Quantification of ¹⁸F-FDG PET images is useful for accurate diagnosis and evaluation of various brain diseases, including brain tumors, epilepsy, dementia, and Parkinson disease. However, accurate quantification of ¹⁸F-FDG PET images requires matched 3-dimensional T₁ MRI scans of the same individuals to provide detailed information on brain anatomy. In this paper, we propose a transfer learning approach to adapt a pretrained deep neural network model from amyloid PET to spatially normalize ¹⁸F-FDG PET images without the need for 3-dimensional MRI. Methods: The proposed method is based on a deep learning model for automatic spatial normalization of ¹⁸F-FDG brain PET images, which was developed by fine-tuning a pretrained model for amyloid PET using only 103 ¹⁸F-FDG PET and MR images. After training, the algorithm was tested on 65 internal and 78 external test sets. All T₁ MR images with a 1-mm isotropic voxel size were processed with FreeSurfer software to provide cortical segmentation maps used to extract a ground-truth regional SUV ratio using cerebellar gray matter as a reference region. These values were compared with those from spatial normalization-based quantification methods using the proposed method and statistical parametric mapping software. Results: The proposed method showed superior spatial normalization compared with statistical parametric mapping, as evidenced by increased normalized mutual information and better size and shape matching in PET images. Quantitative evaluation revealed a consistently higher SUV ratio correlation and intraclass correlation coefficients for the proposed method across various brain regions in both internal and external datasets. The remarkably good correlation and intraclass correlation coefficient values of the proposed method for the external dataset are noteworthy, considering the dataset’s different ethnic distribution and the use of different PET scanners and image reconstruction algorithms. Conclusion: This study successfully applied transfer learning to a deep neural network for ¹⁸F-FDG PET spatial normalization, demonstrating its resource efficiency and improved performance. This highlights the efficacy of transfer learning, which requires a smaller number of datasets than does the original network training, thus increasing the potential for broader use of deep learning–based brain PET spatial normalization techniques for various clinical and research radiotracers.

The peptide hormone ghrelin is produced in cardiomyocytes and acts through the myocardial growth hormone secretagogue receptor (GHSR) to promote cardiomyocyte survival. Administration of ghrelin may have therapeutic effects on post–myocardial infarction (MI) outcomes. Therefore, there is a need to develop molecular imaging probes that can track the dynamics of GHSR in health and disease to better predict the effectiveness of ghrelin-based therapeutics. We designed a high-affinity GHSR ligand labeled with ¹⁸F for imaging by PET and characterized its in vivo properties in a canine model of MI. Methods: We rationally designed and radiolabeled with ¹⁸F a quinazolinone derivative ([¹⁸F]LCE470) with subnanomolar binding affinity to GHSR. We determined the sensitivity and in vivo and ex vivo specificity of [¹⁸F]LCE470 in a canine model of surgically induced MI using PET/MRI, which allowed for anatomic localization of tracer uptake and simultaneous determination of global cardiac function. Uptake of [¹⁸F]LCE470 was determined by time–activity curve and SUV analysis in 3 regions of the left ventricle—area of infarct, territory served by the left circumflex coronary artery, and remote myocardium—over a period of 1.5 y. Changes in cardiac perfusion were tracked by [¹³N]NH₃ PET. Results: The receptor binding affinity of LCE470 was measured at 0.33 nM, the highest known receptor binding affinity for a radiolabeled GHSR ligand. In vivo blocking studies in healthy hounds and ex vivo blocking studies in myocardial tissue showed the specificity of [¹⁸F]LCE470, and sensitivity was demonstrated by a positive correlation between tracer uptake and GHSR abundance. Post-MI changes in [¹⁸F]LCE470 uptake occurred independently of perfusion tracer distributions and changes in global cardiac function. We found that the regional distribution of [¹⁸F]LCE470 within the left ventricle diverged significantly within 1 d after MI and remained that way throughout the 1.5-y duration of the study. Conclusion: [¹⁸F]LCE470 is a high-affinity PET tracer that can detect changes in the regional distribution of myocardial GHSR after MI. In vivo PET molecular imaging of the global dynamics of GHSR may lead to improved GHSR-based therapeutics in the treatment of post-MI remodeling.

Mutations of p53 protein occur in over half of all cancers, with profound effects on tumor biology. We present the first—to our knowledge—method for noninvasive visualization of p53 in tumor tissue in vivo, using SPECT, in 3 different models of cancer. Methods: Anti-p53 monoclonal antibodies were conjugated to the cell-penetrating transactivator of transcription (TAT) peptide and a metal ion chelator and then radiolabeled with ¹¹¹In to allow SPECT imaging. ¹¹¹In-anti-p53-TAT conjugates were retained longer in cells overexpressing p53-specific than non–p53-specific ¹¹¹In-mIgG (mouse IgG from murine plasma)-TAT controls, but not in null p53 cells. Results: In vivo SPECT imaging showed enhanced uptake of ¹¹¹In-anti-p53-TAT, versus ¹¹¹In-mIgG-TAT, in high-expression p53^R175H and medium-expression wild-type p53 but not in null p53 tumor xenografts. The results were confirmed in mice bearing genetically engineered KPC mouse–derived pancreatic ductal adenocarcinoma tumors. Imaging with ¹¹¹In-anti-p53-TAT was possible in KPC mice bearing spontaneous p53^R172H pancreatic ductal adenocarcinoma tumors. Conclusion: We demonstrate the feasibility of noninvasive in vivo molecular imaging of p53 in tumor tissue using a radiolabeled TAT-modified monoclonal antibody.

