Differentiation of radiographically indeterminate solitary pulmonary nodules with

BACKGROUND

The purpose of this preliminary study was to evaluate the efficacy of positron emission tomography (PET) with [18F]fluoro-2-deoxyglucose (FDG) for differentiating benign from malignant solitary pulmonary nodules.

METHODS

Twenty-six patients (12 females, 14 males, age 27-79 years) with radiographically indeterminate solitary pulmonary nodules underwent FDG-PET and the findings were compared with the results of pathological examination of biopsy samples. FDG activity in the lesion was expressed as the ratio of lesion-to-background counts (L/B ratio) for semiquantitative analysis.

RESULTS

The mean L/B ratio of malignant lesions (8.81+/-3.71, n = 20) was not significantly higher than that of benign lesions (4.71+/-3.00, n = 6) (p = 1.00). Using a cut-off L/B ratio of 5.0 for malignancy, FDG-PET correctly detected 19 true positive and three true negative cases, but failed to detect three false positive (two abscesses and one cryptococcus) cases and one false negative (adenocarcinoma) case. The sensitivity, specificity, accuracy, positive predictive value and negative predictive value were 95, 50, 86, 75 and 85%, respectively.

CONCLUSIONS

FDG-PET is a sensitive modality for detecting malignancy, but is not specific enough. Benign lung lesion with active inflammation could demonstrate high FDG uptake, making it difficult to differentiate from malignancy. In the future, we will increase the case numbers to evaluate further the utility of FDG-PET for differentiating radiographically indeterminate solitary pulmonary nodules.

Paclitaxel-Based chemotherapy for non-small cell lung cancer: predicting the response with 99mTc-tetrofosmin chest imaging

The purpose of this study was to retrospectively predict the chemotherapeutic response to paclitaxel for non-small cell lung cancer (NSCLC) using 99mTc-tetrofosmin (TF) uptake and to detect the expression of 170-kDa multidrug resistance-mediated P-glycoprotein (MDR-Pgp).

METHODS

Before chemotherapy with paclitaxel, 20 patients with stage IIIb or IV NSCLC were enrolled in this study to undergo early and delayed 99mTc-TF chest imaging for calculating tumor-to-normal lung ratios (T/NL) and retention indices (RI) for assessment of the MDR-Pgp in NSCLC.

RESULTS

The early and delayed mean T/NLs were 1.59 +/- 0.25 and 1.50 +/- 0.25, respectively, for 10 patients with a good response and 1.09 +/- 0.09 and 1.03 +/- 0.05, respectively, for 10 patients with a poor response. The differences were shown to be significant (P < 0.001) by independent Student t tests. However, no significant differences (P = 0.801) between good-response patients (-5.70% +/- 3.67%) and poor-response patients (-5.23% +/- 4.51%) were found in RI. In addition, other prognostic factors (age, sex, tumor size, stage, and cell type) were not significantly different between good-response patients and poor-response patients.

CONCLUSION

99mTc-TF chest images are potential tools for understanding MDR-Pgp expression in NSCLC and for predicting the chemotherapeutic response to paclitaxel.

Technetium-99m-tetrofosmin scintigraphy in the prediction of chemotherapy response of untreated malignant lymphomas and comparison with other prognostic factors

The aim of this study was to retrospectively predict the chemotherapy response of untreated malignant lymphomas using technetium-99m tetrofosmin (Tc-TF) scintigraphy and to compare the technique with other prognostic factors. In this study, before any chemotherapy, 25 patients with malignant lymphomas (ML) underwent Tc-TF scintigraphy. Scintigraphy was performed 10 minutes after intravenous injection of 20 mCi Tc-TF to calculate the tumor-to-normal (T/N) uptake ratio. In the first 1-2 years after complete chemotherapy, the response was evaluated by clinical and radiological methods. Compared with the 10 ML patients with poor chemotherapy response, the 15 ML patients with good response had a significantly higher mean T/N uptake ratio (3.23 +/- 0.56) versus 1.18 +/- 0.11). All of the 15 patients with good response had positive scintigraphic results whilst the 10 patients with poor response had negative scintigraphic results. When compared with other prognostic factors, Tc-TF scintigraphy was the tool to predict the chemotherapy response of ML patients.

