Prognostic assessment of 18F-boronophenylalanine positron emission tomography (BPA-PET) in salvage boron neutron capture therapy for malignant brain tumors.

Background: Boron neutron capture therapy (BNCT) stands out as a propitious anti-cancer modality. 18F-boronophenylalanine positron emission tomography (BPA-PET) holds the potential to ascertain the concentration of BPA within the tumor, enabling meticulous treatment planning and outcome evaluation. However, no studies have been conducted on comparing the outcomes of those treated with BNCT to those who did not undergo this therapy. This study endeavors to analyze the correlation between BPA-PET and BNCT in the context of malignant brain tumors, and assess the survival outcomes following BNCT. Methods: A cohort study was performed on patients who underwent BPA-PET between February 2017 and April 2022 in our hospital. Patients were stratified into two groups: those subjected to BNCT (Group 1) and those not (Group 2). The tumor to normal tissue (T/N) ratio derived from BPA-PET was set at 2.5. The findings were scrutinized based on clinical follow-up. Student's t-test and Chi-squared test were employed to discern differences between the groups. A cumulative survival curve was constructed employing the Kaplan-Meier method. Differences were considered statistically significant at P<0.05. Results: In total, 116 patients with T/N ratios obtained from BPA-PET were enrolled. BNCT was administered to 58 patients, while mortality was observed in 100 patients. The median overall survival (OS) for the two groups was 8.5 and 6.0 months, respectively. The cumulative OS exhibited no significant discrepancy between the two groups, nor in their T/N ratios. Within Group 1, 44 out of 58 (75.9%) patients exhibited T/N ratios exceeding 2.5. Excluding 3 patients who expired within 3 months, 55 out of 58 patients were evaluated for response after BNCT. The objective response rate (ORR) was 30.9%. Patients achieving ORR displayed substantially higher survival rates compared to those without (median OS 13.5 vs. 8.3 months, P=0.0021), particularly when T/N ratio exceeded 2.5 (median OS 14.8 vs. 9.0 months, P=0.0199). Conclusions: BNCT does not appear indispensable for prolonging the survival of patients afflicted with malignant brain tumors. Nevertheless, it proves advantageous when ORR is attained, a condition closely linked to the values of T/N ratio derived from BPA-PET.

Survival outcomes of radium-223 therapy for metastatic castration-resistant prostate cancer following national health insurance reimbursement in Taiwan.

BACKGROUND: Radium-223 dichloride (Ra-223) prolongs overall survival (OS) in metastatic castration-resistant prostate cancer (mCRPC) with symptomatic bone metastases. However, there is considerable variation in outcomes among individuals. We aimed to evaluate the prognostic determinants associated with patient survival following National Health Insurance (NHI) reimbursement for Ra-223 therapy in Taiwan. METHODS: Patients with mCRPC who underwent Ra-223 treatment at Taipei Veterans General Hospital were retrospectively enrolled. Each intravenous Ra-223 dose was administered at 55 kBq/kg at four-week intervals. Clinical outcomes were obtained from medical records; potential prognostic factors for survival were assessed. Kaplan-Meier analysis was used to generate cumulative survival curves; between-group differences were evaluated using the Chi-squared test. Statistical significance was set at p < 0.05. RESULTS: Seventy-six patients underwent Ra-223 therapy; 62 patients received NHI reimbursement and the remainder self-paid. Fifty patients (65.8%) completed six cycles of treatment; 26 (34.2%) received 1‒5 cycles. Mortality occurred in 47 patients. Factors significantly associated with survival included ≦ five bone metastases (p = 0.0018), baseline prostate-specific antigen (PSA) ≦ 36 ng/mL (p = 0.0004), baseline alkaline phosphate (ALP) < 115 U/L (p = 0.0007), and baseline hemoglobin (Hb) > 12 g/dL (p = 0.0029). Patients who completed six cycles of treatment achieved significantly higher OS compared to those who did not (p < 0.0001). There has been a 4.4-fold increase in the number of patients since reimbursement began; there was no significant difference in OS between patients who received NHI reimbursement and those who self-paid. CONCLUSION: Administration of Ra-223 demonstrates considerable potential to extend the survival of patients with mCRPC. Survival outcomes may be influenced by various prognostic factors. However, no significant difference in OS was observed subsequent to reimbursement of Ra-223 therapy for mCRPC through the NHI system in Taiwan.

