Intra- and postoperative low-dose ketamine for adolescent idiopathic scoliosis surgery: a randomized controlled trial.

BACKGROUND: In this randomized controlled trial, we examined whether intra- and postoperative infusion of low-dose ketamine decreased postoperative morphine requirement and morphine-related adverse effects as nausea and vomiting after scoliosis surgery. METHODS: After IRB approval and informed consent, 36 patients, aged 10-19 years, undergoing posterior correction surgery for adolescent idiopathic scoliosis, were randomly allocated into two groups: intra- and postoperative ketamine infusion at a rate of 2 µg/kg/min until 48 h after surgery (ketamine group, n = 17) or infusion of an equal volume of saline (placebo group, n = 19). All patients were administered total intravenous anesthesia with propofol and remifentanil during surgery and intravenous morphine using a patient-controlled analgesia device after surgery. The primary outcome was cumulative morphine consumption in the initial 48 h after surgery. Pain scores (Numerical Rating Scale, NRS, 0-10), sedation scales, incidence of postoperative nausea and vomiting (PONV), and antiemetic consumption were recorded by nurses blinded to the study protocol for 48 h after surgery. RESULTS: Patient characteristics did not differ between the two groups. Cumulative morphine consumption for 48 h after surgery was significantly lower in the ketamine group compared to the placebo group (0.89 ± 0.08 mg/kg vs. 1.16 ± 0.07 mg/kg, 95% confidence interval for difference between the means, 0.03-0.48 mg/kg, P = 0.019). NRS pain, sedation scales, and incidence of PONV did not differ between the two groups. Antiemetic consumption was significantly smaller in ketamine group. CONCLUSIONS: Intra- and postoperative infusion of low-dose ketamine reduced cumulative morphine consumption and antiemetic requirement for 48 h after surgery.

Superiority of radioisotope over blue dye for sentinel lymph node detection in breast cancer.

BACKGROUND: Sentinel lymph node biopsy (SLNB) is commonly performed using radioisotopes and/or blue dye. However, it is still undefined which reagent is more suitable for identifying sentinel lymph nodes (SLN). PATIENTS AND METHODS: A consecutive series of 640 breast cancer patients who had undergone SLNB at the Keio University Hospital from 2001 to 2006 was analyzed. The SLN was identified by a combination of technetium-99m tin colloid and isosulfan blue dye. The correlation between clinicopathological factors and the distribution of radioisotopes and blue dye was analyzed. The single metastatic lymph node revealed by axillary lymph node dissection (ALND) is the 'true SLN', and the distribution of radioisotopes and blue dye to the 'true SLN' was also analyzed. RESULTS: Blue-dye- and radioisotope-positive SLN were identified in 79.6 and 94.7% of the patients, respectively. Taken together, SLN were identified in 625 patients (97.7%) by radioisotope and/or blue dye. No significant correlation was observed between clinicopathological features and the distribution of the reagents. ALND found 73 patients with single lymph node metastasis, and 73 'true SLN' were identified by blue dye in 65.7% (48/73), and by radioisotope in 95.9% (70/73) of the cases. CONCLUSION: These data suggest that radioisotopes are superior to blue dye in detecting SLN in breast cancer.

Heparin versus danaproid for prevention of venous thromboembolism after hip surgery.

PURPOSE: To compare the prevalence of deep vein thrombosis (DVT), pulmonary thromboembolism (PTE), and bleeding complications in patients receiving heparin or danaproid after hemiarthroplasty or osteosynthesis for hip fractures. METHODS: 37 men and 138 women aged 47 to 100 (mean, 80) years underwent either hemiarthroplasty or osteosynthesis for hip fractures; 5 patients with dementia were excluded. All patients received preoperative elastic stocking and postoperative intermittent pneumatic compression. They were divided into 3 groups based on their admission period: controls (n=71), unfractionated heparin (n=44), and danaproid sodium (n=55). Drugs were administered from postoperative day 1 to 7. At day 7, all patients undertook radioisotope venography of the legs and lung perfusion scintigraphy. RESULTS: In the control, heparin, and danaproid groups respectively, the DVT rates were 31%, 9.1%, and 5.5%, and the PTE rates were 5.6%, 4.5%, and 1.8%. Only the DVT rate in the control group was significantly higher than that in the heparin and danaproid groups. In the heparin group, one patient had gastrointestinal bleeding, 5 developed wound haematomas, and one had leakage from the drain site for 2 weeks. CONCLUSION: Danaproid sodium appeared more effective and safer than heparin, with no bleeding complications occurred.

