Detection of tumour heterogeneity in patients with advanced, metastatic castration-resistant prostate cancer on [Ga]Ga-/[F]F-PSMA-11/-1007, [Ga]Ga-FAPI-46 and 2-[F]FDG PET/CT: a pilot study.

Purpose: In metastatic castration-resistant prostate cancer (mCRPC), some patients show low/absent PSMA expression in tumour lesions on positron emission tomography (PET) scans, indicating heterogeneity and heightened risk of non-response to PSMA-RLT (radioligand therapy). Imaging cancer-associated fibroblasts and glucose uptake may further characterise tumour heterogeneity in mCRPC patients. Here, we aimed to evaluate tumour heterogeneity and its potential implications for management in mCRPC patients assessed for PSMA-RLT using [Ga]Ga-FAPI-46, 2-[F]FDG and [Ga]Ga-/[F]F-PSMA-11/-1007 PET.

GAN-based generation of realistic 3D volumetric data: A systematic review and taxonomy.

With the massive proliferation of data-driven algorithms, such as deep learning-based approaches, the availability of high-quality data is of great interest. Volumetric data is very important in medicine, as it ranges from disease diagnoses to therapy monitoring. When the dataset is sufficient, models can be trained to help doctors with these tasks.

k-strip: A novel segmentation algorithm in k-space for the application of skull stripping.

Background And Objective: We present a novel deep learning-based skull stripping algorithm for magnetic resonance imaging (MRI) that works directly in the information rich complex valued k-space.

Methods: Using four datasets from different institutions with a total of around 200,000 MRI slices, we show that our network can perform skull-stripping on the raw data of MRIs while preserving the phase information which no other skull stripping algorithm is able to work with. For two of the datasets, skull stripping performed by HD-BET (Brain Extraction Tool) in the image domain is used as the ground truth, whereas the third and fourth dataset comes with per-hand annotated brain segmentations.

"A net for everyone": fully personalized and unsupervised neural networks trained with longitudinal data from a single patient.

Background: With the rise in importance of personalized medicine and deep learning, we combine the two to create personalized neural networks. The aim of the study is to show a proof of concept that data from just one patient can be used to train deep neural networks to detect tumor progression in longitudinal datasets.

Methods: Two datasets with 64 scans from 32 patients with glioblastoma multiforme (GBM) were evaluated in this study.

Histology-Based Prediction of Therapy Response to Neoadjuvant Chemotherapy for Esophageal and Esophagogastric Junction Adenocarcinomas Using Deep Learning.

Purpose: Quantifying treatment response to gastroesophageal junction (GEJ) adenocarcinomas is crucial to provide an optimal therapeutic strategy. Routinely taken tissue samples provide an opportunity to enhance existing positron emission tomography-computed tomography (PET/CT)-based therapy response evaluation. Our objective was to investigate if deep learning (DL) algorithms are capable of predicting the therapy response of patients with GEJ adenocarcinoma to neoadjuvant chemotherapy on the basis of histologic tissue samples.

Non-exposed endoscopic wall-inversion surgery with one-step nucleic acid amplification for early gastrointestinal tumors: Personal experience and literature review.

Background: Laparoscopic and endoscopic cooperative surgery is a safe, organ-sparing surgery that achieves full-thickness resection with adequate margins. Recent studies have demonstrated the safety and efficacy of these procedures. However, these techniques are limited by the exposure of the tumor and mucosa to the peritoneal cavity, which could lead to viable cancer cell seeding and the spillage of gastric juice or enteric liquids into the peritoneal cavity.

Voxel-Based Dosimetry Predicts Hepatotoxicity in Hepatocellular Carcinoma Patients Undergoing Radioembolization with Y Glass Microspheres.

Personalized dosimetry holds promise to improve radioembolization treatment outcomes in hepatocellular carcinoma (HCC) patients. To this end, tolerance absorbed doses for nontumor liver tissue are assessed by calculating the mean absorbed dose to the whole nontumor liver tissue (AD-WNTLT), which may be limited by its neglect of nonuniform dose distribution. Thus, we analyzed whether voxel-based dosimetry could be more accurate in predicting hepatotoxicity in HCC patients undergoing radioembolization.

Towards a fast PET/MRI protocol for breast cancer imaging: maintaining diagnostic confidence while reducing PET and MRI acquisition times.

Objectives: To investigate the diagnostic feasibility of a shortened breast PET/MRI protocol in breast cancer patients.

Methods: Altogether 90 women with newly diagnosed T1 (T1) and T2 (T2) breast cancer were included in this retrospective study. All underwent a dedicated comprehensive breast [F]FDG-PET/MRI.

Evaluation of thresholding methods for the quantification of [Ga]Ga-PSMA-11 PET molecular tumor volume and their effect on survival prediction in patients with advanced prostate cancer undergoing [Lu]Lu-PSMA-617 radioligand therapy.

Purpose: The aim of this study was to systematically evaluate the effect of thresholding algorithms used in computer vision for the quantification of prostate-specific membrane antigen positron emission tomography (PET) derived tumor volume (PSMA-TV) in patients with advanced prostate cancer. The results were validated with respect to the prognostication of overall survival in patients with advanced-stage prostate cancer.

