Predicting the Recurrence of Gastric Cancer Using the Textural Features of Perigastric Adipose Tissue on [18F]FDG PET/CT.

This study aimed to assess the relationship between the histopathological and textural features of perigastric adipose tissue (AT) on 2-deoxy-2-[18F]fluoro-D-glucose ([18F]FDG) positron emission tomography/computed tomography (PET/CT) and to evaluate the prognostic significance of perigastric AT textural features in predicting recurrence-free survival (RFS) in patients with gastric cancer. Sixty-nine patients with gastric cancer who underwent staging [18F]FDG PET/CT and subsequent curative surgery were retrospectively reviewed. Textural features of perigastric AT were extracted from PET images. On histopathological analysis, CD4, CD8, and CD163 cell infiltration and matrix metalloproteinase-11 and interleukin-6 (IL-6) expression in perigastric AT were graded. The degree of CD163 cell infiltration in perigastric AT was significantly correlated with the mean standardized uptake value (SUV), SUV histogram entropy, grey-level co-occurrence matrix (GLCM) energy, and GLCM entropy of perigastric AT. The degree of IL-6 expression in the perigastric AT was significantly correlated with the mean and median SUVs of perigastric AT. In multivariate survival analysis, GLCM entropy, GLCM dissimilarity, and GLCM homogeneity of perigastric AT were significant predictors of RFS. The textural features of perigastric AT on [18F]FDG PET/CT significantly correlated with inflammatory response in perigastric AT and were significant prognostic factors for predicting RFS in patients with gastric cancer.

Clinical Utility of Quantitative Parameters of Salivary Gland Scintigraphy for Diagnosing Burning Mouth Syndrome.

Burning mouth syndrome (BMS) is a chronic disorder characterized by a burning sensation in the oral cavity, often accompanied by xerostomia, with no relevant clinical or laboratory findings. This study aimed to investigate diagnostic values of quantitative parameters of salivary gland scintigraphy for BMS in patients with xerostomia. A total of 164 patients who underwent salivary gland scintigraphy for the workup of xerostomia were retrospectively reviewed. All patients were classified into patient groups with primary BMS, secondary BMS, and non-specific xerostomia. From salivary gland scintigraphy, 22 quantitative parameters were calculated and their diagnostic values were assessed based on the area under the receiver operating characteristic curve (AUC) values. Among salivary gland scintigraphy parameters, uptake speed in the left submandibular gland showed the highest AUC value (0.647) for detecting BMS and pre-stimulatory oral activity showed the highest AUC value (0.710) for detecting primary BMS. A salivary gland scintigraphy scoring system based on these two parameters further enhanced the diagnostic ability, demonstrating AUC values of 0.731 for BMS and 0.782 for primary BMS. These results suggest a potential diagnostic value of the quantitative parameters of salivary gland scintigraphy for detecting BMS in patients with xerostomia.

Relationship of FDG PET/CT Textural Features with the Tumor Microenvironment and Recurrence Risks in Patients with Advanced Gastric Cancers.

The relationship between 2-deoxy-2-[18F]fluoro-D-glucose (FDG) positron emission tomography/computed tomography (PET/CT) textural features and histopathological findings in gastric cancer has not been fully evaluated. We investigated the relationship between the textural features of primary tumors on FDG PET/CT with histopathological findings and recurrence-free survival (RFS) in patients with advanced gastric cancer (AGC). Fifty-six patients with AGC who underwent FDG PET/CT for staging work-ups were retrospectively enrolled. Conventional parameters and the first- and second-order textural features of AGC were extracted using PET textural analysis. Upon histopathological analysis, along with histopathological classification and staging, the degree of CD4, CD8, and CD163 cell infiltrations and expressions of interleukin-6 and matrix-metalloproteinase-11 (MMP-11) in the primary tumor were assessed. The histopathological classification, Lauren classification, lymph node metastasis, CD8 T lymphocyte and CD163 macrophage infiltrations, and MMP-11 expression were significantly associated with the textural features of AGC. The multivariate survival analysis showed that increased FDG uptake and intra-tumoral metabolic heterogeneity were significantly associated with an increased risk of recurrence after curative surgery. Textural features of AGC on FDG PET/CT showed significant correlations with the inflammatory response in the tumor microenvironment and histopathological features of AGC, and they showed significant prognostic values for predicting RFS.

Quantitative Scintigraphy Imaging of Lingual Raynaud's Phenomenon Using 3-Dimensional-Ring Cadmium-Zinc-Telluride Single-Photon Emission Computed Tomography/Computed Tomography.

