New predictors of microvascular invasion for small hepatocellular carcinoma ≤ 3 cm.

BACKGROUND: 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. METHODS: 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. RESULTS: 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%, 71.4%, and 81.4%, respectively. CONCLUSIONS: Our scoring system can accurately predict MVI in small HCC ≤ 3 cm, and could contribute to establishing an appropriate treatment strategy.

Total lesion glycolysis by 18 F-fluorodeoxyglucose positron emission tomography predicts tumor aggressiveness in patients with extrahepatic bile duct carcinoma.

BACKGROUND: 18 F-fluorodeoxyglucose positron emission tomography/computed tomography (18 F-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 18 F-FDG-PET/CT in resectable extrahepatic bile duct carcinoma. METHODS: We retrospectively reviewed the records of 100 patients with extrahepatic bile duct carcinoma who had undergone 18 F-FDG-PET/CT and subsequent surgical resection between January 2017 and January 2023. We calculated maximum 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 multivariate 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.

Striatal dopamine transporter binding differs between dementia with Lewy bodies and Parkinson's disease with dementia.

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.

Clinical guidance of pyoderma gangrenosum 2022.

Pyoderma gangrenosum (PG) is a rare, neutrophilic skin disease. For the purpose of accurate diagnosis and proper treatment of PG, the Japanese clinical practice guidance for PG developed by the Japanese Dermatological Association was published in 2022. In this guidance, clinical aspects, pathogenesis, current therapies, and clinical questions on PG are described from the viewpoints of current knowledge and evidence-based medicine. Here, the English version of the Japanese clinical practice guidelines for PG is presented and is intended to be widely referred to in the clinical examination and treatment of PG.

Comparative analysis of different response criteria at early phase after PD-1 blockade in non-small lung cancer.

PURPOSE: To compare different response criteria using computed tomography (CT) and positron emission tomography (PET) in measuring response and survival in the early phase after programmed death-1 (PD-1) blockade monotherapy in patients with advanced non-small cell lung cancer (NSCLC). METHODS: A total of 54 patients with advanced NSCLC who had 2-deoxy-2-[fluorine-18]-fluoro-D-glucose PET or CT at baseline, and 4 and 9 weeks after PD-1 blockade, were registered. Therapeutic response was assessed according to the Response Evaluation Criteria in Solid Tumors (RECIST), the immune-modified RECIST (irRECIST), the PET Response Criteria in Solid Tumors (PERCIST), the immune-modified PERCIST (iPERCIST), and the European Organization for Research and Treatment of Cancer (EORTC) criteria for dichotomous groups, such as responders vs. non-responders and controlled vs. uncontrolled diseases. Cohen's κ was used to evaluate the concordance among the different criteria. RESULTS: The concordance between CT and PET response criteria was fair or slight for responders vs. non-responders, but the agreement between iPERCIST and irRECIST was moderate for controlled vs. uncontrolled diseases. The agreement between EORTC and PERCIST or iPERCIST in detecting responders was higher in the application of metabolic tumor volume (MTV) and total lesion glycolysis (TLG) than in the standardized uptake value corrected for lean body mass (SUL)peak. To distinguish controlled from uncontrolled disease, RECIST, irRECIST, and PET criteria (PERCIST, iPERCIST, and EORTC) defined by MTV or TLG were found to be significant predictors of progression-free survival. To distinguish responders from non-responders, iPERCIST by SULpeak or EORTC by TLG were identified as significant indicators. The EORTC criteria using TLG for the detection of responders or uncontrolled diseases had a significantly higher predictive value for response assessment. CONCLUSIONS: The EORTC criteria based on TLG for the early detection of responders and uncontrolled disease were effective as a response assessment at 4 weeks after the PD-1 blockade. When SULpeak was not used but MTV or TLG was, the agreement between EORTC and PERCIST or iPERCIST was almost perfect.

Usefulness of simulation in optimizing imaging settings for pediatric technetium-99m-dimercaptosuccinic acid single-photon emission computed tomography.

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.

Prospective assessment using 18F-FDG PET/CT as a novel predictor for early response to PD-1 blockade in non-small-cell lung cancer.

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.

Usefulness of dual isotope 123I-IMP and 201Tl SPECT for the diagnosis of primary central nervous system lymphoma and glioblastoma.

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 (123I-IMP) and thallium-201 chloride single-photon emission computed tomography (201Tl SPECT) for the differential diagnosis. METHODS: Twenty-five PCNSL patients and 27 GBM patients who underwent dual isotope imaging, 123I-IMP and 201Tl 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 (ADCmean and ADCmin, respectively) on magnetic resonance imaging were also analyzed. 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 1.32 and 0.83, respectively, in the delayed phase 123I-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 201Tl SPECT, with excellent tumor detection. 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 malignancy and localization of the tumors with high T/N ratio. Dual isotope 123I-IMP and 201Tl SPECT was useful for the preoperative diagnosis of PCNSL and GBM.

