tumor tissues. All 24 patients underwent Tc-99m MIBI scintimammography before surgery or biopsy. Immunohistochemical studies were performed on multiple non-consecutive sections of the same tumor using a Pgp specific monoclonal antibody, JSB-1. Planar images were started 10 min after injection of Tc-99m MIBI. Tumor to background (T/B) ratios calculated from the planar images were correlated with Pgp expression as determined by immunohistochemical studies. The T/B ratios were significantly lower for tumors in eight patients with positive Pgp expression (Group 1) than in 16 patients with negative expression (Group 2) (1.40+/-0.11 and 2.76+/-0.60, P<0. 05). Our data confirmed that Tc-99m MIBI scintimammography is useful for determination of the presence of multidrug resistance due to Pgp expression in patients with breast cancer.

Effects of single dose of 50mg captopril in patients with liver cirrhosis and ascites

BACKGROUND/AIMS

In patients with liver cirrhosis and ascites, the renin angiotensin system is usually activated. Such a correlation supports the hypothesis that activation of the renin-angiotensin system plays an influential role in the pathogenesis of ascites in liver cirrhosis.

METHODOLOGY

In this study, 25 patients with liver cirrhosis and ascites (10 females, 15 males; age: 45-67 years) were enrolled. We evaluated the acute effects of converting enzyme inhibitor (a single dose of 50 mg captopril taken orally) on glomerular filtration rate, effective renal plasma flow, filtration fraction, plasma renin activity, and plasma aldosterone.

RESULTS

Oral intake of a single 50 mg dose of captopril significantly decreased glomerular filtration rate (65 +/- 6 mL/min/1.73 m2 vs. 53 +/- 9 mL/min/1.73 m2), filtration fraction (21.2 +/- 2.7% vs. 15.5 +/- 4.1%), and plasma aldosterone (340 +/- 80 pg/mL vs. 247 +/- 42 pg/mL), but increased plasma renin activity (2.65 +/- 2.19 ng/mL/hr vs. 11.58 +/- 2.70 ng/mL/hr) and effective renal plasma flow (312 +/- 41 mL/min/1.73 vs. 356 +/- 60 mL/min/1.73 m2).

CONCLUSIONS

We suggest that oral intake of a single dose of 50 mg captopril can block the renin-angiotension system, and result in changes in renal hemodynamics and function in cirrhotic patients with ascites.

Technetium-99m tetrofosmin mammoscintigraphy findings related to the expression of P-glycoprotein mediated multidrug resistance

We studied 30 patients with infiltrating ductal breast carcinomas to evaluate the relationship between the degree of accumulation of technetium-99m tetrofosmin (Tc-TETRO) and p-glycoprotein (Pgp) expression in breast tumor tissues. All of the 30 patients underwent Tc-TETRO mammoscintigraphy to calculate breast tumor uptake of Tc-TETRO to background (T/B) ratios before surgery or biopsy. Immunohistochemical analysis was performed to determine Pgp expression in the pathological specimens of the 30 breast tumors. The T/B ratios were significantly lower for tumors in 12 patients with positive Pgp expression (Group A) than for those in 18 patients with negative expression (Group B) (1.20 +/- 0.12 and 1.94 +/- 0.30, p < 0.05). Our results supported the opinion that Tc-TETRO mammoscintigraphy is helpful for determining in vivo the presence of multidrug resistance due to Pgp expression in breast carcinoma patients.

