Safety injections of nuclear medicine radiotracers: towards a new modality for a real-time detection of extravasation events and F-FDG SUV data correction.

Background: F-FDG PET/CT imaging allows to study oncological patients and their relative diagnosis through the standardised uptake value (SUV) evaluation. During radiopharmaceutical injection, an extravasation event may occur, making the SUV value less accurate and possibly leading to severe tissue damage. The study aimed to propose a new technique to monitor and manage these events, to provide an early evaluation and correction to the estimated SUV value through a SUV correction coefficient.

Predictive and Prognostic Role of Pre-Therapy and Interim 68Ga-DOTATOC PET/CT Parameters in Metastatic Advanced Neuroendocrine Tumor Patients Treated with PRRT.

Peptide receptor radionuclide therapy (PRRT) is an effective therapeutic option in patients with metastatic neuroendocrine tumor (NET). However, PRRT fails in about 15-30% of cases. Identification of biomarkers predicting the response to PRRT is essential for treatment tailoring.

A multicentre and multi-national evaluation of the accuracy of quantitative Lu-177 SPECT/CT imaging performed within the MRTDosimetry project.

Purpose: Patient-specific dosimetry is required to ensure the safety of molecular radiotherapy and to predict response. Dosimetry involves several steps, the first of which is the determination of the activity of the radiopharmaceutical taken up by an organ/lesion over time. As uncertainties propagate along each of the subsequent steps (integration of the time-activity curve, absorbed dose calculation), establishing a reliable activity quantification is essential.

How direct measurements of worker eyes with a Scheimpflug camera can affect lensdose coefficients in interventional radiology.

The 2013/59/Euratom Directive reduced the occupational exposure limits for the lens. Since it has become crucial to estimate the dose absorbed by the lens, we have studied the individual variability of exposed workers' ocular conformations with respect to the data estimated from their personal dosimetry. The anterior eye conformations of 45 exposed workers were acquired using Scheimpflug imaging and classified according to their sight conditions (emmetropia, myopia or hypermetropia).

Ga-DOTATOC PET/CT-Based Radiomic Analysis and PRRT Outcome: A Preliminary Evaluation Based on an Exploratory Radiomic Analysis on Two Patients.

This work aims to evaluate whether the radiomic features extracted by 68Ga-DOTATOC-PET/CT of two patients are associated with the response to peptide receptor radionuclide therapy (PRRT) in patients affected by neuroendocrine tumor (NET). This is a pilot report in two NET patients who experienced a discordant response to PRRT (responder vs. non-responder) according to RECIST1.

DNA damage in lens epithelial cells exposed to occupationally-relevant X-ray doses and role in cataract formation.

The current framework of radiological protection of occupational exposed medical workers reduced the eye-lens equivalent dose limit from 150 to 20 mSv per year requiring an accurate dosimetric evaluation and an increase understanding of radiation induced effects on Lens cells considering the typical scenario of occupational exposed medical operators. Indeed, it is widely accepted that genomic damage of Lens epithelial cells (LEC) is a key mechanism of cataractogenesis. However, the relationship between apoptosis and cataractogenesis is still controversial.

Uncertainty analysis of tumour absorbed dose calculations in molecular radiotherapy.

Background: Internal dosimetry evaluation consists of a multi-step process ranging from imaging acquisition to absorbed dose calculations. Assessment of uncertainty is complicated and, for that reason, it is commonly ignored in clinical routine. However, it is essential for adequate interpretation of the results.

Comparison of different calculation techniques for absorbed dose assessment in patient specific peptide receptor radionuclide therapy.

Aim: The present work concerns the comparison of the performances of three systems for dosimetry in RPT that use different techniques for absorbed dose calculation (organ-level dosimetry, voxel-level dose kernel convolution and Monte Carlo simulations). The aim was to assess the importance of the choice of the most adequate calculation modality, providing recommendations about the choice of the computation tool.

Methods: The performances were evaluated both on phantoms and patients in a multi-level approach.

Radiotherapy Planning and Molecular Imaging in Lung Cancer.

Introduction: In patients suitable for radical chemoradiotherapy for lung cancer, 18F-FDGPET/ CT is a proposed management to improve the accuracy of high dose radiotherapy. However, there is a high rate of locoregional failure in patients with locally advanced non-small cell lung cancer (NSCLC), probably due to the fact that standard dosing may not be effective in all patients. The aim of the present review was to address some criticisms associated with the radiotherapy image-guided in NSCLC.

