ESTRO 38 Abstract book

S599 ESTRO 38

left to grow to form clones. At 14 th day of colonization, colonies containing ≥ 50 cells were scored. The whole procedure was repeated three times independently. Clonogenic survival curves were plotted as the log of the surviving fraction as a function of the dose. Dose Modifying Factor (DMF) which can be called as Nanoparticle-mediated Enhancement Ratio (NER- very similar to well-known oxygen enhancement ratio) based on clonogenic assays for each single radiation dose, was derived from cell survival curves. Results By TEM images, dimensions of cit -SPION’s were measured between 6-25nm and they were spherical in shape. Cell viability (trypan blue) and MTT assay were carried out and it was proven that cit- SPION’s at 0.1mg/mL concentration and after 24 hours of incubation did not exhibit cytotoxic effect on all three cell lines . NER values were cell line specific and depended on radiation dose. The highest radiosensitization effects were seen in MCF-7 and MDAH 2447 cells at 2Gy (NER: 1.49 and 1.39 respectively), in MDA-MB-231 cells at 4Gy (NER:1.20). Cell survival fraction was also significantly lower in MDAH 2447 cells at 4Gy (p=0.019). While at 6Gy there was radiosensitization effect only in MCF-7 cells (NER:1.10), at 8Gy there wasn’t any radiosensitization in any cell line (NER:1.03-1.08) Conclusion These results raise the possibility that synergistic effects of SPIONs may cause dose dependent and cell line spesific radiosensitization at 6MV X-ray energies. Since there has been scarce data inquiring information on the "Z" and the X-ray energy dependence and in vitro radiosensitizer effect of SPIONs at high MV energy levels relevant in clinic, our study might be accepted as important. PO-1079 Metabolic changes with the administration of radiotherapy in lung, head and neck cancer patients E. Rodríguez-Tomàs 1 , M. Murcia 2 , M. Arguís 2 , I. Dolz 2 , M. De Abreu 2 , G. Baiges-Gaya 1 , N. Cabré 1 , F. Luciano- Mateo 1 , L. Torres-Royo 2 , M. Árquez 2 , J. Gómez 2 , J. Acosta 2 , D. Gómez 2 , C. Jordi 1 , J. Jorge 1 , S. Sabater 2 , M. Arenas Prat 2 1 Hospital Universitari Sant Joan de Reus, Unitat de Recerca Biomèdica, Reus, Spain ; 2 Hospital Universitari Sant Joan de Reus, Radiation Oncology, Reus, Spain Purpose or Objective Radiotherapy treatment can produce metabolic changes in cancer patients. The application of metabolomics to the study of energy metabolism in cancer is an underdeveloped issue, and only a few studies have investigated this in lung (LC) and head and neck cancer (HNC) patients exposed to radiotherapy (RT), despite its potential relevance in clinical practice. The aims of our study were to analyze the changes produced by RT on the activity and concentration of serum PON1 and the variations in the lipoprotein profile and metabolites of low molecular weight in LC and HNC patients and to correlate these changes with the clinical and pathological characteristics of patients and tumors, and their response to treatment. Material and Methods The study included LC patients (n=33) and HNC patients (n=28) treated with RT. Control group (n= 50) was formed by Mediterranean health people. Blood samples for analyses were obtained before and after 8one month later) the irradiationtreatment. Lipoprotein profile and the metabolites of low molecular weight carried out by nuclear magnetic resonance. Statistical analysis was performed with SPSS 22.0 statistical package. Results Mean ages were 72 (65.50-79.0) and 65 (56.25-73.0) years old in LC and HNC patients, respectively. The most prevalent histologic type was squamous carcinoma in both groups. Even though, the frequency of tumor relapse was

Conclusion NSCLC is a heterogeneous disease, with differences in mutational status, expression of metabolism-related markers between AC and SCC but also within AC subtypes, and response to metabolic inhibition. GLUT1 and SLC1A5 expression correlated with aggressive tumor behavior only in AC. So, these markers could select a group of AC patients that require intensification of treatment. Only a part of NSCLC patients may benefit from the combination of radiation therapy and metabolic inhibition, making stratification necessary. PO-1078 Superparamagnetic Iron Oxide Nanoparticle Mediated Radiosensitization at Megavoltage Radiation E. Korkmaz Kıraklı 1 , G. Takan 2 , S. Hoca 3 , F.Z. Biber Müftüler 2 , A. Yurt Kılçar 2 , S. Arun Kamer 3 , Y. Anacak 3 1 DR. Suat Seren Chest Diseases and Surgery Research and Educational Hospital, Radiation Oncology, İzmir, Turkey; 2 Ege University Institute of Nuclear Sciences, Department of Nuclear Applications, İzmir, Turkey ; 3 Ege University, Radiation Oncology, İzmir, Turkey Purpose or Objective Superparamagnetic Iron Oxide Nanoparticles (SPIONs) in combination with radiotherapy have been representing themselves as novel radiosensitizers in recent years. The purpose of this study was to assess SPION’s in vitro radiosensitizer effect at clinically utilized 6MV energies which remains relatively as an unexplored issue and to calculate Nanoparticle Enhancement Ratio (NER) of SPIONs. Material and Methods Human breast adenocarcinoma (estrogen receptor positive) (MCF-7), human breast adenocarcinoma (triple negative) (MDAMB-231) and human ovarian carcinoma (MDAH-2774) cell lines were used. Citrate coated- SPION’s were synthesized. Morphology and size analysis of cit -SPIONs were performed by transmission electron microscopy (TEM). The size distribution of nanoparticles was determined by dynamic light scattering (DLS). The effect of the cit -SPIONs on cell viability was evaluated using trypan blue exclusion test. MTT assay was applied to determine the safe SPION dose to perform radiation treatment experiments. To achieve full scatter conditions, a special type of solid water phantom was designed which 96 well-plates can be placed in, at 5cm depth along the central axis. Cells were than irradiated with various doses (2,4,6,8Gy). Cells were