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Objective Head motions during brain PET scan cause degradation of brain images, but head fixation or external-maker attachment become burdensome on patients. Therefore, we have developed a motion correction method that uses a 3D face-shape model generated by a range-sensing camera (Kinect) and by CT images. We have successfully corrected the PET images of a moving mannequin-head phantom containing radioactivity. Here, we conducted a volunteer study to verify the effectiveness of our method for clinical data. Methods Eight healthy men volunteers aged 22–45 years underwent a 10-min head-fixed PET scan as a standard of truth in this study, which was started 45 min after 18F-fluorodeoxyglucose (285 ± 23 MBq) injection, and followed by a 15-min head-moving PET scan with the developed Kinect based motion-tracking system. First, selecting a motion-less period of the head-moving PET scan provided a reference PET image. Second, CT images separately obtained on the same day were registered to the reference PET image, and create a 3D face-shape model, then, to which Kinect-based 3D face-shape model matched. This matching parameter was used for spatial calibration between the Kinect and the PET system. This calibration parameter and the motion-tracking of the 3D face shape by Kinect comprised our motion correction method. The head-moving PET with motion correction was compared with the head-fixed PET images visually and by standard uptake value ratios (SUVRs) in the seven volume-of-interest regions. To confirm the spatial calibration accuracy, a test–retest experiment was performed by repeating the head-moving PET with motion correction twice where the volunteer’s pose and the sensor’s position were different. Results No difference was identified visually and statistically in SUVRs between the head-moving PET images with motion correction and the head-fixed PET images. One of the small nuclei, the inferior colliculus, was identified in the head-fixed PET images and in the head-moving PET images with motion correction, but not in those without motion correction. In the test–retest experiment, the SUVRs were well correlated (determinant coefficient, r2 = 0.995). Conclusion Our motion correction method provided good accuracy for the volunteer data which suggested it is useable in clinical settings.

Purpose Esophagectomy with extended lymph node (LN) dissection is a standard treatment for resectable esophageal cancer to prevent recurrence, but severe, potentially life-threatening postoperative complications are still important issues. Accurate diagnosis of LN metastases would enable the decision to dissect or leave the LNs in regions with high risk of complications. Advancements in intraoperative gamma probe and radioactivity detectors have made intraoperative navigation surgery possible using a radiotracer as a marker. F-FDG is one such candidate markers, and the diagnostic power of FDG through counting the radioactivity close to each LN should be elucidated. Materials and methods In 20 patients, 1073 LNs including 38 metastatic LNs were prospectively investigated. Preoperative FDG PET was performed on the same day before esophagectomy and visually surveyed in each LN station to identify abnormal uptake. The FDG radioactivity of each individual dissected LN was measured by a well-type counter, and the pathological diagnosis was compared with LN radioactivity on a one-by-one basis and with the preoperative FDG PET findings for each LN station. Results Lymph node station-based analysis showed a sensitivity and specificity of 28.6% and 96.7%, respectively. One-by-one LN-based analysis using a cutoff value obtained from the receiver operating characteristic curve showed a sensitivity and specificity of 94.7% and 78.7%, respectively, demonstrating higher accuracy compared with the use of LN weight or the shortest diameter. Conclusions The FDG uptake by each LN is a potentially useful marker for navigation surgery in esophageal cancer and has higher accuracy than LN weight or diameter.

123I-metaiodobenzylguanidine scintigraphy is used to differentiate Lewy body disease from other neurodegenerative disorders. We identified 2 cases with remarkably changed pulmonary uptake between 2 metaiodobenzylguanidine scintigraphies; pulmonary uptake was reduced when patients were taking selective serotonin reuptake inhibitor/serotonin noradrenaline reuptake inhibitor and preserved during the medication-naive or withdrawal state, suggesting that pulmonary uptake involves not only the noradrenaline transporter, but also the serotonin transporter. Pulmonary accumulation may affect the heart-to-mediastinum ratio as the region of interest on the planner image is usually placed on the heart and includes part of the lung. Therefore, we should pay attention to the medication state of patients with decreased pulmonary uptake.

This study aimed to assess efficacy and limitations of regional cerebral blood flow imaging using single-photon emission computed tomography (rCBF-SPECT) in the diagnosis of Alzheimer’s disease (AD) with amyloid-positron emission tomography (amyloid-PET). Thirteen patients, who underwent both rCBF-SPECT and amyloid-PET after clinical diagnosis of AD or mild cognitive impairment, were retrospectively identified. The rCBF-SPECTs were classified into 4 grades, from typical AD pattern to no AD pattern of hypoperfusion; amyloid-beta (Aβ) positivity was assessed by amyloid-PET. Four patients were categorized into a typical AD pattern on rCBF-SPECT, and all were Aβ+. The other 9 patients did not exhibit a typical AD pattern; however, 4 were Aβ+. The Mini-Mental State Examination score and Clinical Dementia Rating scale were not significantly different between Aβ+ and Aβ– patients. A typical AD pattern on rCBF-SPECT can reflect Aβ+; however, if not, rCBF-SPECT has a limitation to predict amyloid pathology.

