Predicting Response to [177Lu]Lu-PSMA Therapy in mCRPC Using Machine Learning.

Background/objectives: Radioligandtherapy (RLT) with [177Lu]Lu-PSMA has been newly introduced as a routine treatment for metastatic castration-resistant prostate cancer (mCRPC). However, not all patients can tolerate the entire therapeutic sequence, and in some cases, the treatment may prove ineffective. In real-world conditions, the aim is to distinguish between patients who fully benefit from treatment (those who respond effectively and tolerate the entire therapeutic sequence) and those who do not respond or cannot tolerate the entire sequence.

Absorbed Dose-Response Relationship in Patients with Gastroenteropancreatic Neuroendocrine Tumors Treated with [Lu]Lu-DOTATATE: One Step Closer to Personalized Medicine.

[Lu]Lu-DOTATATE has been approved for progressive and inoperable gastroenteropancreatic neuroendocrine tumors (GEP-NETs) that overexpress somatostatin receptors. The absorbed doses by limiting organs and tumors can be quantified by serial postinfusion scintigraphy measurements of the γ-emissions from Lu. The objective of this work was to explore how postinfusion [Lu]Lu-DOTATATE dosimetry could influence clinical management by predicting treatment efficacy (tumor shrinkage and survival) and toxicity.

[Ga]Ga-FAPI-46 synthesis on a GAIA® module system: Thorough study of the automated radiolabeling reaction conditions.

The influence of several parameters involved in the Ga radiolabeling of FAPI-46 was studied at the scale of the automated reaction. Among the buffers tested, HEPES 0.3 M pH 4 allowed both high radiochemical purity (RCP) and radiochemical yield (RCY), without prepurification of Ga but after final purification of [Ga]Ga-FAPI-46 on a C cartridge.

Identification of F-FDG PET/CT Parameters Associated with Weight Loss in Patients with Esophageal Cancer.

F-FDG PET-CT is routinely performed as part of the initial staging of numerous cancers. Other than having descriptive, predictive and prognostic values for tumors, F-FDG PET-CT provides full-body data, which could inform on concurrent pathophysiological processes such as malnutrition. To test this hypothesis, we measured the F-FDG uptake in several organs and evaluated their association with weight loss in patients at diagnosis of esophageal cancer.

Immunomodulatory effects of targeted radionuclide therapy.

It is now clear that conventional radiation therapy can reinstate cell death immunogenicity. Recent preclinical data indicate that targeted radionuclide therapy that irradiate tumors at continuous low dose rate also can elicit immunostimulatory effects and represents a promising strategy to circumvent immune checkpoint inhibitor resistance. In this perspective, we discuss the accumulating preclinical and clinical data suggesting that activation of the immune system through the cGAS-STING axis and the release of extracellular vesicles by irradiated cells, participate to this antitumor immunity.

Comparison of the Discovery A and Stratos DR densitometers for assessing whole-body and regional bone mineral density and body composition.

Purpose: The agreement between the Stratos DR and Discovery A densitometers was assessed for measurements of whole-body (WB) and regional fat mass (FM), fat-free soft tissue (FFST) and bone mineral density (BMD). Moreover, the precision of the Stratos DR was also evaluated.

Methods: Fifty participants (35 women, 70%) were measured consecutively, once on the Discovery A and once on the Stratos DR.

Clinical Pharmacokinetics of Radiopharmaceuticals from SPECT/CT Image Acquisition by Contouring in Patients with Gastroenteropancreatic Neuroendocrine Tumors: Lu-177 DOTATATE (Lutathera) Case.

Background And Objective: Lu-177 DOTATATE (Lutathera) is a radiolabeled analog of somatostatin administered intravenously in patients with somatostatin receptor-positive gastroenteropancreatic neuroendocrine tumors. Biodistribution of Lu-177 DOTATATE in tumor and healthy tissues can be monitored by serial post-injection scintigraphy imaging. Patient exposure to the drug is variable with the recommended fixed dosage, and hence there is a variable response to treatment.

