Clinicopathologic parameters associated with the FDG-avidity in staging of early gastric cancer using 18F-FDG PET.

This study investigated the clinicopathologic factors associated with 2-[F]fluoro-2-deoxy-D-glucose (F-FDG) uptake of early gastric cancer (EGC) and used them to design a clinical scoring method to predict FDG-avidity of EGC.Two hundred twenty-nine retrospectively enrolled patients underwent preoperative F-FDG positron emission tomography/computed tomography (PET/CT). Histologic information was obtained by gastrectomy (n = 195) or endoscopic mucosal dissection (n = 34). The association between clinicopathologic factors and F-FDG uptake by the primary tumor was determined. The results were used to develop a clinical scoring method.F-FDG uptake was detected in 49 (17.5%) patients. According to univariate analysis, location, gross type, World Health Organization classification, Lauren classification, size, depth of invasion, and lymphatic invasion were significant variables affecting F-FDG uptake (all P < .05). According to multivariate analysis, location (lower 3rd, P = .035), gross type (0-I, 0-IIa, P < .001), size (≥2.5 cm, P = .026), and depth of invasion (submucosa, P = .007) were significantly associated with FDG-avidity. A clinical scoring system, ranged from 0 to 4, was developed by giving one score to 4 independent variables. A cut-off value of 2.5 showed good prediction of FDG-avidity in EGCs, with a sensitivity and specificity of 65.0% and 85.2%, respectively.F-FDG uptake by EGC depends on location, gross type, size, and depth of invasion of the primary tumor. A clinical scoring system based on clinicopathologic variables can predict the FDG-avidity of primary tumors in patients with EGC.

The Utility of Segmental Analysis in Cardiac I-123 MIBG SPECT in Parkinson's Disease.

PURPOSE: Cardiac images using I-123 metaiodobenzylguanidine (MIBG) are widely used to evaluate cardiac sympathetic denervation in Parkinson's disease (PD). The aim of this study was to evaluate the utility of segmental analysis on cardiac MIBG SPECT in PD patients. MATERIALS AND METHODS: In total, 36 patients with PD (n = 26) or essential tremor (ET, n = 10) who underwent MIBG cardiac SPECT were enrolled. The heart-to-mediastinum (H/M) ratios of MIBG uptake were acquired on planar images. For the segmental analysis of SPECT images, we evaluated the summed defect score (SDS) using a 17-segment model. The diagnostic abilities of H/M ratios and segmental parameters on MIBG SPECT were assessed by ROC curve analysis. RESULTS: The H/M ratios were significantly lower in PD than in ET patients (p < 0.05). On segmental analysis, SDS was significantly higher in PD patients than in the ET group (7.04 ± 4.09 vs. 2.90 ± 2.80; p = 0.006). The defect score of the anteroseptal region showed a significant difference between the groups (p = 0.002). The ROC analysis suggested only SDS (AUC = 0.785, p = 0.0003) and defect scores in the anteroseptal (AUC = 0.800, p < 0.0001) and inferior (AUC = 0.667, p = 0.013) regions showed significant diagnostic ability to differentiate PD from ET. CONCLUSIONS: Segmental parameters from cardiac MIBG SPECT images can provide additional information to differentiate PD from ET patients. Beyond H/M ratios from planar images, we recommend an MIBG SPECT study to evaluate sympathetic denervation in PD.

Carotid Artery FDG Uptake May Serve as a Biomarker for Cardiovascular Risk Stratification in Asymptomatic Adults.

