Objective:To analyze the treatment efficacy, safety and dose parameters of optimized hippocampus-avoidance prophylactic cranial irradiation (HA-PCI) in limited-stage small cell lung cancer (LS-SCLC) and explore the corresponding dosimetric parameters under the condition of narrowing the hippocampus avoidance region as hippocampus region plus 2 mm in three dimensions.Methods:Clinical data of patients with LS-SCLC receiving HA-PCI (hippocampus avoidance region defined as hippocampus region plus 2 mm in three dimensions) in Cancer Hospital Chinese Academy of Medical Sciences from August 2014 to June 2020 were retrospectively analyzed. Dose parameters of HA-PCI and adverse events were analyzed using descriptive statistics analysis. Changes of neurocognitive function, such as mini-mental state examination (MMSE) and Hopkins verbal learning test-revised (HVLT-R) scores, were evaluated by analysis of variance and Kruskal-Wallis H test. Overall survival (OS), progression-free survival (PFS) and intracranial PFS (iPFS) were calculated using Kaplan-Meier method. The cumulative incidence of local-regional recurrence (LRR), extracranial distant metastases (EDM), and locoregional recurrence (LR) were investigated under competing risk analysis. Results:A total of 112 patients were included, the median follow-up time was 50 months (95% CI: 45.61-54.38). The median volume of hippocampus was 4.85 ml (range: 2.65-8.34 ml), with the average dose ≤9 Gy in 106 patients (94.6%), ≤8 Gy in 92 patients (82.1%). The median volume of hippocampus avoidance area was 15.00 ml (range: 8.61-28.06 ml), with the average dose ≤12 Gy in 109 patients (97.3%), ≤10 Gy in 101 patients (90.2%). The 2-year cumulative LRR, EDM, LR rates were 16.9%, 23.2% and 28.5%, respectively. The 5-year cumulative LRR, EDM, LR rates were 23.2%, 26.9% and 33.3%, respectively. The 2-year iPFS, PFS and OS rates were 66.1% (95% CI: 57.9%-75.4%), 53.6% (95% CI: 45.1%-63.7%) and 80.4% (95% CI: 73.3%-88.1%), respectively. The most common grade I-Ⅱ adverse events were nausea (33.9%) and dizziness (31.3%), and only 1 patient developed grade Ⅲ nausea and dizziness. MMSE ( n=57) and HVLT-R tests ( n=56) showed no significant decline. Conclusions:Optimized HA-PCI can achieve similar dose limitation with favorable efficacy and light toxicity. No significant decline is observed in short-term neurocognitive function in evaluable patients.

Objective:To evaluate the safety and efficacy of thoracic radiotherapy (TRT) for extensive-stage small cell lung cancer (ES-SCLC) patients in the era of first-line chemoimmunotherapy.Methods:Medical records of 56 patients with ES-SCLC who received thoracic radiotherapy after first-line platinum-based chemotherapy plus immunotherapy in Cancer Hospital Chinese Academy of Medical Sciences from January 2018 to December 2021 were retrospectively analyzed. The control group was not established for clinical causes. The overall survival (OS), progression-free survival (PFS) and local recurrence-free survival (LRFS) were calculated using the Kaplan-Meier method. Univariate and multivariate analyses were employed to identify prognostic factors using the Cox proportional hazards model. The cumulative incidence of local regional recurrence (LRR) was estimated using the Fine-Grey competing risks regression model.Results:Among 56 patients in our cohort, 47 patients received consolidative TRT (cTRT) before progression and 9 patients received salvage TRT after progression. The median follow-up time was 21 months (95% CI=19.8-22.2 months), the median OS was not reached, the median PFS was 9 months (95% CI=7.0-13.0 months), and the 1-year and 18-month OS rates were 84.9%, 62.1%. In the cTRT group, the 1-year and 18-month OS rates were 84.1%, 64.5%, with the median PFS of 10 months; 1-year and 18-month LRFS rates were 73.6% and 66.0%, respectively; the cumulative incidence of LRR at 1-year and 2-year were 24.9% and 30.8%, respectively. No other 4-5 grade adverse events (AE) were reported except 6 patients presenting with 4 grade hematologic toxicities. Three grade radiation esophagitis occurred in 3 patients (5%). Ten patients (18%) developed 1-2 grade treatment-related pneumonitis, including 5 (9%) patients with immune related pneumonitis and 5 (9%) patients with radiation pneumonitis. Conclusion:The application of TRT after first-line chemoimmunotherapy is safe and may has potential survival benefit for patients with ES-SCLC.

