The utility of Ga-DOTATATE and F-FDG PET/CT in predicting the response to tyrosine kinase inhibitors in patients with advanced medullary thyroid cancer.

Background: Tyrosine kinase inhibitors (TKIs) have significantly improved the prognosis of patients with advanced medullary thyroid cancer (MTC). However, treatment response heterogeneity leads to challenges in predicting individual favourable response. This study evaluated the correlation between PET metrics on Ga-DOTATATE and F-FDG PET/CTs prior to treatment, and TKI response.

Repeated Cranial and Large-Vessel Positron Emission Tomography/Computed Tomography Scans and the Association With Structural Aortic Disease in Giant Cell Arteritis: A Five-Year Observational Study.

Objective: Giant cell arteritis (GCA) is characterized by cranial ischemia at diagnosis and late aortic structural disease. Repeated combined cranial and large-vessel fluoro-2-deoxyglucose (FDG) positron emission tomography (PET)/computed tomography (CT) scans were performed to assess the distribution of vasculitis activity over time and the relationship with clinical outcomes.

Methods: Patients were eligible if they were enrolled in a 64-patient inception suspected GCA cohort in 2016 to 2017 and had a positive temporal artery biopsy and/or PET/CT scan at diagnosis.

The role of amino acid PET in radiotherapy target volume delineation for adult-type diffuse gliomas: A review of the literature.

Purpose: To summarise existing literature examining amino acid positron emission tomography (AA-PET) for radiotherapy target volume delineation in patients with gliomas.

Methods: Systematic search of MEDLINE and EMBASE databases.

Results: Twenty studies met inclusion criteria.

[F]FDG PET/CT-Avid Discordant Volume as a Biomarker in Patients with Gastroenteropancreatic Neuroendocrine Neoplasms: A Multicenter Study.

[F]FDG PET/CT and [Ga]Ga-DOTATATE PET/CT are both used to predict tumor biology in neuroendocrine neoplasms. Although the presence of discordant ([F]FDG-avid/non-[Ga]Ga-DOTATATE-avid) disease predicts poor prognosis, the significance of the volume of such discordant disease remains undetermined. The aim of this study is to investigate discordant tumor volume as a potential biomarker in patients with advanced gastroenteropancreatic neuroendocrine neoplasms (GEPNENs).

Development of a novel clinical support tool for active surveillance of low risk papillary thyroid cancer.

Background: Active surveillance (AS) is an alternative to surgery in select patients with very low risk papillary thyroid cancer (PTC). Many clinicians feel ill-equipped in selecting appropriate patients. We aimed to 1) Develop an evidence-based web delivered decision support tool to assist clinicians in identifying patients appropriate for AS; and 2) Evaluate the prevalence of patients suitable for AS in a tertiary high volume thyroid cancer centre.

Delineation and agreement of FET PET biological volumes in glioblastoma: results of the nuclear medicine credentialing program from the prospective, multi-centre trial evaluating FET PET In Glioblastoma (FIG) study-TROG 18.06.

Purpose: The O-(2-[F]-fluoroethyl)-L-tyrosine (FET) PET in Glioblastoma (FIG) trial is an Australian prospective, multi-centre study evaluating FET PET for glioblastoma patient management. FET PET imaging timepoints are pre-chemoradiotherapy (FET1), 1-month post-chemoradiotherapy (FET2), and at suspected progression (FET3). Before participant recruitment, site nuclear medicine physicians (NMPs) underwent credentialing of FET PET delineation and image interpretation.

Cu Treatment Planning and Cu Therapy with Radiolabeled [Cu/Cu]MeCOSar-Octreotate in Subjects with Unresectable Multifocal Meningioma: Initial Results for Human Imaging, Safety, Biodistribution, and Radiation Dosimetry.

Our aim was to report the use of Cu and Cu as a theranostic pair of radionuclides in human subjects. An additional aim was to measure whole-organ dosimetry of Cu and Cu attached to the somatostatin analog octreotate using the sarcophagine MeCOSar chelator (SARTATE) in subjects with somatostatin receptor-expressing lesions confined to the cranium, thereby permitting normal-organ dosimetry for the remainder of the body. Pretreatment PET imaging studies were performed up to 24 h after injection of [Cu]Cu-SARTATE, and normal-organ dosimetry was estimated using OLINDA/EXM.

Dual [Ga]DOTATATE and [F]FDG PET/CT in patients with metastatic gastroenteropancreatic neuroendocrine neoplasms: a multicentre validation of the NETPET score.

