129 - Sequential Chemo-Immunotherapy plus Optimized Thoracic Radiotherapy vs. Standard Thoracic Radiotherapy for Elderly and/ or Frail Stage III Non-Small-Cell Lung Cancer: A Randomized Open-Label Controlled Trial of iLCC-3
Presenter(s)
W. X. Qi1, S. Li2, M. Wang1, H. Li1, H. Zhao1, L. Yao3, Y. Xiang3, J. Y. Chen2, and S. Zhao1; 1Department of Radiation Oncology, Ruijin Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, China, 2Shanghai Key Laboratory of Proton Therapy, Shanghai, China, 3Ruijin hospital, Shanghai jiaotong university, shanghai, China
Purpose/Objective(s): Since the publication of PACIFIC trial, the standardized treatment option for stage III unresectable NSCLC was radical concurrent chemoradiotherapy(cCRT) followed by immune checkpoint inhibitors (ICIs) maintenance for patients who do not progress after cCRT. However, there is still controversy regarding the use of radical cCRT in elderly or frail patients with stage III NSCLC due to its toxicities. Additionally, whether decreased thoracic radiotherapy (RT) to 50Gy/25Fx would impact the survival outcomes of this patient cohort remains unknown.
Materials/Methods: In this prospective study (registered number: NCT05557552), frail/elderly stage III NSCLC patients treated with 4-6 cycle of induction chemoimmunotherapy, would be randomized to receive ICIs maintenance combined with either standard thoracic RT dose 60Gy/30Fx (standard group) or optimized thoracic RT dose 50Gy/25Fx (optimized group).The primary objective was to evaluate the 1-year progression-free survival (PFS) using the Kaplan-Meier method.
Results: Between September 30, 2022, and April 30, 2024, a total of 56 elderly and/ or Frail Stage III NSCLC patients were enrolled, with 50 male and 6 female patients. The median age was 68 years (range 65-79 years). 41 were squamous cell carcinoma, 11 adenocarcinoma and 4 poorly differentiated carcinoma. With a median follow-up of 23 months, the 1-year PFS in standard thoracic RT group(60Gy/30Fx) and decreased thoracic RT group (50Gy/25Fx) was 83% vs 74% (p=0.66). And the 1-year OS was comparable between the two groups (92% for standard thoracic RT group vs. 89% for decreased thoracic RT group, p=0.11). As for the type of recurrence, for the decreased thoracic RT group, ten patients experienced Intrapulmonary progression after treatment, three with distant metastasis and two patients developed malignant pleural effusion. While five patients developed Intrapulmonary progression, one patient presented local and distant metastasis, and three experienced distant metastases. As for treatment-related toxicities, =grade 3 toxicities 85.7% vs 57.1% occurred in standardized and optimized RT group(p=0.038), with three in standardized RT and one in optimized RT group died from treatment toxicities (10.7% vs. 3.6%). There were 14 patients (50%) in both groups interrupted maintenance treatment of ICIs due to treatment toxicities, and 5 patients in decreased thoracic RT group and 6 patients in standardized thoracic RT group resumption of immunotherapy.
Conclusion: The survival outcomes of decreased thoracic RT was comparable to standardized thoracic RT. Although more patients in decreased thoracic RT developed Intrapulmonary progression in comparison with standardized RT group (35.7% vs. 17.9%), less severe treatment-related toxicity could be observed in optimized RT cohort. Sequential chemo-immunotherapy plus decreased thoracic RT followed by maintenance immunotherapy in Elderly And/ or Frail patients with stage III NSCLC was feasible.