ESTRO 2022 - Abstract Book

S991

Abstract book

ESTRO 2022

N. Giannini 1 , G. Gadducci 1 , F. Pasqualetti 1 , A. Gonnelli 1 , G. Malfatti 1 , N. Montemurro 2 , R. Morganti 3 , F. Paiar 1

1 Azienda Ospedaliera Universitaria Pisana AOUP, Radiotherapy, Pisa, Italy; 2 Azienda Ospedaliera Universitaria Pisana AOUP, Neurosurgery, Pisa, Italy; 3 Università degli Studi di Pisa, Dipartimento di Medicina Clinica e Sperimentale, Pisa, Italy Purpose or Objective The impact of different patterns of glioblastoma (GBM) recurrence has not yet been fully established in patients suitable for a second surgery. Through the present observational study carried out at Pisa University Hospital, we aimed to examine the impact of different patterns of GBM failure on patients’ survival and second surgery outcomes. Materials and Methods Overall survival was assessed according to clinical characteristics, including pattern of recurrence, in a prospective cohort of recurrent GBM patients. Survival curves were calculated using the Kaplan-Meier method and the log-rank test was applied to evaluate the differences between curves Results Contact with ventricles, a second surgery and meningeal spread had a statistically impact on patient survival after the diagnosis of GBM recurrence (P=0.032, P=0.019 and P<0.01, respectively). Patients with local recurrence had better survival than patients with non-local ones, 24.1 versus 18.2 months, respectively (P=0.015, HR=1.856 (1.130 -3.050). Considering the cohort as a whole, the second surgery conferred an advantage in recurrent survival respect to non-operated patients. However, this advantage was more evident in patients with local recurrence (P=0.002 with HR 0.212 (95% CI 0.081- 0.552) and P=0.029 with HR=0.522 (95% CI 0.291-0.936), respectively). Conclusion The local recurrence pattern could be a promising field of interest for patients with recurrent GBM suitable for a second surgery. 1 Memorial Sloan Kettering Cancer Center, Radiation Oncology, New York, USA; 2 Memorial Sloan Kettering Cancer Center, Medical Oncology, New York, USA Purpose or Objective Primary extranodal marginal zone lymphoma of bronchus-associated lymphoid tissue (BALT) has an indolent clinical course, and optimal treatment strategies at diagnosis are not well established. Retrospective analyses show equivalent or superior outcomes with surgical resection compared to systemic therapy or active surveillance, however the role of radiotherapy in disease management remains underexplored. Here we evaluated outcomes among nine consecutive patients with primary BALT lymphoma treated with radiotherapy (RT) to test the hypothesis that RT is associated with favorable local control and survival outcomes. Materials and Methods We retrospectively reviewed records for 28 patients with marginal zone lymphoma involving the lung treated at a single institution between 2000 and 2021, of which 9 met criteria for study inclusion. Inclusion criteria included age ≥ 18 years, disease confined to the lungs and hilar and/or mediastinal lymph nodes, and lack of concurrent malignancy. We calculated progression-free (PFS) and overall survival (OS) using the Kaplan-Meier method. Results The median follow-up was 27 months (range, 10 – 176 months). Six patients had newly diagnosed BALT lymphoma, and three patients were treated for progressive disease after rituximab. All patients except for one with bilateral lung involvement received tumor-limited fields with a median dose of 4 Gy (range, 4 – 36 Gy). The majority of patients (n = 5) received low-dose RT with 4 Gy. The 5-year PFS rate was 100%; the median PFS from RT was not reached. The median OS from RT was 124 months. Of 9 treated patients, only one went on to develop recurrent disease in a portocaval lymph node. There were no cases of local recurrence and no reported RT-related toxicities. Poster (digital): Haematology PO-1170 Low-dose radiotherapy for extranodal marginal zone lymphoma of bronchus-associated lymphoid tissue M. Freret 1 , B. Imber 1 , E. Joffe 2 , J. Yahalom 1 , C. Hajj 1