Gene expression profiles by microarray analysis during matrigel-induced tube formation in a human extravillous trophoblast cell line: comparison with endothelial cells.

Endovascular differentiation of extravillous cytotrophoblasts (EVT) during placentogenesis induces remodeling of spiral arteries that increases blood flow toward the intravillous space and is required for maintaining pregnancy. To address the molecular mechanisms involved in this differentiation, we investigated the gene expression profile during matrigel-induced tube formation in TCL1 cells, a human immortalized EVT cell line, and HUV-EC-C, human umbilical vessel endothelial cells, and compared their profiles. The numbers of genes that showed significant up-regulation (>3-fold expression at both 3 and 6h, and/or >5-fold expression at either 3 or 6h) during tube formation and significant down-regulation (0.33-fold expression at both 3 and 6h, and/or less than 0.2-fold expression at either 3 or 6h), were 969 and 659 in TCL1, respectively. In HUV-EC-C, the numbers of genes that showed significant up-regulation and down-regulation were 86 and 65, respectively. Only 73 of 1628 genes that showed significant expression changes in TCL1 were common with HUV-EC-C. The genes showing significant expression change specifically in TCL1 were associated with cellular, metabolisms, proliferation, anti-apoptosis, proteolysis adhesion, and some known to be involved in EVT differentiation or related to angiogenesis. The gene expression profile in EVT during tube formation is very different from that of endothelial cells. Further investigations based on the current data may help to elucidate mechanisms of normal and abnormal placentogenesis.

Hypoxia inducible factor 1 alpha regulates matrigel-induced endovascular differentiation under normoxia in a human extravillous trophoblast cell line.

Extravillous trophoblast (EVT) cells mimic endothelial cells during angiogenesis, inducing remodeling of the spiral arteries that increases blood flow toward the intravillous space. We have previously shown that signals involving the vascular endothelial growth factor (VEGF) axis are essential for endovascular differentiation through integrin signaling from the extracellular matrix: This was accomplished with use of the human EVT cell line TCL1, which shows tube formation that specifically recalls morphological changes in endothelial cells. To investigate endovascular differentiation in EVT further, we investigated the role of hypoxia inducible factor (HIF)1A, a subunit of HIF1 transcription factor that regulates not only adaptive responses to hypoxia, but also many cellular functions under normoxia, which was up-regulated in DNA microarray analysis during matrigel-induced endovascular differentiation under normoxia. HIF1A induces VEGF and ITGAV/ITGB3 aggregation, actions known to be important for cellular survival and endovascular differentiation in EVT. Inhibition of HIF1A up-regulation using siRNA introduction or chemical inhibition suppressed hypoxia-responsive element transcriptional activity, VEGF induction, ITGAV/ITGB3 aggregation accompanied by the inhibition of tube formation in TCL1 cells. These results suggest that HIF1A has a crucial role in regulating EVT behavior including matrigel-induced endovascular differentiation under normoxia.

Disulfide-linked gamma delta T cell antigen receptors expressed on T cells derived from patients with primary immunodeficiency disorders.

