ESTRO 2022 - Abstract Book

S1077

Abstract book

ESTRO 2022

treated in our hospital with High dose re-irradiation either with SBRT or hypofractionated EBRT after local recurrence of NSCLC. Materials and Methods The records of patients treated with thoracic SBRT or hypofractionated EBRT from 2012 through 2019 were retrospectively reviewed. We identified twelve patients treated with prior thoracic radiation therapy for NSCLC with subsequent “in field” re-irradiation, defined as overlapping of PTV of both treatments; or “border field”, defined as overlapping of the recurrence PTV with the previous 30 Gy isodose. Overall survival, local control, recurrences and toxicity were assessed. Results Median age at the time of re-irradiation was 63 years (47-83). The re-irradiation dose ranged from 50 to 60 Gy (BED 75- 180Gy) given in 3-10 fractions. Median follow-up was 23 months. Local control was 91.7% at 1 year and 75% at 2 years, with a median of 15 months of progression-free survival and a median of 24 months for overall survival. One patient died of hemoptysis 3 months after re-irradiation, no other patients presented toxicity above grade 2. Conclusion Results indicate that lung re-irradiation with High dose radiotherapy may offer satisfactory long term disease control, but could present important toxicity. Special care must be taken when treating patients with thoracic reirradiation. 1 National-Hospital Organization Shikoku-Cancer Center, Radiotherapy, Matsuyama-city, Japan; 2 National-Hospital Organization, Shikoku-Cancer Center, Radiotherapy, Matsuyama-city, Japan; 3 National-Hospital Organization Shikoku- Cancer Center, Radiotherpay, Matsuyama-city, Japan; 4 National-Hospital Organization Shikoku-Cancer Center, Radiothreapy, Matsuyama-city, Japan Purpose or Objective Local failure of primary lung cancer treated with stereotactic body radiotherapy (SBRT) occurs even after 2-years or more. Differences in prognosis after local failure between early local failure (ELF, recurred within 2-years from SBRT) cases and delayed local failure (DLF, recurred after >2-years from SBRT) cases were investigated. Materials and Methods Consecutive stage I-IIA lung cancer treated with SBRT was retrospectively reviewed. In SBRT, 48 Gy in four fractions at the isocenter was delivered to the primary tumors in principle. Local failure was diagnosed by periodical follow-up CT with or without FDG-PET/CT. Results Between 2006 and 2012, 173 lung cancer (stage I, 141; Stage IIA, 32) in 155 patients were treated with SBRT. Twenty-eight tumors recurred locally with or without simultaneous regional and/or distant failure (ELF, 14; DLF, 14). Median time to local failure was 13 months (range 4-23 months) for ELF and 43 months (range 28-94 months) for DLF. Simultaneous regional and/or distant failure tended to be more frequent in DLF compared to ELF (57% vs. 21%; X2-test, p = 0.0530). Prognosis after local failure was significantly poor in DLF cases. Two-year overall survival rates calculated from local failure was 60% for ELF cases and 15% for DLF cases (log-rank test, p=0.0195). Conclusion Regarding early-stage lung cancer treated with SBRT, prognosis after local failure was significantly poor in DLF cases compared to ELF cases. In DLF cases, simultaneous regional and/or distant failure tended to be more frequent. N. Kishi 1 , Y. Matsuo 1 , T. Shintani 2 , M. Ogura 3 , T. Mitsuyoshi 4 , N. Araki 5 , K. Fujii 6 , S. Okumura 7 , K. Nakamatsu 8 , T. Kishi 9 , T. Atsuta 10 , T. Sakamoto 11 , S. Otsu 12 , T. Katagiri 13 , M. Narabayashi 2 , S. Fujishiro 14 , Y. Iizuka 15 , H. Ozasa 16 , T. Mizowaki 1 1 Kyoto University Graduate School of Medicine, Department of Radiation Oncology and Image-Applied Therapy, Kyoto, Japan; 2 Japanese Red Cross Fukui Hospital, Department of Radiology, Fukui, Japan; 3 Kishiwada City Hospital, Department of Radiation Oncology, Kishiwada, Japan; 4 Kobe City Medical Center General Hospital, Department of Radiation Oncology, Kobe, Japan; 5 National Hospital Organization Kyoto Medical Center, Department of Radiology, Kyoto, Japan; 6 Kurashiki Central Hospital, Department of Radiation Oncology, Kurashiki, Japan; 7 Hyogo Prefectural Amagasaki General Medical Center, Department of Radiation Oncology, Amagasaki, Japan; 8 Kindai University Faculty of Medicine, Department of Radiation Oncology, Osakasayama, Japan; 9 Osaka Red Cross Hospital, Department of Radiation Oncology, Osaka, Japan; 10 Kitano Hospital, Tazuke Kofukai Medical Research Institute, Department of Radiology, Osaka, Japan; 11 Kyoto Katsura Hospital, Department of Radiation Oncology, Kyoto, Japan; 12 Kyoto City Hospital, Department of Radiation Oncology, Kyoto, Japan; 13 Tenri Hospital, Department of Radiation Oncology, Tenri, Japan; 14 Shinko Hospital, Department of Radiation Oncology, Kobe, Japan; 15 Shizuoka City Shizuoka Hospital, Department of Radiation Oncology, Shizuoka, Japan; 16 Kyoto University Graduate School of Medicine, Department of Respiratory Medicine, Kyoto, Japan PO-1278 Time to local failure and prognosis in lung cancer treated with stereotactic body radiotherapy Y. Hamamoto 1 , H. Kanzaki 2 , K. Nagasaki 3 , K. Makita 4 PO-1279 PFS and recurrence patterns after CCRT with durvalumab for stage III and recurrent NSCLC