Radiolabeled small-molecule DOTA-haptens can be combined with antitumor/anti-DOTA bispecific antibodies (BsAbs) for pretargeted radioimmunotherapy (PRIT). For optimized delivery of the theranostic - and β-emitting isotope ¹⁷⁷Lu with DOTA-based PRIT (DOTA-PRIT), bivalent Gemini (DOTA-Bn-thiourea-PEG4-thiourea-Bn-DOTA, aka (3,6,9,12-tetraoxatetradecane-1,14-diyl)bis(DOTA-benzyl thiourea)) was developed. Methods: Gemini was synthesized by linking 2 S-2-(4-isothiocyanatobenzyl)-DOTA molecules together via a 1,14-diamino-PEG4 linker. [¹⁷⁷Lu]Lu-Gemini was prepared with no-carrier-added ¹⁷⁷LuCl₃ to a molar-specific activity of 123 GBq/μmol and radiochemical purity of more than 99%. The specificity of BsAb-¹⁷⁷Lu-Gemini was verified in vitro. Subsequently, we evaluated biodistribution and whole-body clearance for [¹⁷⁷Lu]Lu-Gemini and, for comparison, our gold-standard monovalent [¹⁷⁷Lu]Lu-S-2-(4-aminobenzyl)-DOTA ([¹⁷⁷Lu]Lu-DOTA-Bn) in naïve (tumor-free) athymic nude mice. For our proof-of-concept system, a 3-step pretargeting approach was performed with an established DOTA-PRIT regimen (anti-GPA33/anti-DOTA IgG-scFv BsAb, a clearing agent, and [¹⁷⁷Lu]Lu-Gemini) in mouse models. Results: Initial in vivo studies showed that [¹⁷⁷Lu]Lu-Gemini behaved similarly to [¹⁷⁷Lu]Lu-DOTA-Bn, with almost identical blood and whole-body clearance kinetics, as well as biodistribution and mouse kidney dosimetry. Pretargeting [¹⁷⁷Lu]Lu-Gemini to GPA33-expressing SW1222 human colorectal xenografts was highly effective, leading to absorbed doses of [¹⁷⁷Lu]Lu-Gemini for blood, tumor, liver, spleen, and kidneys of 3.99, 455, 6.93, 5.36, and 14.0 cGy/MBq, respectively. Tumor–to–normal tissue absorbed-dose ratios (i.e., therapeutic indices [TIs]) for the blood and kidneys were 114 and 33, respectively. In addition, we demonstrate that the use of bivalent [¹⁷⁷Lu]Lu-Gemini in DOTA-PRIT leads to improved TIs and augmented [¹⁷⁷Lu]Lu-Gemini tumor uptake and retention in comparison to monovalent [¹⁷⁷Lu]Lu-DOTA-Bn. Finally, we established efficacy in SW1222 tumor-bearing mice, demonstrating that a single injection of anti-GPA33 DOTA-PRIT with 44 MBq (1.2 mCi) of [¹⁷⁷Lu]Lu-Gemini (estimated tumor-absorbed dose, 200 Gy) induced complete responses in 5 of 5 animals and a histologic cure in 2 of 5 (40%) animals. Moreover, a significant increase in survival compared with nontreated controls was noted (maximum tolerated dose not reached). Conclusion: We have developed a bivalent DOTA-radiohapten, [¹⁷⁷Lu]Lu-Gemini, that showed improved radiopharmacology for DOTA-PRIT application. The use of bivalent [¹⁷⁷Lu]Lu-Gemini in DOTA-PRIT, as opposed to monovalent [¹⁷⁷Lu]Lu-DOTA-Bn, allows curative treatments with considerably less administered ¹⁷⁷Lu activity while still achieving high TIs for both the blood (>100) and the kidneys (>30).

Fibroblast activation protein (FAP) is abundantly expressed in the stroma of most human solid tumors. Clinical-stage radiolabeled FAP ligands are increasingly used as tools for the detection of various cancer lesions. To unleash the full therapeutic potential of FAP-targeting agents, ligands need to remain at the tumor site for several days after administration. We recently described the discovery of OncoFAP, a high-affinity small organic ligand of FAP with a rapid accumulation in tumors and low uptake in healthy tissues in cancer patients. Trimerization of OncoFAP provided a derivative (named TriOncoFAP, or OncoFAP-23) with improved FAP affinity. In this work, we evaluated the tissue biodistribution profile and the therapeutic performance of OncoFAP-23 in tumor-bearing mice. Methods: OncoFAP-23 was radiolabeled with the theranostic radionuclide ¹⁷⁷Lu. Preclinical experiments were conducted on mice bearing SK-RC-52.hFAP (BALB/c nude mice) or CT-26.hFAP (BALB/c mice) tumors. ¹⁷⁷Lu-OncoFAP and ¹⁷⁷Lu-FAP-2286 were included in the biodistribution study as controls. Toxicologic evaluation was performed on Wistar rats and CD1 mice by injecting high doses of OncoFAP-23 or its cold-labeled counterpart, respectively. Results: ¹⁷⁷Lu-OncoFAP-23 emerged for its best-in-class biodistribution profile, high and prolonged tumor uptake (i.e., ~16 percentage injected dose/g at 96 h), and low accumulation in healthy organs, which correlates well with its potent single-agent anticancer activity at low levels of administered radioactivity. Combination treatment with the tumor-targeted interleukin 2 (L19-IL2, a clinical-stage immunocytokine) further expands the therapeutic window of ¹⁷⁷Lu-OncoFAP-23 by potentiating its in vivo antitumor activity. Proteomics studies revealed a potent tumor-directed immune response on treatment with the combination. OncoFAP-23 and ^natLu-OncoFAP-23 exhibited a favorable toxicologic profile, without showing any side effects or signs of toxicity. Conclusion: OncoFAP-23 presents enhanced tumor uptake and tumor retention and low accumulation in healthy organs, findings that correspond to a strongly improved in vivo antitumor efficacy. The data presented in this work support the clinical development of ¹⁷⁷Lu-OncoFAP-23 for the treatment of FAP-positive solid tumors.

