ABSTRACT
BACKGROUND@#Lung cancer is the leading cause of cancer-related death in China. The results from a randomized controlled trial using annual low-dose computed tomography (LDCT) in specific high-risk groups demonstrated a 20% reduction in lung cancer mortality. The aim of tihs study is to establish the China National lung cancer screening guidelines for clinical practice.@*METHODS@#The China lung cancer early detection and treatment expert group (CLCEDTEG) established the China National Lung Cancer Screening Guideline with multidisciplinary representation including 4 thoracic surgeons, 4 thoracic radiologists, 2 medical oncologists, 2 pulmonologists, 2 pathologist, and 2 epidemiologist. Members have engaged in interdisciplinary collaborations regarding lung cancer screening and clinical care of patients with at risk for lung cancer. The expert group reviewed the literature, including screening trials in the United States and Europe and China, and discussed local best clinical practices in the China. A consensus-based guidelines, China National Lung Cancer Screening Guideline (CNLCSG), was recommended by CLCEDTEG appointed by the National Health and Family Planning Commission, based on results of the National Lung Screening Trial, systematic review of evidence related to LDCT screening, and protocol of lung cancer screening program conducted in rural China.@*RESULTS@#Annual lung cancer screening with LDCT is recommended for high risk individuals aged 50-74 years who have at least a 20 pack-year smoking history and who currently smoke or have quit within the past five years. Individualized decision making should be conducted before LDCT screening. LDCT screening also represents an opportunity to educate patients as to the health risks of smoking; thus, education should be integrated into the screening process in order to assist smoking cessation.@*CONCLUSIONS@#A lung cancer screening guideline is recommended for the high-risk population in China. Additional research , including LDCT combined with biomarkers, is needed to optimize the approach to low-dose CT screening in the future.
Subject(s)
Aged , Female , Humans , Male , Middle Aged , China , Epidemiology , Early Detection of Cancer , Lung Neoplasms , Diagnostic Imaging , Epidemiology , Mass Screening , Patient Selection , Practice Guidelines as Topic , Radiation Dosage , Risk , Rural Population , Tomography, Spiral ComputedABSTRACT
Objective To investigate the feasibility and plan quality of the image-guided volumetric modulated arc therapy (VMAT) based voluntary deep exhale breath-holding technique in the stereotactic ablative body radiotherapy (SABR) for liver tumors.Methods Fifteen patients with liver tumors were involved in this study.All patients were immobilized with voluntary deep exhale breath hold (vDEBH) combined with real-time position management (RPM) respiratory gating system.Treatment was planned using VMAT with 2 modified partial arc and re-planned using intensity modulated radiation therapy (IMRT) technique for comparison.Dosimetric parameters were calculated for plan quality assessment.Quality assurance studies included absolute dose and multiple planar dose verifications,total monitor units and delivery time analysis.Daily cone beam computed tomography imaging was used to verify the motions.Results There were no significant dosimetric differences between VMAT and conventional IMRT plans (P ＞0.05).Both techniques were able to minimize doses to organs at risk including normal liver,kidneys,spinal cord,and stomach.However,the average monitor units with VMAT were significantly lower 28.1％ than those with IMRT(t =3.064,P ＜0.05).The average beam-on time in VMAT plans was 31.6％ shorter than that in IMRT plans(t =2.278,P ＜ 0.05).Conclusions The utilization of VMAT in the treatment planning of SABR for liver tumors under breath control mode has better dosimetrics.In comparison to conventional IMRT plans,VMAT plans have higher efficiency and feasibility.
ABSTRACT
Objective To analyze the radiation dose to contra-lateral breasts and estimate the incidence risk of contra-lateral breast cancer for women undergone unilateral breast cancer radiotherapy.Methods The radiation doses of contra-lateral breasts for 49 patients were counted and analyzed in a hospital,and the risk of contra-lateral breast cancer in different age groups that induced by radiotherapy was estimated based on BEIR Ⅶ model combined with the Chinese lifetime table.Results The prescribed doses for the patients were all 50 Gy.The mean dose to contra-lateral breasts ranged from 0.14 Gy to 3.59 Gy,with an average of (1.21 ±0.89) Gy,and the maximum point dose varied from 0.98 Gy to 45.27 Gy,with the average of (17.42 ±13.20) Gy.Both the maximum point dose and the mean dose obviously varied among the patients,and their correlation was significant (R =0.527,P =0.000).Furthermore,no significant differences of the mean dose was found among the ages (P ＞ 0.05).The lifetime attribute risks of contra-lateral breast cancer were estimated to be 2 449,1 857,994,446,173 and 55 for per 100 thousand women corresponding to the ages of 35,40,50,60,70 and 80,respectively.Conclusions In the radiotherapy for unilateral breast cancer,the dose delivered to the contra-lateral breast is about 1 Gy order of magnitude,the risk of contra-lateral breast cancer cannot be ignored for young women.Therefore,the irradiation dose of contra-lateral breasts should be controlled as less as possible in planning the treatment.
ABSTRACT
Objective To evaluate the performance of a customized vacuum-form body immobilization method in the radiotherapy of pelvic malignancies by comparing it with conventional approaches, thus to improve immobilization accuracy in the radiotherapy of pelvic malignancies. Methods A total of 66 patients with pelvic malignancies were enrolled in this study. These patients were divided into three groups according to three immobilization approaches: radiotherapy board ( Group N ) , conventional vacuum cushion ( Group V ) , and a customized vacuum cushion specifically for pelvic immobilization ( Group New-V) . Setup deviations of these immobilizations were comparatively evaluated by translational and rotational errors during intra-fractional measurements. Results The average translational setup errors in vertical(x), longitudinal(y), lateral(z) and rotational error r were (0. 35 ± 0. 37), (0. 21 ± 0. 22), (0. 29 ± 0. 28) cm and (0. 70 ± 0. 65)° for Group New-V; (0. 44 ± 0. 43), (0. 31 ± 0. 62), (0. 45 ± 0. 60) cm and (1. 25 ± 1. 00)° for Group N; (0. 38 ± 0. 36), (0. 27 ± 0. 25), (0. 32 ± 0. 29) cm and (1. 09 ± 0. 77)° for Group V, respectively. Significant differences were observed in r direction among these three method (F=7. 859,P <0. 05). Group New-V with customized cushion showed the least standard deviations in four directions and the least setup error in r direction compared with the other two method (F=3. 166,P<0. 05). Reconstructed dose distribution based on the isocenter shift result ed from setup errors revealed that Group New-V showed the least deviations in the minimum and mean dose and of the planning target volume (PTV) before and after isocenter shift(F=8. 018, P<0. 05). Conclusions The customized vacuum cushion provided best immobilization and dosimetric advantage. It helps to optimize the immobilization accuracy and improve the clinic outcome potentially.
ABSTRACT
Objective To evaluate three compartments of mediastinal anatomy in the diagnosis of space occupying lesions. Methods CT images of 78 mediastinal lesions confirmed by surgery or/and pathology were retrospectively studied. Results According to the occurrence ratio of occupying lesions, anterio superior mediastinal lesions were lymphadenovarix, thymoma, teratoblastoma, and intrathyroma, etc. In anterio inferior mediastinum, heart tumors, teratoblastoma, fatty tumor were found successively. Posterior mediastinal lesions were lymphadenovarix, neurogenic tumors, esophageal tumors, tracheo broncheal tumors, aneurysms, diaphrageal herniation and so on. Conclusion The results suggested that the mediastinal three compartments protocol was more terse and practical than others in the diagnosis of space occupying lesions before operation.