Detection of cervical lymph node metastases of nasopharyngeal carcinomas with technetium-99m tetrofosmin single photon emission computed tomography and comparison with computed tomography

The purpose of this study was to evaluate the usefulness of technetium-99m tetrofosmin (Tc-99m TF) single photon emission computed tomography (SPECT) in the detection of cervical lymph node (LN) metastasis in nasopharyngeal carcinomas (NPC), and to compare Tc-99m TF SPECT results with computed tomography (CT) findings. Fifty patients with biopsy-proven NPC and suspected cervical LN metastases underwent head and neck Tc-99m TF SPECT and CT to detect cervical LN metastases. Cervical LN metastases of 40 patients were confirmed by histopathological examination of biopsy samples. For 22 LN lesions with discordant results between Tc-99m TF SPECT and CT, Tc-99m TF SPECT could correctly detect 4 metastatic and 7 benign LN lesions while CT could correctly detect 5 metastatic and 6 benign LN lesions. Agreement positive results of Tc-99m TF SPECT and CT could correctly detect all of the 18 metastatic LN lesions. Tc-99m TF SPECT has a better specificity but a lower sensitivity for detecting cervical LN metastases in NPC when compared with CT. The combined use of Tc-99m TF SPECT and CT could significantly increase the accuracy of detect cervical LN metastases in NPC compared with the single use of either Tc-99m TF SPECT or CT.

Tissue polypeptide-specific antigen and carcinoembryonic antigen for early prediction of recurrence in lung adenocarcinoma

Fifty patients with lung adenocarcinoma, including 20 cases with recurrence and 30 cases without recurrence 1 year after operation, were enrolled in this study. The serial serum levels of tissue polypeptide-specific antigen (TPS) and carcinoembryonic antigen (CEA) were measured before operation and at 1 week, and at 1, 3, 6, 9, and 12 months after operation for early detection of recurrence. The results revealed that: 1) mean serum values of TPS were significantly higher at 1, 3, 6, 9, and 12 months after operation in 20 patients with recurrent adenocarcinoma, when compared with 30 patients without recurrent adenocarcinoma; 2) mean serum values of CEA were significantly higher at 9 months and 12 months after operation in 20 patients with recurrent adenocarcinoma, when compared with 30 patients without recurrent adenocarcinoma. We conclude that TPS is a better marker than CEA for early prediction of adenocarcinoma recurrence in lung within 1 year after operation. However, a longer follow-up study should be encouraged.

Detection of esophagitis by 99mTc-methoxyisobutylisonitrile chest SPECT

Esophagitis is a common complication of gastroesophageal reflux disease (GERD). Unfortunately, an accurate diagnosis of esophagitis usually requires invasive endoscopy. The purpose of our study was to evaluate the use of noninvasive 99mTc-methoxyisobutylisonitrile (MIBI) chest SPECT to detect esophagitis in GERD patients.

METHODS

Forty GERD patients who underwent endoscopy for diagnosis and grading of esophagitis according to the Savary-Miller grading system were included in this study. 99mTc-MIBI chest SPECT was performed on all patients to detect and grade esophagitis.

RESULTS

On the basis of the endoscopic findings, the sensitivity, specificity, and accuracy of 99mTc-MIBI chest SPECT to detect esophagitis were 100%, 77%, and 95%, respectively. The correlation between the Savary-Miller grading system and 99mTc-MIBI chest SPECT grading was found to be good.

CONCLUSION

Noninvasive 99mTc-MIBI chest SPECT has excellent sensitivity and good accuracy as a screen for esophagitis.

Decreased salivary function in patients with end-stage renal disease requiring hemodialysis

It has been speculated that impaired salivary flow is common in patients with end-stage renal disease (ESRD) requiring hemodialysis (HD). The aim of this study is to investigate the relation between oral manifestations and salivary function in patients with ESRD undergoing HD. Salivary function was measured by quantitative salivary scintigraphy in 60 patients with ESRD undergoing HD, as well as in 36 age- and sex-matched healthy controls for comparison. The 60 patients with ESRD undergoing HD were separated into two subgroups: group 1, 30 patients with oral manifestations, and group 2, 30 patients without oral manifestations. After an intravenous injection of 5 mCi of technetium 99m pertechnetate, sequential images at 1 minute per frame were acquired for 30 minutes. The 1- and 15-minute uptake ratios were calculated as the tracer uptakes in the four major salivary glands over the background regions of interest. Saliva excretion was stimulated by one 200-mg tablet of ascorbic acid administered orally 15 minutes post-tracer injection, then the maximal excretion ratios of the four major salivary glands were calculated. Our results show significantly poorer salivary function in patients with ESRD with oral manifestations compared with patients with ESRD without oral manifestations and healthy controls by means of objective and quantitative salivary scintigraphy.