To date, the imaging and diagnosis of hepatocellular carcinoma (HCC) rely on CT/MRI, which have well-known limitations. Glypican-3 (GPC3) is a cell surface receptor highly expressed by HCC but not by normal or cirrhotic liver tissue. Here we report initial clinical results of GPC3-targeted PET imaging with [⁶⁸Ga]Ga-DOTA-RYZ-GPC3 (RAYZ-8009), a peptide-based GPC3 ligand in patients with known or suspected HCC. Methods: [⁶⁸Ga]Ga-RAYZ-8009 was obtained after labeling the peptide precursor with ⁶⁸Ga from a ⁶⁸Ge/⁶⁸Ga generator and heating at 90°C for 10 min followed by sterile filtration. After administration of [⁶⁸Ga]Ga-RAYZ-8009, a dynamic or static PET/CT scan was acquired between 45 min and 4 h after administration. Radiotracer uptake was measured by SUVs for the following tissues: suspected or actual HCC or hepatoblastoma lesions, non–tumor-bearing liver, renal cortex, blood pool in the left ventricle, and gastric fundus. Additionally, tumor–to–healthy-liver ratios (TLRs) were calculated. Results: Twenty-four patients (5 patients in the dynamic protocol; 19 patients in the static protocol) were scanned. No adverse events occurred. Two patients had no lesion detected and did not have HCC during follow-up. In total, 50 lesions were detected and analyzed. The mean SUV_max of these lesions was 19.6 (range, 2.7–95.3), and the mean SUV_mean was 10.1 (range, 1.0–49.2) at approximately 60 min after administration. Uptake in non–tumor-bearing liver and blood pool rapidly decreased over time and became negligible 45 min after administration (mean SUV_mean, <1.6), with a continuous decline to 4 h after administration (mean SUV_mean, 1.0). The opposite was observed for HCC lesions, for which SUVs and TLRs continuously increased for up to 4 h after administration. In individual lesion analysis, TLR was the highest between 60 and 120 min after administration. Uptake in the gastric fundus gradually increased for up to 45 min (to an SUV_max of 31.3) and decreased gradually afterward. Conclusion: [⁶⁸Ga]Ga-RAYZ-8009 is safe and allows for high-contrast imaging of GPC3-positive HCC, with rapid clearance from most normal organs. Thereby, [⁶⁸Ga]Ga-RAYZ-8009 is promising for HCC diagnosis and staging. Further research is warranted.

Unspecific bone uptake (UBU) related to [¹⁸F]PSMA-1007 PET/CT imaging represents a clinical challenge. We aimed to assess whether a combination of clinical, biochemical, and imaging parameters could predict skeletal metastases in patients with [¹⁸F]PSMA-1007 bone focal uptake, aiding in result interpretation. Methods: We retrospectively analyzed [¹⁸F]PSMA-1007 PET/CT performed in hormone-sensitive prostate cancer (PCa) patients at 3 tertiary-level cancer centers. A fourth center was involved in performing an external validation. For each, a volume of interest was drawn using a threshold method to extract SUV_max, SUV_mean, PSMA tumor volume, and total lesion PSMA. The same volume of interest was applied to CT images to calculate the mean Hounsfield units (HU_mean) and maximum Hounsfield units. Clinical and laboratory data were collected from electronic medical records. A composite reference standard, including follow-up histopathology, biochemistry, and imaging data, was used to distinguish between PCa bone metastases and UBU. PET readers with less (n = 2) or more (n = 2) experience, masked to the reference standard, were asked to visually rate a subset of focal bone uptake (n = 178) as PCa metastases or not. Results: In total, 448 bone [¹⁸F]PSMA-1007 focal uptake specimens were identified in 267 PCa patients. Of the 448 uptake samples, 188 (41.9%) corresponded to PCa metastases. Ongoing androgen deprivation therapy at PET/CT (P < 0.001) with determination of SUV_max (P < 0.001) and HU_mean (P < 0.001) independently predicted bone metastases. A composite prediction score, the bone uptake metastatic probability (BUMP) score, achieving an area under the receiver-operating-characteristic curve (AUC) of 0.87, was validated through a 10-fold internal and external validation (n = 89 bone uptake, 51% metastatic; AUC, 0.92). The BUMP score’s AUC was significantly higher than that of HU_mean (AUC, 0.62) and remained high among lesions with HU_mean in the first tertile (AUC, 0.80). A decision-curve analysis showed a higher net benefit with the score. Compared with the visual assessment, the BUMP score provided added value in terms of specificity in less-experienced PET readers (88% vs. 54%, P < 0.001). Conclusion: The BUMP score accurately distinguished UBU from bone metastases in PCa patients with [¹⁸F]PSMA-1007 focal bone uptake at PET imaging, offering additional value compared with the simple assessment of the osteoblastic CT correlate. Its use could help clinicians interpret imaging results, particularly those with less experience, potentially reducing the risk of patient overstaging.