Glucose Metabolism of Hippocampal Subfields in Medial Temporal Lobe Epilepsy.

PURPOSE: Reduced glucose metabolism in the hippocampus is commonly observed in cases of medial temporal lobe epilepsy (MTLE) with hippocampal sclerosis (HS). Glucose metabolism among the various hippocampal subfields has not been thoroughly investigated. PATIENTS AND METHODS: This study examined 29 patients (18 females; 15-58 years) diagnosed with HS who underwent surgery for drug-resistant epilepsy. FreeSurfer 7.1.1 was used in the processing of MRI data and 18 F-FDG PET scans to derive volumetric data and the FDG SUVr in the whole hippocampus and hippocampal subfields, including the CA1, CA2-4, granule cell and molecular layer of the dentate gyrus (GC-ML-DG), and subiculum. Asymmetries in the volume and SUVr between the 2 sides from the subfields of the hippocampus were defined in terms of an asymmetry index. Comparisons of the asymmetry index among these regions were performed. The correlations between asymmetry index values and postoperative outcomes and presurgical neuropsychological test results were also evaluated. RESULT: The CA1, CA2-4, subiculum, GC-ML-DG, and whole hippocampus presented reductions in volume and hypometabolism ipsilateral to MTLE. Asymmetries in volume and SUVr were significantly less pronounced in the CA1 and subiculum than in the CA2-4 or GC-ML-DG. Postoperative seizure outcomes were not correlated with the asymmetry index for volume or SUVr in any hippocampal subfield. In cases of left MTLE, scores of immediate logical memory and delayed logical memory were positively correlated with the asymmetry index for SUVr in the following subfields: CA1 ( R = 0.829, P = 0.021; R = 0.770, P = 0.043), CA2-4 ( R = 0.825, P = 0.022; R = 0.894, P = 0.007), subiculum ( R = 0.882, P = 0.009; R = 0.853, P = 0.015), GC-ML-DG ( R = 0.850, P = 0.015; R = 0.796, P = 0.032), and whole hippocampus ( R = 0.841, P = 0.018; R = 0.822, P = 0.023). In cases of right MTLE, the scores for delayed face memory were positively correlated with the asymmetry index for SUVr in the subiculum ( R = 0.935, P = 0.006). CONCLUSIONS: In cases of HS, changes in glucose metabolism levels varied among the hippocampal subfields. Asymmetries in glucose metabolism among the CA-1, CA2-4, subiculum, and GC-ML-DG subregions were correlated with scores for verbal memory among patients with left MTLE. Asymmetric glucose metabolism in the subiculum was also correlated with visual memory scores among patients with right MTLE.

Feasibility evaluation of middle-phase 18F-florbetaben positron emission tomography imaging using centiloid quantification and visual assessment.

Background: 18F-florbetaben (FBB) positron emission tomography (PET) scan has been widely used in research and routine clinical practice. Most studies used late-phase (scanning from 90 to 110 min after injection) FBB scans to generate beta-amyloid accumulation data. The feasibility of middle-phase scan is seldom discussed. Using the middle-phase data can shorten the patients' waiting between the injection and scan, and hospital can acquire more flexible schedule of routine scan. Methods: Paired middle-phase (60-80 min) FBB scans and standard (90-110 min) FBB scans were obtained from 27 subjects (12 neurodegenerative dementia, 8 mild cognitive impairment, 3 normal control, and 4 patients not suffering from neurodegenerative dementia). Standardized uptake value ratios (SUVRs) were calculated and converted to centiloid (CL) scale to investigate the impact on image quantification. CL pipeline validation were performed to build an equation converting the middle-phase data into equivalent standard scans. Cohen's kappa of binary interpretation and brain amyloid plaque load (BAPL) score were also used to evaluate the intrareader agreement of the FBB image from the two protocols. Results: The middle-phase FBB SUVR showed an excellent correlation, which provided a linear regression equation of SUVRFBB60-80 = 0.88 × SUVRFBB90-110 + 0.07, with R2=0.98. The slope of the equation indicated that there was bias between the middle and standard acquisition. This can be converted into the CL scale using CL = 174.68 × SUVR - 166.39. Cohen's kappa of binary interpretation and BAPL score were 1.0 (P<0.0001). Conclusions: Our findings indicate that the middle-phase FBB protocol is feasible in clinical applications for scans that are at either end of beta-amyloid spectrum, which provides comparable semiquantitative results to standard scan. Patient's waiting time between the injection and scan can be shortened.