T cell lines or clones from two patients, one with a partial DiGeorge syndrome and one with severe common variable immunodeficiency expressed disulfide-linked gamma delta T cell antigen receptor (TCR) comprised of a gamma-chain polypeptide of 40-43 kD, and a delta-chain polypeptide of 37-40 kD. This gamma delta TCR appears to be similar to that found on T cell clones, and lines derived from peripheral blood lymphocytes from normal donors. Previous studies have shown that T cell lines derived from the peripheral blood of patients with immunodeficiency disorders express non-disulfide-linked gamma delta TCR. In contrast to the latter and coincident with findings in the present study, the vast majority of T cell lines and clones derived from the peripheral blood of normal donors express disulfide-linked gamma delta TCR.

Laparoscopic inguinal hernioplasty after robot-assisted laparoscopic radical prostatectomy.

PURPOSE: To evaluate the efficacy and safety of laparoscopic transabdominal preperitoneal (TAPP) inguinal hernia repair in patients who have undergone robot-assisted laparoscopic radical prostatectomy (RALP). METHODS: From July 2014 to December 2016, TAPP inguinal hernia repair was conducted in 40 consecutive patients who had previously undergone RALP. Their data were retrospectively analyzed as an uncontrolled case series. RESULTS: The mean operation time in patients who had previously undergone RALP was 99.5 ± 38.0 min. The intraoperative blood loss volume was small, and the duration of hospitalization was 2.0 ± 0.5 days. No intraoperative complications or major postoperative complications occurred. During the average 11.2-month follow-up period, no patients who had previously undergone prostatectomy developed recurrence. CONCLUSIONS: Laparoscopic TAPP inguinal hernia repair after RALP was safe and effective. TAPP inguinal hernia repair may be a valuable alternative to open hernioplasty.

The oxidation of ferrocytochrome c by Br2-, (SCN)2-, N3 and OH radicals studied by pulsed-electron and gamma-ray radiolysis.

The reactions of ferrocytochrome c with Br2-, (SCN)2-, N3 and OH radicals were followed by measuring the change in the optical spectra of cytochrome c on gamma-irradiation as well as the rate of change of absorbance upon pulse irradiation. Ferrocytochrome c is oxidized to ferricytochrome c by Br2-, (SCN)2- or N3 radical with an efficiency of about 100% through a second-order process in which no intermediates were observed. The rate constants in neutral solutions at I = 0.073 are 9.7 . 10(8) M-1 . s-1, 7.9 . 10(8) M-1, 1.3 . 10(9) M-1 . s-1 for the oxidation by Br2-, (SCN)2- and N3 radicals, respectively. The rate constants do not vary appreciably in alkaline solutions (pH 8.9). The ionic strength dependence was observed for the rate constants of the oxidation by br2- and (SCN)2-. Those rate constants estimated on the assumption that the radicals react only with the amino acid residues with the characteristic steric correction factors were less than one-tenth of the observed ones. These results suggest that the partially exposed region of the heme is the probable site of electron transfer from ferrocytochrome c to the radical. Hydroxyl radicals also oxidize ferrocytochrome c with a high rate constant (k greater than 1 . 10(10) M-1 . s-1), but with a very small efficiency (5%).

Effects of monovalent cations and anions on ADP-induced aggregation of bovine platelets, and mechanisms thereof.

The effects of monovalent cations-inorganic alkali metal cations and organic quaternary ammonium cations-and monovalent inorganic anions on ADP-induced aggregation of bovine platelets were investigated. In the presence of K+, Rb+, Cs+, choline or tetramethylammonium, aggregation proceeded. However, aggregation was markedly restricted in media containing Li+, Na+, tetrabutylammonium or dimethyldibenzylammonium. With anions, aggregation proceeded in the order Cl- greater than Br- greater than I- greater than ClO4- greater than SCN-. The effects of cations significantly depended on Ca2+ concentration, whereas those of the anions depended little on Ca2+. Anions such as SCN- and ClO4- markedly decreased the fluorescence of the surface charge probe 2-p-toluidinyl-naphthalene-6-sulfonate, whereas cations had less pronounced effects. The relative effects of the anions on the fluorescence were consistent with their relative inhibitory effects on aggregation. These results suggest that inhibition of platelet aggregation by the anions is due to a change in the surface change of the platelet plasma membrane. On the other hand, kinetic analysis suggests that the effects of monovalent cations on platelet aggregation are due to their competition with Ca2+ during the process of aggregation.