This analysis aimed to identify clinical factors associated with positivity on repeat ⁶⁸Ga-PSMA-11 PET/CT after a negative scan in patients with recurrent prostate cancer (PCa) under observation. Methods: This single-center, retrospective analysis included patients who underwent at least 2 ⁶⁸Ga-PSMA-11 PET/CT scans (PET1 and PET2) at UCLA between October 2016 and June 2021 for recurrent PCa with negative PET1 and no PCa-related treatments between the 2 scans. Using Prostate Cancer Molecular Imaging Standardized Evaluation criteria to define negative and positive scans, the final cohort was divided into PET2-negative (PET2-Neg) and PET2-positive (PET2-Pos). The same PET1 was used twice in the more than 2 PET cases with inclusion criteria fulfilled. Patient characteristics and clinical parameters were compared between the 2 cohorts using Mann–Whitney U test and Fisher exact test. Areas under the curve (AUCs) of the receiver operating characteristic and the Youden index were computed to determine the discrimination ability of statistically significant factors and specific cut points that maximized sensitivity and specificity, respectively. Results: The final analysis included 83 sets of 2 PET/CT scans from 70 patients. Thirty-nine of 83 (47%) sets were PET2-Neg, and 44 of 83 (53%) sets were PET2-Pos. Prostate-specific antigen (PSA) increased from PET1 to PET2 for all 83 (100%) sets of scans. Median PSA at PET1 was 0.4 ng/mL (interquartile range, 0.2–1.0) and at PET2 was 1.6 ng/mL (interquartile range, 0.9–3.8). We found higher serum PSA at PET2 (median, 1.8 vs. 1.1 ng/mL; P = 0.015), absolute PSA difference (median, 1.4 vs. 0.7 ng/mL; P = 0.006), percentage of PSA change (median, +270.4% vs. +150.0%: P = 0.031), and median PSA velocity (0.044 vs. 0.017 ng/mL/wk, P = 0.002) and shorter PSA doubling time (DT; median, 5.1 vs. 8.3 mo; P = 0.006) in the PET2-Pos cohort than in the PET2-Neg cohort. Receiver operating characteristic curves showed cutoffs for PSA at PET2 of 4.80 ng/mL (sensitivity, 34%; specificity, 92%; AUC, 0.66), absolute PSA difference of 0.95 ng/mL (sensitivity, 62%; specificity, 71%; AUC, 0.68), percentage of PSA change of a positive 289.50% (sensitivity, 48%; specificity, 82%; AUC, 0.64), PSA velocity of 0.033 ng/mL/wk (sensitivity, 57%; specificity, 80%; AUC, 0.70), and PSA DT of 7.91 mo (sensitivity, 71%; specificity, 62%; AUC, 0.67). Conclusion: Patients with recurrent PCa under observation after a negative ⁶⁸Ga-PSMA-11 PET/CT scan with markedly elevated serum PSA levels and shorter PSA DT are more likely to have positive findings on repeat ⁶⁸Ga-PSMA-11 PET/CT.

Single-domain antibodies (sdAbs) demonstrate favorable pharmacokinetic profiles for molecular imaging applications. However, their renal excretion and retention are obstacles for applications in targeted radionuclide therapy (TRT). Methods: Using a click-chemistry–based pretargeting approach, we aimed to reduce kidney retention of a fibroblast activation protein α (FAP)–targeted sdAb, 4AH29, for ¹⁷⁷Lu-TRT. Key pretargeting parameters (sdAb-injected mass and lag time) were optimized in healthy mice and U87MG (FAP⁺) xenografts. A TRT study in a pancreatic ductal adenocarcinoma (PDAC) patient-derived xenograft (PDX) model was performed as a pilot study for sdAb-based pretargeting applications. Results: Modification of 4AH29 with trans-cyclooctene (TCO) moieties did not modify the sdAb pharmacokinetic profile. A 200-µg injected mass of 4AH29-TCO and an 8-h lag time for the injection of [¹⁷⁷Lu]Lu-DOTA-PEG₇-tetrazine resulted in the highest kidney therapeutic index (2.0 ± 0.4), which was 5-fold higher than that of [¹⁷⁷Lu]Lu-DOTA-4AH29 (0.4 ± 0.1). FAP expression in the tumor microenvironment was validated in a PDAC PDX model with both immunohistochemistry and PET/CT imaging. Mice treated with the pretargeting high-activity approach (4AH29-TCO + [¹⁷⁷Lu]Lu-DOTA-PEG₇-tetrazine; 3 x 88 MBq, 1 injection per week for 3 wk) demonstrated prolonged survival compared with the vehicle control and conventionally treated ([¹⁷⁷Lu]Lu-DOTA-4AH29; 3 x 37 MBq, 1 injection per week for 3 wk) mice. Mesangial expansion was reported in 7 of 10 mice in the conventional cohort, suggesting treatment-related kidney morphologic changes, but was not observed in the pretargeting cohort. Conclusion: This study validates pretargeting to mitigate sdAbs’ kidney retention with no observation of morphologic changes on therapy regimen at early time points. Clinical translation of click-chemistry–based pre-TRT is warranted on the basis of its ability to alleviate toxicities related to biovectors’ intrinsic pharmacokinetic profiles. The absence of representative animal models with extensive stroma and high FAP expression on cancer-associated fibroblasts led to a low mean tumor-absorbed dose even with high injected activity and consequently to modest survival benefit in this PDAC PDX.

