Excessive accumulation of visceral adipose tissue (VAT), or obesity, has an association with cholangiocarcinoma prognosis. We hypothesized that qualitative assessment of VAT would have prognostic significance as well as quantitative assessment. The aim of this study was to measure 18F-fluorodeoxyglucose (18F-FDG) uptake in visceral fat by 18F-FDG positron emission tomography/computed tomography (18F-FDG–PET/CT) and to investigate the prognostic significance of the qualitative assessment of VAT. We retrospectively studied 103 patients with extrahepatic cholangiocarcinoma who underwent surgical resection from April 2017 to April 2023. 18F-FDG–PET/CT was performed before surgery, and the standardized uptake value (SUV) of VAT and blood pool were measured. The VAT-to-blood pool SUV ratio (VBR) was calculated as the ratio of VAT–SUV to blood pool SUV. The optimal VBR cutoff value to predict overall survival (OS) was 0.360. Compared with the low VBR group, the high VBR group was significantly associated with lower body mass index, skeletal muscle index, visceral fat area, subcutaneous fat area, and liver SUV. In the multivariate analysis, patients with a high VBR had poorer OS compared with those with a low VBR. Moreover, the VBR was significantly higher in patients with vs without malnutrition by the GLIM criteria. The VBR showed the lowest Akaike information criteria statistic value among the assessed parameters, indicating that it had the best ability to predict OS. This study suggested that the VBR, determined by 18F-FDG–PET/CT, is associated with the malnutrition and poor OS after resection of extrahepatic cholangiocarcinoma.

This study explored the relationship between mRNA expression profiles obtained through next-generation sequencing (NGS) and 18F-fluorodeoxyglucose positron emission tomography (18F-FDG PET) texture analysis in patients with treatment-resistant oral squamous cell carcinoma (OSCC) who were treated with molecular-targeted drugs. We analyzed the correlation between 18F-FDG PET texture features and NGS data in a small cohort of five patients with recurrent or metastatic OSCC who received molecular-targeted drugs after surgery. Patients were categorized into two groups based on treatment response: responders (n = 3) and non-responders (n = 2). To validate our findings, we examined transcriptomic data from 292 OSCC patients in The Cancer Genome Atlas (TCGA) database. The gene ankyrin repeat and SOCS box containing two (ASB2) was significantly overexpressed in non-responders and strongly correlated with specific PET radiomic features, including GLRLM_GLNU, GLRLM_RLNU, and GLZLM_GLNU (p < 0.05). High ASB2 expression was also associated with poor prognosis in OSCC patients (p < 0.05) and decreased overall survival, as shown by Kaplan–Meier analysis of the TCGA database (p = 0.017). Integrating ASB2 expression data with 18F-FDG PET texture features could potentially improve the prediction of treatment outcomes in treatment-resistant OSCC patients undergoing molecular-targeted therapy.

The present study examined the efficacy of the 18F-FDG PET/CT (18F-FDG PET)-based Lugano Classification for Oral Cancer (Lugano-OC) to stage treatment-resistant oral cancer and its utility for predicting treatment responses. We included 29 oral squamous cell carcinoma (OSCC) patients with disease progression post the primary treatment, who had 18F-FDG PET scans prior to secondary treatment initiation, and were evaluable via Lugano-OC between April 2013 and September 2022. To adapt Lugano-OC to the head and neck region, we designated the clavicle level, a regional lymph node in oral cancer, as the reference standard and visually evaluated 18F-FDG PET accumulation patterns. The primary endpoint was the best overall response, which was assessed according to the Response Evaluation Criteria in Solid Tumors. Patients were categorized into a responder group (n = 7) and non-responder group (n = 22). A univariate analysis revealed significant differences in the CT maximum diameter and metabolic tumor volume (p = 0.050, and 0.037, respectively). A multivariate Cox regression analysis revealed a correlation (hazard ratio 3.59, p = 0.046, 95

