ESTRO 2021 Abstract Book

S1236

ESTRO 2021

the immobilization, simulation and PTV contouring for ostheoarticular non-malignant diseases based upon our own experience. Every patient undergoes a 5mm axial slide CT-Scan simulation. For each location, the PTV is delineated on RayStation planning system (RaySearch®) establishing a relationship with the corresponding anatomical structure to be treated. If needed, previous diagnostic MRI or ultrasound tests of the location affected are also imported and used for volume definition purposes. Results Immobilization procedures: Termoplastic masks are used for shoulders, hands and feet simulation; vaccum bag for elbows and Combi-fix system for knees affections. There is a picture attached of each location that shows how our treatments are planned. PTV contouring: For each location, all bony and/or soft tissue limits are described using anatomical references and the CT-Scan simulation. We support our proposal with multiple examples of CT-Scan axial slides and the final 3D volume delimited.

Conclusion This comprehensive atlas based on CT images might be of great help to anyone interested in the use of LD-RT as a valid and effective alternative for the symptomatic relief of degenerative or inflammatory osteoarticular diseases. PO-1509 Tumours have a sex-relevance to the multifunctional oncoprotein Y-box binding protein-1 (YB- 1) S. Croghan 1,2 , P. Rohan 3,2 , R.P. Manecksha 2,4 , T.H. Lynch 2,2 , L. Marignol 3 1 Trinity St. James’s Cancer Institute , Radiobiology and Molecular Oncology Research Group, Applied Radiation Therapy Trinity, Discipline of Radiation Therapy, Dublin, Ireland; 2 St. James's Hospital, Urology, Dublin, Ireland; 3 Trinity St. James's Cancer Institute, Radiobiology and Molecular Oncology Research Group, Applied Radiation Therapy Trinity, Discipline of Radiation Therapy, Dublin, Ireland; 4 Trinity College Dublin, Surgery, Dublin, Ireland Purpose or Objective Disparities in treatment response between male and female patients are increasingly reported. The reason could lie with the fundamental biological differences between the sexes. Growing evidence report the impact of sex cancer biology. The Y-box binding protein-1 (YB-1) gene codes for a multifunctional oncoprotein that is increasingly being linked to the regulations of many aspects of cancer cell biology that affect the radiation response. In prostate cancer, our lab related nuclear detection in biopsy specimens to radiotherapy treatment failure in high-risk patients. This study aimed to examine the relationship between YB-1 mRNA levels and overall survival in male and female patients across cancer sites. Materials and Methods Kaplan-Meier curves for overall survival up to 60 months were generated from publicly available mRNA data of patients with bladder carcinoma (N=404), Head and Neck squamous cell carcinoma (n=599), Lung adenocarcinoma (n=513) and Rectum adenocarcinoma (n=165) extracted from a combination of the gene expression omnibus, gene expression archive and the Cancer Genome Atlas databases using Kmplot.com. Results YB-1 mRNA expression data for a cohort of 404 bladder cancer patients (106 female, 298 male) was not associated with worse overall survival (HR 1.2 (0.7-1.64) p=0.26). Analysis of the female cohort indicated a significant association between high YB-1 expression levels and improved overall survival hen compared to female patients with low expression levels (0.43 (0.21-0.88), p=0.018). Analysis of the male cohort indicated a significant opposite association between high YB-1 expression levels and poor overall survival (1.58 (1.09- 2.28), p=0.014). In the 499 Head and Neck cancer patients analysed (N=133 female, N= 366 male), high YB-1 mRNA levels were associated with poorer overall survival (1.59 (1.13-2.22), p=0.007). When separated according to sex, this association was confirmed in male (1.63 (1.08-2.46), p=0.019), but was just short of statistical significance in female patients (1.68 (0.99-2.85), p=0.52). In lung adenocarcinoma patients (N= 591; 270 females, 294 males), high expression was significantly associated with poorer overall survival (1.41 (1.04- 1.9), p=0.024). This association was present in the female (1.63 (1.07 - 2.48), p=0.02) but not the male patient population (1.4 (0.89 - 2.19), p=0.14). In rectal cancer patients, YB-1 mRNA levels were not associated with overall survival (1.76 (0.75 - 4.12), p=0.18) when the sexes were combined. Similarly, no