Cancer of unknown primary (CUP) represents a heterogeneous group of metastatic tumors for which standardized diagnostic work-up fails to identify the primary site. We aimed to describe the Peter MacCallum Cancer Centre experience with ¹⁸F-FDG PET/CT in extracervical CUP with respect to detection of a primary site and its impact on management. A secondary aim was to compare overall survival (OS) in patients with and without a detected primary site. Methods: CUP patients treated between 2014 and 2020 were identified from medical oncology clinics and ¹⁸F-FDG PET/CT records. Information collated from electronic medical records included the suspected primary site and treatment details before and after ¹⁸F-FDG PET/CT. Clinicopathologic details and genomic analysis were used to determine the clinically suspected primary site and compared against 2 independent masked reads of ¹⁸F-FDG PET/CT images by nuclear medicine specialists to determine sensitivity, specificity, accuracy, and the rate of detection of the primary site. Results: We identified 147 patients, 65% of whom had undergone molecular profiling. The median age at diagnosis was 61 y (range, 20–84 y), and the median follow-up time was 74 mo (range, 26–83 mo). Eighty-two percent were classified as having an unfavorable CUP subtype as per international guidelines.¹⁸F-FDG PET/CT demonstrated a primary site detection rate of 41%, resulted in a change in management in 22%, and identified previously occult disease sites in 37%. Median OS was 16.8 mo for all patients and 104.7 and 12.1 mo for favorable and unfavorable CUP subtypes, respectively (P < 0.0001). Median OS in CUP patients when using ¹⁸F-FDG PET/CT, clinicopathologic, and genomic information was 19.8 and 8.5 mo when a primary site was detected and not detected, respectively (P = 0.016). Multivariable analysis of survival adjusted for age and sex remained significant for identification of a potential primary site (P < 0.001), a favorable CUP (P < 0.001), and an Eastern Cooperative Oncology Group status of 1 or less (P < 0.001). Conclusion: ¹⁸F-FDG PET/CT plays a complementary role in CUP diagnostic work-up and was able to determine the likely primary site in 41% of cases. OS is improved with primary site identification, demonstrating the value of access to diagnostic ¹⁸F-FDG PET/CT for CUP patients.

Neoadjuvant therapy in patients with locally advanced rectal cancer (LARC) has achieved good pathologic complete response (pCR) rates, potentially eliminating the need for surgical intervention. This study investigated preoperative methods for predicting pCR after neoadjuvant short-course radiotherapy (SCRT) combined with immunochemotherapy. Methods: Treatment-naïve patients with histologically confirmed LARC were enrolled from February 2023 to July 2023. Before surgery, the patients received neoadjuvant SCRT followed by 2 cycles of capecitabine and oxaliplatin plus camrelizumab. ⁶⁸Ga-labeled fibroblast activation protein inhibitor ([⁶⁸Ga]Ga-FAPI-04) PET/MRI, [¹⁸F]FDG PET/CT, and contrast-enhanced MRI were performed before treatment initiation and before surgery in each patient. PET and MRI features and the size and number of lesions were also collected from each scan. Each parameter’s sensitivity, specificity, and diagnostic cutoff were derived via receiver-operating-characteristic curve analysis. Results: Twenty eligible patients (13 men, 7 women; mean age, 60.2 y) were enrolled and completed the entire trial, and all patients had proficient mismatch repair or microsatellite-stable LARC. A postoperative pCR was achieved in 9 patients (45.0%). In the visual evaluation, both [⁶⁸Ga]Ga-FAPI-04 PET/MRI and [¹⁸F]FDG PET/CT were limited to forecasting pCR. Contrast-enhanced MRI had a low sensitivity of 55.56% to predict pCR. In the quantitative evaluation, [⁶⁸Ga]Ga-FAPI-04 change in SUL_peak percentage, where SUL_peak is SUV_peak standardized by lean body mass, had the largest area under the curve (0.929) with high specificity (sensitivity, 77.78%; specificity, 100.0%; cutoff, 63.92%). Conclusion: [⁶⁸Ga]Ga-FAPI-04 PET/MRI is a promising imaging modality for predicting pCR after SCRT combined with immunochemotherapy. The SUL_peak decrease exceeding 63.92% may provide valuable guidance in selecting patients who can forgo surgery after neoadjuvant therapy.

