Tumor Pre-Targeting System Using Streptavidin-Expressing Bacteria.

Purpose: A major obstacle to targeted cancer therapy is identifying suitable targets that are specifically and abundantly expressed by solid tumors. Certain bacterial strains selectively colonize solid tumors and can deliver genetically encoded cargo molecules to the tumor cells. Here, we engineered bacteria to express monomeric streptavidin (mSA) in tumors, and developed a novel tumor pre-targeting system by visualizing the presence of tumor-associated mSA using a biotinylated imaging probe.

Prognostic Significance Of Sequential 18f-fdg Pet/Ct During Frontline Treatment Of Peripheral T Cell Lymphomas.

Background/aims: The prognostic significance of 18F-fluorodeoxyglucose (FDG)-positron emission tomography-computed tomography (PET/CT) in peripheral T-cell lymphomas (PTCLs) are controversial. We explored the prognostic impact of sequential 18F-FDG PET/CT during frontline chemotherapy of patients with PTCLs.

Methods: In total, 143 patients with newly diagnosed PTCLs were included.

Injuries and Illness during the 2019 Gwangju FINA and Masters World Championships in Elite and Amateur Athletes.

Comparative analysis of injury and illness prevalence in elite and amateur athletes provides the basis for the development of tailored prevention programs. The authors analyzed the differences in frequency and characteristics of injuries and illnesses which occurred in elite and amateur athletes during the 2019 Gwangju Federation Internationale de Natation (FINA) and Masters World Championships. The 2019 FINA World Championships hosted 3095 athletes in the disciplines of swimming, diving, high diving, artistic swimming, water polo, and open water swimming.

Prediction of cardiac events following concurrent chemoradiation therapy for non-small-cell lung cancer using FDG PET.

Objective: No imaging biomarkers are available for the prediction of cardiac events following concurrent chemoradiation therapy (CCRT) for non-small-cell lung cancer (NSCLC). We evaluated whether F-18 fluorodeoxyglucose positron emission tomography (FDG PET) early after CCRT, in addition to cardiac dosimetry, could predict late cardiac events in NSCLC.

Methods: We retrospectively enrolled 133 consecutive patients with locally advanced, unresectable stage III NSCLC, who underwent FDG PET early after CCRT and survived at least 6 months.

Clinically viable myocardial CCTA segmentation for measuring vessel-specific myocardial blood flow from dynamic PET/CCTA hybrid fusion.

Background: Positron emission tomography (PET)-derived LV MBF quantification is usually measured in standard anatomical vascular territories potentially averaging flow from normally perfused tissue with those from areas with abnormal flow supply. Previously we reported on an image-based tool to noninvasively measure absolute myocardial blood flow at locations just below individual epicardial vessel to help guide revascularization. The aim of this work is to determine the robustness of vessel-specific flow measurements (MBF) extracted from the fusion of dynamic PET (dPET) with coronary computed tomography angiography (CCTA) myocardial segmentations, using flow measured from the fusion with CCTA manual segmentation as the reference standard.

Precise characterization of a solitary pulmonary nodule using tumor shadow disappearance rate-corrected F-18 FDG PET and enhanced CT.

We aimed to characterize solitary pulmonary nodule (SPN) using imaging parameters for F-18 fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) or enhanced CT corrected by tumor shadow disappearance rate (TDR) to reflect the tissue density.We enrolled 51 patients with an SPN who underwent PET/CT and chest CT with enhancement. The FDG uptake of SPN was evaluated using maximum standardized uptake value (SUVmax) on PET/CT.

KSNM60 in Cardiology: Regrowth After a Long Pause.

The Korean Society of Nuclear Medicine (KSNM) is celebrating its 60th anniversary in honor of the nuclear medicine professionals who have dedicated their efforts towards research, academics, and the more comprehensive clinical applications and uses of nuclear imaging modalities. Nuclear cardiology in Korea was at its prime time in the 1990s, but its growth was interrupted by a long pause. Despite the academic and practical challenges, nuclear cardiology in Korea now meets the second leap, attributed to the growth in molecular imaging tailored for many non-coronary diseases and the genuine values of nuclear myocardial perfusion imaging.

Impact of COVID-19 on Nuclear Medicine in Asia.

Coronavirus disease 2019 (COVID-19) was first detected in China in late 2019 and rapidly spread to nearby Asian countries in early 2020. Outbreaks occurred differently in each country and affected nuclear medicine (NM) practice significantly even before the COVID-19 pandemic. The Asian NM community has worked together from the beginning of the pandemic.

Dynamic cardiac PET motion correction using 3D normalized gradient fields in patients and phantom simulations.

Unlabelled: This work expands on the implementation of three-dimensional (3D) normalized gradient fields to correct for whole-body motion and cardiac creep in [N-13]-ammonia patient studies and evaluates its accuracy using a dynamic phantom simulation model.

Methods: A full rigid-body algorithm was developed using 3D normalized gradient fields including a multi-resolution step and sampling off the voxel grid to reduce interpolation artifacts. Optimization was performed using a weighted similarity metric that accounts for opposing gradients between images of blood pool and perfused tissue without the need for segmentation.

Increasing Use of Cardiac PET/CT for Inflammatory and Infiltrative Heart Diseases in Korea.

