Background: Prostate cancer (PCa) is biologically heterogeneous, requiring management strategies that balance oncologic benefit with preservation of quality of life. Prostate-specific membrane antigen (PSMA) has emerged as a key theranostic biomarker enabling highly sensitive molecular imaging and targeted therapy. Purpose: The present manuscript aims to summarize the clinical role of PSMA-PET/CT in PCa across staging, treatment selection, and response assessment, with a special focus on its contribution to personalized management. Key Findings: PSMA-PET/CT demonstrates superior accuracy compared with conventional imaging, frequently leading to stage migration and changes in therapeutic strategy. It improves detection of metastatic and recurrent disease, guides selection for systemic and PSMA-targeted therapies, and supports metastasis-directed treatment in oligometastatic settings, potentially delaying androgen-deprivation therapy and preserving quality of life. Additionally, PSMA-PET enhances intra-prostatic lesion delineation for focal therapies and radiotherapy planning. Limitations include reduced sensitivity for very small lesions, possible false positives, variability among tracers, and issues related to access and standardization. Conclusions: PSMA-PET/CT is a cornerstone of precision imaging in PCa, enabling more individualized treatment decisions across the disease continuum. Ongoing studies will further define its long-term clinical impact and integration into routine care.

The introduction of combined positron emission tomography (PET) and computed tomography (CT) scanner has made it possible to acquire, in a single study, complementary morpho-structural and functional/metabolic information. In its standard applications hybrid PET/CT imaging, with a low-dose (LD) CT scan without contrast medium administration, can allow attenuation correction and anatomical cross-sectional of functional PET images, while avoiding the increased radiation burden which, instead, is associated with a full-dose (FD) CT. Nevertheless, the association of PET imaging with FDCT and with contrast-enhanced (CE) CT, i.e. diagnostic CT, has been investigated to increase the diagnostic accuracy of PET/CT in some specific clinical scenarios. There are potential clinical and procedural benefits to using single step combined dual imaging PET and FD-CECT. However, radiation protection regulations, guidelines from scientific societies, local provisions, correct clinical decision making and practical considerations, limit the use of PET/CECT to selected patients in which a clinical or procedural justification must be demonstrated, despite current scientific context where there is a lack of significant studies that support its appropriateness.

Purpose This study is to use a simple algorithm based on patient’s age to reduce the overall biological detriment associated with PET/CT. Materials and Methods A total of 421 consecutive patients (mean age 64 ± 14 years) undergoing PET for various clinical indications were enrolled. For each scan, effective dose (ED in mSv) and additional cancer risk (ACR) were computed both in a reference condition (REF) and after applying an original algorithm (ALGO). The ALGO modified the mean dose of FDG and the PET scan time parameters; indeed, a lower dose and a longer scan time were reported in the younger, while a higher dose and a shorter scan time in the older patients. Moreover, patients were classified by age bracket (18–29, 30–60, and 61–90 years). Results The ED was 4.57 ± 0.92 mSv in the REF condition. The ACR were 0.020 ± 0.016 and 0.0187 ± 0.013, respectively, in REF and ALGO. The ACR for the REF and ALGO conditions were significantly reduced in males and females, although it was more evident in the latter gender (all p < 0.0001). Finally, the ACR significantly reduced from the REF condition to ALGO in all three age brackets (all p < 0.0001). Conclusion Implementation of ALGO protocols in PET can reduce the overall ACR, mainly in young and female patients.

Introduction The aim of the narrative review was to analyse the applications of nuclear medicine (NM) techniques such as PET/CT with different tracers in combination with radiotherapy for the clinical management of glioblastoma patients. Materials and methods Key references were derived from a PubMed query. Hand searching and clinicaltrials.gov were also used. Results This paper contains a narrative report and a critical discussion of NM approaches in combination with radiotherapy in glioma patients. Conclusions NM can provide the Radiation Oncologist several aids that can be useful in the clinical management of glioblastoma patients. At the same, these results need to be validated in prospective and multicenter trials.

