ESTRO 36 Abstract Book

S969 ESTRO 36 2017 _______________________________________________________________________________________________

tumours without violating the OAR dose. For smaller tumours the OAR dose was reduced without compromising the target coverage.

BRT was delivered with Iridium – 192 wire implants using plastic bead techniques with varying dose rates. The Biological equivalent doses (BED) were calculated for both BRT and EBRT keeping α/β =10 for tumor and α/β =3 for normal tissue and subsequently median BED doses were calculated and similarly 2 Gy equivalent dose (EQD2) were calculated and loco-regional control and disease free survival was assessed. Results After completion of HDR – BRT, Patients for followed up one month later and subsequently every 3 months for first 2 years and thereafter every 6 months with median follow up period of 25 months (Range 2-84 months). The DFS probability at year 1 was 82.76% and 68.05% at year 7. The overall survival probability was 91.37% at year 1 and 85.89% at year 5. The local control rate was 67.27% and the control rates according to the stage of disease and T size classification are mentioned in Table 1. The rate of local recurrence was 8.62%, Regional Recurrence was 1.72%, Loco-Regional Failure was 3.44% and Distant metastases following local or regional failure was 17.23%. The Median BED for α/β =10 was 86.775Gy and DFS was 74.07% in patients receiving more than 86.775Gy and DFS was 64.82% in patients receiving less than 86.775Gy and Median BED for α/β =3 was 128.76Gy and DFS was 74.07 in patients receiving more than 128.76Gy as compared to 64.82% in patients receiving less than 128.76Gy. The median EQD2 for α/β =10 was 71.6Gy and for α/β =3 was 75.85Gy. The DFS was 75.86% in patients receiving more than median dose of 71.6Gy compared to 61.53% in those receiving less than the median dose. The DFS was 78.57% in patients receiving median dose of 75.85Gy as compared to 59.26% in those receiving less than the median dose. Conclusion The overall outcome in the Patients with oral cavity and oropharyngeal malignancies was good with implementing of HDR – Interstitial Brachytherapy and use of Angiocatheters as carriers of Iridium – 192 wire. The BED10 value of 86.775Gy and BED3 of 128.76Gy showed that the dose received more than the median showed better outcomes in the form of DFS. The EQD2 calculated values suggested the dose received more than 71.6Gy (α/β =10) and 75.85Gy (α/β =3) showed better outcomes .The role of HDR Interstitial Brachytherapy in Head and Neck cancers is a proven, effective and safe treatment method with excellent long term outcome. EP-1792 Nasal function after exclusive brachytherapy for primary SCCs of the nasal vestibulum F. Bussu 1 , L. Tagliaferri 2 , G. Mattiucci 2 , G. Di Cintio 1 , N. Dinapoli 2 , J. Galli 1 , G. Almadori 1 , E. De Corso 1 , G. Passali 1 , G. Paludetti 1 , V. Valentini 2 1 Universita' Cattolica del Sacro Cuore Policlinico Agostino Gemelli, Head and Neck Surgical Sciences, Rome, Italy 2 Universita' Cattolica del Sacro Cuore Policlinico Agostino Gemelli, Radiation Oncology, Rome, Italy Purpose or Objective Squamous cell carcinoma arising from the nasal vestibule is a rare condition accounting for about 1% of head and neck malignancies with several peculiarities concerning both staging and treatment. Exclusive brachytherapy has been proven to be a treatment as effective as surgery under an oncological point of view, with the advantage of much better preserving the complex cartilaginous framework of the nose. The aim of this study is to evaluate, through specific tests, the functionality of the nose after an oncologically effective brachytherapy for SCCs of the nasal vestibulum. Material and Methods 15 consecutive patients diagnosed with primary squamous cell carcinomas of the nasal vestibulum, treated with exclusive brachytherapy between 2010 and 2016, and free of disease since at least 9 months were enrolled. 15

Electronic Poster: Brachytherapy: Anorectal

EP-1790 A balloon applicator with adjustable catheters for image-guided endoluminal rectal brachytherapy M. Heilmann 1 , D. Berger 1 , R. Schmid 1 , J. Bör 1 , B. Wisgrill 1 , R. Pötter 1 , C. Kirisits 1 , M.P. Schmid 1 1 Medizinische Universität Wien Medical University of Vienna, Universitätsklinik für Strahlentherapie, Vienna, Austria Purpose or Objective To investigate the dosimetric results and first clinical experience with an in-house made balloon-based applicator for endoluminal brachytherapy for patients with locally advanced rectal cancer not undergoing surgery. Material and Methods The applicator consists of an inflatable rectal balloon with six attached foley catheters used as guidance for brachytherapy plastic needles. The construction of the applicator and the dosimetric profile in terms of representative dose points in 0, 2, 5, 10 mm ipsilaterally and in 0mm contralaterally are described. Feasibility and treatment response in three patients are reported. Results For all three patients the application was well tolerated and could be performed in an ambulant setting. A reproducible dose gradient was achieved in all patients. The surface dose on the target side was 204±19% of the normalized dose in 5 mm (100%) tissue depth and 143±8% in 2 mm and 64±3% in 10 mm. The surface dose on the contra-lateral side was 20±8%. After radiochemotherapy with 50 Gy external beam radiotherapy and concomitant chemotherapy with capecitabine, a HDR brachytherapy boost in 2-3 fractions of 7-10 Gy each was delivered. All patients achieved a clinical complete response at 3 months and no major toxicity was observed. Conclusion The use of our balloon based applicator was clinically feasible and resulted in a stable and reproducible dose distribution. The dose gradient is similar to 50 kV contact x-rays. First clinical results are promising. EP-1791 HDR Interstitial Brachytherapy for Head and Neck Malignancies and use of Iridium – 192 implants V. Pareek 1 , R. Bhalavat 2 , M. Chandra 2 1 Jupiter Hospital- Thane, Radiation Oncology, Mumbai, India 2 Jupiter Hospital, Radiation Oncology, Thane, India Purpose or Objective To evaluate the treatment outcomes with HDR Interstitial Brachytherapy in Head and Neck Cancers at our Institute with use of Angiocatheters as carrier source of Iridium – 192 wire implants. Material and Methods 58 Patients with Head and Neck malignancies of varying TNM staging as per AJCC staging criteria were analyzed retrospectively between 2008 and 2015. 42 patients (72.41%) received EBRT with HDR – BRT and 26 patients (27.59%) received BRT alone. 23 patients (39.65%) received concurrent Chemotherapy. The age group ranged from 27 to 81 years (Median age 56 years) with 41 patients (70.69%) males and 17 patients (29.31%) females. HDR – Electronic Poster: Brachytherapy: Head and neck