Recently the incidence of inflammatory and infiltrative heart diseases is increasing in Korea. Cardiac PET/CT is a useful technology evaluating inflammatory and infiltrative heart diseases. This study analyzed trends in the use of cardiac PET/CT for evaluating inflammatory and infiltrative heart diseases in the Chonnam National University Hospital and Chonnam National University Hwasun Hospital.

Change of Therapeutic Response Classification According to Recombinant Human Thyrotropin-Stimulated Thyroglobulin Measured at Different Time Points in Papillary Thyroid Carcinoma.

Purpose: We investigated whether response classification after total thyroidectomy and radioactive iodine (RAI) therapy could be affected by serum levels of recombinant human thyrotropin (rhTSH)-stimulated thyroglobulin (Tg) measured at different time points in a follow-up of patients with papillary thyroid carcinoma (PTC).

Methods: A total of 147 PTC patients underwent serum Tg measurement for response assessment 6 to 24 months after the first RAI therapy. Serum Tg levels were measured at 24 h (D1Tg) and 48-72 h (D2-3Tg) after the 2 injection of rhTSH.

A Stepwise Approach Using Metastatic Lymph Node Ratio-Combined Thyroglobulin for Customization of [F]FDG-PET/CT Indication to Detect Persistent Disease in Patients with Papillary Thyroid Cancer.

We investigated whether an indication for [F]FDG-PET/CT to detect FDG-avid persistent disease (PD) could be identified precisely using the extent of metastatic lymph nodes (MLNs) and serum thyroglobulin (Tg) in papillary thyroid cancer (PTC) patients. This retrospective study included 429 PTC patients who underwent surgery and radioactive iodine (RAI) therapy. [F]FDG-PET/CT and serum Tg were evaluated just before RAI therapy.

Determination of [N-13]-ammonia extraction fraction in patients with coronary artery disease by calibration to invasive coronary and fractional flow reserve.

Background: This study presents a new extraction fraction (EF) model based on physiological measures of invasive coronary flow reserve (CFR) and fractional flow reserve (FFR) in patients with suspected coronary artery disease (CAD) and normal index microcirculatory resistance (IMR). To ascertain the clinical relevance of the new EFs, flow measurements using the newly patient-determined EFs were compared to flow measurements using traditional animal-determined EFs.

Methods: 39 patients were retrospectively selected that included a total of 91 vascular territories with invasive coronary angiography physiological measures.

Differences in diagnostic impact of dual-tracer PET/computed tomography according to the extrahepatic metastatic site in patients with hepatocellular carcinoma.

Objectives: We compared the diagnostic performance of C-11 acetate and F-18 fluorodeoxyglucose (FDG) PET/computed tomography (CT) for the detection of extrahepatic metastasis in patients with hepatocellular carcinoma (HCC) and evaluated whether the improvement in the diagnostic performance of dual tracer PET/CT differs by the metastatic site.

Methods: Fifty-eight patients who had extrahepatic metastasis on either C-11 acetate or F-18 FDG PET/CT were enrolled, and 193 metastatic lesions were analyzed in this retrospective study. The metastatic lesions were categorized based on six sites of involvement.

Prognostic impact of F-FDG PET/CT in patients with multiple myeloma presenting with renal impairment.

Renal insufficiency (RI) is a frequent manifestation of multiple myeloma (MM) at time of diagnosis but there is no reliable prognostic factor for patients with MM presenting with RI. This study investigated the prognostic impact of F-fluorodeoxyglucose (F-FDG) positron emission tomography/computed tomography (PET/CT) in patients with MM with RI at diagnosis. The records of 209 patients with MM between June 2011 and November 2018 were retrospectively analyzed.

Worldwide Variation in the Use of Nuclear Cardiology Camera Technology, Reconstruction Software, and Imaging Protocols.

Objectives: This study sought to describe worldwide variations in the use of myocardial perfusion imaging hardware, software, and imaging protocols and their impact on radiation effective dose (ED).

Background: Concerns about long-term effects of ionizing radiation have prompted efforts to identify strategies for dose optimization in myocardial perfusion scintigraphy. Studies have increasingly shown opportunities for dose reduction using newer technologies and optimized protocols.

Clinical Impact of F-18 FDG PET-CT on Biopsy Site Selection in Patients with Suspected Bone Metastasis of Unknown Primary Site.

Purpose: We investigated the clinical role of F-18 fluorodeoxyglucose (FDG) positron emission tomography-computed tomography (PET-CT) in the identification of the primary site and the selection of the optimal biopsy site in patients with suspected bone metastasis of unknown primary site.

Methods: The patients with suspected bone metastasis who underwent PET-CT for evaluation of primary site were enrolled in this study. The primary sites were identified by the histopathologic or imaging studies and were classified according to the FDG uptake positivity of the primary site.

Worldwide Diagnostic Reference Levels for Single-Photon Emission Computed Tomography Myocardial Perfusion Imaging: Findings From INCAPS.

Objectives: This study sought to establish worldwide and regional diagnostic reference levels (DRLs) and achievable administered activities (AAAs) for single-photon emission computed tomography (SPECT) myocardial perfusion imaging (MPI).

Background: Reference levels serve as radiation dose benchmarks to compare individual laboratories against aggregated data, helping to identify sites in greatest need of dose reduction interventions. DRLs for SPECT MPI have previously been derived from national or regional registries.