Objective Patients with chronic kidney disease (CKD) have an increased risk of adverse cardio-cerebrovascular events. The purpose of this study is to evaluate the prognostic predictors over 5 years in patients with CKD including haemodialysis. Methods In this multicenter, prospective cohort study performed with the Gunma-CKD SPECT Study protocol, 311 patients with CKD [estimated glomerular filtration rate (eGFR) < 60 min/ml/1.73 m2], including 50 patients on haemodialysis, undergoing stress Tc-99m-tetrofosmin SPECT for suspected ischaemic heart disease were followed for 5 years. MACCRE was evaluated, and summed stress score, summed rest score, summed difference score (SDS), left ventricular end-diastolic volume (LVEDV), end-systolic volume (LVESV) and ejection fraction (LVEF) were evaluated by electrocardiogram-gated SPECT. Results Of the 311 patients, 268 were followed for 5 years, and of those patients, 126 experienced MACCRE: cardiac death, n = 15; sudden death, n = 5, nonfatal myocardial infarction, n = 5; hospitalization for heart failure, n = 16; cerebrovascular accident, n = 9; revascularization, n = 49; renal events (haemodialysis initiation/kidney transplantation), n = 20 and other cardiovascular events, n = 7. In univariate Cox analysis, eGFR (P < 0.0001), haemoglobin (P = 0.001), SDS (P = 0.0001), LVEDV (P = 0.002), LVESV (P = 0.0003) and LVEF (P < 0.0001) were associated with MACCRE, and in multivariate Cox analysis, eGFR (P = 0.014) and SDS (P = 0.002) were strongly associated with MACCRE. In Kaplan–Meier analysis, the event-free survival rate for MACCRE was better in patients with SDS below 3 than in those with SDS of 3 or higher (P < 0.0001, log-rank test) and in patients with eGFR of 18 or higher than in those with eGFR below 18 (P < 0.0001, log-rank test). Conclusion In patients with CKD, SDS and eGFR are reliable prognostic markers for the occurrence of MACCRE over 5 years.

We report neuroimaging findings from a 74-year-old right-handed male with Alzheimer’s disease (AD) and lesions of cerebral amyloid angiopathy (CAA), utilizing 11C-PiB-PET, 18F-THK5351-PET, and 18F-MK-6240-PET. 11C-PiB-PET showed positive findings consistent with AD. 18F-THK5351 accumulated in regions of astrogliosis due to tau pathology, subcortical hemorrhage, cortical superficial siderosis (cSS), and monoamine oxidase-B rich areas. 18F-MK-6240 accumulated in regions with tau pathology, subcortical hemorrhage, and cSS, but not notably in CAA-related microbleeds (CMBs). 99mTc-ECD SPECT, conducted 9 years post-diagnosis, revealed reduced cerebral blood flow in the bilateral lower temporal lobes and the right posterior temporo-parietal lobes, overlapping the subcortical hemorrhage and cSS. The patient exhibited progression of global cognitive decline and persistent word fluency deficits (name listing) on neuropsychological examination from the early stage of the disease, irrespective of the right hemorrhagic lesions in the non-dominant hemisphere, suggesting possible crossed aphasia. This is the first report of 18F-MK-6240 binding to a subcortical hemorrhage and cSS lesions, highlighting its binding differences compared to smaller vascular leakages, such as CMBs due to CAA. These results may help refine PET imaging interpretation and diagnostic accuracy for AD with concurrent CAA.

We assessed the severity of amyloid-β accumulation and white matter lesions (WML) in the brain, and their association with cognitive decline, in patients (n = 47) with Alzheimer's disease (AD). The mean cortical standardized uptake value ratio (mcSUVR) was derived from amyloid positron emission tomography, while the percentage of WML area relative to brain parenchymal area was determined using magnetic resonance imaging. Cognitive decline was positively correlated with WML severity ( r = 0.50, p = 0.042) but not mcSUVR (Aβ accumulation). Managing vascular risk factors can prevent cognitive decline in patients with AD.

131I-MIBG radionuclide therapy for the recurrence case of phaeochromocytoma and paraganglioma has been used in Europe from the 1980s, and in Japan from the 1990s by patient's expense. 131I-MIBG therapy for malignant phaeochromocytoma and paraganglioma became the insurance adaptation in Japan in 2022, however there are not enough number of the facilities that can enforce this treatment now. Because radioactivity is given by oneself after the treatment, the patient is hospitalized in the lead cover room that is a radiation therapy sickroom. Cooperation of the medical staff having expertise to nuclear medicine treatment is necessary. Although it is not strong, as for the 131I-MIBG therapy, the cytoreductive effect controls progress and is effective in the decrease in serum catecholamine level. In this report, we speak a summary of the 131I-MIBG therapy, a fact of the treatment, toxicities, curative effect, present situation and the future prospects.