Interleukin-1 beta independently stimulates production of prostaglandin E2 and cyclic AMP from human decidual cells.

Interleukin-1 beta (IL-1 beta) increased the production of cyclic AMP and prostaglandin E2 (PGE2) by cultured human decidual cells during 24 h of stimulation, but not over short incubation times (< 6 h). At concentrations of IL-1 beta ranging from 1 to 100 pg/ml, there were parallel changes in cyclic AMP and PGE2 levels, but 1000 pg of IL-1 beta/ml inhibited cyclic AMP production while still stimulating PGE2 synthesis. The possible link between cyclic AMP and PGE2 was therefore studied further. Inhibition of IL-1 beta-stimulated PGE2 synthesis by indomethacin and direct addition of PGE2 had no effect on cyclic AMP levels, indicating that PGE2 did not increase cyclic AMP production by human decidual cells and confirming the independent synthesis of cyclic AMP and PGE2. The increase in cyclic AMP production induced by IL-1 beta is dependent on protein synthesis, but it is not known which component of the adenylate cyclase is increased. A phosphodiesterase inhibitor potentiated the effects of IL-1 beta on cyclic AMP synthesis, indicating that the cytokine may increase cyclic AMP metabolism. We suggest that high concentrations of IL-1 beta activate phosphodiesterase activity more than adenylate cyclase, which gives rise to the low levels of cyclic AMP noted above. IL-1 beta also decreased forskolin-stimulated cyclic AMP production, which again indicates increased cyclic AMP metabolism. Since most concentrations of IL-1 beta alone increased cyclic AMP levels, this stimulation must out-weigh the increase in metabolism apparent in the presence of forskolin, phosphodiesterase inhibitor or high levels of interleukin. It is clear that IL-1 beta increased decidual PGE2 production independently of cyclic AMP, and that other second messenger must mediate the action of this cytokine.

The regulation of progesterone and hCG production from placental cells by interleukin-1beta.

We have investigated the roles of interleukin-1beta as a regulator of progesterone and chorionic gonadotrophin production from human placental cells. In primary placental cells IL-1beta increased hCG synthesis through a cyclic AMP-independent pathway, and was without effect on progesterone or cyclic AMP production. Since dibutyryl cyclic AMP increased progesterone production, this suggests that there is no coupling between the IL-1beta receptor and the adenylate cyclase enzyme in these cells. Immortalised trophoblast cells responded to IL-1beta by increasing progesterone production through a cyclic AMP-dependent mechanism, but hCG production by these cells was unaffected by IL-1beta or dibutyryl cyclic AMP. Further studies are needed to identify the role of IL-1beta as a possible regulator of progesterone production in primary placental cells. While hCG production in first-trimester trophoblast was increased by dibutyryl cyclic AMP and IL-1beta, both these effects may involve other factors such as IL-6, and their second messenger systems.

Reactions of the ferri-ferrocytochrome-c system with superoxide/oxygen and CO2-/CO2 studied by fast pulse radiolysis.

The reduction of ferricytochrome c by O2- and CO2- was studied in the pH range 6.6-9.2 and Arrhenius as well as Eyring parameters were derived from the rate constants and their temperature dependence. Ionic effects on the rate indicate that the redox process proceeds through a multiply-positively charged interaction site on cytochrome c. It is shown that the reaction with O2- (and correspondingly with O2 of ferrocytochrome c) is by a factor of approx. 10(3) slower than warranted by factors such as redox potential. Evidence is adduced to support the view that this slowness is connected with the role of water in the interaction between O2-/O2 and ferri-ferrocytochrome c in the positively charged interaction site on cytochrome c in which water molecules are specifically involved in maintaining the local structure of cytochrome c and participate in the process of electron equivalent transfer.