Purpose of the report This study aimed to determine the most effective metabolic index of FDG-PET and MET-PET to differentiate high- and low-grade gliomas, and then to characterize tumor metabolism according to the 2016 WHO classification. We also developed a new calculation method of potential infiltrative tumor volume to overcome the current limitations of tumor evaluation according to metabolic index, which focuses solely on tumor core area. Materials and methods Patients who underwent both FDG-PET and MET-PET, as well as surgical treatment, were retrospectively identified. All tumors were diagnosed histologically and included 44 high-grade and 19 low-grade gliomas. Metabolic indices of tumor-to-normal (T/N) ratio and maximum value within the tumor itself were compared between high- and low-grade tumors. A calculation method for potential infiltrative tumor volume was developed and compared between these 2 grades. Results T/N, calculated as tumor value divided by normal cortex value, was the most effective (area under the curve, 0.800 for FDG-PET; area under the curve, 0.773 for MET-PET) for differentiating high- and low-grade gliomas. Potential infiltrative volume effectively distinguished between high- and low-grade glioma (43.8 ± 30.2 mL vs 14.0 ± 12.6 mL; P = 0.005 [t test]). A combination of T/N, with a cutoff value of 0.9 or higher on FDG-PET and/or 3.0 or higher on MET-PET, and potential infiltrative volume, with a cutoff value of 20.0 mL or higher, provided a diagnostic accuracy of 89% in distinguishing high- from low-grade gliomas. Conclusions Evaluation of potential infiltrative volume surrounding the tumor core area, in addition to the T/N ratio of the tumor core, may help distinguish between high- and low-grade gliomas.

Background Neoadjuvant chemoradiotherapy followed by an optimal surgery is the standard treatment for patients with locally advanced rectal cancer. FDG-PET/CT is commonly used as the modality for assessing the effect of chemoradiotherapy. Objective The purpose of this study was to investigate whether PET/CT-based volumetry could contribute to the prediction of pathological complete response or prognosis after neoadjuvant chemoradiotherapy. Design This was a retrospective cohort study. Settings This study was conducted at a single research center. Patients Ninety-one consecutive patients with locally advanced rectal cancer were enrolled between January 2005 and December 2015. Intervention Patients underwent PET/CT before and after neoadjuvant chemoradiotherapy. Main outcome measures Maximum standardized uptake value and total lesion glycolysis on PET/CT before and after neoadjuvant chemoradiotherapy were calculated using isocontour methods. Correlations between these variables and clinicopathological factors and prognosis were assessed. Results PET/CT-associated variables before chemoradiotherapy were not correlated with either clinicopathological factors or prognosis. Maximum standardized uptake value was associated with pathological complete response, but total lesion glycolysis was not. Maximum standardized uptake value correlated with ypT, whereas total lesion glycolysis correlated with both ypT and ypN. High total lesion glycolysis was associated with a considerably poorer prognosis; the 5-year recurrence rate was 65% and the 5-year mortality rate 42%, whereas in lesions with low total lesion glycolysis, these were 6% and 2%. On multivariate analysis, high total lesion glycolysis was an independent risk factor for recurrence (HR = 4.718; p = 0.04). Limitations The gain in fluoro-2-deoxy-D-glucose uptake may differ between scanners, thus the general applicability of this threshold should be validated. Conclusions In patients with locally advanced rectal cancer, high total lesion glycolysis after neoadjuvant chemoradiotherapy is strongly associated with a worse prognosis. Total lesion glycolysis after chemoradiotherapy may be a promising preoperative predictor of recurrence and death. See Video Abstract at http://links.lww.com/DCR/A464.