Regorafenib (REG) has been recently approved for the treatment of relapsed glioblastoma. Contrast-enhanced (CE) magnetic resonance (MR) imaging represents the gold standard for diagnosis and surveillance of brain tumors. We evaluated the potential role of 18F-DOPA PET/CT in determining the response to REG in a case series of patients with recurrence of high-grade gliomas. Three patients with recurrence of high-grade gliomas underwent CE-MR and 18F-DOPA PET/CT within 1 week before and at 8-week intervals after REG therapy. 18F-DOPA PET was analyzed using qualitative and quantitative approaches. For the quantitative analysis, maximum (SUVmax), mean standardized uptake values (SUVmean) and metabolic tumor volume (MTV) were obtained. In two patients, an early metabolic response to REG treatment, both visually and in terms of reduction of SUVmax, SUVmean and MTV, was observed. In one subject, no metabolic response was detected. Metabolic PET data were in agreement with morphological and perfusion MRI data in two patients. In one patient, while 18F-DOPA was able to correctly diagnose a metabolic response to REG, MRI had misdiagnosed a pseudo-progression of the disease. These preliminary findings suggest that 18F-DOPA PET/CT allows an early and reliable assessment of metabolic response to the REG treatment. A major advantage of PET seems to be obtained in patients in whom MR is unable to differentiate non-response vs tumor pseudo-progression.

PURPOSE:The Italian Tailored Assessment of Lung Indeterminate Accidental Nodule (ITALIAN) trial is a trial drawn to determine the performance of 18F-FDG-PET/CT in patients with solitary pulmonary nodules (SPN), stratified for a different kind of risk. An additional end-point was to compare the diagnostic information and estimated dosimetry, provided by a segmental PET/CT (s-PET/CT) acquisition instead of a whole body PET/CT (wb-PET/CT), in order to evaluate if segmental thoracic PET/CT can be used in patients with SPN.METHODS:18F-FDG PET/CT of 502 patients, stratified for pre-test cancer risk, was retrospectively analyzed. FDG uptake in SPN was assessed by a 4-point scoring (4PS) system and a semiquantitative analysis using the ratio between SUVmax in SPN and SUVmean in mediastinal blood pool (BP), and between SUVmax in SPN and SUVmean in the liver (L). Histopathology and/or follow-up data were used as a standard of reference. Data obtained on the thoracic part of wb-PET/CT, defined as s - PET/CT, were compared with those deriving from wb-PET/CT.RESULTS:SPNs were malignant in 180 patients (36%), benign in 175 (35%), and indeterminate in 147 (29%). The 355 patients diagnosed with a definitive SPN nature (malignant or benign) were considered for the analysis of PET performance. Sensitivity, specificity, positive (PPV) and negative (NPV) predictive values, and accuracy were 85.6%, 85.7%, 86%, 85.2%, and 85.6%, respectively. Sensitivity and PPV were higher in intermediate and high-risk patients. 18F-FDG uptake indicative of thoracic and extra-thoracic lesions was detectable in 13% and 3% of the patients. Compared to wb-PET/CT, s-PET/CT could save about 2/3 of 18F-FDG dose, radiation exposure or scan-time, without affecting the clinical impact of PET/CT.CONCLUSION:In patients with SPN, the pre-test likelihood of malignancy stratification allows to better define PET clinical setting and its diagnostic power. In subjects with low-intermediate pre-test likelihood of malignancy, s-PET/CT might be planned in advance. The adoption of this segmental strategy could reduce radiation exposure, scan-time, and might allow individually targeted protocols.

Texture analysis (TA) can provide quantitative features from medical imaging that can be correlated to clinical endpoints. The challenges relevant to robustness of radiomics features have been analyzed by many researchers, as it seems to be influenced by acquisition and reconstruction protocols. Delta-texture analysis (D-TA), conversely, consist in the analysis of TA feature variations at different acquisition times, usually before and after a therapy. Aim of this study was to investigate the influence of different CT scanners and acquisition parameters in the robustness of TA and D-TA. We scanned a commercial phantom (CIRS model 467, Gammex, Middleton, WI, USA), that is used for the calibration of electron density, two times by varying the disposition of plugs, using three different scanners. After the segmentation, we extracted TA features with LifeX and calculated TA features and D-TA features, defined as the variation of each TA parameters extracted from the same position by varying the plugs with the formula (Y–X)/X. The robustness of TA and D-TA features were then tested with intraclass coefficient correlation (ICC) analysis. The reliability of TA parameters across different scans, with different acquisition parameters and ROI positions has shown poor reliability in 12/37 and moderate reliability in the remaining 25/37, with no parameters showing good reliability. The reliability of D-TA, conversely, showed poor reliability in 10/37 parameters, moderate reliability in 10/37 parameters, and good reliability in 17/37 parameters. The comparison between TA and D-TA ICCs showed a significant difference for the whole group of parameters (p:0.004) and for the subclasses of GLCM parameters (p:0.033), whereas for the other subclasses of matrices (GLRLM, NGLDM, GLZLM, Histogram), the difference was not significant. D-TA features seem to be more robust than TA features. These findings reinforce the potentiality for using D-TA features for early assessment of treatment response and for developing tailored therapies. More work is needed in a clinical setting to confirm the results of the present study.