Noninvasive prediction of coronary atherosclerosis by quantification of coronary artery calcification using electron beam computed tomography: comparison with electrocardiographic and thallium exercise stress test results.

OBJECTIVES: This study was designed to compare the usefulness of electron beam computed tomography for prediction of coronary stenosis with that of electrocardiographic (ECG) and thallium exercise tests. BACKGROUND: Electron beam computed tomography can quantify coronary calcifications; however, its clinical value has yet to be established. METHODS: Using the volume mode of electron beam computed tomography, we studied 251 consecutive patients who underwent elective coronary angiography because of suspected coronary artery disease and compared the results with those of ECG and thallium exercise tests. The total coronary calcification score was calculated by multiplying the area ( > or = 2 pixels) of calcification (peak density > or = 130 Hounsfield units) by an arbitrarily weighted density score (0 to 4) based on its peak density. The mean of two scans was log transformed. RESULTS: Calcification was first noted in women in the 4th decade of life, approximately 10 years later than its occurrence in men. Among patients with advanced atherosclerosis (two- and three-vessel disease), calcification scores were uniformly high in women but ranged widely in men. Nine percent of patients with significant stenoses ( > or = 75% by densitometry) had no calcification. The calcification scores of patients with significant stenosis in at least one vessel were significantly higher than those of patients without significant stenosis in the study group as a whole and in most patient subgroups classified according to age and gender. A cutoff calcification score for prediction of significant stenosis, determined by receiver operating characteristic curve analysis, showed high sensitivity (0.77) and specificity (0.86) in all study patients; sensitivity was similarly high even in older patients ( > or = 70 years) and was enhanced in middle-aged patients (40 to < or = 60 years). The difference in specificity between calcification scores and ECG exercise test results had borderline significance (p = 0.058) and that between calcification scores and thallium test results was significant (p = 0.001). The latter difference became small but remained significant (p = 0.01) even after the reevaluation of thallium test results in light of each subject's clinical data. CONCLUSIONS: Quantification of coronary artery calcification with electron beam computed tomography noninvasively predicted angiographically confirmed coronary stenosis. Results obtained with this method were at least as useful and potentially better in some patient groups than those obtained with thallium and ECG exercise testing.

Coronary calcification and coronary atherosclerosis: site by site comparative morphologic study of electron beam computed tomography and coronary angiography.

OBJECTIVES: We compared, on a site by site basis, the morphologic features of coronary calcifications determined by electron beam computed tomography (EBCT) and angiographically defined coronary atherosclerosis. BACKGROUND: Quantification of coronary calcification using EBCT is clinically useful for the prediction of coronary stenosis. However, the relation between calcification and angiographic findings has not been evaluated by site. METHODS: We studied 251 consecutive patients who underwent elective coronary angiography for suspected coronary artery disease by EBCT and analyzed findings by site. Coronary calcifications were classified according to their length and width versus the diameter of the coronary artery in which the calcification was observed as: none, spotty, long, wide and diffuse. RESULTS: Coronary calcifications were found in 666 (27%) of 2,470 segments. The positive predictive value (PPV) of coronary calcification for significant stenosis (> or = 75% densitometric narrowing) and for all angiographically detectable atherosclerotic lesions in a segment was 0.36 and 0.80, respectively. The PPV for significant stenosis and all atherosclerotic lesions was 0.04 and 0.17 in none, 0.18 and 0.59 in spotty, 0.32 and 0.87 in long, 0.40 and 0.84 in wide and 0.56 and 0.96 in diffuse calcifications, respectively. The PPV for both significant stenosis and all lesions differed significantly (p = 0.001) among the morphologic groups. Of the 105 eccentric significant stenoses, 54 (53%) were classified as long or diffuse calcifications. Of the 95 significant stenoses with multiple irregularities, 61 (64%) showed diffuse calcification. CONCLUSIONS: Morphologic evaluation of coronary calcifications using EBCT improved the prediction of coronary stenosis on a site by site basis and provided information related to angiographic morphology.