Comparison of 18-fluoro-2-deoxyglucose positron emission tomography and computed tomography in detection of cervical lymph node metastases of nasopharyngeal carcinoma

Neck lymph nodes (LNs) from 18 patients with nasopharyngeal carcinoma (NPC) were evaluated with 18-fluoro-2-deoxyglucose positron emission tomography (FDG-PET). Eighteen NPC patients underwent head and neck FDG-PET and computed tomography (CT) for detection of suspected neck LN metastases. For final diagnosis, biopsies were taken from neck LNs with discordant findings between FDG-PET and CT. Meanwhile, standard uptake values (SUVs) of the FDG-PET images were calculated to differentiate metastatic LNs from benign LNs. A total of 90 neck LNs found on either FDG-PET or CT were evaluated. In addition to 27 concordant positive results and 42 concordant negative LN results, biopsy findings revealed 11 metastatic LNs that were detected by FDG-PET but not by CT. However, the SUVs of the 11 metastatic LNs and 7 benign LNs were not significantly different. The CT scanning showed positive findings for I metastatic LN with negative FDG-PET findings. In addition, the tumor stage was upgraded in 5 patients on the basis of FDG-PET findings. In comparison with CT, FDG-PET has a higher potential for detecting neck LN metastases of NPC and assessing NPC tumor stage.

Genomic organization and the promoter region of the round-spotted pufferfish (Tetraodon fluviatilis) CDC37 gene

The CDC37 gene was isolated from a round-spotted pufferfish genomic library and characterized. This gene is composed of nine exons spanning 3.5 kb. Exon 1 contains the 5'-untranslated region and exon 2 contains the putative translation initiation site. By 5'-RACE (rapid amplication of cDNA ends) and sequence analysis, we deduced the promoter region for the CDC37 gene and found that it does not contain typical TATA or CCAAT box. The 1.8 kb DNA fragment upstream of the putative transcription initiation site contains numerous potential binding sites for transcription factors including CREB, E2A, Ets-1, GATA, NF-IL6 and PEA3. When this DNA fragment was placed upstream of the chloramphenicol acetyltransferase (CAT) reporter gene and transfected into a carp CF cell line, it could drive the synthesis of CAT enzyme four times more efficiently than the promoterless pCAT-Basic did. In addition, the CDC37 gene is linked to the TYK2 gene in a tail-to-head manner with a small intergenic region of 292 bp.

Effects of 90Y-microspheres on liver tumors: comparison of intratumoral injection method and intra-arterial injection method

Internal radiation therapy using intrahepatic arterial injection of 90Y-labeled glass microspheres (90Y-microspheres) has proven to be a promising therapeutic modality for inoperative liver tumor. Recently, direct intratumoral injection of 90Y-microspheres has been performed with even more encouraging results. The purpose of this study was to compare the treatment efficacy of these 2 methods using 90Y-microspheres.

METHODS

Forty-eight male rats, each bearing a hepatic tumor, were divided into 4 groups (12 rats in each group) to evaluate the efficacy of treatment. Group 1 received an intratumoral injection of 37 MBq (1 mCi) 90Y-microspheres. Group 2 received an intratumoral injection of 0.1 mL normal saline as the control group. Group 3 received an intra-arterial injection of 37 MBq (1 mCi) 90Y-microspheres. Group 4 received an intra-arterial injection of 0.1 mL normal saline as the control group. Tumor size was measured by liver sonography before injection as well as at 2 and 4 wk after injection. Survival time was calculated from the day of treatment to 2 mo after treatment by Kaplan-Meier survival analysis. The response rate was evaluated by the change in tumor size and survival time. Fisher's exact, 2-tailed test was used to compare response rates.

RESULTS

In the rats treated by intratumoral injection of 90-Y-microspheres, 83.3% (10/12) showed a good response. In contrast, all 12 rats in the control group showed a poor response. The difference was significant (P < 0.00001). Eighty-three percent (10/12) of the rats survived >60 d after intratumoral injection of 90Y-microspheres, whereas only 25% (3/12) of the control rats survived >60 d. The difference was significant (P = 0.0068). In the rats treated by intra-arterial injection of 90Y-microspheres, 58.3% (7/12) showed a good response to the treatment. All rats in the control group showed a poor response. The difference was significant (P = 0.0023). Sixty-six percent (8/12) of the rats survived >60 d after intra-arterial injection of 90Y-microspheres, whereas only 16.7% (2/12) of the control rats survived >60 d. The difference was significant (P = 0.0385). However, the response rate and survival time between the intratumoral treatment group and the intra-arterial treatment group showed no significant difference (P = 0.3707 and 0.3988, respectively).

CONCLUSION

Both methods (intratumoral treatment and intraarterial treatment) showed a significantly good response rate and prolonged survival time compared with those of the control groups. However, no significant difference was found in the response rate or survival time between intratumoral treatment and intra-arterial treatment.

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.