Ac-Labeled Somatostatin Analogs in the Management of Neuroendocrine Tumors: From Radiochemistry to Clinic.

The widespread use of peptide receptor radionuclide therapy (PRRT) represents a major therapeutic breakthrough in nuclear medicine, particularly since the introduction of Lu-radiolabeled somatostatin analogs. These radiopharmaceuticals have especially improved progression-free survival and quality of life in patients with inoperable metastatic gastroenteropancreatic neuroendocrine tumors expressing somatostatin receptors. In the case of aggressive or resistant disease, the use of somatostatin derivatives radiolabeled with an alpha-emitter could provide a promising alternative.

Development and Implementation of a Professional Practices Evaluation during Radiopharmaceuticals Administration.

Securing both the patient and radiopharmaceuticals (RPs) circuit is an essential concern in nuclear medicine (NM). These circuits converge at the RP administration phase, a key step in patient management in NM. In a continuous quality improvement approach, we developed and implemented an evaluation of professional practices (EPPs) methodology focused on RPs injection to identify and correct deviations from good practices.

Lu-Dotatate administration using an infusion pump or a peristaltic pump: comparison of two methods.

Objectives: Lu-oxodotreotide (Lutathera) is an intravenous peptide receptor radionuclide therapy to treat unresectable metastatic digestive neuroendocrine tumours. The recommended method for Lutathera administration is gravity infusion; however, other appropriate and safe techniques are possible. This work compares two infusion methods from a medico-economic, radiation protection, efficiency and practicality point of view.

Tailored Media-Fill Test Protocols Inspired by Ga Kit-Based Radiopharmaceuticals.

Gallium-68 radiolabeling is an increasingly common activity in radiopharmacy. Single vial cold kits to radiolabel DOTATOC and PSMA-11 with Ga were developed, either for manual or automated preparation. Both approaches are very specific and require aseptic compounding skills, raising the need for dedicated training.

Whole body planar and 3D quantitative imaging after Lu-DOTATATE on CZT SPECT/CT device with MEHRS collimator. First report.

Lutetium-177 (Lu)-based post-therapeutic imaging allows visualization of treated lesions andabsorbed dose measurement. There is an increasing number of cadmium-zinc-telluride (CZT) gamma-cameras in nuclear medicine departments but until now these devices were not adapted to the medium-energy emission of Lu photons. We present here in the first reported images acquired with a new collimator designed for CZT gamma-camera compared to a conventional sodium iodide (NaI) (Tl) gamma-camera.

Implementation and validation of an in-house combined fluorescein/media-fill test to qualify radiopharmacy operators.

Background: The purpose of this work was to design, validate and implement a media-fill test combined with fluorescein (MFT-F) for the specific qualification and training of radiopharmacy operators, in accordance with United States Pharmacopeia General Chapter 797 and European Good Manufacturing Practices. MFT-F was embedded in the quality management system of our radiopharmacy unit. Its validation involved fluorescein concentration choice, media growth promotion test and evaluation protocol controls (with or without intentional aseptic mistakes).

Clinical implementation of PLANET® Dose for dosimetric assessment after [Lu]Lu-DOTA-TATE: comparison with Dosimetry Toolkit® and OLINDA/EXM® V1.0.

Background: The aim of this study was to compare a commercial dosimetry workstation (PLANET® Dose) and the dosimetry approach (GE Dosimetry Toolkit® and OLINDA/EXM® V1.0) currently used in our department for quantification of the absorbed dose (AD) to organs at risk after peptide receptor radionuclide therapy with [Lu]Lu-DOTA-TATE.

Methods: An evaluation on phantom was performed to determine the SPECT calibration factor variations over time and to compare the Time Integrated Activity Coefficients (TIACs) obtained with the two approaches.

Comparison of commercial dosimetric software platforms in patients treated with Lu-DOTATATE for peptide receptor radionuclide therapy.

Purpose: The aim of this study was to quantitatively compare five commercial dosimetric software platforms based on the analysis of clinical datasets of patients who benefited from peptide receptor radionuclide therapy (PRRT) with Lu-DOTATATE (LUTATHERA ).

