Reproducibility of contouring parotid gland using CT and MR images in radiotherapy for nasopharyngeal carcinoma / 国际肿瘤学杂志

Objective To investigate the reproducibility and consistency in contouring parotid gland volume based on computed tomography (CT) and magnetic resonance (MR) images in patients with nasopharyngeal carcinoma during radiotherapy.Methods Twenty-seven patients with nasopharyngeal cancer in Shandong Cancer Hospital from December 2012 to May 2013 were randomly enrolled and underwent intensified CT and MR imaging before radiotherapy.The parotid gland were contoured with unified standard on both CT and T1-MR images by 11 radiotherapists.Specifically,one radiotherapist sketched the parotid gland on CT and MR images for ten times as intra-group comparison,the other ten were asked to sketch the parotid gland on CT and MR images only once as inter-group comparison.The intra-and inter-group's variations of parotid gland volumes were analysed.Results The average volumes of intra-group on CT and MR images were (33.8 ±9.4) cm3(L),(33.2±7.6) cm3(R) and (24.4 ±7.6) cm3(L),(22.5 ±7.4) cm3(R).As well,for inter-group the average volumes were (34.6 ± 12.1) cm3 (L),(34.3 ± 9.0) cm3 (R) and (24.6 ± 7.6) cm3 (L),(23.2 ± 8.1) cm3(R),respectively.The volume variable ratios on CT images were (6.8 ± 1.5)％ (L),(6.3 ± 1.5) ％ (R) for intra-group and (18.0 ± 4.8) ％ (L),(17.4 ± 4.6) ％ (R) for inter-group.Similarly,the intra-and inter-group ratios for contouring on MR images reached (2.3 ±0.4)％ (L),(2.1 ±0.7)％ (R) and (4.7 ±0.7)％ (L),(5.0±0.6)％ (R),respectively.Conclusion Parotid gland contouring based on MR images has a better reproducibility and consistency than that based on CT images.It is beneficial to get a more objective and true indicator to estimate the radiation injury of parotid gland.

Association of T393C single nucleotide polymorphism of GNAS1 gene with non-valvular atrial fibrillation / 南方医科大学学报

<p><b>OBJECTIVE</b>To analyze the association between T393C single nucleotide polymorphism (SNP) of GNAS1 gene and non-valvular atrial fibrillation (AF) in Chinese Han patients.</p><p><b>METHODS</b>Ninety patients with non-valvular AF and 90 healthy subjects were examined for T393C SNP of GNAS1 gene using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). The allele genotypes and the distribution of allele frequencies were analyzed and compared between the two groups. The relationship between allele frequency distribution characteristics and the heart rate variability (HRV) were also studied for analysis of the association between T393C SNP of GNAS1 gene and the autonomic nervous activation in non-valvular AF.</p><p><b>RESULTS</b>The two groups showed a significant difference in the frequencies of genotypes of T393C SNP of GNAS1 gene and allele frequencies (P<0.01). CC genotype and T393C allele frequency were significantly increased in the case group. pNN50, LF, or LF/HF showed no significant difference between different genotypes (P<0.05).</p><p><b>CONCLUTIONS</b>The T393C SNP of GNAS1 gene is closely associated with non-valvular AF in Chinese Han patients.</p>

Dosimetric comparison of simulation treatment planning for thoracic esophageal carcinoma patients in contouring biological tumor volume with FLT and FDG PET-CT / 中华放射医学与防护杂志

Objective To investigate a feasibility of treatment planning in thoracic esophageal carcinoma with 3-deoxy-3-fluorothymidine (FLT) PET-CT and to compare with fluorodeoxyglucose (FDG) PET-CT based on dosimetric analysis.MethodsTwenty-two patients with esophageal squamous cell carcinoma detected by FLT and FDG PET-CT were enrolled.The gross tumor volumes ( GTV ),clinical target volume(CTV) and planning target volume ( PTV ) were delineated using treatment planning system of Philips Pinnacle3 based on the optimal threshold of FLT and FDG PET-CT respectively,and to make two groups simulation treatment planning.The parameters of dose-volume histograms in two groups planning were compared in the similar direction and ensuring prescribed dose line surround 95% target volume.Results The values of GTV,CTV and PTV in FLT PET-CT planning were less than those of FDG,that dose received by spinal cord in two planning were not significantly yet ( t = - 1.60,- 1.55,all P ＞ 0.05 ).While,the values in mean lung dose,V5,V10,V30,V40 and V50 of bilateral lung,mean heart dose,and V30 of heart in FLT PET-CT planning were significant lower than those of FDG( t = -5.442 - -2.637,all P ＜0.05).Conclusions Compared with FDG,FLT PET-CT based treatment planning brings potential benefits for lungs and heart.