PURPOSE: We investigated the relation between carotid artery FDG uptake and cardiovascular risk based on the Framingham risk score (FRS) and evaluated the possible role of FDG uptake in terms of risk stratification of asymptomatic adults. METHODS: We evaluated 290 adults who underwent FDG PET/CT as part of general health screens. We calculated target-to-background ratios, corrected for pre-scan blood glucose levels, and obtained "TBRglu" values for both common carotid arteries. The FRS and the presence/absence of metabolic syndrome were recorded for each subject. Relationships among TBRglu values, metabolic syndrome status, and clinical parameters were assessed. RESULTS: Carotid artery FDG uptake was significantly associated with clinical risk factors. Stepwise multiple regression analysis revealed that triglyceride levels, diabetes, and metabolic syndrome were independent determinants of high TBRglu. Of subjects with metabolic syndrome, those exhibiting high carotid artery FDG uptake had significantly higher levels of high sensitivity C-reactive protein (hsCRP). In subjects who did not have metabolic syndrome, FRSs were significantly elevated in those exhibiting high carotid artery FDG uptake compared to those with low uptake (13.1 ± 7.0 vs. 8.2 ± 7.4), as was also true of subjects with the syndrome (21.8 ± 16.0 vs. 13.5 ± 11.9). CONCLUSION: High carotid FDG uptake is significantly associated with clinical risk factors and a greater FRS. Of subjects with metabolic syndrome, those with high carotid uptake had significantly higher hsCRP concentrations and FRSs. Therefore, carotid artery FDG activity may serve as a possible biomarker allowing cardiovascular risk stratification of asymptomatic populations.

Significance of Salivary Gland Radioiodine Retention on Post-ablation (131)I Scintigraphy as a Predictor of Salivary Gland Dysfunction in Patients with Differentiated Thyroid Carcinoma.

PURPOSE: We investigated whether (131)I whole-body scintigraphy could predict functional changes in salivary glands after radioiodine therapy. METHODS: We evaluated 90 patients who received initial high-dose (≥3.7 GBq) radioiodine therapy after total thyroidectomy. All patients underwent diagnostic (DWS) and post-ablation (TWS) (131)I whole-body scintigraphy. Visual assessment of salivary radioiodine retention on DWS and TWS was used to divide the patients into two types of groups: a DWS+ or DWS- group and a TWS+ or TWS- group. Salivary gland scintigraphy was also performed before DWS and at the first follow-up visit. Peak uptake and %washout were calculated in ROIs of each gland. Functional changes (Δuptake or Δwashout) of salivary glands after radioiodine therapy were compared between the two groups. RESULTS: Both peak uptake and the %washout of the parotid glands were significantly lower after radioiodine therapy (all p values <0.001), whereas only the %washout were significantly reduced in the submandibular glands (all p values <0.05). For the parotid glands, the TWS+ group showed larger Δuptake and Δwashout after radioiodine therapy than did the TWS- group (all p values <0.01). In contrast, the Δuptake and Δwashout of the submandibular glands did not significantly differ between the TWS+ and TWS- groups (all p values >0.05). Likewise, no differences in Δuptake or Δwashout were apparent between the DWS+ and DWS- groups in either the parotid or submandibular glands (all p values >0.05). CONCLUSION: Salivary gland radioiodine retention on post-ablation (131)I scintigraphy is a good predictor of functional impairment of the parotid glands after high-dose radioiodine therapy.

Prognostic significance of the intratumoral heterogeneity of (18) F-FDG uptake in oral cavity cancer.

BACKGROUNDS: We evaluated the prognostic value of the intratumoral heterogeneity of (18) F-FDG uptake in oral cavity cancer. MATERIALS AND METHODS: We enrolled 45 patients who underwent pretreatment (18) F-FDG PET/CT. The intratumoral heterogeneity of (18) F-FDG uptake was represented as the heterogeneity factor (HF), defined as the derivative (dV/dT) of a volume-threshold function for a primary tumor. We measured the maximum standardized uptake value (SUVmax ) and volumetric PET parameters. The relationship between HF and clinical parameters, as well as other PET parameters, was evaluated. RESULTS: The HF was significantly correlated with SUVmax (r = -0.353, P = 0.017), metabolic tumor volume (r = -0.708, P < 0.0001), and total lesion glycolysis (r = -0.709, P < 0.0001). A multivariate analysis revealed not only cervical lymph node metastasis (hazard ratio = 5.983; P = 0.022) but also HF (hazard ratio = 2.49 × 10(-4) ; P = 0.002) to be independent predictors of overall survival. Those patients with HF < -0.13 showed a worse prognosis than those with HF ≥ -0.13 (P = 0.005). CONCLUSIONS: The intratumoral heterogeneity of (18) F-FDG uptake may be a significant prognostic factor for overall survival in addition to cervical lymph node metastasis in oral cavity cancer. J. Surg. Oncol. 2014 110:702-706. © 2014 Wiley Periodicals, Inc.