Microvascular invasion (MVI) is a risk factor for postoperative recurrence of hepatocellular carcinoma (HCC), even in early-stage HCC. In small HCC ≤ 3 cm, treatment options include anatomical resection or non-anatomical resection, and MVI has a major effect on treatment decisions. We aimed to identify the predictors of MVI in small HCC ≤ 3 cm. We retrospectively studied 129 patients with very early or early-stage HCC ≤ 3 cm who had undergone 18F-fluorodeoxyglucose positron emission tomography/computed tomography and subsequent hepatic resection from January 2016 to August 2023. These patients were divided into the derivation cohort (n = 86) and validation cohort (n = 43). We examined the risk factors for MVI using logistic regression analysis, and established a predictive scoring system in the derivation cohort. We evaluated the accuracy of our scoring system in the validation cohort. In the derivation cohort, a Lens culinaris agglutinin-reactive fraction of alpha-fetoprotein (AFP-L3), prothrombin induced by vitamin K deficiency or antagonist-II (PIVKA-II), and metabolic tumor volume (MTV) were independent predictors of MVI. We established the scoring system using these three factors. In the validation test, there were no MVI-positive cases with a score of 0 and 1, and all cases were MVI-positive with a score of 4. Moreover, with a score ≥ 2, the sensitivity, specificity, and accuracy of our scoring system were 100

Dialysis patients are at an increased risk of developing renal cell carcinoma (RCC); however, differentiating between RCC and benign cysts can sometimes be difficult using modalities, such as computed tomography (CT) and ultrasonography. 18F-Fluorodeoxyglucose positron emission tomography (FDG-PET)/CT efficiently detects malignant tumors; however, physiological accumulation of FDG in the kidney limits its efficacy in detecting renal tumors. However, in patients with severely impaired renal function, the renal accumulation of FDG is decreased, possibly improving the detection of renal malignancies in this patient population. This study evaluated the usefulness of FDG-PET/CT as a screening tool for detecting RCC in patients with end-stage renal disease. This prospective study recruited 150 participants from 2012 to 2016 who were on dialysis or underwent renal transplantation and were on dialysis until transplantation. FDG-PET/CT was performed to screen for RCC. Three radiologists independently evaluated the images. No protocol was defined for the additional management of positive examinations, leaving decisions to the discretion of each participant. Negative examinations were observed until the end of 2019. In total, 150 participants (mean age, 58 ± 13 years; 105 men) underwent FDG-PET/CT. Twenty patients (13.4

Background: F-18- fluorodeoxyglucose positron emission tomography/computed tomography ((FF)-F-18- FDG- PET/CT) parameters are prognostic factors in multiple malignancies. However, the prognostic value in bile duct carcinoma is unclear. We evaluated the impact of metabolic parameters of (FF)-F-18- FDG- PET/CT in resect-able extrahepatic bile duct carcinoma. Methods: We retrospectively reviewed the records of 100 patients with extrahe-patic bile duct carcinoma who had undergone (FF)-F-18- FDG- PET/CT and subsequent surgical resection between January 2017 and January 2023. We calculated maxi-mum standardized uptake value (SUVmax), metabolic tumor volume (MTV), and total lesion glycolysis (TLG) and investigated their prognostic significance. Results: The optimal cutoff values of SUVmax, MTV, and TLG for predicting overall survival (OS) after surgery were 3.88, 3.55 and 7.55, respectively. In mul-tivariate analysis, each metabolic parameter influenced both OS and recurrence- free survival (RFS). TLG showed the lowest Akaike information criteria statistic value, indicating that it had the best ability to predict OS and RFS. High TLG was significantly associated with the number of lymph node metastases and poorly differentiated type. Patients with high TLG showed poorer RFS and OS, which were significantly worse than in those with low TLG. Conclusions: Tumor TLG predicted tumor malignancy potential and could be a useful prognostic predictor for extrahepatic bile duct carcinoma.