SummaryObjective Multiple hippocampal transection (MHT) is a surgical procedure developed to avoid postoperative memory decline. Its efficacy has been documented in only a few small series with relatively short observation periods. We prospectively evaluated the long-term seizure and cognitive outcomes of MHT combined with multiple subpial transection or lesionectomy (MHT + MST/L). Moreover, we quantitatively evaluated the structural and metabolic neuroradiologic changes after the procedure to elucidate the anatomofunctional correlates of memory preservation. Methods Twenty-four patients underwent MHT + MST/L for treatment of drug-resistant mesial temporal lobe epilepsy (mTLE) and were followed for more than 5 years. Indications for the procedure were the following: (1) verbally dominant-sided surgery in patients with a radiologically normal hippocampus or normal/near normal memory, and (2) surgery for patients with concomitant epileptic activity on the contralateral side, that is, when the surgery was considered a high risk for severe postoperative memory decline. Seizure outcome was evaluated using Engel's classification 1, 2, and 3 years after surgery, and at the last visit (LV). Three subgroups were evaluated as well: magnetic resonance imaging (MRI) negative (MN), hippocampal sclerosis (HS), and normal hippocampus with extrahippocampal lesion (NHEL). The long-term cognitive outcome was followed through to LV in patients who underwent verbally dominant-sided surgery. Hippocampal volume (HV), diffusion tensor parameters (DTP), and glucose utilization (GU) were determined from MRI and fluorodeoxyglucose–positron emission tomography (FDG-PET) studies performed before and >6 months after surgery. Results Whereas the rate of Engel class I as a whole was 71% at 1 year and 67% at LV, the rates in the MN, HS, and NHEL groups were 60%, 67%, and 100% at 1 year, respectively, and 70%, 56%, and 80% at LV, respectively. Memory indices after verbally dominant-sided surgery transiently declined at 1 month but recovered to and remained at the preoperative level through LV. The HV, DTP of the fornix, and GU of the temporal lobe on the treated side showed pathologic changes even when the transiently declined memory indices had recovered to the preoperative level. Significance The long-term outcome for complex partial seizures after MHT + MST/L was comparable to that seen after anterior temporal lobectomy. The long-term cognitive outcome was favorable, even for patients with a high risk of severe postoperative memory decline. MHT + MST/L may be a treatment option for mTLE in which resective surgery carries a risk of postoperative memory decline, particularly in patients without MRI lesion. A discrepancy between the preserved memory and the pathologic neuroradiologic changes indicates the necessity for further studies including functional MRI.

The number of patients diagnosed with renal tumor has been increasing with the extensive application of ultrasonography and computed tomography (CT).1 Surgical resection remains necessary for a definitive diagnosis of renal tumor, but it is not always clinically beneficial, especially for elderly patients or those with severe comorbidities. For these patients, avoiding surgery and proceeding to active surveillance has become the mainstay of patient management.2,3 Without surgical intervention, the evaluation of tumor malignancy is helpful for treatment strategy decisions such as the timing of surgery or maintaining active surveillance. F-18 fluorodeoxyglucose (FDG) positron emission tomography (PET) is a widely used effective modality for evaluating tumor activity by estimating glucose metabolism. The usefulness of FDG-PET imaging in oncology is based on a correlation between glucose metabolism and the degree of tumor malignancy, which has been reported for various tumors.4–12 Although we have observed differential FDG uptake in renal tumor, there are few studies concerning FDG-PET for renal cell carcinoma (RCC), most likely because of difficulties in differentiating the radioactivity of FDG accumulated in renal tumors from the radioactivity of FDG excreted via the urinary system during physiological processes. In addition, false-negative cases can lead to a low sensitivity for RCC detection.13–15 The use of FDG-PET for routine evaluation of renal tumors has not been recommended. However, recently dedicated PET-CT have improved image resolution and signal-to-noise ratio. In addition, attached-CT for photon attenuation correction provides anatomical information on FDG-PET images. A comparison of diagnostic CT and attached-CT facilitates the identification of renal tumors on FDG-PET images, which enable us to place region of interest (ROI) on renal tumor more accurately. Calculation semiquantitative values using these ROI help elucidate the characteristics of FDG uptake of a renal tumor. In this study, we hypothesized that glycolytic metabolism would reflect tumor aggressiveness in renal tumors. Pathological findings such as histological subtype, nuclear grade, and TNM stage are the most widely used indicators for renal tumor aggressiveness.16–18 We investigated the correlation of preoperative renal tumor metabolic activity with tumor pathology. This study applied a semiquantitative value of metabolism as defined by the standardized uptake value (SUV) in a greater number of cases than previously investigated.