Perfusion scintigraphy with the acquisition of planar blood flow and pool images of bilateral hands has been used to aid diagnosis and to evaluate treatment response to Raynaud's phenomenon (decreased blood flow to hand or foot). However, because of the difficulty in imaging the tongue area with a conventional gamma camera, perfusion scintigraphy imaging of patients with lingual Raynaud's phenomenon has yet to be reported. Here, we report the case of a 59-year-old man with lingual Raynaud's phenomenon in which blood pool imaging of the tongue was performed using three-dimensional (3D)-ring cadmium-zinc-telluride (CZT) single-photon emission computed tomography/computed tomography (SPECT/CT). During follow-up, the patient's lingual symptoms had worsened, and follow-up blood pool SPECT/CT images also revealed decreased blood pool uptake of the tongue, showing a decreased blood pool of more than 25% on quantitative analysis. This case suggests that blood pool imaging of the tongue using 3D-ring CZT SPECT/CT has clinical significance in evaluating patients with lingual Raynaud's phenomenon.

Clinical values of left ventricular mechanical dyssynchrony assessment by gated myocardial perfusion SPECT in patients with acute myocardial infarction and multivessel disease.

PURPOSE: The aim of this study was to evaluate the prognostic value of additional evaluation of left ventricular mechanical dyssynchrony (LVMD) by gated myocardial perfusion single-photon emission computed tomography (GMPS) in patients with acute myocardial infarction (MI) and multivessel disease. METHODS: One hundred and nine acute MI patients with >50 % stenosis in at least one non-culprit artery who underwent GMPS within 2 weeks were enrolled. All patients underwent successful revascularization of the culprit arteries. Those with previous MI, atrial fibrillation, or frequent ventricular premature complexes, cardiac devices, significant patient motion, or procedure-related events were excluded. Phase standard deviation (PSD) and phase histogram bandwidth (PBW) were measured for assessment of LVMD. Patients were followed up for a median of 26 months after index MI, for composite major adverse cardiac events (MACE), which consisted with all-cause death, unplanned hospitalization due to heart failure and severe ventricular arrhythmias (sustained ventricular tachycardia or ventricular fibrillation). Independent predictors of MACE were evaluated. RESULTS: MACE occurred in 22 patients (20 %). Stress PSD (53.3 ± 17.3° vs. 35.3 ± 18.9°; p <0.001), stress PBW (147.6 ± 54.6° vs. 96.8 ± 59.2°; p = 0.001) and resting PBW (126.8 ± 37.5° vs. 96.6 ± 48.9°; p = 0.001) were significantly higher in patients with MACE compared to those without. Multivariate analysis revealed that stress PSD ≥45.5° and stress PBW ≥126.0° were predictive of MACE, as well as suboptimal non-culprit artery revascularization (SNR) and renin-angiotensin system (RAS) blockade medication. Higher stress PSD and stress PBW were associated with poorer prognosis both in patients with and without SNR, and those with RAS blockade medication, but not in those without RAS blockade medication. CONCLUSIONS: LVMD measured by GMPS showed added prognostic value in acute MI with multivessel disease. GMPS could serve as a comprehensive evaluation imaging tool in patients with acute MI and multivessel disease.

Coronary flow reserve and relative flow reserve measured by N-13 ammonia PET for characterization of coronary artery disease.

OBJECTIVE: We evaluated the relationships between coronary flow reserve (CFR) and relative flow reserve (RFR) measured by N-13 ammonia positron emission tomography (PET) for characterization of epicardial coronary artery disease (CAD). METHODS: Sixty-nine consecutive stable angina patients underwent N-13 ammonia PET, coronary computed tomography angiography (CCTA), and if necessary, invasive coronary angiography (CAG) within 2 weeks. Myocardial blood flow (MBF), CFR, RFR, and coronary vascular resistance of the reference arterial territory (CVRref) were measured by N-13 ammonia PET. The presence of significant stenosis (SS) and diffuse atherosclerosis (DA) was evaluated on CCTA and CAG. Functional parameters measured by PET were compared among arteries with and without SS and DA. RESULTS: Arteries with SS and those with DA showed significantly lower stress MBF, as compared to those without. RFR was significantly lower in arteries with SS as compared to those without, while CFR was not. CFR was significantly lower in arteries with DA as compared to those without, while RFR was not. Among arteries without SS, CFR was significantly lower in those with DA as compared to those without. However, among arteries with SS, CFR was similar between those with and without DA. In contrast, RFR was significantly lower in arteries with SS, regardless of the presence of DA. CFR and RFR showed a weak positive correlation (r = 0.269) with discordance in 24 cases (35%). Among the arteries with CFR-RFR discordance, the prevalence of DA was significantly higher in those with low CFR but preserved RFR, as compared to those with preserved CFR but low RFR (75 vs 25%, p = 0.028). CVRref was significantly higher in arteries with DA, implicating a correlation of DA with underlying microvascular disease. CONCLUSIONS: CFR and RFR measured by myocardial perfusion PET could provide a comprehensive information for characterization of epicardial CAD.

