BackgroundRadiomics 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, as well as by the segmentation of the region of interest (ROI). Prostate cancer (PCa) represents a difficult playground for this technique, due to discrepancies in the identification of the cancer lesion and the heterogeneity of the acquisition protocols. The aim of this study was to investigate the reliability of radiomics in PCa magnetic resonance imaging (MRI).MethodsA homogeneous cohort of patients with a PSA rise that underwent multiparametric MRI imaging of the prostate before biopsy was tested in this study. All the patients were acquired with the same MRI scanner, with a standardized protocol. The identification and the contouring of the region of interest (ROI) of an MRI suspicious cancer lesion were done by two radiologists with great experience in prostate cancer (>10 years). After the segmentation, the texture features were extracted with LIFEx. Texture features were then tested with intraclass coefficient correlation (ICC) analysis to analyze the reliability of the segmentation.ResultsForty-four consecutive patients were included in the present analysis. In 26 patients (59.1%), the prostate biopsy confirmed the presence of prostate cancer, which was scored as Gleason 6 in 6 patients (13.6%), Gleason 3 + 4 in 8 patients (18.2%), and Gleason 4 + 3 in 12 patients (27.3%). The reliability analysis conversely showed poor reliability in the majority of the MRI acquisition (61% in T2, 89% in DWI50, 44% in DWI400, and 83% in DWI1,500), with ADC acquisition only showing better reliability (poor reliability in only 33% of the texture features).ConclusionsThe low ratio of reliability in a monoinstitutional homogeneous cohort represents a significant alarm bell for the application of MRI radiomics in the field of prostate cancer. More work is needed in a clinical setting to further study the potential of MRI radiomics in prostate cancer.

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.

Despite being usually delivered in oncological patients, radiotherapy can be used as a successful treatment for several non-malignant disorders. Even though this use of radiotherapy has been scarcely investigated since the 1950s, more recent interest has actually shed the light on this approach. Thus, the aim of this narrative review is to analyze the applications of non-oncological radiotherapy in different disorders. Key references were derived from a PubMed query. Hand searching and clinicaltrials.gov were also used. This review contains a narrative report and a critical discussion of non-oncological radiotherapy approaches. In conclusion, non-oncological radiotherapy is a safe and efficacious approach to treat several disorders that needs to be further investigated and used in clinical practice.

241 Background: We performed a retrospective analysis of metastatic colorectal cancer (mCRC) patients enrolled in CAVE trial. Cave mCRC is a single arm, academic, multicenter, phase II trial that evaluated the efficacy of cetuximab rechallenge plus avelumab in mCRC patients. Methods: CT imaging of patients were collected and retrospectively analysed. Inclusion criteria included evidence of liver metastases that could be measured and segmented, availability of an enhanced contrast phase at baseline and restaging CT imaging (within 3 months from baseline). The gross tumor volume (GTV) of liver metastases was evaluated at both baseline and first restaging CT. Multiple texture parameters were extracted with LifeX Software, and delta-texture analysis (D-TA) was calculated as percentage variations in the two time points. Patients were divided in a training cohort (coordinating center, University of Campania “L. Vanvitelli”) and validation cohort (other centers involved in CAVE mCRC trial). Patients were further divided in responders/non-responders according to median progression free survival (mPFS). ROC curve were calculated to obtain a cut-off. Survival analysis of progression free survival (PFS) and overall survival (OS) with Kaplan-Meier method was used in the two subgroups to test the cut-off found with the methods previously described. Results: The original dataset of CAVE mCRC protocol included 77 patients. Liver metastasis were present in 55 patients (71%); after application of inclusion and exclusion criteria, a total of 42 patients were included in the current analysis. The training cohort consisted of 22 patients (for a total of 32 liver metastasis) and the validation cohort of 20 patients (for a total of 28 liver metastasis). After Bonferroni correction, the only D-TA parameters that significantly correlated with mPFS in the training cohort were EntropyHistogram (p:0,021), HomogeneityGLCM (p<0,001) and Dissimilarity GLCM (p:0,002). At multivariate analysis only HomogeneityGLCM resulted significant both in training (p:0,001, OR 0,1) and validation cohort (p:0,021, OR 0,3). ROC curves were generated and the cut-off of HomogeneityGLCM was equal to 0. Patients who developed a reduction of HomogeneityGLCM at first restaging CT scan showed a better PFS and OS (in both training and validation cohorts). Conclusions: Our results suggest that D-TA parameter such as HomogeneityGLCM is able to discriminate better survival outcomes in patient treated with cetuximab rechallenge plus avelumab, further prospective investigations are needed. [Table: see text]