ESTRO 37 Abstract book

ESTRO 37

S424

5-year overall survival

and type 2 in 6pt (16.6%); Grade: 1 in 23pt (63.8%), 2 in 13pt (36.1%), 3 in 0pt; Myometrial invasion <50% 22pt (61.1%), ≥50% 14pt (38.8%); Lymphovascular invasion was present in 8pt (22.2%) and absent in 28pt (77.7%). Radiotherapy: 6pt had exclusive vaginal-cuff brachytherapy (VCB) and 30pt (83.3%) external beam irradiation (EBI) + VCB. The sample was classified according to severe/non-severe comorbidity using CCI. Late toxicities were assessed using the RTOG score for rectum, small bowel and bladder and the objective LENT- SOMA criteria for vagina. Statistical analysis: descriptive analysis and Chi-square test. Results Mean age (y): 82.5 (80-90); mean follow-up (months): 68.4 (11-146). Cause of death: EC 7pt (31.8%) and other 15pt (68.1%- 6pt second neoplasms and 9pt comorbidities). Relapses. Vagina: 4pt (11.1%), Pelvic: 1pt (2.7%) and Distant metastasis 6pt (16.6%). Non-severe CCI (0-1): 23pt (63.8%) and severe (≥2):13pt (36.1%). Late toxicity. Small bowel: 7pt (19.4%) 4-G1,1-G2, 1-G3, 1-G4; Rectum: 2pt (5.5%) 2-G2; Bladder: 2pt (5.5%) 1-G1, 1-G2; Vagina 9pt (25%) 3-G1, 6-G2. A significant difference was found in small bowel late toxicity in patients receiving EBI compared to those with exclusive VCB. The distribution of late small bowel toxicity was: non-severe CCI 7pt (30%) and severe: 2pt (15.3%). The mean survival at five years related exclusively to comorbidity was 38% (14pt)- CCI distribution: non-severe 9pt (64%) versus severe 5pt (35.7%). The mean survival in non- severe CCI was 69.6m, being 66.3m in severe CCI. Conclusion 1- In our series patients ≥ 80y with EC treated with P-RT had a mean survival of 68.4 months, despite 68.1% being deaths not related to EC. 2- The only relevant late toxicity associated with treatment was in the small bowel in patients receiving EBI. 3- When considering CCI, late small bowel toxicity was more frequent in the non-severe CCI group. 4- Considering survival rates patients ≥80y should receive irradiation when indicated and IMRT techniques should be considered in order to reduce late small bowel toxicity. PO-0814 Initial experiences with coverage probability- based nodal SIB RT in cervical cancer C. Glavak 1 , G. Toller 1 , Z. Volgyi 1 , A. Faour 1 , A. Balint 2 , A. Miovecz 1 , K. Kisivan 1 , I. Repa 1 , J. Hadjiev 1 , F. Lakosi 1 1 University of Kaposvar Health Center, Oncoradiology, Kaposvar, Hungary 2 Kaposi Mor Teaching Hospital, Clinical Oncology, Kaposvar, Hungary Purpose or Objective Coverage probability (CovP) based simultaneous integrated boost (SIB) in locally advanced cervical cancer (LACC) has been recently introduced in EMBRACE 2 study. We present our preliminary dosimetry results and clinical experiences (nodal control, acute toxicity) with this technique. Material and Methods Twelve node positive FIGO stage ≥1B2 LACC patients were treated with radiochemotherapy+image guided adaptive brachytherapy. The treatment consisted of 45 Gy pelvic±paraaortic (PAO) external beam radiotherapy (EBRT) using volumetric arc therapies with online CBCT verification. PAO RT was given in 7/12 cases. Nodal gross tumor volumes (GTV-N) were contoured on empty-full bladder CTs/PET-CT and MRI. Clinical target volume (CTV-N) was formed by fusion of these volumes. A 5-mm margin expansion was used for planning target volume (PTV-N). Nodes in the small pelvis were boosted to 55 Gy/25 fx, while common iliac and para-aortic nodes received 57.5 Gy/25 fx. Planning aims followed the EMBRACE II protocol: PTV-N D98≥90%, CTV-N D98≥100%

Conclusion In this retrospective study, OS and SDS at 5 years were 44% and 63% respectively, showing that comorbidities were the first cause of death in this cohort. Severe to life-threatening morbidity was limited in this analysis. RT is a safe and curative option for inoperable patients with endometrial cancer in terms of disease control and toxicity. Nevertheless, surgery is the first option and medically inoperable patients should be re-evaluated in specialized high-risk surgical patients units. PO-0813 Charlson Index in Very Elderly Patients Receiving Radiotherapy for Endometrial Cancer Treatment K.S. Cortés Mateus 1 , A.G. Glickman 2 , S. Valdes 2 , O. Córdova 3 , C. Ascaso 4 , A. Torne 2 , E.A. Camprubí 1 , J.P. Cabello-García 1 , A. Herreros 1 , C. Quilis 1 , A. Rovirosa 1 1 Hospital Clinic Universitari, Radiation Oncology Deparment, Barcelona, Spain 2 Hospital Clinic Universitari, Gynecological Cancer Unit, Barcelona, Spain 3 Hospital Rebagliati, Radiation Oncology Department, Lima, Peru 4 Universitat de Barcelona, Epidemiology Department, Barcelona, Spain Purpose or Objective To determine whether a severe or non-severe Charlson Comorbidity Index (CCI) is associated with late toxicity in very elderly patients, ≥80 years(y), with endometrial carcinoma (EC) receiving postoperative radiation therapy (P-RT). Material and Methods Thirty-six patients (pt) older than 80 years treated with P-RT for EC were recruited from 2013 to 2016. The 2009 FIGO Stage was: IA in 7pt (19.4%), IB in 15pt (41.6%), II in 7pt (19.4%), IIIA in 2pt (5.5%), IIIC1 in 4pt (11.1%), IIIC2 in 1pt (2.7%). Pathology: EC Type: type-1 in 30pt (83.3%)