ESTRO 2022 - Abstract Book

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Abstract book

ESTRO 2022

A total of 18 patients were referred. Two patients received WBRT and were excluded. Sixteen patients were included in the study all of whom had a papillary serous adenocarcinoma. Nine patients had extra-cranial metastases at the time of referral. The median age was 60 years (range 42 to 73). A total number of 19 metastases were treated. Nine were in-situ and 10 post-operative. The median GTV in cc for the in-situ lesions was 7.0 cc and that of the post-operative cavity was 7.7 cc. Seven metastases were treated with a single fraction, 7 with 3 fractions and 5 with 5 fractions.The median single fraction dose used was 18 Gray (range 16 to 24 Gy).The median 3 fraction dose was 27 Gy (range 24 to 27 Gy). The median normal tissue V12 for the single fraction treatment was 4.2 cc. The median normal tissue V18 and V24 for the three fraction treatments was 15.2 cc and 9.8 cc respectively. The most common toxicities documented were effect on memory and fatigue. Five patients had intracranial disease recurrence with metastases elsewhere in the brain. Progression free survival (PFS) was 6.9 months. Thirteen patients (81%) out of the 16 died. An estimated 47% (95% CI: 22% to 72%) and 39% (95% CI: 14% to 65%) were surviving at 1 and 2 years respectively. Median overall survival (OS) was 10.6 months. Conclusion The outcome of patients with brain metastases from EOC remains very poor. Our retrospective analysis has showed that SRS is an effective treatment option and results in comparable OS rates as per reported literature. Future studies should focus on the effective integration of SRS into a multimodal treatment approach to obtain better treatment outcomes for patients 1 SHAT Oncology Varna, Department of Radiotherapy, Varna, Bulgaria; 2 MHAT Uni Hospital, Department of Radiotherapy, Panagyurishte, Bulgaria; 3 UMHAT St Marina, Department of Oncology, Varna, Bulgaria; 4 UMHAT St Marina , Department of Clinical Pathology, Varna, Bulgaria; 5 UMHAT Lozenetz, Department of Forensic Medicine, Sofia, Bulgaria; 6 MHAT Nadezhda, Department of Oncology, Sofia, Bulgaria Purpose or Objective Optimal treatment decisions for patients with Glioblastoma Multiforme (GBM) require reliable prognostic and predictive information. Leucine-rich repeats and immunoglobulin-like domains (LRIG1) is a transmembrane cell-surface protein, that serves as a pan-negative regulator of EGFR, MET- and RET-receptors, whose higher expression can established in astrocytic differentiation tumor samples but its precise prognostic role remains unclear in GBM. Materials and Methods A retrospective study with patients with GBM diagnosed and treated between 2012 and 2016 was performed. A total of 74 patients with unresectable GBM in WHO IV disease, treated with Temozolomide concurrent radiotherapy, were included in this study. Expression of LRIG1 was investigated with immunohistochemistry on paraffin embedded tumor samples. The H- score was defined as: (% of cells stained at intensity category 1 x 1) + (% of cells stained at intensity category 2 x 2) + (% of cells stained at intensity category 3 x 3), giving a range of 0 to 300, where 300 was equal to 100% of tumour cells stained strongly (3 +). Then sample were classified as diffuse and perinuclear and low ( ≤ median) and high (>median) expression levels. Results The cohort included 41 men (55.6%) and 33 women (44.4%), with a total mean age of 60.4 (±11.9) years. There was no significant difference in the LRIG1 expression between males and females, as well as age. There was no significant difference between patients with perinuclear expression (mean OS 8.8 months, 95% CI, 5.2 – 12.4) and diffuse expression (mean OS 7.2 months, 95% CI, 4.4 – 10.0) of LRIG1. However patients with low expression had significantly shorter OS than patients with high expression (mean OS 4.6 months, 95% CI, 3.1 – 6.1; vs mean OS 11.3 months, 95% CI, 7.4 – 15.2, respectively; log-rank test p=0.003). Moreover, in Cox regression model, the low expression of LRIG1 is associated with poor outcome (HR 2.07, 95% CI 1.2-3.4, p=0.007). PO-1143 High LRIG1 expression is associated with better prognosis for patients with Glioblastoma Multiforme H. Ivanovska-Peneva 1 , K. Zhelev 2 , Z. Zahariev 2 , N. Conev 3 , G. Stoyanov 4 , R. Hadgiev 5 , I. Donev 6

Conclusion LRIG1 expression is a novel potential prognostic marker in patients with GBM.

PO-1144 Determinants of survical on Brazilian pediatric patients with high grade gliomas

G. Marta 1 , M.T. Starling 2 , S. Hanna 2 , A. Pereira 3

1 Hospital Sírio-Libanês, Radiation Oncology , Sao Paulo, Brazil; 2 Hospital Sírio-Libanês, Radiation Oncology, Sao Paulo, Brazil; 3 Hospital Sírio-Libanês, Clinical Oncology, Sao Paulo, Brazil Purpose or Objective Despite being the second most frequent tumor in children, pediatric central nervous system (CNS) tumors are rare entities, with limited epidemiological data. The current study aimed to determine the survival rates of patients diagnosed with high grade gliomas in Brazil accounting for the influence of age, treatment modalities, public and private practices using a population-based national database.

Materials and Methods