N-Ammonia PET-CT for Evaluating Response to Antiangiogenic Therapy and Prognosis in Patients with Advanced Hepatocellular Carcinoma: A Pilot Study.

Purpose: To prospectively investigate dynamic N-ammonia PET-CT for evaluating early treatment response and predicting prognosis in advanced hepatocellular carcinoma (HCC) patients who have undergone antiangiogenic therapy.

Methods: Dynamic N-ammonia PET-CT was performed in 23 advanced HCC patients before antiangiogenic therapy (baseline) and in 18/23 patients after 8-10 weeks of treatment (post-therapy). At kinetic PET-CT analysis, mean, maximum, and peak values of (mL/cm/min) and (min) were estimated in HCC lesions and non-neoplastic liver using cardiologic N-ammonia PET-CT in 15 patients without any liver diseases as normal controls.

Impact of data transfer between treatment planning systems on dosimetric parameters.

Purpose: In radiotherapy it is often necessary to transfer a patient's DICOM (Digital Imaging and COmmunications in Medicine) dataset from one system to another for re-treatment, plan-summation or registration purposes. The aim of the study is to evaluate effects of dataset transfer between treatment planning systems.

Materials And Methods: Twenty-five patients treated in a 0.

Motion and dosimetric criteria for selecting gating technique for apical lung lesions in magnetic resonance guided radiotherapy.

Introduction: Patients treatment compliance increases during free-breathing (FB) treatment, taking generally less time and fatigue with respect to deep inspiration breath-hold (DIBH). This study quantifies the gross target volume (GTV) motion on cine-MRI of apical lung lesions undergoing a SBRT in a MR-Linac and supports the patient specific treatment gating pre-selection.

Material And Methods: A total of 12 patients were retrospectively enrolled in this study.

Why we should care about gas pockets in online adaptive MRgRT: a dosimetric evaluation.

Introduction: Contouring of gas pockets is a time consuming step in the workflow of adaptive radiotherapy. We would like to better understand which gas pockets electronic densitiy should be used and the dosimetric impact on adaptive MRgRT treatment.

Materials And Methods: 21 CT scans of patients undergoing SBRT were retrospectively evaluated.

An update on the use of image-derived input functions for human PET studies: new hopes or old illusions?

Background: The need for arterial blood data in quantitative PET research limits the wider usability of this imaging method in clinical research settings. Image-derived input function (IDIF) approaches have been proposed as a cost-effective and non-invasive alternative to gold-standard arterial sampling. However, this approach comes with its own limitations-partial volume effects and radiometabolite correction among the most important-and varying rates of success, and the use of IDIF for brain PET has been particularly troublesome.

Innovations in imaging modalities: a comparative review of MRI, long-axial field-of-view PET, and full-ring CZT-SPECT in detecting bone metastases.

The accurate diagnosis of bone metastasis, a condition in which cancer cells have spread to the bone, is essential for optimal patient care and outcome. This review provides a detailed overview of the current medical imaging techniques used to detect and diagnose this critical condition focusing on three cardinal imaging modalities: positron emission tomography (PET), single photon emission computed tomography (SPECT) and magnetic resonance imaging (MRI). Each of these techniques has unique advantages: PET/CT combines functional imaging with anatomical imaging, allowing precise localization of metabolic abnormalities; the SPECT/CT offers a wider range of radiopharmaceuticals for visualizing specific receptors and metabolic pathways; MRI stands out for its unparalleled ability to produce high-resolution images of bone marrow structures.

The Importance of Uncertainty Analysis and Traceable Measurements in Routine Quantitative Y-PET Molecular Radiotherapy: A Multicenter Experience.

Molecular Radiation Therapy (MRT) is a valid therapeutic option for a wide range of malignancies, such as neuroendocrine tumors and liver cancers. In its practice, it is generally acknowledged that there is a need to evaluate the influence of different factors affecting the accuracy of dose estimates and to define the actions necessary to maintain treatment uncertainties at acceptable levels. The present study addresses the problem of uncertainty propagation in Y-PET quantification.

Dose-response Analysis in Hepatic Tumors Treated with 90Y-TARE According to a Personalized Dosimetric Workflow: Preliminary Results.

Background: Transarterial Radioembolization (TARE) is a widespread radiation therapy for unresectable hepatic lesions, but a clear understanding of the dose-response link is still missing. The aim of this preliminary study is to investigate the role of both dosimetric and clinical parameters as classifiers or predictors of response and survival for TARE in hepatic tumors and to present possible response cut-off.

Methods: 20 patients treated with glass or resin microspheres according to a personalized workflow were included.

Tuning the optimal diffusion-weighted MRI parameters on a 0.35-T MR-Linac for clinical implementation: A phantom study.

Purpose: This study aims to assess the quality of a new diffusion-weighted imaging (DWI) sequence implemented on an MR-Linac MRIdian system, evaluating and optimizing the acquisition parameters to explore the possibility of clinically implementing a DWI acquisition protocol in a 0.35-T MR-Linac.

Materials And Methods: All the performed analyses have been carried out on two types of phantoms: a homogeneous 24-cm diameter polymethylmethacrylate (PMMA) sphere (SP) and a homemade phantom (HMP) constating in a PMMA cylinder filled with distilled water with empty sockets into which five cylindrical vials filled with five different concentrations of methylcellulose water solutions have been inserted.

Short 2-[F]Fluoro-2-Deoxy-D-Glucose PET Dynamic Acquisition Protocol to Evaluate the Influx Rate Constant by Regional Patlak Graphical Analysis in Patients With Non-Small-Cell Lung Cancer.

To test a short 2-[F]Fluoro-2-deoxy-D-glucose (2-[F]FDG) PET dynamic acquisition protocol to calculate K using regional Patlak graphical analysis in patients with non-small-cell lung cancer (NSCLC). 24 patients with NSCLC who underwent standard dynamic 2-[F]FDG acquisitions (60 min) were randomly divided into two groups. In group 1 ( = 10), a population-based image-derived input function (pIDIF) was built using a monoexponential trend (10-60 min), and a leave-one-out cross-validation (LOOCV) method was performed to validate the pIDIF model.

Dynamic C-Methionine PET-CT: Prognostic Factors for Disease Progression and Survival in Patients with Suspected Glioma Recurrence.

Purpose: The prognostic evaluation of glioma recurrence patients is important in the therapeutic management. We investigated the prognostic value of C-methionine PET-CT (MET-PET) dynamic and semiquantitative parameters in patients with suspected glioma recurrence.

Methods: Sixty-seven consecutive patients who underwent MET-PET for suspected glioma recurrence at MR were retrospectively included.

Which Is the Optimal Scan Time of 18F-DOPA PET/CT in Patients With Recurrent Medullary Thyroid Carcinoma?: Results From a Dynamic Acquisition Study.

Purpose: The aim of this retrospective study was to determine, by dynamic acquisition, the optimal scan time of F-DOPA PET/CT in patients with recurrent medullary thyroid carcinoma (MTC).

Methods: Twenty-one patients with suspected recurrent MTC underwent dynamic F-DOPA PET/CT (lasting 45 minutes) followed by whole-body scan. Three different time intervals of dynamic acquisition were evaluated: ultra-early phase (2-5 minutes), early phase (5-10 minutes), and late phase (40-45 minutes).