Introduction Anti-myelin oligodendrocyte glycoprotein (MOG) antibodies have recently been associated with epilepsy with FLAIR hyperintense cortical lesions on MRI. Association between anti-MOG antibodies and epilepsy without detectable structural brain lesion on MRI is unknown. Case report A 48-year-old right-handed man with a four-and-a-half year history of anti-MOG antibody associated demyelinating disease presented with persistent global aphasia. Brain MRI showed no new lesion or cortical lesion in the left hemisphere. Electroencephalogram, magnetoencephalography, and brain perfusion single-photon emission computed tomography suggested epileptic foci in the left temporal and parietal lobes, and the patient's aphasia transiently responded to intravenous diazepam, compatible with aphasic status epilepticus. Cerebrospinal fluid showed mildly elevated cell count and positive oligoclonal bands. The patient only partially responded to antiepileptic drugs but responded to steroid pulse therapy. Six months later, the patient again exhibited global aphasia. Brain MRI showed tumefactive white matter lesion in the left temporo-parietal lobes. Conclusion Autoimmune epilepsy without obvious causative lesion on MRI can be seen in the course of anti-MOG antibody associated demyelinating disease. The subsequent emergence of tumefactive lesion closely located to the epileptic foci may suggest some association between autoimmune epilepsy and demyelinating lesions.

Identification of secondary colonic neoplasia proximal to obstructing colorectal cancer is essential for determining the range of colorectal resection. We examined the accuracy of 18-fluoro deoxy glucose-positron emission tomography (FDG-PET) for detection of colonic neoplasia. We recruited patients with obstructing colorectal cancer from our registry. Preoperative FDG-PET was performed, and the detection rate for colonic neoplasia was estimated. Preoperative colonoscopy or postoperative colonoscopy within a year after operation was employed as the indexed standard. Ninety-three patients were included in this study. Colonic neoplasia proximal to obstruction was confirmed in 83 cases. The sensitivity and positive predictive value of FDG-PET were 25.3% and 77.8%, respectively. The sensitivity was higher in larger lesions (3.2% for 21 mm) and in higher pathological grade lesions (14.6% for low-grade adenoma, 38.5% for high-grade adenoma, 66.7% for carcinoma in situ, and 100% for invasive carcinoma). The round shape in PET images was a predictor for neoplasia, with an area under the curve of 0.75293 at an aspect ratio of 1.70. FDG-PET should be used as a screening modality for invasive colorectal cancer (CRC) proximal to obstructing colorectal cancer.

Background and aim The predictors of severe gastrointestinal (GI) events in GI lymphoma patients are unclear. We aimed to develop a risk scoring system for GI events requiring surgery. Methods In this retrospective study of 192 patients with GI lymphoma, the state of lymphoma, macroscopic findings, examination results, and International Prognostic Index were assessed. We developed a risk score for GI events that required surgery and assessed its accuracy by calculating the area under the receiver operating characteristic curve (AUC). Internal validation was performed using bootstrap resampling. Results Severe GI events occurred in 21 (11%) patients. We developed a 4-point scoring system (the FLASH score) comprising the following three independent predictors (weighted by regression coefficients): (i) focal appearance and large size (≥ 40 mm), 1 point; (ii) aggressive lymphoma of the small bowel, 2 points; and (iii) high (18)F-fluorodeoxyglucose positron emission tomography uptake, 1 point. The score predicted severe GI events with an AUC value of 0.91 (internal validation; AUC, 0.86). Risk was classified into three categories: the GI event rate was 0% in the low-risk group (0 points), 9% in the intermediate-risk group (1-2 points), and 61% in the high-risk group (3-4 points) (AUC, 0.89). Conclusions We developed and internally validated a risk scoring system (the FLASH score) that included macroscopic findings to predict severe GI events in GI lymphoma patients. Patients with high scores are candidates for elective surgery to prevent GI events.

Cerebellar liponeurocytoma is a rare tumor that usually develops in adult patients, and is categorized as World Health Organization grade II. Because of the small number of reports on its radiological and pathological features, the disease remains poorly characterized. The current case involved a 59-year-old man with tumor in the upper cerebellar vermis. Preoperative positron emission tomography (PET) showed high uptake on (11)C-methionine PET, but low uptake on (18)F-fluorodeoxyglucose PET. These findings resemble those of central neurocytoma and oligodendroglioma, but are incompatible with other brain tumors. Subtotal tumor removal was performed by suboccipital craniotomy. Histopathological examinations showed sheets of small, isomorphic cells with round nuclei and clear cytoplasm, and focal vacuolated cells resembling adipose cells. On immunohistochemistry, tumor cells were positive for synaptophysin and NeuN. Vacuolated cells were immunoreactive for perilipin. Based on these findings, cerebellar liponeurocytoma was diagnosed. Genetic analyses revealed absences of both chromosome 1p/19q loss and isocitrate dehydrogenase 1 mutation, further ruling out oligodendroglioma. These radiological and genetic aspects of cerebellar liponeurocytoma, which are mostly in common with central neurocytoma, should prove helpful in differentiating this rare tumor from other tumors with similar morphology.