Understanding which patients with human epidermal growth factor receptor 2 (HER2)–negative or –low metastatic breast cancer (MBC) benefit from HER2-targeted strategies is urgently needed. We assessed the whole-body heterogeneity of HER2 expression on ⁸⁹Zr-trastuzumab PET (HER2 PET) and the diagnostic performance of HER2 PET in a large series of patients, including HER2-negative and -low MBC. Methods: In the IMPACT-MBC study, patients with newly diagnosed and nonrapidly progressive MBC of all subtypes were included. Metastasis HER2 status was determined by immunohistochemistry and in situ hybridization.⁸⁹Zr-trastuzumab uptake was quantified as SUV_max and SUV_mean. HER2 immunohistochemistry was related to the quantitative ⁸⁹Zr-trastuzumab uptake of all metastases and corresponding biopsied metastasis, uptake heterogeneity, and qualitative scan evaluation. A prediction algorithm for HER2 immunohistochemistry positivity based on uptake was developed. Results: In 200 patients, ⁸⁹Zr-trastuzumab uptake was quantified in 5,163 metastases, including 186 biopsied metastases. With increasing HER2 immunohistochemistry status, uptake was higher (geometric mean SUV_max of 7.0, 7.6, 7.3, and 17.4 for a HER2 immunohistochemistry score of 0, 1, 2, or 3+, respectively; P < 0.001). High uptake exceeding 14.6 (90th percentile) was observed in one third of patients with a HER2-negative or -low metastasis biopsy. The algorithm performed best when lesion site and size were incorporated (area under the curve, 0.86; 95% CI, 0.79–0.93). Conclusion: HER2 PET had good diagnostic performance in MBC, showing considerable whole-body HER2 heterogeneity and uptake above background in HER2-negative and -low MBC. This provides novel insights into HER2-negative and -low MBC compared with standard HER2 immunohistochemistry on a single biopsy.

This study evaluates the diagnostic utility of PET/MRI for primary, locoregional, and nodal head and neck squamous cell carcinoma (HNSCC) through systematic review and metaanalysis. Methods: A systematic search was conducted using PubMed and Scopus to identify studies on the diagnostic accuracy of PET/MRI for HNSCC. The search included specific terms and excluded nonhybrid PET/MRI studies, and those with a sample size of fewer than 10 patients were excluded. Results: In total, 15 studies encompassing 638 patients were found addressing the diagnostic test accuracy for PET/MRI within the chosen subject domain. Squamous cell carcinoma of the nasopharynx was the most observed HNSCC subtype (n = 198). The metaanalysis included 12 studies, with pooled sensitivity and specificity values of 93% and 95% per patient for primary disease evaluation, 93% and 96% for locoregional evaluation, and 89% and 98% per lesion for nodal disease detection, respectively. An examination of a subset of studies comparing PET/MRI against PET/CT or MRI alone for evaluating nodal and locoregional HNSCC found that PET/MRI may offer slightly higher accuracy than other modalities. However, this difference was not statistically significant. Conclusion: PET/MRI has excellent potential for identifying primary, locoregional, and nodal HNSCC.

The tumor marker cancer antigen 15-3 (CA 15-3) is that most commonly used to monitor metastatic breast cancer during active therapy and surveillance for disease recurrence after treatment. The association of CA 15-3 and ¹⁸F-FDG PET/CT findings can be considered complementary, since any significant rise may indicate the presence of disease and imaging is able to map the tumor sites. Although current guidelines do not recommend the routine performance of CA 15-3 in asymptomatic patients being followed up after definitive breast cancer treatment, most oncologists perform serial assessment of the tumor markers as part of routine follow-up of patients. The aim of this study was to evaluate the correlation between CA 15-3 levels and ¹⁸F-FDG PET/CT scan findings in patients with recurrent breast cancer. Methods: This was a cross-sectional study with data collected retrospectively. Patients being evaluated for breast cancer recurrence with ¹⁸F-FDG PET/CT imaging and CA 15-3 level were included. Evaluation of the association between CA 15-3 levels and ¹⁸F-FDG PET/CT scan findings was then done. Results: In total, 154 cases were included in this study; 62 patients had recurrence (positive) on the ¹⁸F-FDG PET/CT scans, whereas 92 patients had normal (negative) findings on follow-up ¹⁸F-FDG PET/CT scans. There was an association between CA 15-3 levels and the presence or absence of recurrence on ¹⁸F-FDG PET/CT scans, with 84.4% (27/32) of patients who had elevated CA 15-3 levels having disease recurrence on ¹⁸F-FDG PET/CT and 84.4% (27/32) of patients who had elevated CA 15-3 levels having disease recurrence on ¹⁸F-FDG PET/CT as well as a correlation with the burden of metastases. Most patients with disease recurrence on ¹⁸F-FDG PET/CT, however, had normal CA 15-3 levels. Conclusion: Higher CA 15-3 levels correlate with breast cancer recurrence on ¹⁸F-FDG PET/CT as well as with burden of metastasis. Notably, CA 15-3 levels within the reference range do not exclude breast cancer disease recurrence since more than half of patients with recurrence had normal CA 15-3 levels. ¹⁸F-FDG PET/CT should therefore be considered in patients with suspected breast cancer recurrence but normal CA 15-3 levels.

Can Cyprus Be Reunified? 18 July 2018 — 12:30PM TO 1:30PM Anonymous (not verified) 29 June 2018 Chatham House | 10 St James's Square | London | SW1Y 4LE

The latest round of Cyprus peace negotiations to resolve the Cypriot issue broke down in Crans-Montana, Switzerland in July 2017. The speaker will offer the Turkish Cypriot perspective on future developments to reunifying the divided island.