Follow-up Tc-99 m pyrophosphate cardiac scan for patients with transthyretin cardiac amyloidosis treated with tafamidis.

BACKGROUND: Tafamidis has been used for treatment of transthyretin cardiac amyloidosis (ATTR-CA). However, Tc-99 m pyrophosphate (PYP) cardiac scan for follow-up after tafamidis therapy has not been reported. METHODS: From May 2017 to March 2022, five patients with or without tafamidis therapy had received two Tc-99 m PYP cardiac scans. Tc-99 m PYP cardiac scan was performed with planar image and single photon emission computed tomography/computed tomography (SPECT/CT) 3 h after administration of Tc-99 m PYP. Perugini grading system was applied to determine positive or negative result of the scan. Heart to contralateral lung (H/CL) ratio as well as the difference of H/CL ratio between first and second Tc-99 m PYP cardiac scans (ΔH/CL ratio) was calculated. RESULTS: In the five patients participated in this study, three received tafamidis therapy and H/CL ratio was significantly decreased (p = 0.02) after tafamidis therapy. Besides, the ΔH/CL ratio was larger in patients with tafamidis therapy than that in those without tafamidis therapy, albeit not reaching statistical significance (p = 0.2). CONCLUSION: A decrease in H/CL ratio was found after tafamidis therapy in patients with ATTR-CA, albeit the magnitude of changes in the H/CL ratio (ΔH/CL ratio) was not significantly different from that of patients without tafamidis therapy. Future study with larger population might be required to further clarify the effect of tafamidis therapy on myocardial uptake of Tc-99 m PYP. CLINICAL TRIAL REGISTRATION: No clinical trial was conducted in our retrospective study.

Extrastriatal 99m Tc-TRODAT-1 Uptake in the Previous Hemorrhage With Hemosiderin Deposition.

ABSTRACT: We reported a 91-year-old man who was suspected of having parkinsonism, and brain 99m Tc-TRODAT-1 scan revealed an extrastriatal uptake in the left side of brainstem, which was correlated to a previously hemorrhagic lesion with hemosiderin deposition. Macrophage or microglia might accumulate in the previous hemorrhagic lesion to phagocytize hemosiderin. We assumed that the 99m Tc-TRODAT-1 uptake in the hemosiderin deposition might be partially mediated by macrophage expressing dopamine transporter.

Machine Learning Quantitative Analysis of FDG PET Images of Medial Temporal Lobe Epilepsy Patients.

PURPOSE: 18F-FDG PET is widely used in epilepsy surgery. We established a robust quantitative algorithm for the lateralization of epileptogenic foci and examined the value of machine learning of 18F-FDG PET data in medial temporal lobe epilepsy (MTLE) patients. PATIENTS AND METHODS: We retrospectively reviewed patients who underwent surgery for MTLE. Three clinicians identified the side of MTLE epileptogenesis by visual inspection. The surgical side was set as the epileptogenic side. Two parcellation paradigms and corresponding atlases (Automated Anatomical Labeling and FreeSurfer aparc + aseg) were used to extract the normalized PET uptake of the regions of interest (ROIs). The lateralization index of the MTLE-associated regions in either hemisphere was calculated. The lateralization indices of each ROI were subjected for machine learning to establish the model for classifying the side of MTLE epileptogenesis. RESULT: Ninety-three patients were enrolled for training and validation, and another 11 patients were used for testing. The hit rate of lateralization by visual analysis was 75.3%. Among the 23 patients whose MTLE side of epileptogenesis was incorrectly determined or for whom no conclusion was reached by visual analysis, the Automated Anatomical Labeling and aparc + aseg parcellated the associated ROIs on the correctly lateralized MTLE side in 100.0% and 82.6%. In the testing set, lateralization accuracy was 100% in the 2 paradigms. CONCLUSIONS: Visual analysis of 18F-FDG PET to lateralize MTLE epileptogenesis showed a lower hit rate compared with machine-assisted interpretation. While reviewing 18F-FDG PET images of MTLE patients, considering the regions associated with MTLE resulted in better performance than limiting analysis to hippocampal regions.