Objective:To evaluate the efficacy and safety of hippocampal avoidance whole-brain irradiation with simultaneous integrated boost in the treatment of brain metastases of lung cancer.Methods:Forty lung cancer patients with brain metastases who received whole-brain radiotherapy with simultaneous integrated boost and hippocampal avoidance in Cancer Hospital, Chinese Academy of Medical Sciences from 2014 to 2020 were enrolled in this study. Brain MRI, survival follow-up and evaluation of side effects were performed before radiotherapy and at 1, 3, 6 and 12 months after radiotherapy, respectively. Overall survival (OS), progression-free survival (PFS) and changes in cognitive function were analyzed. Continuous data were described as Mean ± SD. Categorical data were described by frequency and composition ratio or percentage. Survival analysis was conducted by Kaplan-Meier method. Influencing factors of survival were identified by univariate and multivariate Cox's regression analyses.Results:A total of 40 patients were enrolled in the study. The median follow-up time was 14.2 months and the median OS, PFS and intracranial PFS of all patients were 14.8 months, 6.7 months and 14.8 months, respectively. Multivariate analysis showed that male gender and newly diagnosed stage Ⅳ disease were associated with worse OS and PFS, respectively. The Hopkins verbal learning test-revised (HVLT-R) scores at baseline and 1, 3 and 6 months after radiotherapy were 21.94±2.99, 20.88±3.12, 20.03±3.14, and 19.78±2.98, respectively. The HVLT-R score at 6 months after radiotherapy was decreased by approximately 9.8% compared with the baseline. No grade 3 or above toxic and side effect occurred in the entire cohort.Conclusion:Hippocampal avoidance whole-brain irradiation with simultaneous integrated boost is a safe and effective treatment for brain metastases of lung cancer, which is expected to reduce the impact of radiotherapy on cognitive function.

Objective:To evaluate the safety and tolerance of sequential thoracic radiotherapy combined with PD-1/PD-L1 inhibitors in patients with extensive-stage small cell lung cancer (ES-SCLC) after induction systemic therapy.Methods:ES-SCLC patients from a phase I trial and a real-world study were enrolled for those who received thoracic radiotherapy after induction systemic treatment (chemotherapy/chemotherapy combined with PD-1/PD-L1 inhibitors) and consolidated with PD-1/PD-L1 inhibitors. These two studies were both approved by the Ethics Committee of Chinese Academy of Medical Sciences Cancer Hospital (Clinical Trials.gov number, NCT03971214, NCT04947774).Results:Between January 2019 and March 2021, a total of 11 patients with ES-SCLC were analyzed, aged 52-73 years, with a median age of 62 years. Among them, five patients (45.5%) received induction chemotherapy and six patients (54.5%) received chemotherapy combined with PD-1/PD-L1 inhibitor, and then all received intensity-modulated thoracic radiotherapy after evaluation of systemic treatment efficacy. Two patients developed treatment-related grade G3-5 toxicity (18.2%, 1 treatment-related pneumonitis and 1 radiation esophagitis). G 1-G 2 hematologic toxicity, pneumonia, and anorexia were common mild toxicities. Only one patient (9.1%) terminated immunotherapy due to immune-related pneumonitis. During a median follow-up time of 12.5 months (range: 3.5-16.4 months), the median disease progression-free survival and overall survival was 7.4 months (95% CI: 6.9-8.0 months) and 14.6 months (95% CI: 9.0-20.2 months), respectively. Conclusions:Sequential thoracic radiotherapy followed by PD-1/PD-L1 inhibitor is safe and feasible in patients with ES-SCLC after induction therapy. Given that both thoracic radiotherapy and immunotherapy benefits the ES-SCLC in survival, this comprehensive treatment modality warrants further investigation.