Among diffuse gliomas, oligodendrogliomas show relatively better prognosis, respond well to radiotherapy and chemotherapy, and seldom progress to very aggressive tumors. To elucidate the genetic and epigenetic background for such behavior and tumor evolution during tumor relapse, we comparatively analyzed 12 pairs of primary and recurrent oligodendrogliomas with 1p/19q-codeletion. Initial treatment for these patients was mostly chemotherapy alone. Temozolomide was used for 3, and procarbazine, nimustine and vincristine (PAV chemotherapy) were used for 7 patients. World Health Organization histological grade at recurrence was mostly stable; it was increased in 2, the same in 9, and decreased in 1 cases. Whole-exome sequencing demonstrated that the rate of shared mutation between the primary and recurrent tumors was relatively low, ranging from 3.2-57.9% (average, 33.3%), indicating a branched evolutionary pattern. The trunk alterations that existed throughout the course were restricted to IDH1 mutation, 1p/19q-codeletion, and TERT promoter mutation, and mutation of the known candidate tumor suppressor genes CIC and FUBP1 were not consistently observed between primary and recurrent tumors. Multiple sampling from different regions within a tumor showed marked intratumoral heterogeneity. Notably, in general, the number of mutations was not significantly different after recurrence, remaining under 100, and no hypermutator phenotype was observed. FUBP1 mutation, loss of chr. 9p21, and TCF12 mutation were among a few recurrent de novo alterations that were found at recurrence, indicating that these events were clonally selected at recurrence but were not enough to enhance malignancy. Genome-wide methylation status, measured by Illumina 450 K arrays, was stable between recurrence and the primary tumor. In summary, although oligodendroglioma displays marked mutational heterogeneity, histological malignant transformation accompanying events such as considerable increase in mutation number and epigenetic profile change were not observed at recurrence, indicating that noticeable temporal and spatial genetic heterogeneity in oligodendrogliomas does not result in rapid tumor progression. Electronic supplementary material The online version of this article (doi:10.1186/s40478-017-0422-z) contains supplementary material, which is available to authorized users.

Background Myofibroma is a fibrous tumor of infancy that sometimes affects a single patient in a multiple fashion (infantile myofibromatosis). Its intracranial involvement is extremely rare, and its clinical picture has been poorly characterized. Here we report an interesting case of myofibromatosis with an intracranial lesion that behaved like an aggressive tumor and yet demonstrated very benign pathology. Case Description A 36-year-old man had never been diagnosed with infantile myofibromatosis despite his lifelong history of multiple tumors of various diagnoses. He presented with simple partial seizure and progressive right finger paresis. A series of brain magnetic resonance imaging scans revealed a rapidly growing lesion at his left frontal convexity, which corresponded to a high uptake area on a 18 F-fluorodeoxyglucose-positron emission tomography scan, highly suspicious of malignancy. He underwent complete tumor resection and his symptoms quickly resolved postoperatively. The pathological diagnosis was myofibroma with a MIB-1 labeling index of 1%−2%. A retrospective review of his previous tumors demonstrated the same pathology, which led to the diagnosis of myofibromatosis. Follow-up magnetic resonance imaging illustrated stabilization or regression of other preexisting lesions as well as formation of a new intracranial lesion. Conclusions The discrepancy between rapid tumor growth associated with increased uptake on metabolic imaging and benign pathologic findings with a low proliferative index is noteworthy and should be recognized in the management of an intracranial lesion in a patient with infantile myofibromatosis. Given de novo formation of a lesion in this adult patient, long-term follow-up is essential in this disease.

Background Alice in Wonderland syndrome (AIWS) is a rare neuropsychiatric syndrome that typically manifests in distortion of extrapersonal visual image, altered perception of one’s body image, and a disturbed sense of the passage of distance and time. Several conditions have been reported to contribute to AIWS, although its biological basis is still unknown. Here, we present the first case demonstrating a clear concurrence of recurrent depressive disorder and AIWS. The clinical manifestations and pre- and post-treatment fluorodeoxyglucose positron-emission tomographic (FDG-PET) images provide insights into the psychopathological and biological basis of AIWS. Case presentation We describe a 63-year-old Japanese male who developed two distinct episodes of major depression concurrent with AIWS. In addition to typical AIWS perceptual symptoms, he complained of losing the ability to intuitively grasp the seriousness of news and the value of money, which implies disturbance of high-order cognition related to estimating magnitude and worth. Both depression and AIWS remitted after treatment in each episode. Pre-treatment FDG-PET images showed significant hypometabolism in the frontal cortex and hypermetabolism in the occipital and parietal cortex. Post-treatment images showed improvement of these abnormalities. Conclusions The clinical co-occurrence of depressive episodes and presentation of AIWS can be interpreted to mean that they have certain functional disturbances in common. In view of incapacity, indifference, devitalization, altered perception of one’s body image, and disturbed sense of time and space, the features of AIWS analogous to those of psychotic depression imply a common psychopathological basis. These high-order brain dysfunctions are possibly associated with the metabolic abnormalities in visual and parietotemporal association cortices that we observed on the pre- and post-treatment FDG-PET images in this case, while the hypometabolism in the frontal cortex is probably associated with depressive symptoms.

