Clinical analysis of 54 cases of lung cancer treated by domestic carbon ion system / 中华放射肿瘤学杂志

ABSTRACT

Objective:To evaluate clinical prognosis and prognostic factors of patients with early stage (Ⅰ stage) and locally advanced (Ⅱ/Ⅲ stage) lung cancer treated with carbon ion radiotherapy (CIRT).Methods:Clinical data, treatment, adverse reactions, survival and so on of 54 lung cancer patients who received CIRT and follow-up in the Heavy Ion Center of Wuwei Cancer Hospital of Gansu Province from March 2020 to September 2022 were retrospectively analyzed. The survival curve was plotted using Kaplan-Meier method. Difference tests were performed using log-rank test. Logistic regression analysis was used to identify prognostic factors.Results:According to inclusion and exclusion criteria, 54 patients were enrolled in the study, including 10 patients with early stage lung cancer and 44 patients with locally advanced lung cancer. The median follow-up time for 10 patients with early stage lung cancer was 11.0 (6.75, 17.25) months, and the median dose of irradiation was 60 Gy [relative biological effect (RBE)]. Upon the last follow-up, 3 patients had complete response (CR) and 3 patients had partial response (PR). Four patients had stable disease (SD) and no progressive disease (PD). The 1-year and 2-year local control rates (LCR), progression-free survival (PFS) rates and overall survival (OS) rates were 100%. During treatment and follow-up, 2 patients developed grade 1 radiation pneumonia, 1 case of grade 2 radiation pneumonia, 1 case of chest wall injury (chest wall pain), and there were no adverse reactions greater than grade 2. The median follow-up time of 44 patients with locally advanced stage was 12.5 (4.25, 21.75) months, and the median irradiation dose was 72 Gy (RBE). Thirty-two (73%) patients received concurrent chemotherapy during treatment, 20 (45%) patients received sequential chemotherapy after treatment, 14 (32%) patients received immune maintenance therapy and 3 (7%) patients obtained PD and received targeted drugs. Upon the last follow-up, 3 (7%) patients had CR, 17 (39%) patients had PR, 19 (43%) patients obtained SD, and 5 (11%) patients had PD. The 1-year and 2-year LCR were 96.0% and 87.3%, 90.9% and 84.1% for the 1-year and 2-year PFS rates, and 93.2% and 86.4% for the 1-year and 2-year OS rates, respectively. The median OS and PFS of patients were not reached. Multivariate logistic regression analysis showed that maintenance therapy after radiotherapy ( P=0.027) and clinical target volume (CTV) irradiation volume ( P=0.028) were the factors affecting PFS. Simultaneous chemoradiotherapy ( P=0.042) and maintenance therapy after radiotherapy ( P=0.020) were the factors affecting OS. And gross tumor volume (GTV) ≥215 ml ( P=0.068) might be an independent risk factor for grade 2 and above radiation pneumonia. Conclusions:The domestic carbon ion system has definite clinical effect and controllable toxic and side effects in the treatment of early stage and locally advanced lung cancer. The combination of synchronous chemotherapy and further maintenance treatment can significantly improve clinical prognosis of patients without significantly increasing the risk of toxic and side effects.