ESTRO 38 Abstract book

S781 ESTRO 38

Velocity, a treatment planning evaluation system, we integrated imaging scans and treatments information from particular patient. Therefore, combined dose was associated with images for review of treatment plans using isodose curves and DVH. Furthermore we analysed blood parameters and patient performance status. Results Several fractionation schemes were used, for primary therapy df 12-15 Gy to the total dose 36-48 Gy, for second course of irradiation df 10-15 to the total dose 30-48, third (8 pts) df 3-15 Gy to the total dose 15-50. Median total dose was 90 Gy (range 72-209). Median highest total radiation dose to one GTV volume was 48 Gy (range 36- 95). Stereotactic radiotherapy is a good local therapy for liver tumours since in majority of cases (28 GTV) first liver re- irradiation was administered to previously non-irradiated area and only in 6 GTV to previously treated volume. Median interval from initial RT to first retreatment was 8.5 months (range 3.4-50.8). Patients who underwent third radiotherapy were irradiated for recurrent tumour after first treatment (4 GTV) and after second course (4 GTV), but also 3 patients underwent radiotherapy to previously not irradiated volume. Median time from first radiotherapy to last visit was 19.5 months (range 3.5-60). We did not noticed significant decrease in mean liver volume which was 1516 cm 3 (range 947-2875) at the time of first radiotherapy and 1458 cm 3 (range 1047-2673) at last treatment, although it was irradiated with high doses. Median dose to the 700 cm 3 of functional liver was 16.8 Gy (range 3.7-33.7). The cumulative mean dose to the liver was 20.2 Gy (range 10.2-32.7). mean volume receiving 10 Gy was 61.5 % (range 26-80.2), and 21 Gy was 36.3 % (range 13.5-54.9). High doses used in our patients did not translate into significant liver dysfunction. Grade 1 increase in the level of AST was found in 5 patients, and only in one patients grade 2. Grade 1 ALT increase was found in 1 patients, and single patients experienced G1, and G2 increase of bilirubin level. The elevation of liver enzymes was related to the progression of the disease within and outside the liver. Conclusion High dose re-irradiation with SBRT to the liver tumors is a safe and tolerable option that allows prolongation of survival with advanced liver disease. Prospective studies are needed to establish accurate dose constraints and treatment guidelines. EP-1439 The role of FDG PET / CT in SBRT of primary tumors in the upper abdomen N. Bartl 1 , S. Adebahr 1 , S. Kirste 1 , I. Popp 1 , H. Schäfer 1 , A. Grosu 1 , T.B. Brunner 1 , E. Gkika 1 1 Medical Center- Faculty of Medicine- University of Freiburg- German Cancer Consortium DKTK Partner Site Freiburg- German Cancer Research Center DKFZ- Heidelberg- Germany, Department of Radiation Oncology, Freiburg, Germany Purpose or Objective In this analysis, we evaluated the role of FDG PET / CT in the planning of stereotactic body radiation therapy (SBRT) of primary tumors in the upper abdomen (pancreatic carcinoma, cholangiocellular carcinoma, hepatocellular carcinoma). Material and Methods Consecutive patients (n = 101) who were treated with SBRT for upper abdominal carcinoma [pancreas n = 17, cholangiocellular carcinoma (CCC), n = 37, hepatocellular carcinoma (HCC), n = 48] were included in this analysis. In total, 42 patients (41%) had FDG PET / CT or 4D FDG PET / CT available for defining the target volume and 59 patients (59%) had no FDG PET / CT. Results The local control (LC) was 75% for all treatments after 1 year. In the patients who had FDG PET / CT, the LC was

value = 0.184]. Also, tumours with GTV < 350 cc volumes had a better overall survival (24 months) compared to GTV of greater than 350 cc (8 months) [p value = 0.004]. On multivariate analysis tumour volume >350 cc remained the only predictor for adverse OS (p=0.005). Conclusion This study showed that SBRT can be used safely and effectively to treat large HCCs with or without prior loco- regional therapies, resulting in good local control and survival with acceptable toxicity. EP-1437 The prognostic significance of neutrophil / lymphocyte ratio for SBRT of cholangiocellular carcinoma N. Bartl 1 , S. Adebahr 1 , S. Kirste 1 , I. Popp 1 , H. Schäfer 1 , A. Grosu 1 , T.B.B. Brunner 1 , E. Gkika 1 1 Medical Center- Faculty of Medicine- University of Freiburg- German Cancer Consortium DKTK Partner Site Freiburg- German Cancer Research Center DKFZ- Heidelberg- Germany, Department of Radiation Oncology, Freiburg, Germany Purpose or Objective In this analysis, we evaluated the prognostic significance of the neutrophil / lymphocyte ratio (NLR) in patients treated with stereotactic body radiation therapy (SBRT) for cholangiocellular carcinomas. Material and Methods Consecutive patients (n = 26) with histologically confirmed cholangiocellular carcinoma who were treated with SBRT between 2007 and 2017 are included in this analysis. The majority of patients were treated for local recurrence after primary therapy or as primary therapy because there was no operative treatment option. Patients received a median total dose of 50 (range 21-66) Gy in 3-12 fractions. Results Median survival was 14 months with overall survival (OS) 1 year after SBRT of 61% with median progression-free survival (PFS) at 13 months and 51% at 1 year. The local control was 72% after 1 year. The median NLR was 3 (range 2-10) with a median CRP of 15 (3-96) mg / L with a median bilirubin of 1 (1-22) mg / dL and a median LDH of 233 (156- 462) U / l. The OS did not correlate significantly with the NLR (HR 1.231, 95% CI 0.992-1.572, p = 0.059) neither was it correlated with NLR above the median (18 vs 14 months, p = 0.34). Furthermore, no correlation could be shown between CRP, LDH or bilirubin with overall Survival. Conclusion In this analysis, no correlation could be demonstrated between NLR and survival in patients with cholangiocellular carcinoma treated with SBRT. EP-1438 Safety and tolerability of liver re-irradiation using high dose SBRT D. Gabrys 1 , R. Kulik 2 , L. Dolla 2 , K. Trela-Janus 1 , A. Roch- Zniszczol 1 , S. Blamek 1 1 Maria Sklodowska-Curie Memorial Cancer Center and Institute of Oncology, Radiotherapy Department, Gliwice, Poland ; 2 Maria Sklodowska-Curie Memorial Cancer Center and Institute of Oncology, Department of Radiotherapy and Brachytherapy Planning, Gliwice, Poland Purpose or Objective The liver can tolerate a high dose of radiation if a sufficient volume of healthy liver tissue is spared. In the current paper we examined the safety and tolerability of liver reirradiation and dose volume histograms (DVH) of combined treatment plans. Material and Methods From patients who were treated with at least twice SBRT irradiaiton to the liver we choose 23 patients treated with high dose liver irradiation. The patients underwent retreatment for a primary (one patient with HCC) or metastatic recurrent or new liver tumour. With the use of