Objective This study explored the application of four-dimensional cone beam computed tomography (4D CBCT) in lung cancer patients, seeking to improve the accuracy of radiotherapy and to establish a uniform protocol for the application of 4D CBCT in radiotherapy for lung cancer. Methods 4D CBCT was applied to evaluate tumor volume response (TVR), motion, and center coordinates during radiotherapy in 67 eligible individuals with lung cancer diagnoses. The differences between 4D CBCT and 3D CBCT in different registration methods were compared. Results TVR was observed during treatment in 41% of patients (28/67), with a mean volume reduction of 41.7% and a median time to TVR of 19 days. Tumor motion was obvious in 16 patients, with a mean value of 0.52 cm (0.22 to 1.34 cm), and in 3 of 6 tumors close to the diaphragm (0.28 to 0.66 cm). Gray value registration based on mean density projection could still achieve close results to the 4D gray value registration. However, when the registration was based on bone alone, partial off-targeting occurred in the treatment in 41.8% of cases. The off-target rate was 19.0% when the tumor motion was ≤ 0.5 cm and 52.2% when the motion was > 0.5 cm. Conclusion Tumor volume and motion of intrapulmonary lesions in individuals diagnosed with lung cancer varied significantly in the third week of radiotherapy. 4D CBCT may be more advantageous for isolated lesions without reference to relative anatomical structures or those near the diaphragm. Grayscale registration based on mean density projection is feasible.
Objective: This study explored the application of four-dimensional cone beam computed tomography (4D CBCT) in lung cancer patients, seeking to improve the accuracy of radiotherapy and to establish a uniform protocol for the application of 4D CBCT in radiotherapy for lung cancer. Methods: 4D CBCT was applied to evaluate tumor volume response (TVR), motion, and center coordinates during radiotherapy in 67 eligible individuals with lung cancer diagnoses. The differences between 4D CBCT and 3D CBCT in different registration methods were compared. Results: TVR was observed during treatment in 41% of patients (28/67), with a mean volume reduction of 41.7% and a median time to TVR of 19 days. Tumor motion was obvious in 16 patients, with a mean value of 0.52 cm (0.22 to 1.34 cm), and in 3 of 6 tumors close to the diaphragm (0.28 to 0.66 cm). Gray value registration based on mean density projection could still achieve close results to the 4D gray value registration. However, when the registration was based on bone alone, partial off-targeting occurred in the treatment in 41.8% of cases. The off-target rate was 19.0% when the tumor motion was ≤0.5 cm and 52.2% when the motion was >0.5 cm. Conclusion: Tumor volume and motion of intrapulmonary lesions in individuals diagnosed with lung cancer varied significantly in the third week of radiotherapy. 4D CBCT may be more advantageous for isolated lesions without reference to relative anatomical structures or those near the diaphragm. Grayscale registration based on mean density projection is feasible.
TD+ group and TD-group according to postoperative pathology for tumor deposits. Overall survival (OS), progression-free survival (PFS), distant metastasis free survival (DMFS), and local recurrence free survival (LRFS) were evaluated by Kaplan-Meier method, log-rank test, and Cox models. Results: There were 37 patients in the TD+ group and 301 patients in the TD-group. The age of patients in the TD+ group was higher than that in the TD-group (median age 57 years vs 53 years, pZ0.029); patients in TD+ group were mostly middle(43.2%) and low(45.9%) rectal cancer, while mostly low rectal cancer(56.1%) in TD-group(pZ0.021). The median follow-up time was 64 months. The 5-year OS, PFS, and DMFS in the TD-group were higher than those in the TD+ group (p 0.001), and there was no significant difference in LRFS between the two groups(pZ0.679). The 5-year OS, DMFS, RFS, and PFS of pN2 patients (nZ68) in the TD-group were superior to those of the TD+ group (nZ34) (p<0.001). Administration of adjuvant chemotherapy and number of TDs did not influence the prognosis of these two groups (pZ0.103, pZ0.923, respectively). In multivariate analysis, TD is associated with a worse OS [HRZ2.343 (1.257-4.363), PZ0.007]. Conclusion: For patients with stage III rectal cancer undergoing multidisciplinary treatment (Chemoradiotherapy and surgery), TD+ patients have a worse prognosis. TD is an independent predictor of survival, while there is no benefit from postoperative adjuvant chemotherapy, regardless of the presence or absence of TD. Prospective randomized trials are expected to validate the impact of tumor deposit on the prognosis of patients with stage III rectal cancer and whether they benefit from postoperative adjuvant chemotherapy.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.