Objective:Simultaneous integrated boost radiation technique in limited-stage small cell lung cancer is lack of evidence. This prospective study aims to evaluate whether the simultaneous integrated boost is as efficacious and safe as conventional fractionated radiotherapy.Methods:Patients diagnosed with treatment-naive and confirmed limited-stage SCLC were eligible. Participants were randomly assigned (1: 1) to receive simultaneous integrated boost radiotherapy (PGTV 60.2 Gy/2.15 Gy/28F, PTV 50.4 Gy/1.8 Gy/28F) or conventional fractionated radiotherapy (PTV 60 Gy/2 Gy/30F). The primary endpoint was 2-year progression-free survival, and the secondary endpoints were 2-year overall survival, 2-year local-regional recurrence-free survival and toxicity.Results:Between February 2017 and July 2019, 231 patients were enrolled. We analyzed 216 patients whose follow-up time was more than 2 years or who had died, among whom 106 patients in the conventional fractionated radiotherapy group and 110 patients in the simultaneous integrated boost radiotherapy group. The median follow-up time was 37 months (95% CI: 35.2-38.7). The 2-year progression-free survival rates were 45.2% vs. 38.2%( HR=1.22, 95% CI: 0.87-1.72, P=0.2). The 2-year overall survival rates were 73.5% vs. 60.9%( HR=1.35, 95% CI: 0.90-2.04, P=0.14). The 2-year local-regional recurrence-free survival rates were 68.7% vs. 69.9%( HR=0.98, 95% CI: 0.62-1.56, P=1.0). Multivariate analysis showed that early radiotherapy yielded better 2-year progression-free survival, overall survival and local-regional recurrence-free survival than delayed radiotherapy in two groups ( HR=1.69, 95% CI: 1.18-2.41, P=0.003; HR=1.72, 95% CI: 1.09-2.70, P=0.018; HR=1.66, 95% CI: 1.01-2.73, P=0.046). Tumor staging was an influencing factor of overall survival (stage Ⅲ vs. stage Ⅰ-Ⅱ, HR=3.64, 95% CI: 1.15-11.57, P=0.028). The most common grade 3-4 adverse events were myelosuppression (21.7% vs. 15.4%, P=0.83), radiation pneumonitis (4.7% vs. 2.7%, P=0.44) and radiation esophagitis (3.8% vs. 1.8%, P=0.51). Conclusions:Simultaneous integrated boost radiotherapy yields equivalent efficacy and toxicities to conventional fractionated radiotherapy for limited-stage small cell lung cancer. Early radiotherapy can enhance clinical prognosis.

Objective:To explore the effect of pretreatment body mass index (BMI) on the prognosis of patients with unresectable locally advanced non-small cell lung cancer (NSCLC) after chemoradiotherapy.Methods:The clinical data of 711 patients with locally advanced NSCLC treated with radiotherapy, sequential chemoradiotherapy or concurrent chemoradiotherapy from January 2013 to December 2017 in Cancer Hospital of Chinese Academy of Medical Science and Peking Union Medical College were retrospectively analyzed. Radiotherapy was performed with intensity-modulated radiotherapy (IMRT) or volumetric-modulated arc therapy (VMAT), and the chemotherapy regimens were paclitaxel+carboplatin, pemetrexed+cisplatin or etoposide+cisplatin. The effects of pretreatment BMI and other clinical factors on overall survival (OS) of patients were analyzed. Survival analysis was performed by using Kaplan-Meier method; univariate and multivariate analyses were performed by using Cox proportional hazards model.Results:According to the World Health Organization (WHO) recommended BMI grouping method for Asian, the median OS time of low BMI group (<18.5 kg/m 2, 23 cases), normal BMI group (18.5-23.9 kg/m 2, 293 cases) and high BMI group (≥24.0 kg/m 2, 395 cases) was 17 months (95% CI 11-29 months), 29 months (95% CI 22-36 months) and 30 months (95% CI 27-34 months), respectively. OS in the low BMI group was poorer than that in the normal BMI group and high BMI group ( χ2 = 11.20, P = 0.004). Maximally selected rank statistics was used to determine the optimal cut-off value of BMI for prediction of survival as 21.31 kg/m 2, according to which patients were divided into low BMI group (BMI<21.31 kg/m 2, 130 cases) and high BMI group (BMI≥21.31 kg/m 2, 581 cases), the median OS time of the two groups was 20 months (95% CI 17-27 months) and 32 months (95% CI 28-35 months), respectively. OS in the low BMI group was poorer than that in the high BMI group ( χ2 = 12.30, P < 0.001). Multivariate analysis showed that age ≥ 65 years old, male, Karnofsky score < 80 points, low BMI, smoking, histological type of squamous cell carcinoma and radiotherapy alone were independent risk factors for OS (all P < 0.05). Conclusions:For patients with unresectable locally advanced NSCLC who received chemoradiotherapy, those with low pretreatment BMI have poor prognosis.