Prediction of coronary artery calcium progression by FDG uptake of large arteries in asymptomatic individuals.

PURPOSE: The purpose of this study is to evaluate whether fluorodeoxyglucose (FDG) uptake of the large arteries can predict coronary artery calcium (CAC) progression in asymptomatic individuals. METHODS: Ninety-six asymptomatic individuals who underwent FDG positron emission tomography (PET) and CAC scoring on the same day for health screening and follow-up CAC scoring ≥1 year after baseline studies (mean 4.3 years) were included. Vascular FDG uptake was measured and corrected for blood pool activity to obtain peak and average target-to-blood pool ratios (TBRpeak and TBRavg, respectively) for the carotid arteries, and ascending and abdominal aorta. CAC scores at baseline and follow-up of each individual were measured and absolute CAC change (ΔCAC), annual CAC change (ΔCAC/year), and annual CAC change rate (ΔCAC%/year) were calculated. CAC progression was defined as ΔCAC >0 for individuals with negative baseline CAC; ΔCAC/year ≥10 for those with baseline CAC of 0

Iodine Uptake Patterns on Post-ablation Whole Body Scans are Related to Elevated Serum Thyroglobulin Levels After Radioactive Iodine Therapy in Patients with Papillary Thyroid Carcinoma.

PURPOSE: Serum thyroglobulin (Tg) level is frequently elevated shortly after radioactive iodine (RAI) ablation therapy. The authors studied the relationship between the elevation of serum Tg after RAI therapy and iodine uptake pattern on post-ablation whole body scans (RxWBSs) in patients with papillary thyroid carcinoma (PTC). MATERIALS AND METHODS: The study subjects were patients with PTC that had undergone first RAI therapy with thyroid hormone withdrawal after total thyroidectomy. Patients with a high level of serum anti-Tg antibody (TgAb, ≥ 60 U/mL), possible regional or distant metastasis as determined by pre-ablation or post-ablation studies, and negative iodine uptake of the anterior neck on RxWBS were excluded. Serum Tg was checked twice, that is, 7 days after (post-ablation Tg) and on the day of RAI therapy (pre-ablation Tg). Ratio of pre-ablation Tg to post-ablation Tg (Tg ratio) was used to assess changes in serum Tg levels after RAI therapy. Patients were classified into two groups according to the presence of midline uptake above the thyroidectomy bed on RxWBS (negative (group 1) or positive (group 2) midline uptake). Variables were subjected to analysis to identify differences between the two groups. RESULTS: Two hundred and fifty patients were enrolled in this study; 101 in group 1 and 149 in group 2. Based on univariate analysis, post-ablation Tg (8.12 ± 11.05 vs. 34.12 ± 54.31; P < 0.001) and Tg ratio (7.81 ± 8.98 vs. 20.01 ± 19.84; P < 0.001) were significantly higher in group 2. On the other hand, gender, tumor (T) stage, lymph node (N) stage, size, multiplicity or bilaterality of primary tumor, dose of 131I, serum TgAb and thyroid-stimulating hormone (TSH) level (before or after RAI therapy) were not significantly different in the two groups. Variables with P values of < 0.25 by univariate analysis were subjected to multivariate analysis, which showed post-ablation Tg (OR 1.060, 95 % CI = 1.028-1.092; P < 0.001) and Tg ratio (OR 1.059, 95 % CI = 1.028-1.092; P = 0.001) were significantly higher in group 2. CONCLUSION: Serum Tg level after RAI therapy was significantly higher in patients with midline uptake on RxWBS, compared with patients without midline uptake on RxWBS. Further investigations are needed to reveal the correlation between serum Tg elevation and clinical outcome according to the presence of midline uptake.

Open-Mouth Bone Scintigraphy Is Better than Closed-Mouth Bone Scintigraphy in the Diagnosis of Temporomandibular Osteoarthritis.

PURPOSE: Closed-mouth bone scintigraphy (CM scan) and closed-mouth single-photon emission computed tomography (CM SPECT) are used for conventional evaluation of osteoarthritis of the temporomandibular joint (TMJ). However, the adequacy of open-mouth bone scintigraphy (OM scan) has not yet been evaluated. Therefore, the purpose of this study was to compare the diagnostic performance of CM scan, CM SPECT, and OM scan. METHODS: Thirty-six patients with suspicion of an abnormality of the TMJ and who underwent a (99m)Tc-HDP CM scan, CM SPECT, and an OM scan were enrolled. The scans were assessed visually for the presence of positive focal uptake in the TMJ. Osteoarthritis was defined as arthralgia plus crepitus or radiologic signs of arthrosis. RESULTS: Of 72 TMJs, 21 (29.2 %) were diagnosed with osteoarthritis. The sensitivity, specificity, positive predictive value, negative predictive value and accuracy were 90.5 %, 49.0 %, 42.2 %, 92.6 % and 61.1 % for the CM scan, 81.0 %, 58.8 %, 44.7 %, 88.2 % and 65.3 % for CM SPECT, and 81.0 %, 82.4 %, 65.4 %, 91.3 % and 81.9 % for the OM scan, respectively. The accuracy of the OM scan was higher than that of CM SPECT and the CM scans (p = 0.004 and p < 0.001, respectively). CONCLUSIONS: The OM scan was more accurate than the conventional CM scan and even CM SPECT for diagnosing TMJ osteoarthritis.