Methods: The dosimetric analysis was performed on two patients during two cycles of PRRT with Lu. Single photon emission computed tomography/computed tomography images were acquired at 4, 24, 72, and 192 h post injection.

Implementation of patient dosimetry in the clinical practice after targeted radiotherapy using [Lu-[DOTA0, Tyr3]-octreotate.

Background: This study's aim was to develop our dosimetric methodology using a commercial workstation for the routine evaluation of the organs at risk during peptide receptor radionuclide therapy (PRRT) with Lu.

Methods: First, planar and SPECT sensitivity factors were determined on phantoms. The reconstruction parameters were optimized by SPECT/CT image acquisition using a NEMA IEC phantom containing a 500 ml bottle of Lu, to simulate a kidney.

Artificial nutrition in patients with cancer has no impact on tumour glucose metabolism: Results of the PETANC Study.

Background & Aims: Nutrition support is recommended in cachexic patients with cancer. However, there is no clear evidence about its impact on tumour growth. Glycolysis, which is usually higher in cancer than normal cells, can be monitored by F-fluorodeoxyglucose positron emission tomography/computed tomography (F-FDG PET/CT) imaging that is widely used for cancer staging and therapy efficacy assessment.

Phase II Study of a Radiotherapy Total Dose Increase in Hypoxic Lesions Identified by F-Misonidazole PET/CT in Patients with Non-Small Cell Lung Carcinoma (RTEP5 Study).

See an invited perspective on this article on page 1043.This multicenter phase II study investigated a selective radiotherapy dose increase to tumor areas with significant F-misonidazole (F-FMISO) uptake in patients with non-small cell lung carcinoma (NSCLC). Eligible patients had locally advanced NSCLC and no contraindication to concomitant chemoradiotherapy.

Extended liver venous deprivation before major hepatectomy induces marked and very rapid increase in future liver remnant function.

Objective: The aim of this study was to assess the safety and efficacy of extended liver venous deprivation (eLVD), i.e. combination of right portal vein embolisation and right (accessory right) and middle hepatic vein embolisation before major hepatectomy for future remnant liver (FRL) functional increase.

18F-Florbetaben: A New Tool for Amyloidosis Staging?

We report the case of a 73-year-old man with a documented (renal biopsy) light-chain amyloidosis (AL) imaged with F-AV-1 (F-florbetaben) compared with a volunteer. A cardiac amyloidosis was suspected. As it was an AL and not a transthyretin amyloidosis, F-FDG and F-florbetaben PET/CT were preferred to bone scan.

In myotonic dystrophy type 1 reduced FDG-uptake on FDG-PET is most severe in Brodmann area 8.

Background: In myotonic dystrophy type 1 (DM1), only one FDG-PET study used statistical parametric mapping (SPM) showing frontal reduced FDG-uptake. Our aim was to 1) identify the FDG-PET area with the most severe reduced FDG-uptake using SPM8 in a larger group of patients 2) assess potential correlation between CTG-numbers and FDG-PET.

Methods: FDG-PET was performed in 24 patients and compared to 24 controls.

Glucose metabolism in nine patients with probable sporadic Creutzfeldt-Jakob disease: FDG-PET study using SPM and individual patient analysis.

Only one large series using statistical parametric mapping (SPM) reports on FDG-PET in sporadic (Heidenhain and non-Heidenhain variant) Creutzfeldt-Jakob disease (sCJD), describing hypometabolism in bilateral parietal, frontal, and occipital cortices. Our aim was to study FDG-PET in non-Heidenhain probable sCJD patients in order to assess the most pertinent FDG-PET pattern, and to compare FDG-PET and MRI data. We used both SPM and NeuroGam(®) software analysis, compared with healthy controls, to describe the FDG-PET abnormalities.

(18)F-FDG PET/CT imaging of critical ischemia in the diabetic foot.

A 72-year-old patient with type 2 diabetes mellitus underwent F-FDG PET/CT for diabetic foot infection. No increased focal uptake was seen. F-FDG uptake was absent in the second, third, and fourth toes of the right foot.