THIS EVENT IS NOW FULL AND REGISTRATION HAS CLOSED.

Turkey Needs Radical New Direction to Save the Economy Expert comment NCapeling 23 November 2020

Turkey should emulate the reformist approach it adopted after the 2001 crisis to prevent an economic and financial breakdown - but this looks highly unlikely.

Although Ankara has witnessed what appears to be an abrupt change of its top economic team with two fresh appointments to key positions – Naci Ağbal as governor of the central bank and Lütfi Elvan as finance and treasury minister – a cardinal rule of thumb in Turkish politics is that the more drama one sees, the less policy change there will actually be.

Financial markets reacted positively to the moves in the expectation they will signal a change of Turkey’s overall economic approach, but the reality is Turkish president Recep Tayyip Erdoğan is simply putting loyalists into key bureaucratic positions to help ensure the primary role of these functions becomes ‘selling’ his policies more effectively, rather than altering them.

The hope from the markets – which saw the beleaguered Turkish lira appreciate against the US dollar at the news – is that Turkey adopts substantial interest rate increases as well as measures to repress liquidity expansion in order to temper its controversial so-called ‘Triple C’ approach of using cheap credit to stimulate growth with an unsustainable consumption and construction boom.

But instead, Erdoğan’s declaration after the appointments were made indicates the new restrictions in which they will now operate, saying ‘we are in a historic struggle against those who want to force Turkey into modern capitulations through the shackles of interest rates, foreign exchange rates and inflation’.

Learn from past successes

To resolve its current underlying economic problems, Turkey should actually be looking to its recent past and aiming to emulate the approach pursued by former prime minister Bülent Ecevit during the 2001 financial crisis when he recruited Kemal Derviş, a senior World Bank official with extensive experience and international contacts in economic, financial, and monetary affairs.

As economy minister with a broad mandate to spearhead a durable economic recovery plan, Dervis established independent market regulatory agencies covering banking, telecommunications, energy, and other key sectors, and strengthened the competition authority.

He also either liquidated or merged insolvent banks, granted central bank autonomy to guarantee price stability, and ensured recruitment was based on competence, expertise, and meritocracy. Crucially, his productivity-enhancing restructuring blueprint was designed in Turkey rather than being imposed by the International Monetary Fund (IMF) or another external agency.

Ecevit also turbocharged reforms motivated in part by a desire to join the EU with constitutional, political and legal modernization which widened personal freedom, significantly curtailed capital punishment, liberalized the cultural environment for Kurds, and fortified the rule of law. And one of his coalition partners in that work, the right-wing pro-Turkish National Action Party (MHP), is now allied with the current ruling Justice and Development Party (AKP).

His foreign minister Ismail Cem also enhanced Turkey’s relations with both Europe and the US, initiated the so-called ‘earthquake diplomacy’ with his Greek counterpart George Papandreou after twin tragedies struck both nations in 1999, and largely avoided entanglement in Middle Eastern conflicts.

The net result of all these actions was that Turkey emerged from the crisis with greater resilience, a more robust regulatory framework, upgraded political and economic institutions, rapidly decreasing inflation, a credible central bank, a stronger financial system, closer relations with the EU and US, and heightened domestic and foreign investor confidence.

But now that similar woes are engulfing Turkey anew, is Erdogan and the AKP/MHP alliance able – and willing – to repeat the Ecevit recipe? Present signs indicate they are highly unlikely to as they are too committed to entrenching the Triple C model.

Although this model will likely further consolidate their power, it will also empty the civil service of qualified professionals, restrict civil liberties and freedoms, and create more ideological politics, affecting Turkey’s foreign policy.

Such a stubborn refusal to shift direction is increasing the inevitability of a deep economic and financial breakdown and so, unless Turkey undertakes a serious policy departure instead of continuing to resort to the quick fix approach, there is real likelihood it will simply accelerate towards disaster.

McKesson Medical-Surgical Inc. entered into an agreement with the Labor Department on Monday resolving employment discrimination issues involving nearly 900 Black, Hispanic, and White applicants at a distribution center

The Supreme Court appeared skeptical that companies should be required to include past events in their risk disclosure statements during oral arguments for Facebook Inc. vs. Amalgamated Bank on Wednesday.

As Nissan on Thursday reported a roughly half-billion- dollar revenue drop in 2024, the Japanese automaker said it will cut 9,000 jobs and reduce manufacturing capacity by 20%.

More than 500,000 space heaters from GoveeLife and GoveeSmart Electric are being recalled because of safety issues, according to the U.S. Consumer Product Safety Commission.

Tesla Friday reached a $1 trillion market capitalization value for the first time since 2022 in a post-election stock rally.

President-elect Donald Trump wants legal authorities to investigate what he said were possibly illegal rumors he is going to sell his majority stock stake in Trump Media. He claims he won't sell.

Costco voluntarily recalled 79,200 pounds of two types of its store-brand butter over the past month because their labels may not have said the products contain milk.

Canada ordered striking dock workers back to the ports of Vancouver, Prince Rupert and Montreal on Tuesday to clear out more than a week of container congestion bound for the United States and Canada.