Objective: Urinary drainage (ureteral stenting, percutaneous nephrostomy) is a standard treatment for malignant ureteral obstruction (MUO), but its exact indications have yet to be determined. 99mTc-mercaptoacetyltriglycine (MAG3) renal scintigraphy evaluates urinary obstruction using radioisotopes and may help to determine whether there is an indication for urinary drainage in patients with MUO. In this study, we investigated the ability of MAG3 scintigraphy to avoid unnecessary urinary drainage by following up patients who did not undergo urinary drainage after evaluation of residual renal function using this imaging modality. Methods: Fifty patients who received MAG3 scintigraphy for MUO between April 2020 and January 2022 were included. These patients were classified according to the excretion pattern seen on MAG3 scintigraphy and followed up for renal function, development of pyelonephritis, and low back pain after 1, 2, 3, and 6 months. Results: Fifteen patients received conservative treatment after evaluation by MAG3 scintigraphy. The median patient age was 72 years, and the median creatinine level was 0.79 mg/dl. Hydronephrosis was present on the left side in seven cases, the right side in seven cases, and on both sides in one case. The MAG3 pattern on the affected side was non-function in seven cases, delayed voiding in seven cases, and obstruction in one case. Three patients died as a consequence of their primary malignancy during follow-up. There were no instances of decreased renal function or development of pyelonephritis on conservative treatment. However, one patient underwent ureteral stenting for low back pain on the side contralateral to the nonfunctional kidney. Conclusion: Fourteen of 15 patients with MUO who were treated conservatively after MAG3 scintigraphy did not experience troublesome renal events during up to 6 months of follow-up. MAG3 scintigraphy may be a valuable tool for preventing unnecessary urinary drainage. We would recommend conservative treatment for patients with a non-functional pattern.

123I-ioflupane single-photon emission computed tomography (SPECT) is a highly sensitive and established neuroimaging technique for parkinsonian syndromes (PS). However, differentiating PS by visual inspection or analysis of regions of interest is challenging. To date, image analysis has not been able to differentiate dementia with Lewy bodies (DLB) from Parkinson's disease with dementia (PDD). This study aimed to differentiate PS based on the characteristics of striatal dopamine transporter (DAT) binding using voxel-based analysis. We acquired 123I-ioflupane SPECT data from patients with DLB (n = 30), Parkinson's disease (PD; n = 122), PDD (n = 19), multiple system atrophy with predominant parkinsonism (MSA-P; n = 18), and progressive supranuclear palsy (PSP; n = 45). DAT binding was reduced in the posterior striatum of patients with PD and PDD, whereas it was similar in MSA-P, PSP, and DLB. Hippocampal atrophy, visually evaluated by cerebral magnetic resonance imaging, did not affect striatal DAT binding in DLB. DAT binding in the anterior striatum was inversely correlated with the severity of parkinsonism in PD and PDD but not in DLB. Thus, the appearance of striatal DAT binding might indicate different pathological processes in DLB and PDD.

Background Preoperative differential diagnosis between primary central nervous system lymphoma (PCNSL) and glioblastoma (GBM) is important because these tumors require different surgical strategies. This study investigated the usefulness of dual isotope, iodine-123-labeled N -isopropyl- p -iodo-amphetamine ( 123 I-IMP) and thallium-201 chloride single-photon emission computed tomography ( 201 Tl SPECT) for the differential diagnosis. Methods Twenty-five PCNSL patients and 27 GBM patients who underwent dual isotope imaging, 123 I-IMP and 201 Tl SPECT, are included. Tumor-to-normal (T/N) ratio was calculated from the ratio of maximum tracer counts in the lesion to the mean counts in the contralateral cerebral cortex. The mean and minimum apparent diffusion coefficient values (ADC mean and ADC min, respectively) on magnetic resonance imaging were also analyzed. Results Delayed phase 123 I-IMP SPECT was the most useful imaging examination for the differentiation between PCNSL and GBM compared with early phase 123 I-IMP SPECT, early and delayed phase 201 Tl SPECT, ADC mean , and ADC min . However, the median T/N ratios of PCNSL and GBM were 1.32 and 0.83, respectively, in the delayed phase 123 I-IMP SPECT. On the other hand, the median T/N ratios of PCNSL and GBM were 3.10 and 2.34, respectively, in the delayed phase 201 Tl SPECT, with excellent tumor detection. Conclusion Delayed phase 123 I-IMP SPECT could differentiate between PCNSL and GBM with high accuracy, but T/N ratio was low and tumor detection was poor. 201 Tl SPECT was useful for estimation of the malignancy and localization of the tumors with high T/N ratio. Dual isotope 123 I-IMP and 201 Tl SPECT was useful for the preoperative diagnosis of PCNSL and GBM.

