ESTRO 36 Abstract Book

S668 ESTRO 36 _______________________________________________________________________________________________

1 LMU Munich, Department of Radiation Oncology, Munich, Germany 2 German Cancer Research Center DKFZ, Department of Molecular Radiation Oncology, Heidelberg, Germany Purpose or Objective To report our experience with stereotactic body irradiation in primary and secondary liver lesions. Material and Methods We retrospectively analysed 37 patients who had not been eligible for other local treatment options (surgery, RFA) and therefore received SBRT to 1-2 liver lesions (43 lesions in total) in our institution from 2011-2015. Median age was 66 years (31 – 83 years) and 20 patients were male. 16 patients suffered from HCC/CCC, 21 patients had oligometastatic liver disease, mainly originating from colorectal cancer. The majority presented in good performance status (median KPS 90%, range 60%-100%) with adequate liver function (cirrhosis Child A: 13, Child B: 2, Child C: 1, none: 21). Immobilization included a vacuum pillow in all patients and the use of abdominal compression since 2014. Treatment planning was based on 4D-CT (contrast-enhanced since 2014) usually after placement of fiducial markers and rigid registration with diagnostic MRI images. Median ITV to PTV margin was 6 mm. Results Mean follow-up was 14 months (range 1 - 47) Fiducials were needed in 29 patients (78%). Placement was feasible without any complications in all patients. Abdominal compression was used in 12 patients since 2014 to reduce breathing motion. Dose and fractionation varied dependent on localisation, size, motion and liver function. The most common schemes were 37.5 Gy/65% isodose in 3 fractions, 40 Gy/80% in 5 fx and 54Gy/80% in 9 fx. Median GTV volume on free-breathing CT was 13 ccm (1-247) and median PTV volume was 126 ccm (15-537). Local recurrence (in field) was observed in 6 patients (16%) resulting in a 1-year LC rate of 92%. New lesions in the liver (out-field) occured in 20 patients (54%), 15 (40%) patients developed extrahepatic progression. 5 patients have died, resulting in a 1-year overall survival of 87% in all patients. No significant differences in any endpoint have been observed between HCC/CCC and oligometastatic patients, although the latter ones had a higher absolute 1-year OS rate (73% vs 87%). Toxicity was generally mild (grade 1: 8 pts., grade 2: 2 pts.), except one patient with Child C cirrhosis who developed hepatic failure shortly after SBRT which was successfully treated by liver transplantation. Conclusion SBRT is a locally effective and well tolerated treatment method for primary and secondary liver lesions. Given the high rates of intrahepatic outfield failures, careful pretreatment evaluation and patient selection seems mandatory. EP-1240 Stereotactic radiotherapy in pancreatic cancer: a systematic review on pain relief M. Buwenge 1 , G. Macchia 2 , F. Deodato 2 , S. Cilla 3 , L. Caravatta 4 , A. Farioli 5 , A. Guido 1 , A. Arcelli 1,6 , F. Bertini 1 , F. Cellini 7 , G.C. Mattiucci 7 , M.C. Di Marco 8 , S. Cammelli 1 , G. Tolento 1 , V. Valentini 7 , L. Fuccio 5 , A.G. Morganti 1 1 University of Bologna, Radiation Oncology Center- Department of Experimental- Diagnostic and Specialty Medicine - DIMES, Bologna, Italy 2 Fondazione di ricerca e cura "Giovanni Paolo II", Radiotherapy unit, Campobasso, Italy 3 Fondazione di ricerca e cura "Giovanni Paolo II", Medical Physics Unit, Campobasso, Italy 4 Centro di Radioterapia e Medicina Nucleare- P.O. Businco, Radiotherapy Unit, Cagliari, Italy 5 University of Bologna, Department of Medical and

Surgical Sciences - DIMEC, Bologna, Italy 6 Ospedale Bellaria, Radiotherapy Department, Bologna, Italy 7 Policlinico Universitario "A. Gemelli"- Università Cattolica del Sacro Cuore, Department of Radiotherapy, Roma, Italy 8 University of Bologna, Oncology Center- Department of Experimental- Diagnostic and Specialty Medicine - DIMES, Bologna, Italy Purpose or Objective In locally advanced pancreatic carcinoma (LAPC) standard radiotherapy and concurrent chemoradiation are able to reduce pain. Stereotactic radiotherapy (SBRT) is an emerging treatment technique but its role in pain palliation is not well known. Therefore, aim of this analysis was to systematically review the palliative effect of SBRT in LAPC. Material and Methods A systematic review based on PRISMA methodology of papers reporting pain control after SBRT in LAPC patients was performed using PubMed database. Combination with chemotherapy was allowed. Only article published in English were considered. Results A total of 11 studies reporting data on pain control after SRT in LAPC patients met the inclusion criteria. SBRT was performed using both standard and robotic Linacs. The prescribed SBRT median total dose 24 Gy (range: 14-45 Gy), and the median number of fraction was 3 (range: 1- 6). Median EQD 2 using α/β: 10 and α/β: 3 were 65.5 Gy (range 31.3-93.8) and 95.0 Gy (range 40.0-162.0), respectively. Nine of the 11 studies reported different rates pain reduction. Particularly, median pain ORR was 57.0% (range: 44.0-100.0%) with 2 studies reporting pain CR in 48.4% and 81.3% of patients. Reduction of analgesic consumption was recorded in 65.0-100.0% of patients. One study reported no significant pain reduction, while another study reported a significant worsening of pain 2 weeks after SBRT. Acute and late toxicity (grade ≥ 3) ranged between 3.3-18.0% and 6.0-8.2%, respectively. All recorded toxicity were GI complications. Conclusion SBRT was able to achieve pain reduction in most studies with a reasonable rate of side effects. Therefore, further prospective studies on palliative role of SBRT in LAPC seems to be justified. Aim of these trials should be the definition of the optimal dose/fractionation and the best way to combine SBRT with systemic therapies. Finally, being treatment of LAPC patients mainly palliative, quality of life and particularly pain control should be considered as an end point in future SBRT trials. EP-1241 Successful pain relief after a short course of palliative radiotherapy in painful pancreatic cancer. G. Ebrahimi 1 , C.R.N. Rasch 1 , G. Van Tienhoven 1 1 Academic Medical Center, Radiation oncology, Amsterdam, The Netherlands Purpose or Objective Patients with pancreatic cancer have a high burden of symptoms. At time of diagnosis 30-40% of the patients report pain as a dominant symptom, which rises up to 90% shortly before death. Because of a poor overall survival, the burden of a palliative treatment should be balanced against the expected effect. This study was conducted to assess the effect of a short course of palliative radiotherapy on pain symptoms. Material and Methods All patients who were treated with palliative radiotherapy because of painful pancreatic cancer between 1998 and 2015 were retrospectively analyzed. Primary endpoint was pain relief and secondary endpoint was overall survival.