Objective:To evaluate the clinical efficacy and failure patterns of prophylactic cranial irradiation (PCI) in patients with limited-stage small cell lung cancer (LS-SCLC) on the basis of modern chemoradiotherapy and diagnostic techniques.Methods:In this retrospective study, clinical data of 201 LS-SCLC patients treated with chemotherapy (EP/CE regimens, ≥4 cycles) and intensity-modulated radiotherapy (IMRT) in Cancer Hospital of Chinese Academy of Medical Sciences from 2006 to 2014 were reviewed. All patients were primarily managed with concurrent or sequential chemoradiotherapy and achieved complete response (CR) or partial response (PR). Ninety percent of patients were revaluated for brain metastasis (BM) by MRI and 10% by CT scan. Long-term survival and failure patterns were compared between the PCI ( n=91) and non-PCI groups ( n=110). Results:The median follow-up time was 77.3 months (95% CI 73.0-81.5 months). The median overall survival (OS), 2-and 5-year OS rates were 58.5 months, 72.5% and 47.7% in the PCI group, and 34.5 months, 61.7% and 35.8% in the non-PCI group ( P=0.075). The median progression-free survival (PFS), 2-and 5-year PFS rate were 22.0 months, 48.0% and 43.4% in the PCI group, significantly higher than 13.9 months, 34.4% and 26.7% in the non-PCI group ( P=0.002). The 2- and 5-year cumulative incidence of BM were 6.6% and 12.2% in the PCI group, and 30.0% , 31.0% in the non-PCI group ( P=0.001). The median time and rate of BM as an isolated first site of relapse were 11.9 months and 4.4% in the PCI group, and 8.7 months and 25.5% in the non-PCI group ( P<0.001). Multivariate analysis showed that response after chemoradiotherapy ( P<0.001) and PCI ( P=0.033) were the independent prognostic factors for PFS. Stratified analysis demonstrated that PCI significantly improved the 5-year PFS in patients who achieved CR (72.7% vs. 48.0%, P=0.013), while it did not improve the 5-year PFS in patients who obtained PR (26.1% vs. 20.2%, P=0.213). Conclusion:In the new era of standard chemoradiotherapy and more accurate diagnostic methods for BM, PCI was associated with improved PFS and lower incidence of BM in LS-SCLC patients.

Objective:To summarize survival outcomes and prognostic factors in esophageal cancer (EC) patients treated with intensity-modulated radiotherapy (IMRT).Methods:A retrospective analysis was performed on the clinical and follow-up data of 1 637 patients with EC who were admitted to our hospital from January 2005 to December 2017 and met the inclusion criteria.The 5-year overall survival (OS), progression-free survival (PFS) and pattern of recurrence were analyzed. The Kaplan-Meier method was used to calculate survival rates, Log-rank test for univariate analysis and Cox method for multivariate analysis were used to detect survival difference.Results:1-year, 3-year and 5-year OS and PFS of the entire group were 65.9% and 45.8%, 34.2% and 25.0%, 27.0% and 18.5%, respectively. Median OS and PFS were 19.4 months (95% CI=18.0-20.7 months) and 10.4 months (95% CI=9.3-11.3 months), respectively. Univariate analysis showed that the sex, KPS, tumor location, T stage, N stage, M stage, TNM stage, radiation dose and treatment modality were prognostic factors for 5-year OS and PFS of EC patients ( P<0.05). Multivariate analysis indicated that the sex, KPS, TNM stage, radiation dose and treatment modality were independent prognostic factors for 5-year OS and PFS ( P<0.05). Conclusions:EC patients treated with IMRT can obtain a promising survival. The sex, KPS, TNM stage, radiation dose and treatment modality are independent prognostic factors for prognosis.