Isolated splenic metastasis of ovarian cancer detected with 18F-FDG PET/CT.

We report a case of isolated splenic metastasis from ovarian cancer detected with 18F-FDG PET/CT. A 66-year-old woman with ovarian cancer was referred for 18F-FDG PET/CT to determine the cause of elevated serum CA-125 levels about 48 months after surgery. 18F-FDG PET/CT showed focal, intense uptake in the spleen, with no other abnormal findings. A splenectomy was performed, and the lesion was confirmed as metastasis from ovarian cancer pathologically.

Inflammatory pseudotumor in the mediastinum: imaging with (18)F-fluorodeoxyglucose PET/CT.

Mediastinal inflammatory pseudotumor is a rare benign disease with its capability for local invasion and rapid growth. We present a case of middle-mediastinal inflammatory pseudotumor and report its contrast-enhanced chest computed tomography, (18)F-fluorodeoxyglucose positron emission tomography/computed tomography and pathologic findings.

Incidental focal uptake in oropharynx due to lingual thyroid on diagnostic 131I whole-body scan after total thyroidectomy.

After total thyroidectomy for papillary thyroid carcinoma, a 37-year-old woman underwent a 2-mCi (131)I whole-body scan which demonstrated focal uptake in the anterior neck and in the oropharynx. Preoperative contrast-enhanced neck computed tomography demonstrated a small enhancing nodule typical for ectopic thyroid at the tongue base. She was then treated with 150 mCi (131)I. Small asymptomatic lingual thyroid remnants typically do not affect high-dose (131)I therapy.

Ultrashort-acting insulin may improve on 18F-FDG PET/CT image quality in patients with uncontrolled diabetic mellitus.

OBJECTIVE: It is known that the poor image quality of (18)F-fluorodeoxyglucose ((18)F-FDG) PET scans leads to interpretation difficulty in patients with uncontrolled diabetes mellitus (DM). We usually delay (18)F-FDG PET examination when patients show high glucose levels. This study was performed to evaluate the usefulness and effects of ultrashort-acting insulin on (18)F-FDG PET/computed tomography (CT) imaging in DM patients. MATERIALS AND METHODS: A total of 105 DM patients (68 men and 37 women) were included. Ultrashort-acting insulin was intravenously injected when patients showed high glucose levels (>190 mg/dl). (18)F-FDG was injected 60 min after ultrashort-acting insulin injection, and PET/CT images were acquired. Image quality was graded by consensus using the following scale: 1, good; 2, moderate; and 3, poor. The mean standardized uptake value (SUV(mean)) of the liver, gluteal muscle, and brain was assessed to evaluate the effects of ultrashort-acting insulin. RESULTS: The group administered ultrashort-acting insulin (n=52, blood glucose level: 243.7 ± 46.2 mg/dl) showed a significantly higher glucose level compared with the group not administered ultrashort-acting insulin (n=53, 177.1 ± 5.2 mg/dl). Nevertheless, the image quality of the group with ultrashort-acting insulin was not significantly different from that of the group without ultrashort-acting insulin (χ(2) -test, P=0.47). No significant differences were seen in SUV(mean) in the liver (P=0.13), gluteal muscle (P=0.71), and brain (P=0.16) between groups. CONCLUSION: Ultrashort-acting insulin can be used to improve the image quality of F-FDG PET/CT in uncontrolled DM patients without significant differences in SUV.

Symptomatic late-onset sialadenitis after radioiodine therapy in thyroid cancer.