Background: Gastroenteropancreatic neuroendocrine neoplasms (GEPNENs) are heterogeneous in clinical course, biology, and outcomes. The NETPET score predicts survival by scoring uptake on dual [Ga]DOTATATE and [F]FDG PET/CT scans. We aimed to validate previous single-centre findings in a multicentre, international study.

I-PET score: Combining whole body iodine and F-FDG PET/CT imaging to predict progression in structurally or biochemically incomplete thyroid cancer.

Objective: We propose a new scoring system (I-PET) combining whole body scan (WBS) and FDG findings to identify patients who have or are likely to become refractory to radioactive iodine.

Design: Retrospective analysis of 142 patients age >18 with differentiated thyroid cancer who had a F-18 labelled fluoro-2-deoxyglucose ( F-FDG) positron emission tomography (PET) and WBS within a 6-month period between 2010 and 2020. Pairs of F-FDG PET and WBS were reviewed by three independent nuclear medicine physicians and an I-PET score was assigned: I-PET [0]: Iodine -ve/FDG -ve, I-PET [1]: Iodine +ve/FDG -ve, I-PET [2]: Iodine +ve/FDG +ve and I-PET [3]: Iodine -ve/FDG +ve.

A Retrospective Cohort Study with Validation of Predictors of Differentiated Thyroid Cancer Outcomes.

The goal of radioactive iodine (RAI) in differentiated thyroid cancer (DTC) is to treat metastasis and reduce recurrence risk. International guidelines provide broad risk stratification to aid treatment decisions, but a more nuanced approach to individualize care is warranted. We developed a predictive risk model for DTC.

The Clinical Significance of Small Vessel Vasculitis on Temporal Artery Biopsies.

Background: Giant cell arteritis (GCA) is the most common type of systemic vasculitis in the elderly. Untreated, it can lead to irreversible blindness. Its diagnosis relies on a temporal artery biopsy (TAB).

Change in Practice of Radioactive Iodine Administration in Differentiated Thyroid Cancer: A Single-Centre Experience.

Objective: Our study aimed to analyse temporal trends in radioactive iodine (RAI) treatment for thyroid cancer over the past decade; to analyse key factors associated with clinical decisions in RAI dosing; and to confirm lower activities of RAI for low-risk patients were not associated with an increased risk of recurrence.

Methods: Retrospective analysis of 1,323 patients who received RAI at a quaternary centre in Australia between 2008 and 2018 was performed. Prospectively collected data included age, gender, histology, and American Joint Committee on Cancer stage (7th ed).

Is 67gallium dead? A retrospective review of 67gallium imaging in a single tertiary referral centre.

Background: [67Ga]Ga-citrate scanning has been used to investigate patients with known or suspected infection for over 50 years, continuing to maintain a clinical niche in many centres. The introduction of single photon emission tomography/computed tomography (SPECT/CT) in addition to planar imaging has improved the specificity of diagnosis.

Aim: To examine the experience of modern [67Ga]Ga-citrate scanning in a single tertiary referral centre, considering the diagnostic yield of the study.

Case Report of 18F-FDG PET/CT Features of Polyacrylamide Hydrogel Mammoplasty.

A 57-year-old woman with a history of previous bilateral breast polyacrylamide hydrogel injection presented for 18F-FDG PET/CT imaging to investigate recurrent retroperitoneal liposarcoma. Incidental symmetrical FDG-positive accumulation was noted in the bilateral axillae tracking between the interpectoral planes. The finding is consistent with a chronic inflammatory process secondary to the migration of the polyacrylamide hydrogel injections.

Interim Results of a Prospective Prostate-Specific Membrane Antigen-Directed Focal Stereotactic Reirradiation Trial for Locally Recurrent Prostate Cancer.

Purpose: To report the feasibility, toxicity, and preliminary outcomes (metabolic and biochemical) of Ga-prostate-specific membrane antigen (PSMA) positron emission tomography/computed tomography (PET/CT)-directed focal prostate reirradiation using linear accelerator (LINAC)-based stereotactic body radiation treatment (SBRT).

Methods And Materials: From March 2016 to March 2019, 25 patients were enrolled in a prospective single institution trial (ACTRN12617000035325). Eligibility criteria included patients with biopsy proven isolated prostate recurrence after definitive irradiation, with concordant multiparametric MRI and Ga-PSMA PET/CT findings, and a prostate-specific antigen of less than 15 ng/mL at the time of recurrence.