Inter-ictal (18)F-2-fluoro-deoxy-D: -glucose-positron emission tomography (FDG-PET) is widely used for preoperative evaluation to identify epileptogenic zones in patients with temporal lobe epilepsy. In this study, we combined statistical parametric mapping (SPM) with the asymmetry index and volume-of-interest (VOI) based extent analysis employing preoperative FDG-PET in unilateral mesial temporal lobe epilepsy (MTLE) patients. We also evaluated the detection utility of these techniques for automated identification of abnormalities in the unilateral hippocampal area later confirmed to be epileptogenic zones by surgical treatment and subsequent good seizure control.FDG-PET scans of 17 patients (9 males, mean age 35 years, age range 16-60 years) were retrospectively analyzed. All patients had been preoperatively diagnosed with unilateral MTLE. The surgical outcomes of all patients were Engel class 1A or 1B with postoperative follow-up of 2 years. FDG-PET images were spatially normalized and smoothed. After two voxel-value adjustments, one employing the asymmetry index and the other global normalization, had been applied to the images separately, voxel-based statistical comparisons were performed with 20 controls. Peak analysis and extent analysis in the VOI in the parahippocampal gyrus were conducted for SPM. For the extent analysis, a receiver operating characteristic (ROC) curve was devised to calculate the area under the curve and to determine the optimal threshold of extent.The accuracy of the method employing the asymmetry index was better than that of the global normalization method for both the peak and the extent analysis. The ROC analysis results, for the extent analysis, yielded an area under the curve of 0.971, such that the accuracy and optimal extent threshold of judgment were 92 and 32.9%, respectively.Statistical z-score mapping with the asymmetry index was more sensitive for detecting regional glucose hypometabolism and more accurate for identifying the side harboring the epileptogenic zone using inter-ictal FDG-PET in unilateral MTLE than z-score mapping with global normalization. Moreover, the automated determination of the side with the epileptogenic zone in unilateral MTLE showed improved accuracy when the combination of SPM with the asymmetry index and extent analysis was applied based on the VOI in the parahippocampal gyrus.

Background Gastric cancer exhibits various degrees of fluorine F-18 fluorodeoxyglucose (18F-FDG) uptake on positron emission tomography/computed tomography (PET/CT). We evaluated the relationship between 18F-FDG uptake and the presence/absence of metastasis in individual lymph nodes (LN) on a one-to-one basis. Methods We analyzed 21 patients with gastric cancer. We injected 18F-FDG intravenously in the morning, and gastrectomy with LN dissection was performed in the afternoon of the same day. Radiation doses were measured at each LN using a well-type counter, and we then compared 18F-FDG uptake, the shortest diameter, and pathological examination results for each LN. Results In our study, 906 LNs were analyzed, including 115 metastatic LNs. Metastatic LNs showed significantly higher 18F-FDG uptake (P

Objective. To elucidate the time course of tumor metabolism during the first 3 months after90Y-ibritumomab tiuxetan radioimmunotherapy (RIT) in patients with refractory malignant lymphoma.Materials and Methods. Seven patients with recurrent follicular lymphoma underwent FDG-PET imaging before and after 1-, 4-, and 12-week RIT with90Y-ibritumomab tiuxetan. Tumor metabolic activity on FDG-PET scans was assessed as the maximum standard uptake value (SUVmax).Results. Decrease in metabolism was detected 1 week after RIT. In the most decreased lesion, SUVmax decreased to 20% of the baseline value during the first week. Most lesions continued to decrease for up to 4 weeks. Some lesions showed increased metabolism from 4 to 12 weeks, while the level of FDG accumulations at 12 weeks was still lower than the baseline.Conclusions. Tumor response to RIT could be observed as early as 1 week after the administration of RIT. After tumor activity decreases, the metabolism may increase at least between 4 and 12 weeks. It suggests that the metabolic changes should be carefully evaluated during this period.

We herein report the efficacy of FDG-PET for detecting yolk sac tumors in two teenage patients. One patient had a rare bone metastasis and the other had tiny recurrent lesions at the mediastinum. Both lesions were difficult to detect by conventional diagnostic modalities. In contrast, FDG-PET was very effective for detecting these lesions. Furthermore, the SUVmax of the lesion reflected the tumor activity, which was also suggested by the fluctuating values of serum alpha-fetoprotein (AFP), an established marker of yolk sac tumors. FDG-PET may be a useful procedure to detect tiny and metastatic, pediatric yolk sac tumors.

