Objective This study evaluated the dosimetric consequences of selective partial salivary gland sparing during intensity-modulated radiotherapy(IMRT) for patients with nasopharyngeal carcinoma(NPC).Methods Ten patients...Objective This study evaluated the dosimetric consequences of selective partial salivary gland sparing during intensity-modulated radiotherapy(IMRT) for patients with nasopharyngeal carcinoma(NPC).Methods Ten patients with NPC were enrolled in the study.Two IMRT plans were produced for each patient:conventional(control) and partial salivary glands-sparing(treatment),with dose constraints to the entire parotid glands or partial salivary glands(including the parotid and submandibular glands,delineated with the adjacent distance of at least 0.5 cm between the glands and PTV,the planning target volume) in planning,respectively.Dosimetric parameters were compared between the two plans,including the V_(110%),V_(100%),V_(95%)(the volume covered by more than 110%,100%,or 95% of the prescribed dose),Dmin(the minimum dose) of PTV,homogeneity index(HI),conformity index(CI),and the mean dose and percentage of the volume receiving 30 Gy or more(V_(30)) for the parotid glands and submandibular glands.Results Treatment plans had significantly lower mean doses and V_(30) to both the entire parotid glands and partial parotid glands than those in control plans.The mean doses to the partial submandibular glands were also significantly lower in treatment plans than in control plans.The PTV coverage was comparable between the two plans,as indicated by V_(100%),V_(95%),Dmin,CI,and HI.The doses to critical structures,including brainstem and spinal cord,were slightly but not significantly higher in treatment plans than in control plans.Conclusion A selective partial salivary gland-sparing approach reduces the doses to parotid and submandibular glands during IMRT,which may decrease the risk of post-radiation xerostomia while not compromising target dose coverage in patients with NPC.展开更多
The Russian wheat aphid （RWA）, Diuraphis noxia （Mordvilko） （Homoptera： Aphididae）, is a major pest of small grains. As with plant-feeding aphids in general, the interaction between RWA and host plants is govern...The Russian wheat aphid （RWA）, Diuraphis noxia （Mordvilko） （Homoptera： Aphididae）, is a major pest of small grains. As with plant-feeding aphids in general, the interaction between RWA and host plants is governed, on the insect side, by proteins and enzymes in saliva. In this work, we examined sequence variations in transcripts encoding proteins and enzymes of RWA salivary glands. We conducted reverse transcription - polymerase chain reaction in RWA biotypes 1 and 2 using primers derived from pea aphid orthologs, and cloned regions of 17 putative salivary gland transcripts. For four of the transcripts, we observed no difference in sequences between the two biotypes. For the other 13 transcripts, for example, the transcripts encoding sucrase, trehalase and protein C002, large amount of variations, both within each biotype and between the two biotypes, were observed. Usually the two biotypes shared only one variant, which was typically the most common variant in both biotypes. Most of the transcripts had more non-synonymous than synonymous codon changes among their variants. Our results offer possible molecular markers for distinguishing the two biotypes and insights into their evolution.展开更多
基金Supported by a grant from the Science and Technology Program Project Funds of Qianjiang(No.2014046)
文摘Objective This study evaluated the dosimetric consequences of selective partial salivary gland sparing during intensity-modulated radiotherapy(IMRT) for patients with nasopharyngeal carcinoma(NPC).Methods Ten patients with NPC were enrolled in the study.Two IMRT plans were produced for each patient:conventional(control) and partial salivary glands-sparing(treatment),with dose constraints to the entire parotid glands or partial salivary glands(including the parotid and submandibular glands,delineated with the adjacent distance of at least 0.5 cm between the glands and PTV,the planning target volume) in planning,respectively.Dosimetric parameters were compared between the two plans,including the V_(110%),V_(100%),V_(95%)(the volume covered by more than 110%,100%,or 95% of the prescribed dose),Dmin(the minimum dose) of PTV,homogeneity index(HI),conformity index(CI),and the mean dose and percentage of the volume receiving 30 Gy or more(V_(30)) for the parotid glands and submandibular glands.Results Treatment plans had significantly lower mean doses and V_(30) to both the entire parotid glands and partial parotid glands than those in control plans.The mean doses to the partial submandibular glands were also significantly lower in treatment plans than in control plans.The PTV coverage was comparable between the two plans,as indicated by V_(100%),V_(95%),Dmin,CI,and HI.The doses to critical structures,including brainstem and spinal cord,were slightly but not significantly higher in treatment plans than in control plans.Conclusion A selective partial salivary gland-sparing approach reduces the doses to parotid and submandibular glands during IMRT,which may decrease the risk of post-radiation xerostomia while not compromising target dose coverage in patients with NPC.
文摘The Russian wheat aphid （RWA）, Diuraphis noxia （Mordvilko） （Homoptera： Aphididae）, is a major pest of small grains. As with plant-feeding aphids in general, the interaction between RWA and host plants is governed, on the insect side, by proteins and enzymes in saliva. In this work, we examined sequence variations in transcripts encoding proteins and enzymes of RWA salivary glands. We conducted reverse transcription - polymerase chain reaction in RWA biotypes 1 and 2 using primers derived from pea aphid orthologs, and cloned regions of 17 putative salivary gland transcripts. For four of the transcripts, we observed no difference in sequences between the two biotypes. For the other 13 transcripts, for example, the transcripts encoding sucrase, trehalase and protein C002, large amount of variations, both within each biotype and between the two biotypes, were observed. Usually the two biotypes shared only one variant, which was typically the most common variant in both biotypes. Most of the transcripts had more non-synonymous than synonymous codon changes among their variants. Our results offer possible molecular markers for distinguishing the two biotypes and insights into their evolution.
