ESTRO 36 Abstract Book

S977 ESTRO 36 _______________________________________________________________________________________________

EP-1777 Cervical cancer outcomes in the high-dose- rate brachytherapy era: A single institution experience N. Alyamani 1 , G. Bhattacharya 1 , R. Samant 1 , C. E 1 , T. Le 1 , K. Lupe 1 1 The Ottawa Hospital Regional Cancer Centre, Radiation Oncology, Ottawa, Canada¨ Purpose or Objective Since 2008, the management of cervix cancer with primary radiotherapy at our institution has included the use of HDR (high-dose-rate) brachytherapy; prior to this, LDR (low- dose-rate) brachytherapy was used. The aim of this study is to review our experience with HDR brachytherapy and to evaluate patient outcomes. Material and Methods A retrospective review of cervical cancer patients treated with curative intent using radical external beam radiotherapy and HDR brachytherapy, from 2008 to 2014 inclusive was performed. Overall survival (OS) and progression-free survival (PFS) were analyzed using the Kaplan-Meier method. Results A total of 76 patients were treated with radical radiotherapy incorporating HDR brachytherapy during this time period. The median age was 47 years with a median follow-up of 38 months. The histology was squamous cell carcinoma in 88% and adenocarcinoma in 11%. The distribution according to stage was as follows: stage I 16%, stage II 38%, stage III 40% and stage IV 5%. All patients received weekly Cisplatin chemotherapy with a median of 5 cycles delivered. The median dose of external beam radiotherapy was 45Gy delivered in 25 fractions over 5 weeks. The median brachytherapy dose was a total of 24Gy in 3 weekly fractions of 8Gy. The 5-year OS and PFS rates were 74% and 63% respectively. The 5-year locoregional control rate was 82%. There were a total of 25 failure and 12 of these had a component of local failure. However, only 3 of these had exclusively local failure. Of note is that the majority of patients with recurrences had a component of distant failure (19/25; representing 77% of relapses). Using the Common Terminology Criteria for Adverse Events version 4.0 (CTCAE v.4.0), it appears as though severe acute (Grade 3/4) Gastrointestinal (GI) and Genitourinary (GU) toxicity was present in approximately 21% of patients, along with Grade 3/4 Hematologic toxicity seen in 34%. These results are similar to the published literature and compare favorably with our previous LDR brachytherapy There has been a shift towards incorporation of HDR brachytherapy world-wide in the management of cervix cancer and our institutional experience indicates that long-term outcomes for patients remain good, with generally high rates of local control. EP-1778 Combined intracavitary-interstitial IGABT of cervical cancer –First dosimetric experience in Hungary G. Fröhlich 1 , J. Vízkeleti 1 , N.N. Anhhong 1 , N. Mészáros 1 , T. Major 1 , C. Polgár 1 1 National Institute of Oncology, Centre of Radiotherapy, Budapest, Hungary Purpose or Objective Dosimetric evaluation of combined intracavitary- interstitial high-dose-rate image-guided adaptive brachytherapy (IGABT) of cervical cancer, implemented in Hungary. Material and Methods Since April 2016, 9 patients with cervical cancer were treated with overall 22 fractions of combined intracavitary-interstitial IGABT. After transrectal US- experience. Conclusion

guided implantation of Utrecht or Fletcher applicator and needles, High-Risk-CTV (HR-CTV), bladder (b), rectum (r) and sigmoid (s) were contoured on CT, based on the post- teletherapy MRI of the patients. Dose-volume criterions of treatment plans were based on the recommendations of GEC-ESTRO Gyn WG. Treatment plans were compared to the conventional intracavitary 2D plans (the dose was prescribed to point A) and to CT-based 3D optimized plans (without needles) with Friedman and Kruskal-Wallis ANOVA and Spearman rank correlation tests. Results Median number of implanted needles was 3 (range: 2-4), mean volume of HR-CTV was 39.8 cm 3 (8.3-100.2 cm 3 ). For intracavitary-interstitial IGABT, intracavitary 2D and intracavitary 3D optimized plans, difference was found almost in all dose-volume parameters: V100 were 90.4%, 83% and 87.1% (p=0.043), DHI were 0.34, 0.30 and 0.27 (p=0.0137), D2(b) were 4.8 Gy, 6.9 Gy and 5.9 Gy (p<001), D2(r) were 3.3 Gy, 6.6 Gy and 3.5 Gy (p<0.001), D2(s) were 3.6 Gy, 5.3 Gy and 4.6 Gy (p=0.045), respectively. Needle number showed inverse correlation with D2(r) (p=0.0264) and D1(r) (p=0.0433) parameters. Volume of HR-CTV correlated with D2(r) (r 2 =0.58) and D2(s) (r 2 =0.71). Conclusion Dosimetric results of combined intracavitary-interstitial IGABT were comparable to international literature. Dosimetric quality of these plans was significantly higher than intracavitary 2D and 3D optimized plans. Although 3D optimisation improved the quality of conventional 2D plans, IGABT plans resulted in even more homogeneous dose distribution and significantly lower doses to organs at risks. EP-1779 High-dose rate brachytherapy for inoperable endometrial cancer: definitive results L. Draghini 1 , F. Trippa 2 , M. Casale 2 , P. Anselmo 1 , F. Arcidiacono 1 , S. Fabiani 1 , M. Italiani 1 , E. Maranzano 1 1 Radiation Oncology Centre "S.Maria" Hospital Terni, Oncology Departement, Terni, Italy 2 Radiation Oncology Centre- “S.Maria” Hospital Terni, Oncology Department, Terni, Italy Purpose or Objective Purpose/Objective: To report our experience on three dimensional (3D) high-dose rate brachytherapy (HDR-BRT) in patients with stage I-III inoperable endometrial cancer. Material and Methods Material/Methods: Between March 2005 and April 2016 17 patients underwent HDR-BRT or HDR-BRT after external beam radiotherapy (EBRT) as definitive treatment. Median age was 79 years (range, 60-95), median KPS 90% (range, 60-100). Histology was endometrial adenocarcinoma in 14 (82%) and non-endometrial in 3 (18%) patients. In 15 (88%) patients FIGO clinical stage was I and in remaining 2 (12%) III. All patients were evaluated with computed tomography (CT) and endometrial biopsy, in 2 cases also magnetic resonance imaging (MRI) was done. Using the Fletcher applicator, a CT-based planning HDR-BRT was delivered. Follow-up was performed with physical examination, cervical cytology and CT or MRI. Local control (LC) was obtained when there was an interruption of vaginal bleeding. Results Results: All patients had a clinical LC, table 1 shows dose schedules used. After a median follow-up of 36 months (range, 6-131), 3 and 6 years LC rates were 86% and 69%, respectively. Cancer specific survival (CSS) at 1, 2 and 6 years was 93%, 85%, 85%, respectively. Age, stage, dose and type of radiotherapy did not result significant prognostic factors for LC and CSS. Only histology significantly influenced LC: for high risk histology (i.e., non-endometrial carcinoma or grade (G)3 endometrial adenocarcinoma) LC was 73% at 1 year and 36% at 6 years,