Objective To investigate the prevalence of vitiligo in China through a multi-center and larse-population epidemiological survey.Methods A community-based survey was conducted in 6 cities from 6 provinces.Cluster sampling method was used.Subjects were required to fulfill the self-report questionnaires and received physical examination by dermatologists.EpiData and SPSS11.5 were utilized for statistical analysis. Results Totally,19 974 patients participated in this study,and 17 345 valid questionnaires were retrieved with a return rate of 86.84%.Of them,122 were found to have vitiligo.The prevalence and standardized prevalence of vitiligo was 0.70% and 0.56% in all patients,0.95% (75) and 0.69% in male patients and 0.50% (47) and O.45% in female patients.respectively.A significant elevation was observed in the prevalence of vitiligo in males than in females (P<0.01).The prevalence of vitiligo was increased with age and peaked in patients aging from 60 to 69 years and those over 70 years.The age at onset of vitiligo varied from 0 to 19 years in 21.85% of these patients,from 20 to 49 years in 47.05%.The most connnon type was focal vitiligo,which accounted for 36.06%,while the rarest type wag segmental type (2.46%).The pesitivity rate of family history of vitiligo was 9.84% in patients and 1.31% in community population (P<0.01).About 31.97% of the patients complained of negative influence of vitiligo on quality of life.Conclusions The standardized prevalence of vitiligo is 0.56%in 6 provinces from China.Males seem to have a higher prevalence of vifiligo than females.

Objective: To evaluate the clinical efficacy and side effects of cyberknife therapy in the treatment of retroperitoneal lymph node metastatic tumor. Methods: Among the 81 patients presenting with postoperative retroperitoneal lymph node metastases, 33 cases suffered from abdominal pain or low back pain, 7 had unilateral hydronephrosis and ureteral dilatation, and 8 developed unilateral or bilateral lower limb swelling. Using stereotactic radiotherapy with a cyberknife, DT was delivered at 33-45 Gy/3-6 F. The improvement of symptoms, objective tumor response rate, and irradiation-induced side effects were observed. Results: At 4 weeks after treatment, pain and swelling of the lower extremities were completely mitigated, and hydronephrosis was fully healed in all patients. Enhanced CT or MRI was performed every 2 to 3 months. After 6-month follow-up, the complete response (CR) rate was calculated as 77%(62/81), 21%(17/81) for the partial response (PR) rate, 3%(2/81) for the stable disease (SD) rate and the effective rate (CR+ PR) was 98%.No case progressed. The main side effect was intestinal injury, including grade 1 in 16%(13/81), grade 2 in 9%(7/81). Multivariate analysis demonstrated the CR rate was not correlated with the type of the primary tumor or the size of the tumor (P>0.05), but was significantly associated with the distance of>0.5 cm between the tumor and intestine and the BED (α/β=10)>70 Gy of the tumor irradiation (P<0.01). The incidence of irradiation-related side effects was correlated with the maximum diameter of tumor>5 cm and the distance of<0.5 cm between the tumor and intestine (P<0.01). Conclusion Cyberknife is an efficacious and safe approach in the treatment of retroperitoneal lymph node metastatic tumors.