This study aims to elucidate differences in preoperative cerebral glucose metabolism between patients who did and did not become seizure free after unilateral mesial temporal lobe epilepsy (mTLE) surgery. We hypothesized that regional glucose metabolism on preoperative fluorodeoxyglucose positron emission tomography (FDG-PET) in patients with seizure-free outcomes differed from that in patients who were not seizure free after appropriate epilepsy surgery for unilateral mTLE. In this study, we compared preoperative FDG-PET findings between these two patient groups by applying a statistical analysis approach, with a voxel-based Asymmetry index (AI), to improve sensitivity for the detection of hypometabolism. FDG-PET scans of 28 patients with medically refractory mTLE, of whom 17 achieved a seizure-free outcome (Engel class 1 a–b) during a postoperative follow-up period of at least 2 years, were analyzed retrospectively. Voxel values were adjusted by the AI method as well as the global normalization (GN) method. Two types of statistical analysis were performed. One was a voxel severity analysis with comparison of voxel values at the same coordinate, and the other was extent analysis with comparison of the number of significant voxels in the anatomical areas predefined with Talairach’s atlas. In the voxel severity analysis, significant hypometabolism restricted to the ipsilateral temporal tip and hippocampal area was detected in the postoperative seizure-free outcome group as compared to controls. No significant area was detected in the non-seizure-free group as compared to controls (family-wise error corrected, p

Assessment of the activity of rheumatoid arthritis (RA) is important for the prediction of future articular destruction. (18)F-FDG PET is known to represent the metabolic activity of inflammatory disease, which correlates with the pannus volume measured by MRI or ultrasonography. To evaluate the correlation between (18)F-FDG accumulation and RA pathology, we assessed (18)F-FDG accumulation in vivo using collagen-induced arthritis (CIA) animal models and (3)H-FDG uptake in vitro using various cells involved in arthritis.(18)F-FDG PET images of rats with CIA were acquired on days 10, 14, and 17 after arthritis induction. The specimens were subsequently subjected to macroautoradiography, and the (18)F-FDG accumulation was compared with the histologic findings. (3)H-FDG uptake in vitro in inflammatory cells (neutrophils, macrophages, T cells, and fibroblasts) was measured to evaluate the contributions of these cells to (18)F-FDG accumulation. In addition, the influence on (3)H-FDG uptake of inflammatory factors, such as cytokines (tumor necrosis factor alpha [TNFalpha], interleukin 1 [IL-1], and IL-6), and hypoxia was examined.(18)F-FDG PET depicted swollen joints, and (18)F-FDG accumulation increased with the progression of arthritis. Histologically, a higher level of (18)F-FDG accumulation correlated with the pannus rather than the infiltration of inflammatory cells around the joints. In the in vitro (3)H-FDG uptake assay, fibroblasts showed the highest (3)H-FDG uptake, followed by neutrophils. Although only a small amount of (3)H-FDG was incorporated by resting macrophages, a dramatic increase in (3)H-FDG uptake in both fibroblasts and macrophages was observed when these cells were exposed to inflammatory cytokines, such as TNFalpha and IL-1, and hypoxia. Although neutrophils showed relatively high (3)H-FDG uptake without activation, no increase in (3)H-FDG uptake was observed in response to inflammatory cytokines. (3)H-FDG uptake by T cells was much lower than that by other cells. Thus, fibroblasts and activated macrophages contribute to a high level of (18)F-FDG accumulation in the pannus, and hypoxia as well as cytokine stimulation significantly increases (18)F-FDG uptake by these cells.(18)F-FDG accumulation in RA reflects proliferating pannus and inflammatory activity enhanced by inflammatory cytokines and hypoxia. (18)F-FDG PET should be effective for quantifying the inflammatory activity of RA.

