Shanghai Chest Hospital, Shanghai JiaoTong University Hefei, Anhui
X. Y. Li1,2, B. Yan1, Y. He3, and D. Qian4; 1The First Affiliated Hospital of USTC, Hefei, Anhui, China, 2The First Affiliated Hospital of USTC, Hefei, China, 3The First Affiliated Hospitalof USTC, Division of Life Sciences and Medicine.University of Science and Technology of China,Hefei,Anhui,230001,China, hefei, Anhui, China, 4The First Affiliated Hospital of The University of Science and Technology of China (USTC), Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, China
Purpose/Objective(s):Concurrent chemoradiotherapy is the standard modality for locally advanced small-cell lung cancer, achieving median overall survival of 25 mos. According to previous studies, higher definitive dose may bring better survival outcome. Hypofractionated radiotherapy was a useful modality to increase biological effective dose with the advantage of short duration and convenience. This trial is designed to explore the safety and primary efficacy of hypofraction radiotherapy (4Gy/f) for limited-stage small cell lung cancer.Materials/
Methods: Patients diagnosed with limited-stage small-cell lung cancer were enrolled to be assigned to two arms: Low-dose arm (48Gy/12f) and High-dose arm (60Gy/15f). The enrolled patients should receive 4 to 6 cycles of standard chemotherapy. Definitive radiotherapy could be administered concurrently at any cycle of chemotherapy. Either hippocampus-sparing prophylactic cranial irradiation or MRI surveillance could be chosen. The primary endpoints were the rate of radiation-induced pneumonitis, proximal bronchial tree injury, esophagitis and myelosuppression. The second endpoints were 1-year local-regional control rate, 1-year progression-free survival rate, 1-year overall survival rate. Results: Totally 40 patients (27 males and 11 females) were enrolled consecutively from Mar 1 2022 to April 30 2023. The median age was 63-year-old (52-80). There were 1, 2, 7, 23, 7 patients diagnosed as clinical stage IA, IIB, IIIA, IIIB, IIIC respectively. 10 patients received sequential chemoradiotherapy and 30 patients for concurrent chemoradiotherapy respectively. There were 18 and 22 patients receiving 48Gy/12f and 60Gy/15f respectively. 10 patients received hippocampus-sparing cranial prophylactic irradiation. Medium follow-up is 17 months (5-21 mos). There were 2, 1 and 1 patients who died due to hemoptysis, trachea-mediastinum fistula and tracheal pseudomembranous mucositis respectively. 14 patients developed radiation-induced esophagitis (2 for Grade I and 12 for Grade II). 22 patients developed radiation-induced pneumonitis (20 for Grade I and 2 for Grade II). 27 patients developed myelosuppression (4 for Grade I, 16 for Grade II, 6 for Grade III and 1 for Grade IV). 3 patients in low-dose arm and 9 patients in high-dose arm developed atelectasis respectively. The 1-year overall survival rate and 1-year progression-free survival rate was 86.2% and 79.5% respectively. The PFS and OS in low-dose group and high-dose group demonstrated no significant difference. Conclusion: The hypofraction radiotherapy (4Gy/f) for limited-stage small cell lung cancer is safe and efficacy. Hypofractionated-Radiation-induced proximal bronchial tree injury should be highly alerted. Moderate hypofraction (48Gy/12f) may strike a balance between efficacy and toxicity, which was worthy for further exploration. (NCT05523908)
