ESTRO 2023 - Abstract Book

S814

Monday 15 May 2023

ESTRO 2023

PD-0966 Patterns of recurrence, treatment, and outcome of lymph node recurrence after SBRT for lung cancer T.H. Lee 1 , H. Shin 2 , Y.C. Ahn 2 , M.K. Kang 3 , C. Song 4 , W.C. Kim 5 , S.H. Moon 6 , J.H. Kim 7 , J. Cho 8 , H.J. Park 9 , H.K. Lee 10 , B.H. Kim 11 , H.J. Kim 1 1 Seoul National University Hospital, Department of Radiation Oncology, Seoul, Korea Republic of; 2 Samsung Medical Center, Department of Radiation Oncology, Seoul, Korea Republic of; 3 Kyungpook National University School of Medicine, Department of Radiation Oncology, Daegu, Korea Republic of; 4 Seoul National University Bundang Hospital, Department of Radiation Oncology, Seongnam, Korea Republic of; 5 Inha University Hospital, Department of Radiation Oncology, Incheon, Korea Republic of; 6 National Cancer Center, Proton Therapy Center, Goyang, Korea Republic of; 7 Dongsan Medical Center, Department of Radiation Oncology, Daegu, Korea Republic of; 8 Yonsei Cancer Center, Department of Radiation Oncology, Seoul, Korea Republic of; 9 Hanyang University Hospital, Department of Radiation Oncology, Seoul, Korea Republic of; 10 Jeonju Jesus Hospital, Department of Radiation Oncology, Jeonju, Korea Republic of; 11 Seoul Metropolitan Government-Seoul National University Boramae Medical Center, Department of Radiation Oncology, Seoul, Korea Republic of Purpose or Objective To report multi-institutional data of patterns of recurrence, treatment approach, and clinical outcomes for regional lymph node (LN) recurrence after stereotactic body radiation therapy (SBRT) for primary lung cancer. Materials and Methods Medical records of 114 patients who experienced regional LN recurrence as the first recurrence after lung SBRT were retrospectively reviewed. Patterns of recurrence was classified as local recurrence, regional recurrence, and distant metastasis. Types of additional treatment was recorded. Clinical outcomes including progression-free survival (PFS) and overall survival (OS) were analyzed. Results Half of the patients had regional LN recurrence only. The most frequent simultaneous recurrence was distant metastasis (38.6%). Common site of regional recurrence was ipsilateral hilar (47.2%), ipsilateral upper mediastinal (40.6%), and subcarinal (42.5%) LN station. Detailed sites of LN recurrence in 106 analyzable patients are illustrated in the following figure. 24 (21.1%) patients underwent salvage radiation therapy (RT), and 44 (38.6%) patients underwent palliative treatment. Better OS was reported in salvage RT group (P = 0.025). 1-year PFS and OS were 27.7% and 55.2% with salvage RT, 14.0% and 39.9% with palliative treatment, and 22.8% and 26.8% with no additional treatment, respectively. Multivariate analysis showed that salvage RT (PFS, HR 0.463, P = 0.050; OS, HR 0.312, P = 0.002), palliative treatment (PFS, HR 0.436, P = 0.013; OS, HR 0.553, P = 0.050) and simultaneous distant metastasis (PFS, HR 2.335, P = 0.005; OS, HR 1.726, P = 0.054) were associated with clinical outcomes.

Conclusion Many regional LN recurrence still confined in locoregional extent, and appropriate treatment can improve the prognosis of these patients. PD-0967 Validation of the Graded Prognostic Assessment for Patients with Lung Cancer and Brain Metastases S.W. Hong 1 , C. Song 2 , W. Jeon 3 , J. Kim 4 1 Seoul National University Hospital, Department of Radiation Oncology, Seoul, Korea Republic of; 2 Seoul National University Bundang Hospital, Department of Radiation Oncology , Seongnam, Korea Republic of; 3 Dongnam Institute of Radiological and Medical Science, Department of Radiation Oncology, Busan, Korea Republic of; 4 Seoul National University Bundang Hospital, Department of Radiation Oncology, Seongnam, Korea Republic of Purpose or Objective Patients with non-small cell lung cancer (NSCLC) and brain metastases represent a markedly heterogeneous population. The original diagnosis-specific graded prognostic assessment is a prognostic index based on data from patients diagnosed between 1985 and 2005 and includes patients age, performance status, extracranial disease, and number of brain metastases. An updated prognostic index (Lung-molGPA) that incorporates molecular features (EGFR and ALK alterations) was created in 2016 based on the North American retrospective database analysis of 2186 patients with NSCLC and newly