A positive scan in pretransplantation fluorine-18 fluorodeoxyglucose positron emission tomography (FDG-PET) has been shown to be associated with a poor prognosis in patients with lymphoma undergoing high-dose chemotherapy followed by autologous stem cell transplantation (ASCT). For those with a positive FDG-PET scan, treatment that includes allogeneic stem cell transplantation (allo-SCT) may be an alternative. However, it is uncertain whether allo-SCT can overcome a poor prognosis. Therefore, we conducted a retrospective analysis of 14 patients with lymphoma who had undergone FDG-PET scan within one month before allo-SCT at our institution. Eleven patients were FDG-PET-positive and three were negative. With a median follow-up of 17 months (range: 6-44) after allo-SCT, the cumulative incidence of progression was 29.3% in FDG-PET-positive patients and 0% in the FDG-PET-negative patients. Four of the 11 patients who had post-transplantation FDG-PET showed FDG-avid lesions on the first post-transplantation scan. In two of the four, regression of the lesions was observed during the scheduled reduction of immunosuppressant without donor lymphocyte infusion and remained without progression at the last follow-up (34 and 8 months). Durable responses after allo-SCT, at least with conventional conditioning regimens, can be expected in patients with FDG-PET-positive lesions before transplantation. Thus, conventional allo-SCT could be an attractive modality compared to ASCT for patients with positive FDG-PET after the completion of conventional salvage chemotherapy, and particularly for patients with T and NK-cell lymphomas.

We present 3 cases with abnormal accumulation of FDG in the aortic wall. Their clinical manifestations were vague or asymptomatic, and laboratory data were consistent with inflammatory reaction. These 3 patients were diagnosed with Takayasu arteritis, inflammatory aortic aneurysm (IAA), and retroperitoneal fibrosis (RF), respectively. FDG-PET and CT images showed the intense FDG uptake corresponding to the arterial walls and/or the soft tissue density surrounding the artery. It was deduced that FDG was probably taken up by inflammatory cells which infiltrated the arterial walls and/or the soft tissue mass. These cases indicated that FDG-PET is a useful method for localization of inflammatory lesion in patients with unspecific clinical findings and laboratory data.

Radionuclide cisternography is an indispensable examination to detect cerebrospinal fluid (CSF) leakage in patients suspected of having spontaneous intracranial hypotension (SIH). However, it sometimes fails to demonstrate the site of CSF leakage, and in such cases, early bladder visualization is utilized for the diagnosis of SIH as an indirect finding. The aim of this work is to improve the diagnostic ability of radionuclide cisternography and to reevaluate the reliability of early bladder visualization as an indirect finding of CSF leakage. Methods: We obtained serial images during the first hour after injection as well as the following time points in 4 patients with SIH and 5 with normal pressure hydrocephalus (NPH) as a control. We also performed blood sampling over time to measure blood radioactivity concentrations. Results: All 4 patients with SIH demonstrated leakage, 2 of 4 within one hour after injection. Bladder visualization was observed falsely in 4 of 5 patients with NPH, considered to be the result of a lumbar puncture complication. In this false bladder visualization, blood radioactivity showed a more rapid raise and fall than in CSF leakage of SIH. Conclusions: The combination of radionuclide cisternography, including early time points and blood sampling, may enable accurate diagnosis of SIH.

Synaptotagmin (p65), an integral membrane protein of synaptic vesicles, is thought to be involved in calcium-dependent exocytosis of synaptic vesicles. Here, we report the cloning and tissue distribution of a novel isoform of synaptotagmin, designated synaptotagmin III. The cDNA clones encoding synaptotagmin III have been isolated from a rat brain cDNA library. Rat synaptotagmin III is a protein of 588 amino acids having 40.5, 38.3, and 64.0% identity with rat synaptotagmin I, rat synaptotagmin II, and o-p65-C, a third synaptotagmin isoform of marine ray Discopyge ommata, respectively. The region of the two internal repeats homologous to the regulatory domain (C2 domain) of protein kinase C is highly conserved among synaptotagmin I, II, and III. RNA blotting studies reveal that synaptotagmin III mRNA is expressed in brain, various endocrine tissues, and hormone-secreting clonal cells. These results suggest that rat synaptotagmin III is a mammalian homolog of o-p65-C and is involved in Ca(2+)-dependent exocytosis of secretory vesicles in endocrine cells, as well as in neurons.

Carcinoma exhibiting signet ring cell appearance in the prostatic gland is rare. An example of this rare tumor is presented herein.

We report a 3-year follow-up of high-dose ubiquinol supplementation in a case of familial multiple system atrophy (MSA) with compound heterozygous nonsense (R387X) and missense (V393A) mutations in COQ2. A high-dose ubiquinol supplementation substantially increased total coenzyme Q10 levels in cerebrospinal fluid as well as in plasma. The patient was at the advanced stage of MSA, and the various scores of clinical rating scales remained stable without changes during the 3 years. The cerebral metabolic ratio of oxygen measured by 15O2 PET, however, increased by approximately 30% after administration of ubiquinol, suggesting that ubiquinol can improve mitochondrial oxidative metabolism in the brain. It also suggests the therapeutic potential of ubiquinol for patients with MSA with COQ2 mutations. Further clinical trials of administration of high-dose ubiquinol to MSA patients are warranted.