ESTRO 2022 - Abstract Book

S1063

Abstract book

ESTRO 2022

Conclusion Lung cancer survivors report to suffer dyspnea, fatigue, cough and a poor health status after completing radiotherapy treatment.

PO-1259 Practical results of salvage treatment for regional recurrences after primary SABR for lung cancer

C. Lee 1 , H.J. Kim 1 , H. Wu 2 , B.H. Kim 3

1 Seoul National University Hospital, Department of Radiation Oncology, Seoul, Korea Republic of; 2 Seoul National University Hospital, Department of Radiation Oncology,, Seoul, Korea Republic of; 3 SMG-SNU Boramae Medical Center, Department of Radiation Oncology, Seoul, Korea Republic of Purpose or Objective Stereotactic ablative radiotherapy (SABR) to early stage lung cancer has been shown promising results, but the development of regional recurrences are not uncommon and salvage treatment strategies are not established. We aimed to investigate treatment patterns, prognostic factors, and survival outcomes for these patients. Materials and Methods Retrospective analysis was performed to 391 patients who received SABR to primary lung cancer from 2012 to 2019. Among these patients, 90 patients (23.0%) experienced recurrence; local recurrence which was defined 2cm within PTV (n = 9), regional recurrence (n = 33), distant metastasis (n = 57). Further analysis was performed only for patients with regional recurrence and 8 (24.2%) of them were accompanied by simultaneous distant metastasis (DM). Survival analysis was performed by Kaplan-Meier method in overall survival (OS), post-recurrence overall survival (PR-OS), 1 st progression free survival (1 st PFS) and 2 nd progression free survival (2 nd PFS). Median follow-up duration was 17.3 months. Results Median age was 75 years and most patients received primary SABR due to poor lung function (69.7%). Various salvage treatments were applied for regional recurrences; chemotherapy (n = 15), radiotherapy (n = 7), concurrent chemoradiotherapy (n = 2), and best supportive care (n = 9). Overall, median 1 st PFS and 2 nd PFS were 6.6 and 10.0 months, respectively. Median OS and PR-OS were 22.9 and 11.2months, respectively. In univariate analysis for PR-OS, trend for better survival was observed for patients with isolated recurrence (p = 0.065) and those received radiotherapy without chemotherapy (p = 0.080). The non-receipt of salvage treatment (p =0.493) and simultaneous DM (p = 0.950)were not associated with decreased PR-OS. In multivariate analysis, age ≤ 75 years (HR = 0.36, p = 0.040), isolated recurrence (HR = 0.34, p = 0.037) and radiotherapy without chemotherapy (HR = 0.25, p = 0.024) were significant prognostic factors for PR-OS. Patients with 1 st PFS < 7 months showed worse OS (p = 0.029). In patients receiving salvage chemotherapy, 4 patients (23.5%) developed grade 4 or more toxicities. Conclusion PR-OS was less than 1 year after regional recurrence in our frail patients group underwent primary SABR to lung despite of various salvage treatments. Toxicities of salvage chemotherapy could be quite severe requiring careful patient selection. Further research is needed to validate our findings.

PO-1260 Adaptive Radiotherapy in Lung Cancer – Is it Worthwhile??

J.P. AGARWAL 1 , A. Tibdewal 2 , K. Prabhas 3 , N. Mummudi 1 , R. Mhatre 4 , R. Kinhikar 4

1 Tata Memorial Centre, Homi Bhabha National Institute, Department of Radiation Oncology, Mumbai, India; 2 Tata Memorial centre, Homi Bhabha National Institute, Department of Radiation Oncology, Mumbai, India; 3 Tata Memorial Centre, Homi Bhabha National Institute, Department of Medical Oncology, Mumbai, India; 4 Tata Memorial Centre, Homi Bhabha National Institute, Department of Medical Physics, Mumbai, India Purpose or Objective Adaptive radiotherapy (ART) in lung cancer is required in approximately a quarter of patients, most common reason being resolution of atelectasis and rapid shrinkage of tutor during treatment. Adaptive radiotherapy requires timely detection, planning and execution with delineation uncertainties involved at the time of ART. In this study, we evaluated survival outcomes of patients who underwent ART in patients who on curative( chemo) radiotherapy.