Determination of flow and rate constants in a kinetic model of [99mTc]-hexamethyl-propylene amine oxime in the human brain.

The values for flow and rate constants for a kinetic model of [99mTc]-hexamethylpropyleneamine oxime (HM-PAO) distribution in the human brain were determined. The single-pass extraction ratio of HM-PAO was also determined in the rat brain by the indicator diffusion method; a value of 0.90 +/- 0.02 (mean +/- SEM, n = 5) was obtained. Time course data of brain activity and arterial blood activity of the tracer were fitted to a four compartment model: Values of blood flow and the first-order rate constants for backdiffusion of the diffusible tracer from brain to blood (k2), conversion of the lipophilic tracer to the hydrophilic one in brain (k3), and conversion of the diffusible tracer to the nondiffusible one in blood (k5) were determined. Conversion of hydrophilic tracer back to a lipophilic form in both blood and brain was assumed to be negligible during the course of the experiment. The values obtained for blood flow, k2, and k3 were, respectively, 0.40 +/- 0.03 ml/g/min, 0.38 +/- 0.04 min-1, and 0.92 +/- 0.05 min-1 in the gray matter (n = 4), and 0.23 +/- 0.01 ml/g/min, 0.17 +/- 0.01 min-1, and 1.01 +/- 0.05 min-1 in the white matter (n = 2) in patients with cerebrovascular disorder. The k5 value was 1.14 +/- 0.06 min-1 (n = 4). These experimentally determined values agree well with the theoretical ones previously reported by Lassen et al. The results suggest the relative constancy of the k3 and k5 values and the more prominent initial backdiffusion of the lipophilic HM-PAO from brain to blood in high flow regions compared to low flow regions.

Oxindole derivatives as orally active potent growth hormone secretagogues.

A series of substituted oxindole derivatives was synthesized and evaluated for growth hormone (GH) releasing activity using cultured rat pituitary cells. (+)-6-Carbamoyl-3-(2-chlorophenyl)-(2-diethylaminoethyl)-4-trifluoromethyloxindole (SM-130686, 37S) was found to have potent activity (EC(50) = 3.0 nM), while the other enantiomer 37R had reduced activity. The absolute configuration of 37S was confirmed by X-ray crystallographic analysis. Compound 37S showed a good pharmacokinetic profile in rats with 28% oral bioavailability at 10 mg/kg and excellent in vivo activity as evidenced by a significant weight gain after 4 days of oral administration at 10 mg/kg twice a day. Compound 37S displaced the binding of (35)S-MK-677 to human GHS-R with an IC(50) value of 1.2 +/- 0.2 nM.

Evaluation of cerebral collateral circulation by technetium-99m HM-PAO brain SPECT during Matas test: report of three cases.

Three cases with cerebral ischemic symptoms and an intracranial aneurysm are presented. Using [99mTc]hexamethyl-propyleneamine oxime (HM-PAO) single photon emission computed tomography imaging before and during the Matas test, a quantitative measurement method was developed for evaluating brain collateral circulation. The evaluation correlated well with findings of contrast carotid angiography. This noninvasive method seems to be useful for selection of patients for appropriate surgical treatment.

Thallium-201 single photon emission computed tomography in the evaluation of suspected lung cancer.

