ESTRO 2020 Abstract book

S528 ESTRO 2020

No date or publication restrictions were imposed. The last search date is April 2018. ELIGIBILITY CRITERIA / STUDY SELECTION / STUDIO DESIGN: 1595 articles were initially selected from PUBMED and 2464 from EMBASE for a total of 3035 articles eliminating the double ones. The articles were selected by 3 independent authors based on the title; subsequently selected by an author using the abstract’s information and then on the content of the text. At the end of the research we identified 17 publications concerning 14 retrospective studies.

The greatest evidence of radiological changes is from the sixth month after irradiation. PO-0902 Prognostic value of SVZ involvement in relation to tumor volume defined by MRI and FET PET in GBM M. Harat 1 , B. Małkowski 2 , R. Makarewicz 1 1 Collegium Medicum Nicolaus Copernicus University, Oncology and Brachytherapy, Bydgoszcz, Poland ; 2 Franciszek Lukaszyk Memorial Oncology Center, Nuclear Medicine, Bydgoszcz, Poland Purpose or Objective Subventricular zone (SVZ) involvement is associated with a dismal prognosis in patients with glioblastoma multiforme (GBM). Dual-time point (dtp) O-(2-[ 18 F]fluoroethyl)-L- tyrosine (FET) PET/CT (PET) may be a time- and cost- effective alternative to dynamic FET PET, but its prognostic value, particularly with respect to SVZ involvement, is unknown. Material and Methods Thirty-five patients had two scans 5-15 and 50-60 minutes after i.v. FET injection to define tumor volumes and SVZ involvement before starting radiotherapy. Associations between clinical progression markers, MRI- and dtp FET PET-based tumor volumes, or SVZ involvement and progression-free (PFS) and overall survival (OS) were assessed in univariable and multivariable analyses. Results The extent of resection was not related to outcomes. Albeit non-significant, dtp FET PET detected more SVZ infiltration than MRI (60% vs. 51%, p=0.25) and was significantly associated with poor survival (p<0.03), but PET-T1-Gad volumes were larger in this group (p<0.002). Survival was shorter in patients with larger MRI tumor volumes, larger PET tumor volumes, and worse Karnofsky performance status (KPS), with fused PET-T1-Gad and KPS significant in multivariable analysis (p<0.03). Uptake kinetics was not associated with treatment outcomes. Conclusion FET PET-based tumor volumes may be useful for predicting the worse prognosis of glioblastoma. The independent value of dtp FET PET parameters and SVZ infiltration as prognostic markers pre-irradiation has not been confirmed. Additionally the presence of SVZ infiltration is linked to higher PET/MRI-based tumor volumes. PO-0903 Cellular phones radiofrequency exposure and malignant brain tumor:sistematic review and metaanalisys A. Guaineri 1 , G. Peretto 1 , L. Triggiani 1 , A. Alghisi 1 , D. Tomasini 1 , P. Borghetti 1 , M. Maddalo 1 , S. Pedretti 1 , C. Tomasi 2 , L. Spiazzi 3 , S.M. Magrini 1 , M. Buglione 1 1 Spedali Civili di Brescia, Radiotherapy, Brescia, Italy ; 2 University of Brescia, Radiological Sciences and Public Health, Brescia, Italy ; 3 Spedali Civili di Brescia, Medical Physics, Brescia, Italy Purpose or Objective BACKGROUND In recent years there has been an increase in the incidence of new glial neoplasias diagnoses, as well as an increase in the use of mobile telephony devices has been recorded. OBJECTIVE our goal is to evaluate the role that exposure to radio frequencies emitted by mobile phones has in the onset of glial neoplasms. Material and Methods DATA SOURCES We conducted a systematic review and meta-analysis (PRISMA Statement) of articles in English, Italian, French and Spanish using EMBASE and PUBMED as search engines. The search was conducted by entering the following string:"cellular phone" OR "mobile phone" OR "wireless" ) AND ( "neoplasms" OR "cancer" OR "brain tumor" OR "glioma" OR "meningioma" OR "neurinoma".

Results STUDY EVALUATION In the overall analysis the data were extracted and measured in terms of the odds ratio (OR) and 95% confidence interval (CI) using the Fixed model. The model resulted in a heterogeneity of 88.8%, therefore the Random model was applied and it was significant for all the publications analyzed. DATA EXTRACTION: The combined data showed that there was an association between mobile phone use and glioma odds ratio (OR) = 1.104 (95% confidence interval [CI]: 1.031-1.177,P > 0.001). In the Funnel graphical representation relating to the so- called publication bias, such a bias is evident that we conduct a subsequent pooled analysis. The pooled analisys showed no association between the time spent in the use of the mobile phone (years of exposition) and the diagnosis of malignant brain tumors: neither for exposition less than 5 years, 5 -10 years or >10 years. The same was true if the analysis was done for patients exposed to cell phones using analogic technology compared to those exposed to mobile phones with digital technology. Analyzing the studies focusing only on the correlation between cell phones and gliomas, again it is not evident a relationship correlation between exposition and neoplasia. A further analysis demonstrates the absence of correlation between the site of glioma and the exposure to radiofrequencies (ipsilaterality or contralaterality to the use of mobile phones).