Cranial and large vessel activity on positron emission tomography scan at diagnosis and 6 months in giant cell arteritis.

Aim: Positron emission tomography/computed tomography (PET/CT) can detect cranial and large vessel inflammation in giant cell arteritis (GCA). We aimed to determine the change and significance of vascular activity at diagnosis and 6 months.

Method: Newly diagnosed GCA patients underwent time-of-flight fluorine-18-fluoro-2-deoxyglucose PET/CT from vertex to diaphragm within 72 hours of commencing corticosteroids and were followed for 12 months.

Evaluation of Fluorodeoxyglucose Positron Emission Tomography Scanning in the Neoadjuvant Therapy Paradigm in Pancreatic Ductal Adenocarcinoma.

Objectives: Little data exist on the utility of fluorodeoxyglucose positron emission tomography (FDG-PET) in operable pancreatic ductal adenocarcinoma (PDAC) treated with neoadjuvant (NA) therapy.

Methods: Consecutively treated patients with potentially operable PDAC were recruited from a quaternary referral center between 2015 and 2018. Data were collated on demographic, clinical, radiological, treatment, and disease-free and overall survival (OS) outcome measures, correlated with FDG-PET findings.

Quantifying the effects of absorbed dose from radioembolisation on healthy liver function with [Tc]TcMebrofenin.

Purpose: To quantify the effects of absorbed radiation dose on healthy liver parenchyma following radioembolisation (RE) using [Tc]TcMebrofenin to analyse both global and regional liver function.

Methods: Patients having RE to treat hepatic disease underwent a [Tc]TcMebrofenin hepatobilliary scintigraphy (HBS) study at both baseline and 8 weeks following treatment. Changes in global liver uptake rate were compared with healthy liver absorbed dose measures derived from the post-treatment Y PET/CT, including average dose, minimum dose to 70% of the volume (D70) and volume receiving at least 50 Gy (V50).

High Metabolic Tumour Volume on 18-Fluorodeoxyglucose Positron Emission Tomography Predicts Poor Survival from Neuroendocrine Neoplasms.

Introduction: 18-Fluorodeoxyglucose (18F-FDG) positron emission tomography (PET) avidity in neuroendocrine neoplasms (NENs) has been associated with higher-grade disease. 18F-FDG avidity and high SUVmax have been demonstrated to predict poor outcome. Quantitative metrics of 18F-FDG PET, specifically metabolic tumour volume (MTV) and total lesion glycolysis (TLG), have been shown to be prognostic factors in other malignancies, but these have not been investigated to date in NENs.

Diagnostic Accuracy of Positron Emission Tomography/Computed Tomography of the Head, Neck, and Chest for Giant Cell Arteritis: A Prospective, Double-Blind, Cross-Sectional Study.

Objective: Positron emission tomography/computed tomography (PET/CT) has not been well studied as a first-line test for giant cell arteritis (GCA), due, in part, to historical limitations in visualizing the cranial arteries. The Giant Cell Arteritis and PET Scan (GAPS) study was therefore carried out to assess the accuracy of a newer generation PET/CT of the head, neck, and chest for determining a diagnosis of GCA.

Methods: In the GAPS study cohort, 64 patients with newly suspected GCA underwent time-of-flight PET/CT (1-mm slice thickness from the vertex to diaphragm) within 72 hours of starting glucocorticoids and before undergoing temporal artery biopsy (TAB).

Influence of molecular classification in anaplastic glioma for determining outcome and future approach to management.

Introduction: Assess survival of patients with anaplastic glioma (AG) and the relationship to molecular subtype.

Methods: Patients with AG managed with IMRT between 2008 and 2014 were entered into a prospective database assessing relapse-free survival (RFS) and overall survival (OS). Isocitrate dehydrogenase (IDH) mutations were assessed prospectively from 2011, and subsequent testing of historical patients allowing categorisation under WHO 2016 classification as anaplastic astrocytoma IDH wild type (AAwt), anaplastic astrocytoma IDH mutated (AAmut), anaplastic oligodendroglioma (AOD) or other glial tumour (OTH).

Diffuse Large B-Cell Lymphoma Recurring as Neurolymphomatosis on FDG PET/CT.

Two patients with diffuse large B-cell lymphoma relapsing as neurolymphomatosis diagnosed on FDG PET/CT are presented. Both patients were treated initially with chemotherapy and had a complete metabolic response. Patient 1 represented with lower-limb pain.