Diagnosis of solitary pulmonary nodule (SPN) is an important public health issue and 18F-FDG PET/CT has proven to be more effective than CT alone. Pre-test risk stratification and clinical presentation of SPN could affect the diagnostic strategy. A relevant issue is whether thoracic segmental (s)-PET/CT could be implemented in patients with SPN. This retrospective multicenter study compared the results of FDG whole-body (wb)-PET/CT to those of s-PET/CT.

The aim of this study was to determine the performance of 18F-FDG-PET/CT in patients with solitary pulmonary nodule (SPN), stratifying the risk according to the likelihood of pulmonary malignancy.

Poster: EANM 18 / EP-0509 / Cost-analysis of a new diagnostic strategy in patients with solitary pulmonary nodule: the Italian Tailored Assessment of Lung Indeterminate Accidental Nodule (ITALIAN) multicenter trial by: Evangelista1, L. Pace2, L. Mansi3, E. Mazziotti4, S. Del Vecchio4, G. Pepe5, L. Basso6, S. ANNUNZIATA7, A. Golemi8, A. Chiaravalloti9, R. Galicchio10, L. Guerra11, M. Zuffante12, N. Frega13, V. Rizzo14, A. Lambertini15, A. Cuocolo4, M. Spadafora16; 1Veneto Institute of Oncology IOV - IRCCS, Padova, ITALY, 2Universita di Salerno, Salerno, ITALY, 3Centro Universitario di Ricerca per lo Sviluppo Sostenibile, Napoli-Roma, ITALY, 4Universita degli Studi di Napoli “ Federico II°”, Napoli, ITALY, 5Humanitas Cancer Center, Milano, ITALY, 6SDN – IRCCS, Napoli, ITALY, 7Universita’ Cattolica di Roma, Roma, ITALY, 8Ospedale di Bolzano, Bolzano, ITALY, 9Universita Tor Vergata, Roma, ITALY, 10CROB – IRCCS; Rionero in Vulture, Potenza, ITALY, 11Ospedale San Gerardo – AAST Monza, Monza, ITALY, 12Azienda Universitaria Integrata di Verona, Verona, ITALY, 13Medicina Futura Acerra, Napoli, ITALY, 14Ospedale san Giuseppe Moscati, Avellino, ITALY, 15Universita degli Studi di Bologna, Bologna, ITALY, 16Ospedale del Mare, Napoli, ITALY

BACKGROUND The Italian Tailored Assessment of Lung Indeterminate Accidental Nodule (ITALIAN) is a retrospective, multicenter trial designed to compare the diagnostic information provided by segmental positron emission tomography (PET)/computed tomography (CT) (s-PET/CT) with those of whole body (wb)-PET/CT in patients with single pulmonary nodules (SPN). This report describes the details and implications of the ITALIAN trial design. METHODS AND RESULTS Between September 2016 and May 2017, 502 consecutive patients (302 men, mean age 67±12 years) with SPN undergoing 18F-fluorodeoxyglucose (FDG) PET/CT were enrolled. PET/CT images will be visually and semiquantitatively evaluated. For visual analysis, a 4-point scoring system (1=absent; 2=mild; 3=moderate and 4=intense) will be used; for semiquantitative analysis, maximum standardized uptake value (SUV) in the SPN and mean SUV in the mediastinal blood pool and in the liver will be computed. CONCLUSION The results of this trial might help to define the role of s-PET/CT in patients with SPN. This trial will also evaluate the impact on radiobiology and costs subsequent the introduction of this alternative imaging acquisition modality.