Texture analysis and multiple-instance learning for the classification of malignant lymphomas.

Background And Objectives: Malignant lymphomas are cancers of the immune system and are characterized by enlarged lymph nodes that typically spread across many different sites. Many different histological subtypes exist, whose diagnosis is typically based on sampling (biopsy) of a single tumor site, whereas total body examinations with computed tomography and positron emission tomography, though not diagnostic, are able to provide a comprehensive picture of the patient. In this work, we exploit a data-driven approach based on multiple-instance learning algorithms and texture analysis features extracted from positron emission tomography, to predict differential diagnosis of the main malignant lymphomas subtypes.

Partial volume effect of SPECT images in PRRT with 177Lu labelled somatostatin analogues: A practical solution.

Background: At present activity quantification is one of the most critical step in dosimetry calculation, and Partial Volume Effect (PVE) one of the most important source of error. In recent years models based upon phantoms that incorporate hot spheres have been used to establish recovery models. In this context the goal of this study was to point out the most critical issues related to PVE and to establish a model closer to a biological imaging environment.

Effect of image registration on 3D absorbed dose calculations in Lu-DOTATOC peptide receptor radionuclide therapy.

Peptide receptor radionuclide therapy (PRRT) is an effective MRT (molecular radiotherapy) treatment, which consists of multiple administrations of a radiopharmaceutical labelled with Lu or Y. Through sequential functional imaging a patient specific 3D dosimetry can be derived. Multiple scans should be previously co-registered to allow accurate absorbed dose calculations.

Labelling of Y- and Lu-DOTA-Bioconjugates for Targeted Radionuclide Therapy: A Comparison among Manual, Semiautomated, and Fully Automated Synthesis.

In spite of the hazard due to the radiation exposure, preparation of Y- and Lu-labelled radiopharmaceuticals is still mainly performed using manual procedures. In the present study the performance of a commercial automatic synthesizer based on disposable cassettes for the labelling of Lu- and Y-DOTA-conjugated biomolecules (namely, DOTATOC and PSMA-617) was evaluated and compared to a manual and a semiautomated approach. The dose exposure of the operators was evaluated as well.

Added diagnostic value of respiratory-gated 4D 18F-FDG PET/CT in the detection of liver lesions: a multicenter study.

Purpose: The aim of the present study was to evaluate the added diagnostic value of respiratory-gated 4D18F-FDG PET/CT in liver lesion detection and characterization in a European multicenter retrospective study.

Methods: Fifty-six oncological patients (29 males and 27 females, mean age, 61.2 ± 11.

18F-fluorodeoxyglucose positron emission tomographic scan in solid-type p-stage-I pulmonary adenocarcinomas: what can produce false-negative results?

Objective: False-negative (FN) uptake of 18F-fluorodeoxyglucose (FDG) can be divided into those cases related to technological limitations of positron emission tomography (PET) and those related to inherent properties of neoplasms. Our goal was to clarify possible factors causing FN PET results in patients with solid-type pulmonary adenocarcinomas (PAs).

Methods: From January 2007 to December 2014, of the 255 patients with p-stage-1 non-small-cell lung cancer observed and treated (surgically) in our institution, we retrospectively reviewed the PET/computed tomography (CT) records, the clinical information, the preoperative thin-section CT images, and the pathological features [classified by the International Association for the Study of Lung Cancer/American Thoracic Society/European Respiratory Society (IASLC/ATS/ERS) subtyping criteria] of 94 consecutive solid-type p-stage-1 PAs.

The Italian multicentre dosimetric study for lesion dosimetry in Ra therapy of bone metastases: Calibration protocol of gamma cameras and patient eligibility criteria.

Purpose: The aims of this work were to explore patient eligibility criteria for dosimetric studies in Ra therapy and evaluate the effects of differences in gamma camera calibration procedures into activity quantification.

Methods: Calibrations with Ra were performed with four gamma cameras (3/8-inch crystal) acquiring planar static images with double-peak (82 and 154keV, 20% wide) and MEGP collimator. The sensitivity was measured in air by varying activity, source-detector distance, and source diameter.