OBJECTIVE: The aim of this study was to document the subjective and objective findings of symptomatic late-onset sialadenitis after radioiodine therapy in patients with differentiated thyroid cancer. METHODS: Subjective symptoms related to sialadenitis and Tc-99m pertechnetate salivary gland scintigram findings were assessed in 118 patients (26 males, 92 females) both before and during the late phase (mean 338 days) after the administration of radioiodine. RESULTS: Twelve of the 118 patients (10.2 %) complained of symptomatic sialadenitis in the late phase without symptoms during the early phase (within 7 days of radioiodine administration). Significant associations were found between subjective symptoms and visual scintigram findings during the late phase (p = 0.023). Furthermore, uptake and excretion by both parotid glands were significantly affected by radioiodine therapy. CONCLUSIONS: Symptomatic late-onset sialadenitis occurred at an incidence of 10.2 %, and salivary gland function was affected in both parotids in most patients.

Usefulness of (18)F-fluoride PET/CT in Breast Cancer Patients with Osteosclerotic Bone Metastases.

PURPOSE: Bone metastasis is an important factor for the treatment and prognosis of breast cancer patients. Whole-body bone scintigraphy (WBBS) can evaluate skeletal metastases, and (18)F-FDG PET/CT seems to exhibit high specificity and accuracy in detecting bone metastases. However, there is a limitation of (18)F-FDG PET in assessing sclerotic bone metastases because some lesions may be undetectable. Recent studies showed that (18)F-fluoride PET/CT is more sensitive than WBBS in detecting bone metastases. This study aims to evaluate the usefulness of (18)F-fluoride PET/CT by comparing it with WBBS and (18)F-FDG PET/CT in breast cancer patients with osteosclerotic skeletal metastases. MATERIALS AND METHODS: Nine breast cancer patients with suspected bone metastases (9 females; mean age ± SD, 55.6 ± 10.0 years) underwent (99m)Tc-MDP WBBS, (18)F-FDG PET/CT and (18)F-fluoride PET/CT. Lesion-based analysis of five regions of the skeletons (skull, vertebral column, thoracic cage, pelvic bones and long bones of extremities) and patient-based analysis were performed. RESULTS: (18)F-fluoride PET/CT, (18)F-FDG PET/CT and WBBS detected 49, 20 and 25 true metastases, respectively. Sensitivity, specificity, positive predictive value and negative predictive value of (18)F-fluoride PET/CT were 94.2 %, 46.3 %, 57.7 % and 91.2 %, respectively. Most true metastatic lesions on (18)F-fluoride PET/CT had osteosclerotic change (45/49, 91.8 %), and only four lesions showed osteolytic change. Most lesions on (18)F-FDG PET/CT also demonstrated osteosclerotic change (17/20, 85.0 %) with three osteolytic lesions. All true metastatic lesions detected on WBBS and (18)F-FDG PET/CT were identified on (18)F-fluoride PET/CT. CONCLUSION: (18)F-fluoride PET/CT is superior to WBBS or (18)F-FDG PET/CT in detecting osteosclerotic metastatic lesions. (18)F-fluoride PET/CT might be useful in evaluating osteosclerotic metastases in breast cancer patients.

Primary Malignant Fibrous Histiocytoma in Mediastinum: Imaging with (18)F-FDG PET/CT.

Malignant fibrous histiocytoma (MFH) is the most common soft tissue tumor which often occurs in the extremities and the retroperitoneum. Primary mediastinal MFH is rare; thus, findings on (18)F-fluorodeoxyglucose positron emission tomography/computed tomography ((18)F-FDG PET/CT) of mediastinal MFH have not been reported yet. We report herein the case of a 64-year-old man who was presented with a superior mediastinal mass. The mass showed intense (18)F-FDG uptake with central metabolic defect on PET/CT. The maximum standardized uptake value was 17.4. After tumor removal via median sternotomy, an MFH of the storiform-pleomorphic type was diagnosed on histopathologic examination. We present the first report of (18)F-FDG PET/CT imaging of MFH in the superior mediastinum.