Definitive treatment of lung cancer with radiotherapy is challenging, as respiratory motion and anatomical changes can increase the risk of severe off-target effects during radiotherapy. Online adaptive radiotherapy (ART) is an evolving approach that enables timely modification of a treatment plan during the interfraction of radiotherapy, in response to physiologic or anatomic variations, aiming to improve the dose distribution for precise targeting and delivery in lung cancer patients. The effectiveness of online ART depends on the seamless integration of multiple components: sufficient quality of linear accelerator-integrated imaging guidance, deformable image registration, automatic recontouring, and efficient quality assurance and workflow. This review summarizes the present status of online ART for lung cancer, including key technologies, as well as the challenges and areas of active research in this field.
Humans ; Lung Neoplasms/radiotherapy* ; Radiotherapy Planning, Computer-Assisted/methods*

Objective:To evaluate the impact of prophylactic cranial irradiation (PCI) on the prognosis of patients with limited-stage small cell lung cancer (SCLC) in the era of widespread application of MRI.Methods:Clinical data were collected from an open-lable prospective clinical trial on thoracic radiotherapy target volumes for limited-stage SCLC conducted in Sun Yat-sen University Cancer Center and Zhejiang Cancer Hospital between June 2002 and January 2017. In this study, patients who achieved complete remission (CR) or partial remission (PR) after definitive chemoradiotherapy (CRT) were retrospectively analyzed. Stratified analysis was performed according to different clinical efficacies. Patients were divided into different groups according to whether PCI was conducted or not. Survival analysis of patients was carried out. Survival data were calculated by Kaplan-Meier method, and Cox proportional hazards model was applied for multivariate prognostic analysis.Results:Among 309 patients with limited-stage SCLC who received CRT, 133 patients achieved CR and 140 cases obtained PR. These 273 patients were enrolled in this study. Among 133 patients with CR, 29 of them did not receive PCI, and 89 (85.6%) of the remaining 104 patients receiving PCI underwent brain MRI to exclude brain metastasis (BM) before PCI. With a median follow-up time of 22.1 months, the cumulative BM rates were 18.3% and 37.9% in patients who received or did not receive PCI ( P=0.020). The median overall survival (OS) was 30.2 and 30.5 months, and the 1-, 3- and 5-year OS rates were 93.3%, 41.9%, 27.7% and 82.8%, 44.8%, 40.8%, respectively ( P=0.910). Multivariate analysis indicated that baseline Karnofsky performance status (KPS) = 90 was a favorable independent prognostic factor for OS in CR patients ( HR=0.93, 95% CI: 0.89-0.98, P=0.006). Among 140 patients achieving PR, 52 cases did not receive PCI and 80 (90.9%) of the remaining 88 patients received brain MRI before PCI. With a median follow-up time of 18.9 months, the cumulative BM rates were 10.2% and 44.2% ( P<0.001). The median OS was 26.0 and 18.0 months, and the 1-, 3-, and 5-year OS rates were 86.4%, 37.9%, 32.2% and 75.0%, 17.3%, 10.8%, respectively ( P=0.001). Baseline KPS = 90 ( HR=0.93, 95% CI: 0.89-0.97, P=0.001) and PCI ( HR=0.54, 95% CI: 0.36-0.80, P=0.002) were favorable prognostic factors for OS in PR patients. Conclusions:PCI significantly reduces the incidence of BM and prolongs the OS in patients with limited-stage SCLC who achieve PR after CRT, but it fails to significantly prolong the OS of CR patients.

Objective:To evaluate the impact of prophylactic cranial irradiation (PCI) on the prognosis of patients with limited-stage small cell lung cancer (SCLC) in the era of widespread application of MRI.Methods:Clinical data were collected from an open-lable prospective clinical trial on thoracic radiotherapy target volumes for limited-stage SCLC conducted in Sun Yat-sen University Cancer Center and Zhejiang Cancer Hospital between June 2002 and January 2017. In this study, patients who achieved complete remission (CR) or partial remission (PR) after definitive chemoradiotherapy (CRT) were retrospectively analyzed. Stratified analysis was performed according to different clinical efficacies. Patients were divided into different groups according to whether PCI was conducted or not. Survival analysis of patients was carried out. Survival data were calculated by Kaplan-Meier method, and Cox proportional hazards model was applied for multivariate prognostic analysis.Results:Among 309 patients with limited-stage SCLC who received CRT, 133 patients achieved CR and 140 cases obtained PR. These 273 patients were enrolled in this study. Among 133 patients with CR, 29 of them did not receive PCI, and 89 (85.6%) of the remaining 104 patients receiving PCI underwent brain MRI to exclude brain metastasis (BM) before PCI. With a median follow-up time of 22.1 months, the cumulative BM rates were 18.3% and 37.9% in patients who received or did not receive PCI ( P=0.020). The median overall survival (OS) was 30.2 and 30.5 months, and the 1-, 3- and 5-year OS rates were 93.3%, 41.9%, 27.7% and 82.8%, 44.8%, 40.8%, respectively ( P=0.910). Multivariate analysis indicated that baseline Karnofsky performance status (KPS) = 90 was a favorable independent prognostic factor for OS in CR patients ( HR=0.93, 95% CI: 0.89-0.98, P=0.006). Among 140 patients achieving PR, 52 cases did not receive PCI and 80 (90.9%) of the remaining 88 patients received brain MRI before PCI. With a median follow-up time of 18.9 months, the cumulative BM rates were 10.2% and 44.2% ( P<0.001). The median OS was 26.0 and 18.0 months, and the 1-, 3-, and 5-year OS rates were 86.4%, 37.9%, 32.2% and 75.0%, 17.3%, 10.8%, respectively ( P=0.001). Baseline KPS = 90 ( HR=0.93, 95% CI: 0.89-0.97, P=0.001) and PCI ( HR=0.54, 95% CI: 0.36-0.80, P=0.002) were favorable prognostic factors for OS in PR patients. Conclusions:PCI significantly reduces the incidence of BM and prolongs the OS in patients with limited-stage SCLC who achieve PR after CRT, but it fails to significantly prolong the OS of CR patients.