Skin dose saving of the staff in 90Y/177Lu peptide receptor radionuclide therapy with the automatic dose dispenser.

Objective: When handling Y-labelled and Lu-labelled radiopharmaceuticals, skin exposure is mainly due to β-particles. This study aimed to investigate the equivalent dose saving of the staff when changing from an essentially manual radiolabelling procedure to an automatic dose dispenser (ADD).

Materials And Methods: The chemist and physician were asked to wear thermoluminescence dosimeters on their fingertips to evaluate the quantity of Hp(0.

The (68)Ge phantom-based FDG-PET site qualification program for clinical trials adopted by FIL (Italian Foundation on Lymphoma).

Purpose: The quantitative assessment of Positron Emission Tomography (PET) scans using standardized uptake value and derived parameters proved to be superior to traditional qualitative assessment in several retrospective or mono-centric prospective reports. Since different scanners give different quantitative readings, a program for clinical trial qualification (CTQ) is mandatory to guarantee a reliable and reproducible use of quantitative PET in prospective multi-centre clinical trials and in every-day clinical life.

Methods: We set up, under the auspices of Italian Foundation on Lymphoma (FIL), a CTQ program consisting of the PET/CT scan acquisition and analysis of (18)F and (68)Ge NEMA/IEC image quality phantoms for the reduction of inter-scanner variability.

Therapeutic schemes in 177Lu and 90Y-PRRT: radiobiological considerations.

Background: The purpose of this work is to implement a radiobiological model to compare different treatment schedules for Peptide Receptor Radionuclide Therapy (PRRT) with 177Lu and 90Y. The principal radiobiological quantities were studied as a function of radionuclides, fractionation schemes, activity distribution in kidneys and tumor radiosensitivity.

Methods: Clinical data were used to derive representative absorbed doses for several treatment schemes for 177Lu-PRRT and for 90Y-PRRT and considered as input data for the radiobiological model.

Time Evolution of DOTATOC Uptake in Neuroendocrine Tumors in View of a Possible Application of Radioguided Surgery with β- Decay.

Unlabelled: A novel radioguided surgery (RGS) technique exploiting β- radiation has been proposed. To develop such a technique, a suitable radiotracer able to deliver a β- emitter to the tumor has to be identified. A first candidate is represented by 90Y-labeled DOTATOC, a compound commonly used today for peptide radioreceptor therapy.

Radiation protection procedures in 131I treatments for thyroid cancer in patients requiring hemodialysis.

Background: Hemodialysis is essential for patients with renal failure, and iodine-131 ((131)I) administration is the standard of care in thyroid carcinoma treatment. Although the need for hemodialysis during (131)I treatment is very rare, it raises some concerns due to the involvement of personnel not exposed to radiation and to the contamination of devices used for other patients. In this paper, a radioprotection protocol to perform hemodialysis safely on patients during (131)I treatment has been presented.

Metabolic tumour volumes measured at staging in lymphoma: methodological evaluation on phantom experiments and patients.

Purpose: The presence of a bulky tumour at staging on CT is an independent prognostic factor in malignant lymphomas. However, its prognostic value is limited in diffuse disease. Total metabolic tumour volume (TMTV) determined on (18)F-FDG PET/CT could give a better evaluation of the total tumour burden and may help patient stratification.

Differentiated thyroid cancer: a new perspective with radiolabeled somatostatin analogues for imaging and treatment of patients.

Background: The expression of somatostatin receptors (SSTR) in thyroid cells may offer the possibility to identify metastatic lesions and to select patients for peptide receptor radionuclide therapy (PRRT). We investigated (68)Ga-DOTATOC positron emission tomography/computed tomography (PET/CT) to select patients with progressive differentiated thyroid cancer (DTC) for PRRT as well as treatment response and toxicity in treated patients.

Methods: We enrolled 41 patients with progressive radioiodine-negative DTC (24 women and 17 men; mean age=54.

Respiratory gated PET/CT in a European multicentre retrospective study: added diagnostic value in detection and characterization of lung lesions.

Purpose: The aim of our work is to evaluate the added diagnostic value of respiratory gated (4-D) positron emission tomography/computed tomography (PET/CT) in lung lesion detection/characterization in a large patient population of a multicentre retrospective study.

Methods: The data of 155 patients (89 men, 66 women, mean age 63.9 ± 11.