Materials And Methods: A total of 78 patients who underwent [Lu]Lu-PSMA-617 radionuclide therapy from January 2018 to December 2020 were retrospectively included in this study.

Novel measures for the diagnosis of hepatic steatosis using contrast-enhanced computer tomography images.

Purpose: Hepatic steatosis is often diagnosed non-invasively. Various measures and accompanying diagnostic thresholds based on contrast-enhanced CT and virtual non-contrast images have been proposed. We compare these established criteria to novel and fully automated measures.

Simultaneous multislice diffusion-weighted imaging versus standard diffusion-weighted imaging in whole-body PET/MRI.

Objective: To compare standard (STD-DWI) single-shot echo-planar imaging DWI and simultaneous multislice (SMS) DWI during whole-body positron emission tomography (PET)/MRI regarding acquisition time, image quality, and lesion detection.

Methods: Eighty-three adults (47 females, 57%), median age of 64 years (IQR 52-71), were prospectively enrolled from August 2018 to March 2020. Inclusion criteria were (a) abdominal or pelvic tumors and (b) PET/MRI referral from a clinician.

Positive Prostate-specific Membrane Antigen Findings: How To Interpret Them.

Prostate-specific membrane antigen (PSMA) positron emission tomography/computed tomography (PET/CT) is more accurate than conventional imaging for primary staging of high-risk prostate cancer and localization of biochemical recurrence. Knowledge of PSMA expression patterns and standardized reporting facilitate accurate interpretation of positive PSMA findings. PSMA PET/CT should be adopted as part of clinical routine, as recommended in international guidelines.

Novel Ga-FAPI PET/CT Offers Oncologic Staging Without COVID-19 Vaccine-Related Pitfalls.

In the setting of ongoing coronavirus disease 2019 vaccination, vaccine-related tracer uptake in locoregional lymph nodes has become a well-known issue in tumor staging by F-FDG PET/CT. Ga-fibroblast-activation protein inhibitor (FAPI) PET/CT is a new oncologic imaging tool that may overcome this limitation. We assessed postvaccine head-to-head and same-day F-FDG and Ga-FAPI-46 PET/CT findings in a series of 11 patients from a large, prospective imaging registry.

Molecular Imaging of Lymphoma: Future Directions and Perspectives.

More than 250,000 patients die from Hodgkin or non-Hodgkin lymphoma each year. Currently, molecular imaging with F-FDG-PET/CT is the standard of care for lymphoma staging and therapy response assessment. In this review, we will briefly summarize the role of molecular imaging for lymphoma diagnosis, staging, outcome prediction, and prognostication.

Role of one-step nucleic acid amplification in colorectal cancer lymph node metastases detection.

Current histopathological staging procedures in colorectal cancer (CRC) depend on midline division of the lymph nodes (LNs) with one section of hematoxylin and eosin staining. Cancer cells outside this transection line may be missed, which could lead to understaging of Union for International Cancer Control Stage II high-risk patients. The one-step nucleic acid amplification (OSNA) assay has emerged as a rapid molecular diagnostic tool for LN metastases detection.

The future of radiosynoviorthesis: bright or bleak?

Radiosynoviorthesis (RSO) is a decades known, effective intra-articular nuclear medicine local therapy, with few rare side-effects, in which inflamed synovial membrane is treated by means of colloidal beta-emitters. There are major variations worldwide in terms of acceptance, frequency of use and approved indications for this procedure. Thus, reliable figures that reflect reality are only available for a few countries.

Medical deep learning-A systematic meta-review.

Deep learning has remarkably impacted several different scientific disciplines over the last few years. For example, in image processing and analysis, deep learning algorithms were able to outperform other cutting-edge methods. Additionally, deep learning has delivered state-of-the-art results in tasks like autonomous driving, outclassing previous attempts.

COVID-19 Pandemic: What Have We Learned and What to Expect in the Future?

The COVID-19 pandemic resulted in an unprecedented and unexpected challenge for societies and healthcare systems, including nuclear medicine providers. This article summarizes the major events imposed on nuclear medicine by COVID-19 from a global perspective, focuses on the major lessons learned regarding attitude, medical procedures, organizational implications and strategical considerations, and then discusses what to expect (and how to prepare) for the future. While the look back to what has happened is clearly evidence based, the look ahead and the conclusions drawn require the disclaimer of only representing the personal opinion and prediction of the authors.

The influence of 68Ga-prostate-specific membrane antigen PET/computed tomography on prostate cancer staging and planning of definitive radiation therapy.

Objectives: Prostate-specific membrane antigen (PSMA) PET/computed tomography (CT) is a novel imaging tool with an evolving role in the management of prostate cancer. This study aims to retrospectively evaluate the impact of 68Ga-PSMA PET/CT on prostate cancer staging and definitive radiation therapy planning.

Methods: Between April 2015 and June 2020, 366 men with prostate cancer were evaluated with 68Ga-PSMA PET/CT.