Thallium-201 SPECT was performed in 30 patients with suspected lung cancer. Both early and delayed scans demonstrated abnormal accumulation in all of 23 malignant pulmonary lesions including 21 lung cancer and in two of seven benign conditions. There were significant differences in delayed ratio (uptake ratio of the lesion to the normal lung on delayed scan) and retention index (degree of retention in the lesion) between lung cancer and benign conditions, respectively (p less than 0.01, p less than 0.05). The delayed ratio and retention index revealed that adenocarcinoma showed higher 201Tl accumulation than squamous cell carcinoma and small cell carcinoma (p less than 0.05) and 201Tl clearance in squamous cell carcinoma was faster than in the other two (p less than 0.05). Mediastinal involvement was detected in five of seven patients on delayed scans. The smallest lesion depicted was 1.5 cm in diameter. Two false negatives had small metastases less than 1.0 cm in diameter. This method seems to be useful to detect lung cancer, to differentiate malignant from benign lesions, and to evaluate mediastinal involvement from lung cancer.

FDG PET measurement of the proliferative potential of non-small cell lung cancer.

UNLABELLED: The goals of this study were to correlate FDG uptake with cell proliferation and cellular density in non-small cell lung cancer. METHODS: Thirty-one patients with 32 non-small cell lung cancers were examined with FDG PET. For semiquantitative analysis, standardized uptake values (SUVs) were calculated. All patients underwent thoracotomy within 4 wk after the FDG PET study. Cell proliferation was immunohistochemically assessed as the relative number of cells expressing the proliferating cell nuclear antigen ([PCNA] labeling index). Cellular density was also evaluated using light microscopy. RESULTS: SUVs correlated significantly with PCNA labeling index (r = 0.740; P < 0.0001) but only weakly with cellular density (r = 0.392; P = 0.0266). High FDG uptake correlated with high PCNA expression. The PCNA labeling index and SUVs were significantly lower in bronchioloalveolar carcinomas (n = 8) (12.3 +/- 9.45% and 1.45 +/- 0.76, respectively) than in nonbronchioloalveolar carcinomas (n = 19) (33.5 +/- 21.8%, P = 0.015, and 3.75 +/- 1.93, P = 0.003, respectively). However, no significant differences in cellular density were seen between bronchioloalveolar carcinomas and nonbronchioloalveolar carcinomas. CONCLUSION: FDG uptake is related to cell proliferation rather than to the cellular density of non-small cell lung cancer.

Comparison of fluorine-18-FDG PET and thallium-201 SPECT in evaluation of lung cancer.

UNLABELLED: We compared the diagnostic value of [18F]2-fluoro-2-deoxy-D-glucose (FDG) PET imaging and 201Tl SPECT imaging in the detection of primary lung cancer and mediastinal lymph node metastases. METHODS: Thirty-three patients with histologically-proven primary lung cancer were examined with both FDG PET and TI SPECT (early and delayed scans) within a week of each study. For semiquantitative analysis, the tumor-to-nontumor activity ratio (T-to-N ratio) was calculated. RESULTS: Although both techniques delineated focal lesions with an increase in tracer accumulation in 28 patients, PET identified three additional patients in whom Tl SPECT images did not visualize any lesions on both early and delayed scans. In the detection of lung cancer of less than 2 cm in size, FDG PET provided higher sensitivity (six of seven, 85.7%) than did Tl SPECT early scan (one of seven, 14.3%) and delayed scan (four of seven, 57.1%). Neither technique visualized any lesions in two patients who had bronchioloalveolar carcinoma. The T-to-N ratio was significantly higher with FDG PET (10.39 +/- 6.63) than it was with Tl SPECT (early scan, 2.37 +/- 0.86; delayed scan, 3.01 +/- 1.01) (p < 0.0001), whereas there was significant positive correlation between the FDG T-to-N ratio and the thallium T-to-N ratio (p < 0.01). Twenty-two patients had thoracotomies. Regarding the staging of mediastinal nodes, FDG PET detected mediastinal lymph node metastasis that was negative on Tl SPECT, whereas both techniques excluded tumor involvement in enlarged node at CT. CONCLUSION: Both techniques have clinical value for the noninvasive detection of primary lung cancer that is 2 cm or greater in diameter. However, if a PET camera is available, FDG PET is considered the method of choice for the evaluation of patients with suspected primary lung cancer that is less than 2 cm in diameter.