An open-label, single-arm, multi-center, phase II clinical trial of single-dose [131I]meta-iodobenzylguanidine therapy for patients with refractory pheochromocytoma and paraganglioma.

OBJECTIVE: In this phase II study, we aimed to investigate the efficacy and safety of single-dose [131I]meta-iodobenzylguanidine (131I-mIBG) therapy in patients with refractory pheochromocytoma and paraganglioma (PPGL). PATIENTS AND METHODS: This study was designed as an open-label, single-arm, multi-center, phase II clinical trial. The enrolled patients were administered 7.4 GBq of 131I-mIBG. Its efficacy was evaluated 12 and 24 weeks later, and its safety was monitored continuously until the end of the study. We evaluated the biochemical response rate as the primary endpoint using the one-sided exact binomial test based on the null hypothesis (≤ 5%). RESULTS: Seventeen patients were enrolled in this study, of which 16 were treated. The biochemical response rate (≥ 50% decrease in urinary catecholamines) was 23.5% (90% confidence interval: 8.5-46.1%, p = 0.009). The radiographic response rates, determined with CT/MRI according to the response evaluation criteria in solid tumors (RECIST) version 1.1 and 123I-mIBG scintigraphy were 5.9% (0.3%-25.0%) and 29.4% (12.4%-52.2%), respectively. The most frequent non-hematologic treatment-emergent adverse events (TEAEs) were gastrointestinal symptoms including nausea, appetite loss, and constipation, which were, together, observed in 15 of 16 patients. Hematologic TEAEs up to grade 3 were observed in 14 of 16 patients. No grade 4 or higher TEAEs were observed. All patients had experienced at least one TEAE, but no fatal or irreversible TEAEs were observed. CONCLUSION: A single dose 131I-mIBG therapy was well tolerated by patients with PPGL, and statistically significantly reduced catecholamine levels compared to the threshold response rate, which may lead to an improved prognosis for these patients.

Enhancing the accumulation level of 3-[18F]fluoro-L-α-methyltyrosine in tumors by preloading probenecid.

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.

Nonclinical study and applicability of the absorbed dose conversion method with a single biodistribution measurement for targeted alpha-nuclide therapy.

BACKGROUND: We recently reported a new absorbed dose conversion method, RAP (RAtio of Pharmacokinetics), for 211At-meta-astatobenzylguanidine (211At-MABG) using a single biodistribution measurement, the percent injected dose/g. However, there were some mathematical ambiguities in determining the optimal timing of a single measurement of the percent injected dose/g. Thus, we aimed to mathematically reconstruct the RAP method and to examine the optimal timing of a single measurement. METHODS: We derived a new formalism of the RAP dose conversion method at time t. In addition, we acquired a formula to determine the optimal timing of a single measurement of the percent injected dose/g, assuming the one-compartment model for biological clearance. RESULTS: We investigated the new formalism's performance using a representative RAP coefficient with radioactive decay weighting. Dose conversions by representative RAP coefficients predicted the true [211At]MABG absorbed doses with an error of 10% or less. The inverses of the representative RAP coefficients plotted at 4 h post-injection, which was the optimal timing reported in the previous work, were very close to the new inverses of the RAP coefficients 4 h post-injection. Next, the behavior of the optimal timing was analyzed by radiolabeled compounds with physical half-lives of 7.2 h and 10 d on various biological clearance half-lives. Behavior maps of optimal timing showed a tendency to converge to a constant value as the biological clearance half-life of a target increased. The areas of optimal timing for both compounds within a 5% or 10% prediction error were distributed around the optimal timing when the biological clearance half-life of a target was equal to that of the reference. Finally, an example of RAP dose conversion was demonstrated for [211At]MABG. CONCLUSIONS: The RAP dose conversion method renovated by the new formalism was able to estimate the [211At]MABG absorbed dose using a similar pharmacokinetics, such as [131I]MIBG. The present formalism revealed optimizing imaging time points on absorbed dose conversion between two radiopharmaceuticals. Further analysis and clinical data will be needed to elucidate the validity of a behavior map of the optimal timing of a single measurement for targeted alpha-nuclide therapy.

Recurrent Lobar Hemorrhages and Multiple Cortical Superficial Siderosis in a Patient of Alzheimer's Disease With Homozygous APOE ε2 Allele Presenting Hypobetalipoproteinemia and Pathological Findings of 18F-THK5351 Positron Emission Tomography: A Case Report.