The role of Tc-99m methoxyisobutylisonitrile scintimammography as compared to mammography in evaluating palpable breast masses of Taiwanese women

Eighty-one Taiwanese women (age range 31 to 79 years old) with palpable breast masses detected by mammography and or physical examination underwent technetium-99m methoxyisobutylisonitrile (Tc-99m-MIBI) scintimammography to assess its value in the detection of breast carcinomas and their differentiation from benign breast masses. The results showed that 58 of the 66 cases of breast carcinoma were detected by Tc-99m-MIBI scintimammography. Only 2 our of 15 patients with benign breast lesions had an abnormal scintimammographic finding. The mammography diagnosed 55 of the 66 cases of breast carcinoma, whilst 8 out of 15 patients with benign breast lesions had positive mammographic findings. The diagnostic sensitivity specificity and accuracy of Tc-99m-MIBI scintimammography were 88% 87% and 88%, respectively, whilst these parameters for mammography were 83%, 47% and 77%, respectively, regarding the differentiation of malignant from benign breast masses. We concluded that Tc-99m-MIBI scintimammography significantly improves the sensitivity and specificity for the detection of breast cancer in Taiwanese women with dense and small breasts.

Usefulness of technetium-99m tetrofosmin mammoscintigraphy as compared to mammography for detecting and differentiating palpable breast masses of young Taiwanese women

Sixty young Taiwanese women with palpable breast masses detected by mammography and/or physical examinations underwent technetium-99m tetrofosmin (Tc-TETRO) mammoscintigraphy to assess its value for detecting and differentiating breast masses. The results showed that 42 of the 45 cases of breast carcinoma were detected by Tc-TETRO mammoscintigraphy. Fourteen of the 15 o benign breast lesions were differentiated by Tc-TETRO mammoscintigraphy. The diagnostic sensitivity, specificity, positive predictive value negative predictive value and accuracy of Tc-TETRO mammoscintigraphy were 93% 93% 98% 82% and 93% respectively. Thirty-eight of the 45 cases of breast carcinoma were detected by mammography. Twelve of the 15 of benign breast lesions were differentiated by mammography. The diagnostic sensitivity, specificity, positive predictive value, negative predictive value and accuracy of mammography were 84% 80% 93% 63% and 83% respectively. We concluded that Tc-TETRO mammoscintigraphy when compared to mammography significantly improves the accuracy of detection and differentiation of breast cancer in Taiwanese women.

Comparison and discrepancy of 18F-2-deoxyglucose positron emission tomography and Tc-99m MDP bone scan to detect bone metastases

The purpose of this study was to evaluate the usefulness of positron emission tomography with 18F-2-deoxyglucose (FDG-PET) for the detection of malignant bone metastases, and to compare FDG-PET results with conventional technetium-99m methylene diophosphate (Tc-99m MDP) bone scan findings. Twenty-four patients (10 females, 14 males, ages: 39-71 years) with biopsy-proven malignancy and suspected bone metastases, underwent whole body FDG-PET and bone scan to detect bone metastases. Bone metastases were established in 39 discordant bone lesions by histopathological examination of biopsy samples, MRI/CT, and follow-up bone scan/FDG-PET findings showing progressively and extensively widespread bone lesions. A total of 98 bone lesions found on either FDG-PET or bone scan were evaluated For 39 bone lesions with discordant findings between FDG-PET and bone scan, histopathological examination, MRI/CT and follow-up bone scan/FDG-PET findings revealed 8 metastatic and 0 benign bone lesions with positive FDG-PET findings, not detected on bone scan. Eleven metastatic and 20 benign bone lesions with positive bone scan findings were not detected on FDG-PET. FDG-PET has a better specificity, but a lower sensitivity for detecting malignant bone metastases when compared with bone scan.

Recurrent hyperfunctioning parathyroid gland demonstrated on radionuclide imaging and an intraoperative gamma probe

Radionuclide imaging with Tc-99m MIBI is the preferred mode of parathyroid localization in current practice. It also successfully identifies hyperfunctioning autotransplanted parathyroid tissue. The authors report a case with recurrent hyperparathyroidism after total parathyroidectomy and autotransplantation in the forearm. Double-phase Tc-99m MIBI imaging successfully localized the hyperfunctioning parathyroid tissue, which was missed by magnetic resonance imaging and ultrasonography. In addition, the parathyroid tissue was localized using an intraoperative probe at subsequent surgery.