Anti-programmed death-1 (PD-1) blockade is a standard treatment for advanced non-small-cell lung cancer (NSCLC). However, no appropriate modality exists for monitoring its therapeutic response immediately after initiation. Therefore, we aimed to elucidate the clinical relevance of 18F-FDG PET/CT versus CT in predicting the response to PD-1 blockade in the early phase. This prospective study included a total of 54 NSCLC patients. 18F-FDG PET/CT was performed at 4 weeks and 9 weeks after PD-1 blockade monotherapy. Maximum standardized uptake values (SULmax), metabolic tumor volume (MTV), and total lesion glycolysis (TLG) were evaluated. Among all patients, partial metabolic response and progressive metabolic disease after PD-1 blockade were observed in 35.2% and 11.1% on SULmax, 22.2% and 51.8% on MTV, and 27.8% and 46.3% on TLG, respectively, whereas a partial response (PR) and progressive disease (PD), respectively, based on RECIST v1.1 were recognized in 35.2% and 35.2%, respectively. The predictive probability of PR (MTV: 57.9% vs. 21.1%, p = 0.044; TLG: 63.2% vs. 21.1%, p = 0.020) and PD (MTV: 78.9% vs. 47.3%, p = 0.002; TLG: 73.7% vs. 21.1%, p = 0.007) detected based on RECIST at 4 weeks after PD-1 blockade initiation was significantly higher using MTV or TLG on 18F-FDG uptake than on CT. Multivariate analysis revealed that metabolic response by MTV or TLG at 4 weeks was an independent factor for response to PD-1 blockade treatment. Metabolic assessment by MTV or TLG was superior to morphological changes on CT for predicting the therapeutic response and survival at 4 weeks after PD-1 blockade.

INTRODUCTION:3-[18F]fluoro-α-methyl-L-tyrosine ([18F]FAMT) is a promising amino acid tracer targeting L-type amino acid transporter 1 (LAT1). One concern regarding the diagnosis using [18F]FAMT is the possibility of false-negative findings because of its relatively low accumulation level even in malignant tumors. Moreover, preloading probenecid, an organic anion transporter inhibitor, markedly increased the tumor accumulation level of radioiodine-labeled α-methyltyrosine. In this study, we evaluated the usefulness of preloading probenecid in improving the tumor-imaging capability of [18F]FAMT.METHODS:Three biodistribution studies of [18F]FAMT were conducted in normal mice to elucidate the usefulness of probenecid preloading. Later, a biodistribution study and positron emission tomography (PET) imaging of [18F]FAMT were conducted with or without probenecid injection in tumor-bearing mice.RESULTS:Probenecid preloading significantly delayed blood clearance and consequently enhanced the accumulation of [18F]FAMT in the pancreas, a LAT1-positive organ. The effects of probenecid preloading were independent of the administration route. Tumor accumulation level in the biodistribution study and the maximum standardized uptake value in tumors on PET imaging of the probenecid preloading group were significantly higher than those of the control (without probenecid injection) group in tumor-bearing mice.CONCLUSIONS:Preloading probenecid significantly delayed blood clearance and consequently enhanced the accumulation of [18F]FAMT in tumors. These results indicate that preloading probenecid could improve the diagnostic accuracy of [18F]FAMT.