Fractionated deep-inspiration breath-hold ZTE Compared with Free-breathing four-dimensional ZTE for detecting pulmonary nodules in oncological patients underwent PET/MRI.

The zero echo time (ZTE) technique has improved the detection of lung nodules in PET/MRI but respiratory motion remains a challenge in lung scan. We investigated the feasibility and performance of fractionated deep-inspiration breath-hold (FDIBH) three-dimensional (3D) ZTE FDG PET/MRI for assessing lung nodules in patients with proved malignancy. Sixty patients who had undergone ZTE FDG PET/MRI and chest CT within a three-day interval were retrospectively included. Lung nodules less than 2 mm were excluded for analysis. Two physicians checked the adequacy of FDIBH ZTE and compared the lung nodule detection rates of FDIBH 3D ZTE and free-breathing (FB) four-dimensional (4D) ZTE, with chest CT as the reference standard. FDIBH resolved the effect of respiratory motion in 49 patients. The mean number and size of the pulmonary nodules identified in CT were 15 ± 31.3 per patient and 5.9 ± 4.6 mm in diameter. The overall nodule detection rate was 71% for FDIBH 3D ZTE and 70% for FB 4D ZTE (p = 0.73). FDIBH 3D ZTE significantly outperformed FB 4DZTE in detecting lung base nodules (72% and 68%; p = 0.03), especially for detecting those less than 6 mm (61% and 55%; p = 0.03). High inter-rater reliability for FDIBH 3D ZTE and FB 4D ZTE (k = 0.9 and 0.92) was noted. In conclusion, the capability of FDIBH 3D ZTE in respiratory motion resolution was limited with a technical failure rate of 18%. However, it could provide full expansion of the lung in a shorter scan time which enabled better detection of nodules (< 6 mm) in basal lungs, compared to FB 4D ZTE.

Different Pattern of Bone Scintigraphy in Mandibular Osteosarcoma Arising From Fibrous Dysplasia in a Patient With McCune-Albright Syndrome.

McCune-Albright syndrome is a rare condition consisting of triad of fibrous dysplasia, hyperfunctioning endocrinopathy, and café au lait macules of skin. A 31-year-old man was diagnosed with fibrous dysplasia 18 years before presenting with pathologic fracture. No workup for polyostotic fibrous dysplasia was performed at that time. He now presented with left facial swelling and skeletal features of acromegaly. MRI revealed a 15-cm enhancing tumor diagnosed histopathologically as high-grade osteosarcoma. Tc-methylene diphosphonate bone scintigraphy revealed decreased uptake at the tumor site contrary to the usual finding of avid uptake by the neoplastic bone forming tumor.

Unusual Presentation of Postradiation Sarcoma With Subsequent Intestinal Metastasis Revealed by 18F-FDG PET/CT.

Radiation-related sarcoma is a rare but serious complication for patients after receiving radiation therapy initially for their primary malignancy. However, it usually takes several years and needs enough in-field radiation dose to develop this sarcoma. We describe a 60-year-old man with right axillary sarcoma revealed by whole-body F-FDG PET/CT 1 year after chemoradiotherapy, which presented ultrashort latency period and did not match the consensus definition of radiation-related sarcoma. Besides, metastatic sarcoma to small intestine was accidentally noted in the F-FDG PET/CT image.