Correlation of Angina Pectoris and Perfusion Decrease by Collateral Circulation in Single-Vessel Coronary Chronic Total Occlusion Using Myocardial Perfusion Single-Photon Emission Computed Tomography.

PURPOSE: To evaluate the perfusion decrease in donor myocardium by collateral circulation and its correlation with angina pectoris in patients with chronic total occlusion (CTO) using myocardial perfusion single-photon emission computed tomography (MPS). MATERIALS AND METHODS: Thirty-six patients with single-vessel CTO without any other stenosis were included. All patients underwent MPS and coronary angiography (CAG) within 2 months. Total 72 donor arteries were evaluated for the grades of collaterals to the CTO artery using the Rentrop grading system on CAG. Perfusion defects and perfusion scores in donor and CTO territories were analyzed on MPS. Myocardial perfusion of donor and CTO territories were evaluated according to the presence of angina pectoris and the grades of collateral circulation. RESULTS: When the CTO territory was ischemic, symptomatic patients showed higher summed difference scores in the CTO territory compared to asymptomatic patients (3.5 ± 2.4 vs. 1.5 ± 0.8 for symptomatic and asymptomatic groups respectively; p = 0.034). However, when the CTO territory was nonischemic, symptomatic patients showed higher summed stress scores (SSS, 4.3 ± 2.9 vs. 1.6 ± 1.2; p = 0.032) and summed rest scores (SRS, 4.2 ± 2.5 vs. 1.5 ± 1.1; p = 0.003) in the donor territories. On the per-vessel analysis, perfusion defects in donor territories were more frequent (0 % vs. 53 % vs. 86 % for Rentrop 0, Rentrop 1-2 and Rentrop 3, respectively; p < 0.001) and showed higher SSS (0.0 ± 0.0, 1.3 ± 1.6 and 2.1 ± 1.1 for Rentrop 0, Rentrop 1-2 and Rentrop 3, respectively; p = 0.001) and SRS (0.0 ± 0.0, 1.0 ± 1.4 and 1.7 ± 1.2; p = 0.003) at higher Rentrop grades, but their patterns were variable. CONCLUSION: Angina pectoris was related to either ischemia of the myocardium beyond CTO or a perfusion decrease in the donor myocardium. The perfusion decrease in donor myocardium positively correlated with the collateral grades.

Stimulated Serum Thyroglobulin Level at the Time of First Dose of Radioactive Iodine Therapy Is the Most Predictive Factor for Therapeutic Failure in Patients With Papillary Thyroid Carcinoma.

PURPOSE: To investigate the clinical importance of serum thyroglobulin (Tg) levels just before high-dose I-131 ablation therapy (preablation Tg) for predicting therapeutic failure in patients with papillary thyroid carcinoma (PTC). METHODS: Patients with PTC (n = 132) undergoing total thyroidectomy followed by the first high-dose I-131 ablation therapy (HI-Rx) were included in this retrospective review. Just before HI-Rx, preablation Tg, anti-Tg antibody, and TSH were measured. The patients were followed up for a mean period of 7 months (range 6-23 months) by I-123 whole-body scans (f/u IWBS) and stimulated Tg (f/u Tg). Therapeutic failure was defined by positive f/u IWBS or f/u Tg >2 ng/ml. We classified patients into three groups according to the value of preablation Tg (group 1, <1 ng/ml; group 2, ≥1 and <10 ng/ml; group 3, ≥10 ng/ml) and compared clinical variables to therapeutic response. RESULTS: Therapeutic failure was noted in 39 patients (29.5 %). On univariate analysis, T stage, tumor size, and preablation Tg were the statistically significant factors that could predict therapeutic failure. After multivariate analysis, preablation Tg was the only independent predictor of therapeutic failure (P < 0.001). The therapeutic failure rate was significantly increased as the preablation Tg level increased (11.3 %, 33.3 %, and 87.5 % in groups 1, 2, and 3, respectively; P < 0.001). Individuals with preablation Tg levels ≥10 ng/ml had 25.5 times greater chance of therapeutic failure than those with levels <10 ng/ml (95 % CI = 5.43-119.60; P < 0.001). CONCLUSIONS: A high preablation Tg level is the most significant predictor of therapeutic failure at the time of first HI-Rx in patients with PTC.