ESTRO 2020 Abstract Book

S599 ESTRO 2020

followed by radical hysterectomy. Among 33 patients with locally advanced disease (≥IB2), 32 underwent chemoradiation +/- brachytherapy boost. After a median follow-up of 5.4 years (range, 0.15-21.7 years), 18/55 (33%) patients experienced tumor relapse. Local recurrence occurred in 2/22 (9%) patients with early disease (treated with upfront surgery) and in 3/32 (9%) patients with locally advanced disease. Most frequent relapses were distant, occurring in a total of 11/55 patients (20%). PFS rates at 5-year were 86.4% (95% CI: 63.4-95.4) for early stage versus 75.9 % (95%CI: 55.2-89.2) for locally advanced stages, respectively (p=0.18). Conclusion Conclusion: Large cohort data are warranted to guide the optimal management of GCC. From this retrospective analysis, a multimodal approach yielded to good disease control in early stages tumors. Given the high risk of distant failure, consideration should be given to adjuvant chemotherapy in locally advanced disease. PO-1136 Combined intracavitary and interstitial brachytherapy in locally advanced cervical cancer. F. Piccolo 1 , B. Pappalardi 1 , M. Carrara 1 , C. Tenconi 1 , T. Giandini 1 , C. Delle Curti 2 , C. Fallai 1 , A. Cerrotta 1 1 Fondazione IRCCS Istituto Nazionale dei Tumori, Dipartimento di diagnostica per immagini e radioterapia, Milano, Italy ; 2 Università degli studi di Milano Bicocca, radioterapia, Milano, Italy Purpose or Objective To improve target volume coverage with the implementation of combined intracavitary and interstitial brachytherapy (ICIS-BT) in the locally advanced cervical cancer treatment. Material and Methods Intracavitary brachytherapy and external-beam radiotherapy (EBRT) is a standard treatment for locally advanced cervical cancer. In patients with large-volume tumors at the time of brachytherapy, with minor parametrial response, and/or in the case of unfavorable topography, intracavitary technique is not optimal choice. In these situations additional interstitial brachytherapy has been applied to improve target coverage. In our department, from October 2017 to October 2018, eleven patients were treated using combined ICIS-BT for primary cervical cancer. The morphological and/or dimensional features of the target volume (i.e. ≥30 cc) drove our choice. All patients received EBRT (VMAT) with concomitant chemotherapy and sequential brachytherapy boost. The prescribed dose was 45 Gy in 25 fractions over 5 weeks. Chemotherapy regimen was weekly Cisplatin (40 mg/m2). Image-guided adaptive brachytherapy (IGABT) based on magnetic resonance imaging (MRI) was performed for all 11 patients. According to GEC ESTRO working group, GTV, High Risk CTV (HR- CTV), Intermediate Risk CTV (IR-CTV), bladder, rectum and sigmoid were delineated at the time of each brachytherapy fraction on para-axial MR images with the applicator in place. Dose-volume histograms were calculated to evaluate doses to tumor target and organs at risk. The total dose prescribed was 28 Gy in 4 fractions. Acute genitourinary, gastro-enteric and vaginal toxicity was monitored at each fraction and recorded according to the CTCAE criteria version 4.03. The planning aims, according to the EMBRACE II protocol, have been achieved for all 11 patients. Also the hard constraints for the organs at risk were never exceeded. To demonstrated that the implementation of interstitial component was essential to improve target dose coverage, the treatment of the 11 patients were rescheduled avoiding interstitial needles dose contribution. The D90 to HR-CTV obtained with ICIS-BT and without the use of needles were compared. Results Brachytherapy treatment was well tolerated by all 11 patients. Patients didn’t show G3 toxicities or higher.

Figure 1 shows the variation of the D90 CTV-HR for each of the eleven patients and one treatment fraction, with and without the contribution of the interstitial needles. The average gain in terms of target coverage was of 25% in favor of the ICIS-BT treatments. Conclusion Brachytherapy is a part of the standard treatment for cervical uterine cancers in the locally advanced stage. In patients with large-volume tumors at the time of brachytherapy, with minor parametrial response, and/or in the case of unfavorable topography, the implementation of the interstitial technique alongside the intracavity technique allows to guarantee an adequate coverage of the target, with a consequent better local control of the disease. PO-1137 Preoperative18FDG PETCT SUV correlation to CD8+ CD4+FOXP3+TLymphocytes in Cervical Cancer Milieu H.A. Zagloul 1 1 Clinical Oncology Department Alexanderia University Egypt, Clinical Oncology Department Alexandria Egypt, alexandria, Egypt Purpose or Objective Purpose: To scrutinize on the competence of preoperative18F-FDG (PET/CT) Maximum Standardized Uptake Value (SUV Max ) of cervical cancer primaries and immune-modulating T lymphocytes (CD8 + , CD4 + , FOXP3 + ) within tumor milieu in forecasting the outcome following Methods: The preoperative PET-CT SUV max and intensities of CD8 + ,CD4 + ,FOXP3 + T lymphocytes permeating the tumor milieu in radical hysterectomies were interrelated with emphasis on their influence on clinical- pathological characteristics. Additionally, their aptitude in survival outcome predilections was explored using Log rank and Cox regression Results Results: We evaluated 35 patients had who radical hysterectomies. Reduced median levels of primary tumor SUV Max were substantially interrelated with limited intensities of FOXP3 + and accentuated CD8 + /CD4 + ratio (OR 2.3 , 95% CI 1.6-6.1 , OR 2.2, 95%CI 1.5- 7.5),respectively. The decreased primary cervical SUV alongside the enhanced intensities of CD8 + , CD8 + /CD4 + and limited FOXP3 + cells permeating tumor milieu were attributed to node negativity, early stage, absence of lympho-vascular incursion and adjuvant radiation. The multivariate regression revealed that the enhanced primary SUV Max along with nodal dissemination were independently correlated with dismal outcomes with hazard ratio (HR 2.86 (95% confidence interval [CI], 2.35- 6.34), 3.23 (95% CI, 2.24-6.22) for overall survival(OS) and (HR 5.21 (95% CI, 3.21-12.23) and 4.32 (95% CI, 2.83-9.42) for disease free survival (DFS),respectively . Additionally , FOXP3 + ≥ 19 and CD8 + /CD4 + < 2 were considerably attributed to worsened OS (HR 3.82 ( 95% CI ,2.98-10.27) , 2.56 (95%CI ,2.38-7.42) and abysmal DFS (HR 2.91 ( 95% CI ,2.58-7.42) , 3.52(95%CI ,3.73- 8.52),respectively . Conclusion Conclusion: The preoperative PET-CT SUV max, CD8 + , FOXP3 + and C8/CD4 + T-lymphocytes permeating tumor milieu were substantial interrelated and linked to different clinical-pathological factors in surgically treated cervical cancer patients. Additionally, they may be considered as competent authorized forecasters of clinical outcomes. PO-1138 Quality of life in vaginal brachytherapy for endometrial carcinoma IN THE ELDERLY. R. Rubiato Aragon 1 , S. Cordoba 2 , M. Gaztañaga 2 , M.G. Vázquez 2 , G. Marquina 2 , U.A. Corro 1 , J. Romero 1 , J. radical hysterectomy. Material and Methods