Objective:To analyze the survival benefits and treatment related toxic effects of simultaneous integrated boost intensity-modulated radiotherapy (SIB-RT) for non-operative esophageal squamous cell carcinoma patients.Methods:The data of 2 132 ESCC patients who were not suitable for surgery or rejected operation, and underwent radical radiotherapy from 2002 to 2016 in 10 hospitals of Jing-Jin-Ji Esophageal and Esophagogastric Cancer Radiotherapy Oncology Group (3JECROG) were analyzed. Among them, 518 (24.3%) cases underwent SIB (SIB group) and 1 614 (75.7%) cases did not receive SIB (No-SIB group). The two groups were matched with 1∶2 according to propensity score matching (PSM) method (caliper value=0.02). After PSM, 515 patients in SIB group and 977 patients in No-SIB group were enrolled. Prognosis and treatment related adverse effects of these two groups were compared and the independent prognostic factor were analyzed.Results:The median follow-up time was 61.7 months. Prior to PSM, the 1-, 3-, and 5-years overall survival (OS) rates of SIB group were 72.2%, 42.8%, 35.5%, while of No-SIB group were 74.3%, 41.4%, 31.9%, respectively ( P=0.549). After PSM, the 1-, 3-, and 5-years OS rates of the two groups were 72.5%, 43.4%, 36.4% and 75.3%, 41.7%, 31.6%, respectively ( P=0.690). The univariate survival analysis of samples after PSM showed that the lesion location, length, T stage, N stage, TNM stage, simultaneous chemoradiotherapy, gross tumor volume (GTV) and underwent SIB-RT or not were significantly associated with the prognosis of advanced esophageal carcinoma patients who underwent radical radiotherapy ( P<0.05). Cox model multivariate regression analysis showed lesion location, TNM stage, GTV and simultaneous chemoradiotherapy were independent prognostic factors of advanced esophageal carcinoma patients who underwent radical radiotherapy ( P<0.05). Stratified analysis showed that, in the patients whose GTV volume≤50 cm 3, the median survival time of SIB and No-SIB group was 34.7 and 30.3 months ( P=0.155), respectively. In the patients whose GTV volume>50 cm 3, the median survival time of SIB and No-SIB group was 16.1 and 20.1 months ( P=0.218). The incidence of radiation esophagitis and radiation pneumonitis above Grade 3 in SIB group were 4.3% and 2.5%, significantly lower than 13.1% and 11% of No-SIB group ( P<0.001). Conclusions:The survival benefit of SIB-RT in patients with locally advanced esophageal carcinoma is not inferior to non-SIB-RT, but without more adverse reactions, and shortens the treatment time. SIB-RT can be used as one option of the radical radiotherapy for locally advanced esophageal cancer.

Objective:To summarize survival outcomes and prognostic factors in esophageal cancer (EC) patients treated with intensity-modulated radiotherapy (IMRT).Methods:A retrospective analysis was performed on the clinical and follow-up data of 1 637 patients with EC who were admitted to our hospital from January 2005 to December 2017 and met the inclusion criteria.The 5-year overall survival (OS), progression-free survival (PFS) and pattern of recurrence were analyzed. The Kaplan-Meier method was used to calculate survival rates, Log-rank test for univariate analysis and Cox method for multivariate analysis were used to detect survival difference.Results:1-year, 3-year and 5-year OS and PFS of the entire group were 65.9% and 45.8%, 34.2% and 25.0%, 27.0% and 18.5%, respectively. Median OS and PFS were 19.4 months (95% CI=18.0-20.7 months) and 10.4 months (95% CI=9.3-11.3 months), respectively. Univariate analysis showed that the sex, KPS, tumor location, T stage, N stage, M stage, TNM stage, radiation dose and treatment modality were prognostic factors for 5-year OS and PFS of EC patients ( P<0.05). Multivariate analysis indicated that the sex, KPS, TNM stage, radiation dose and treatment modality were independent prognostic factors for 5-year OS and PFS ( P<0.05). Conclusions:EC patients treated with IMRT can obtain a promising survival. The sex, KPS, TNM stage, radiation dose and treatment modality are independent prognostic factors for prognosis.