SAN JOSE, Calif., Oct. 16, 2024 — Supermicro, Inc. is launching a new optimized storage system for high performance AI training, inference and HPC workloads. This JBOF (Just a Bunch […]

The post Supermicro Introduces JBOF Storage Platform Powered by NVIDIA BlueField-3 for Scalable AI and HPC appeared first on HPCwire.

HANOVER, Md., Nov. 5, 2024 — Ciena has announced that its optical and routing and switching innovations will once again support the SCinet network at SC24, taking place November 17–22 […]

The post Ciena Powers SC24’s SCinet with High-Speed Connectivity and Advanced Optical Solutions appeared first on HPCwire.

Oct. 24, 2024 — The San Diego Supercomputer Center (SDSC), part of the School of Computing, Information and Data Sciences at UC San Diego, has been leading the Open Storage Network (OSN) program for years, and along […]

The post SDSC Leads Expansion of Open Storage Network to More Campus Computing Sites appeared first on HPCwire.

An American woman who was traveling in Hungary was killed in Budapest last week allegedly by a man she met on vacation.

A hologram of a sex worker who was murdered in Amsterdam more than a decade ago could help solve the cold case, investigators hope.

A pair of strong earthquakes has struck off the southern coast of Cuba, inflicting damage and causing landslides.

Ukraine's military intelligence has intercepted what it claims are radio communications between North Korean soldiers in Russia, amid media reports of a massive troop buildup ahead of an attack in the Kursk region.

Oct. 16, 2024 — The ISC High Performance Jack Dongarra Early Career Award and Lecture Series is an annual event that honors the remarkable contributions of Professor Jack Dongarra to […]

The post ISC Opens Nominations for 2025 Jack Dongarra Early Career Award in HPC appeared first on HPCwire.

The Dallas Cowboys agreed to trade a fourth-round pick in the 2025 NFL Draft to the Carolina Panthers in exchange for wide receiver Jonathan Mingo and a seventh-round pick, a league source told UPI on Tuesday.

Alex Ovechkin calmly slid into the right circle and sniped a snapshot past a blinded Juuse Saros to lead the Washington Capitals to a 3-2 triumph over the Nashville Predators.

The Carolina Panthers signed running back Chuba Hubbard to a four-year contract extension worth $33.2 million, a league source told UPI on Thursday.

All-Pro left tackle Tristan Wirfs and tight ends Sam LaPorta and Dalton Kincaid were among key players injured in Week 10 of the NFL season.

FC Cincinnati midfielder Marco Angulo has died from injuries he sustained from a car crash, the MLS franchise and Ecuadorian Football Association announced Tuesday. He was 22.

Chicago Bears coach Matt Eberflus has fired offensive coordinator Shane Waldron, the team said Tuesday. The dismissal came less than a day after Eberflus committed to quarterback Caleb Williams, but promised "changes."

Aug. 19, 2024 — SURF’s innovation department recently collaborated with Cornelis Networks to advance networking capabilities for high-performance computing (HPC) clusters. The collaboration marks a new step forward for SURF […]

The post Cornelis Networks Partners with SURF to Enhance HPC Cluster Networking Capabilities appeared first on HPCwire.

In AI, time is money. Top AI players are spending billions to create computing infrastructures to satisfy that need for speed. However, these companies are bottlenecked by computing constraints at […]

The post Ayar Labs CEO: Optical Chiplets Coming to SOCs Soon appeared first on HPCwire.

Noritaka Hoshi, Senior Manager, AI Platform Division, talks about the impetus for and challenges within the development of SX-Aurora TSUBASA or a massive SIMD, created to handle enormous computing and […]

The post Advance Science, Technology and Sophistication with SX-Aurora TSUBASA or Vector Processor or Vector Engine (VE) appeared first on HPCwire.

The demand for high-performance computing (HPC) and artificial intelligence (AI) is rising dramatically as organizations rush to put their data to work. Several industries see a significant increase in HPC […]

The post Harness Insights with Cutting-edge AI Capabilities from HPE appeared first on HPCwire.

What can be achieved using applications such as AI/ML, Deep Learning, and Big Data Analytics has been revolutionized by Magnum IO GPUDirect Storage’s capabilities. Agencies have invested in these solutions […]

The post Accelerating GPU Based Applications with NVIDIA Validated Magnum IO GPUDirect Storage and Pavilion appeared first on HPCwire.

How can manufacturers apply lessons learned from the dawn of the “Exascale Era” to Computer-Aided Engineering to achieve results like never before? Join Addison Snell, CEO, Intersect360 Research, Bill Mannel, VP, High Performance […]

The post Leveraging Exascale Era Technology for Advanced Computer-Aided Engineering appeared first on HPCwire.

Oct. 29, 2024 — ORCA Computing today announced the unveiling of the PT-2, the latest advancement in its PT Series of photonic quantum systems. Building on the success of the […]

The post ORCA Computing Unveils PT-2 to Integrate Quantum Computing with Generative AI and HPC appeared first on HPCwire.

A zoo on England's Isle of Wight announced the saga of its escaped raccoons came to a happy ending with the final animal safely recaptured.

A South Carolina woman ended up calling the police for help after she walked into her apartment's bathroom and found a large ball python behind her toilet.

Police in a small South Carolina town are warning residents to keep their doors and windows locked after 43 monkeys escaped from a research facility.