Purpose Technetium-99m (99mTc) dimercaptosuccinic acid (DMSA) single-photon emission computed tomography (SPECT) has been used to diagnose renal scarring. The Japanese Society of Nuclear Medicine recently revised the ‘Consensus Guidelines for Pediatric Nuclear Medicine Examination.’ In this study, we compared simulation data with actual data obtained using a pediatric phantom for 99mTc-DMSA examinations and evaluated the usefulness of simulations in determining the optimal acquisition conditions for SPECT images. Methods A SPECT quality assurance (QA) phantom study produced images with a renal-to-background 99mTc ratio of 283:1 kBq/ml. The projection data for the simulation were simulated using the simulation of imaging nuclear detectors. To compare the actual measurements and simulations, recovery factors were used for the SPECT QA phantom for image quality assessment. Defect contrast and visual evaluation using Scheffe’s method of pairwise comparison were used for the pediatric kidney phantom. Results The optimal imaging settings using a kidney phantom required an acquisition time of more than 8 min. The maximum difference in the recovery coefficient between the simulation and actual measurement using the SPECT QA phantom was 6%. Conclusion We showed that an acquisition time of more than 8 min was necessary for DMSA-SPECT. In addition, phantom simulations were approximately equivalent to the actual measurement data and the adaptability of simulations was confirmed.

Radiological technologists in nuclear medicine departments (NMRTs) are exposed to higher radiation doses than other nuclear medicine staff. Consequently, the Australian Radiation Protection and Nuclear Safety Agency recommends using a 0.5-mm lead equivalence protective apron (PA) for staff with radiation exposure > 800 MBq of 99m Tc. However, 0.5 mm PA is heavy and cumbersome to use. We evaluated the effectiveness of a 0.25 mm lead equivalence lightweight protective apron (L-PA) for NMRT radiation exposure during daily nuclear medicine procedures. The work was performed both with a phantom and in a real situation in our study. The phantom study was conducted with five radioisotopes (RI) placed 0.5 m from the human phantom with and without L-PA. In the clinical study, NMRT recorded the radiation dose for 20 days inside and outside the L-PA using clinical agents (140 examinations). In the phantom study, L-PA decreased the measured doses by 63% with 201 Tl, 41% with 99m Tc, 27% with 67 Ga, 33% with 123 I, and 10% with 131 I. In the clinical study, L-PA reduced the average dose per day by 43%. Therefore, L-PA could have sufficient shielding ability for daily work, mainly using 99m Tc, and could be recommended by considering PA weight.

Abstract Background Preoperative differential diagnosis between primary central nervous system lymphoma (PCNSL) and glioblastoma (GBM) is important because these tumors require different surgical strategies. This study investigated the usefulness of dual isotope, iodine-123-labeled N-isopropyl-p-iodoamphetamine (123I-IMP) and thallium-201 chloride single photon emission computed tomography (201Tl SPECT) for the differential diagnosis. Methods Sixteen PCNSL patients and 20 GBM patients who underwent dual isotope imaging, 123I-IMP and 201Tl SPECT, are included. Early and delayed SPECT images were obtained after 30 minutes and 4 hours, respectively. Tumor to normal (T/N) ratio was calculated from the ratio of maximum tracer counts in the lesion to the mean counts in the contralateral cerebral cortex. The mean and minimum apparent diffusion coefficient values (ADCmean and ADCmin, respectively) on magnetic resonance imaging were also analyzed for comparison of diagnostic accuracy. Results Delayed phase 123I-IMP SPECT was the most useful imaging examination for the differentiation between PCNSL and GBM compared with early phase 123I-IMP SPECT, early and delayed phase 201Tl SPECT, ADCmean and ADCmin. However, the median T/N ratios of PCNSL and GBM were 1.29 and 0.84, respectively, in the delayed phase 123I-IMP SPECT, and the tumor detection was inadequate. On the other hand, the median T/N ratios of PCNSL and GBM were 3.23 and 2.34, respectively, in the delayed phase 201Tl SPECT, with excellent tumor detection. Thirty-five of 36 patients (97.2%) showed a tracer retention rate of 201Tl SPECT 0.7 or higher, which indicates malignant property of brain tumors. Conclusion Delayed phase 123I-IMP SPECT could differentiate between PCNSL and GBM with high accuracy, but T/N ratio was low and tumor detection was poor. 201Tl SPECT was useful for estimation of the localization and the malignant property of the tumors. The combination of these isotopes was useful for the diagnosis of PCNSL and GBM.