In Alzheimer's disease, the apolipoprotein E gene (APOE) ε2 allele is a protective genetic factor, whereas the APOE ε4 allele is a genetic risk factor. However, both the APOE ε2 and the APOE ε4 alleles are genetic risk factors for lobar intracerebral hemorrhage. The reasons for the high prevalence of lobar intracerebral hemorrhage and the low prevalence of Alzheimer's disease with the APOE ε2 allele remains unknown. Here, we describe the case of a 79-year-old Japanese female with Alzheimer's disease, homozygous for the APOE ε2 allele. This patient presented with recurrent lobar hemorrhages and multiple cortical superficial siderosis. The findings on the 11C-labeled Pittsburgh Compound B-positron emission tomography (PET) were characteristic of Alzheimer's disease. 18F-THK5351 PET revealed that the accumulation of 18F-THK 5351 in the right pyramidal tract at the pontine level, the cerebral peduncle of the midbrain, and the internal capsule, reflecting the lesions of the previous lobar intracerebral hemorrhage in the right frontal lobe. Moreover, 18F-THK5351 accumulated in the bilateral globus pallidum, amygdala, caudate nuclei, and the substantia nigra of the midbrain, which were probably off-target reaction, by binding to monoamine oxidase B (MAO-B). 18F-THK5351 were also detected in the periphery of prior lobar hemorrhages and a cortical subarachnoid hemorrhage, as well as in some, but not all, areas affected by cortical siderosis. Besides, 18F-THK5351 retentions were observed in the bilateral medial temporal cortices and several cortical areas without cerebral amyloid angiopathy or prior hemorrhages, possibly where tau might accumulate. This is the first report of a patient with Alzheimer's disease, carrying homozygous APOE ε2 allele and presenting with recurrent lobar hemorrhages, multiple cortical superficial siderosis, and immunohistochemically vascular amyloid ß. The 18F-THK5351 PET findings suggested MAO-B concentrated regions, astroglial activation, Waller degeneration of the pyramidal tract, neuroinflammation due to CAA related hemorrhages, and possible tau accumulation.

Topical Management of Peristomal Pyoderma Gangrenosum: A Report of 3 Case Studies.

BACKGROUND: Peristomal pyoderma gangrenosum (PPG) presents multiple challenges for healthcare providers. The diagnosis of PPG may be delayed, and it may be mistaken for an irritant dermatitis or an infection. Patients with ostomies secondary to inflammatory bowel disease (IBD) may experience PPG. Issues related to PPG include difficulty maintaining a seal of the ostomy pouching system and preventing contamination of the painful, necrotic ulcerations characteristic of this condition. Treatment focuses on the appropriate assessment of the ulcers, successful pouch application, and proper management of IBD through a collaborative effort of both dermatologists and certified WOC nurses (CWOCN). CASES: We treated 3 patients diagnosed with Crohn's disease (CD) who developed refractory PPG. All 3 were treated with a topical steroid lotion, prednisone, and adalimumab or a combination of these agents. Ostomy products and application were tailored to prevent leakage and protect areas of ulceration. All ulcers were healed within 6 months of our initial consultation. CONCLUSION: We successfully managed 3 patients with CD and PPG with appropriate ostomy care, including revision of the ostomy pouching techniques, topical steroid treatment, and treatment based on assessment of ulcer status by the dermatologist and the WOC nurse.

Texture analysis of [18F]-fluorodeoxyglucose-positron emission tomography/computed tomography for predicting the treatment response of postoperative recurrent or metastatic oral squamous cell carcinoma treated with cetuximab.

OBJECTIVE: To assess the value of the texture analysis of fluorine-18F-fluorodeoxyglucose-positron emission tomography/computed tomography (18F-FDG-PET/CT) in predicting the treatment response of postoperative recurrent or metastatic oral squamous cell carcinoma (POR/M-OSCC) treated with cetuximab. METHODS: A total of 14 patients undergoing 18F-FDG-PET/CT with POR/M-OSCC were divided into the responder and non-responder groups according to cetuximab response by Response Evaluation Criteria in Solid Tumors (RECIST). The regions of interest (ROI) were set at the POR/M-OSCC lesions with the highest uptake of 18F-FDG, and the volumetric and texture features were analyzed. The features with correlation coefficient of 0.6 or more were further evaluated using the logistic regression analysis to create a model. RESULTS: The SHAPEVolume(vx), SHAPEVolume(mL), metabolic tumor volume (MTV), and gray-level run-length matrix run-length nonuniformity (GLRLMRLNU) were significantly different between the responder (n = 6) and non-responder (n = 8) groups (p = 0.044, 0.042, 0.047, and 0.012, respectively). The model's area under the curve (AUC) was found to be 0.83, 0.83, 0.79, and 0.92, respectively. The heatmap with PET feature dendrogram showed four distinct clusters including them in patient's responder and non-responder groups. CONCLUSIONS: Higher MTV, GLRLMRLNU, SHAPEVolume(vx), and SHAPEVolume(mL) in 18F-FDG-PET images may have the prediction values for treatment response with POR/M-OSCC treated with cetuximab.