ESTRO 2021 Abstract Book

S1054

ESTRO 2021

of data and likely the result of high bladder uptake overlapping with BM structure.

Conclusion Active and inactive bone marrow has been shown to response differentially to concurrent chemoradiotherapy. Significantly, median absolute response of inactive bone marrow has been shown to be near zero with a relatively unskewed distribution about zero when controlling for outliers. This result would support the definition of active bone marrow currently as FDG uptake greater than mean of the whole structure including bone as being representative of underlying cell physiology. PO-1277 Practice of Radiation Therapy for Anal Cancer in Austria –A Survey on behalf of the ÖGRO-GIT S. Gerum 1 , W. Iglseder 2 , R. Schmid 3 , K. Peterka 4 , T. Knocke Abulesz 5 , P. Harl 6 , S. Schwaiger 7 , I. Reiter 8 , J. Sallinger 9 , C. Venhoda 10 , G. Kurzweil 11 , M. Poetscher 12 , R. Jäger 13 , B. Celedin 14 , P. Clemens 15 , F. Sedlmayer 16 , F. Roeder 16 1 University hospital, Mediacal Paracelsus University, Landeskrankenhaus Salzburg, Department of radiation and radiation - oncology , Salzburg, Austria; 2 University hospital for radiation and radioonkology, Landeskrankenhaus, Medical Paracelsus University , Department of radiation and radiation-oncology, Salzburg, Austria; 3 Universitiy hospital AKH Wien,Comprehensive Cancer Center Vienna,, Department for radiation and radiooncology, Wien, Austria; 4 Kaiser-Franz-Josef-Spital / SMZ Süd-Klinik Favoriten, Wien, Department for radiooncology, Wien, Austria; 5 Wiener Gesundheitsverbund Klinik Hietzing, Department of radiation , Wien, Austria; 6 SMZ – Ost Donauspital der Stadt Wien, Department of radiation oncology, Wien, Austria; 7 Klinik Ottakring, Wilhelminenspital der Stadt Wien, Department of radiation oncology, Wien, Austria; 8 Landesklinikum Wiener Neustadt, Department of radiation and radiooncology, Wiener Neustadt, Austria; 9 University Krems, Karl Landsteiner Privatuniversität für Gesundheitswissenschaften, Department of radiation and radioonkology, Krems, Austria; 10 Klinikum der Barmherzigen Schwestern, Ordensklinikum Linz, , Department of radiatiooncology, Linz, Austria; 11 Salzkammergutklinikum Vöcklabruck, Department of radiation and radiooncology, Vöcklarbruck, Austria; 12 University hospital Graz, Comprehensive Cancer Center Graz, Department of radiation and radiooncology, Graz, Austria; 13 University hospital Innsbruck, , Department of radiation and radiooncology, Innsbruck, Austria; 14 Klinikum Klagenfurt am Wörthersee, Department of radiooncology, Klagenfurt, Austria; 15 Landeskrankenhaus Feldkirch, Department of radiation Purpose or Objective Chemoradiation is the mainstay of treatment for locally confined anal cancer. While the general indication is widely accepted, international consensus for adequate staging procedures, radiation technique, dose/fractionation, target volume definition, supportive care, follow-up and treatment of early lesions is less uniform. We conducted a nationwide patterns-of-care survey in Austria to evaluate areas of disagreement and to identify possible targets for further standardization and research. Materials and Methods We developed an anonymous questionnaire comprising 38 questions. The survey was sent to all 14 Austrian radiation oncology departments. Results were analyzed descriptively and compared to two major international guidelines (NCCN and ESMO) in their latest version. Results We received 13 answers (response rate 93%). Work-up generally included DRE, endoscopy and cross-sectional imaging of chest, abdomen (mainly CT) and pelvis (mainly MRI). PET-CT was used by 38%. Screening for HIV and biopsies of suspicious lymph nodes (LN) (15% each) were infrequently used. All centers use IMRT with some kind of (mainly daily) IGRT. Median doses to the primary tumor were 54.7Gy (50.4-59.4) for T1-2 and 59.4Gy (55-64.4) for T3-4 lesions. Boosts are applied mainly sequentially. Doses to elective nodal areas varied from 30.6 to 60Gy depending on whether the patient was cN0 or cN+, but most centers prescribe 45-50.4Gy to all elective nodal areas. Suspicious nodes usually receive a boost independent of their size to a median dose of 54Gy (50-60Gy). Target delineation of elective nodal areas seems generally uniform with inclusion of the common iliac nodes as the only area of disagreement. No agreement was found for OAR delineation and dose constraints. Concurrent chemotherapy was Mitomycin and 5-FU/Capecitabine in all centers with 54% favoring capecitabine. Supportive care like nutritional counseling or psycho-oncological care was infrequently offered. Intensive follow-up was performed overall for at least 5 years. Treatment of T1N0 showed considerable disagreement (46% surgery, 31% radiation, 23% chemoradiation). Median dose to primary tumor was 57.2Gy and radiooncology, Feldkirch, Austria; 16 University hospital, medical paracelsus university, Landeskrankenhaus , Department of radiation and radiooncology, Salzburg, Austria