Vitamin D participates in a variety of biological processes. 1,25-dihydroxyvitamin D [1,25-(OH)2D]is the active form of vitamin D. Besides its classical role in bone and calcium homeostasis, 1,25-(OH)2D has many non-classical functions such as regulating proliferation and differentiation of cells in various tissues, including tumor cells as well. However, the role of 1,25-(OH)2D in thyroid cancer is not clear yet. There are three integral components of the vitamin D pathway in thyroid cells. These components are the vitamin D receptor, 1α-hydroxylase (CYP27B1), and 24-hydroxylase (CYP24A1). Differences in the expression levels of these components in normal thyroid tissue and thyroid cancer tissue may offer clues and lay the foundation for study of the inhibitory function in the pathogenesis of thyroid cancer.This review focuses on the insights gained in the elucidation of the role of 1,25-(OH)2D pathway in thyroid cancer, one of the most common endocrine malignancies.

Objective The aim of this work is to compare the performances of EDR2 film dosimetry with two-dimensional ion chamber array (2DICA) in quality assurance (QA) procedures and to investigate the origin of possible discrepancies between the two methods.Methods A 2DICA, I′mRT MatriXX and MULTICube equivalent solid water phantom from IBA Company were used to verify the dose distribution of 15 tomotherapy plan cases.The combined phantom which includes EDR2 film on the array was set up to measure the dose distribution from coronal and sagittal orientations.After the irradiation, the dose distributions of 2DICA and film were compared with those calculated in the planning system for verification.The results and efficiency were evaluated independently in the two methods.Results The mean number of points satifying γ parameter ≤1 in the coronal and sagittal planes was 97.00%±1.56%& 95.98%±2.52%(t=-2.22,P=0.043) and 98.28%±1.55%& 95.42%±1.99%(t=0.75,P=0.464) of the 15 cases respectively for 2DICA and EDR2 film.The ratio of more than 90% and 95% were 93.3% and 66.7%.The results we presented show a very good agreement between the two methods when used to assess the dose distribution between calculated and measured doses,and a certain degree of correlation (r=0.14,P=0.001).Conclusions The 2DICA may effectively replace both film and ion chamber dosimetry in routine IMRT QA.The good agreement between 2DICA and EDR2 film may give a possible check regularly just as a gold standard.

Objective To investigate the feasibility of dose verification of intensity modulated (IM) planning of helical tomotherapy (HT) using two-dimensional ion chamber array (2DICA),and develop an efficient way to validate the dose delivered under the parameters mirroring those during the treatment. Meth-ods A 2DICA,I'mRT MatriXX and MULTICube equivalent solid water phantom from IBA company were used to verify the dose distribution of 10 IM planning. The combined phantom was set up to measure the dose distributions on coronal and sagittal surface. The precise setup of phantom was guided by HTMVCT images. After the irradiation, the measured dose distributions on the coronal and sngittal plane were compared with those calculated by the IM planning system for verification. The results were evaluated and the feasibility of the different measuring methods was studied. Results The dose distribution measured by the MatriXX 2DICA was well consistent with that calculated by the treatment planning system. The errors between the measured dose and predicted dose in the selected points were within ±3%. In the comparison of the pixel-segmented ionization chamber versus treatment planning system using the 3 mm/3% γ criteria, the passing ratio of pixels with γ parameter ≤1 was 97.76% and 96.83%, respectively. Conclusions MatriXX is a-ble to measure the absolute and relative dose distributions simultaneously,which can be used for dose verifi-cation of IM planning.

Objective To compare the dosimetric characteristics of helical tomotherapy(HT)and step-and-shoot intensity modulated radiotherapy(IMRT)for post-operative cervix cancer patients. Methods Ten patients with post-operative cervix cancer were enrolled in this study.HT and IMRT plans were developed for each patient.The dose distributions of the targets,organs at risk(OARs),CI and HI were analyzed and compared.The prescribed dose was 60 Gy/25 f for CTV1,50 Gy/25 f for CTV2.The iso-dose line of 50 Gy was used.Results The homogeneity indexes(HI)(0.94±0.03),conformity index(C1)(1.28±0.02)in HT group were better than in IMRT group(0.85±0.01 and 1.36±0.03),respectively(t=5.12,-6.34,P<0.001).The Dmean of PTV in HT group(51.77 Gy)was lower than that in IMRT group(54.53 Gy)(t=-8.01,P<0.05).The Dmax ,Dmean,V30,V40 and V50 of bladder、rectum and small bowel were lower in HT group than those in IM RT group.The Dmax,Dmean,V30 and V40 of right and left femoral head were lower in HT group than those in IMRT group.Conclusion Helical tomotherapy treatment plan has a better homogeneity,steeper dose gradient,and a better protection for organs at risk.

Objective To investigate the dosimetric characteristics of helical tomotherapy(HT),intensity-modulated radiation therapy(IMRT)and three.dimensional conformal radiation therapy(3D-CRT)for the post-operative breast cancer as well as their comparison in protecting the normal tissues.Methods The CT images of 10 postoperative patients with early stage breast cancer were transferRed into HT and IMRT and 3D- CRT planning system respectively after the target region and normal tissues were drawn out with the same doctor.Each prescribed dose for three kinds of plans was 50 Gy/25 fractions.Inrradiation doses and volume at heart and double lungs as well as conformity index(CI)and homogeneity index(HI)were evaluated.Results The PTV volume of prescribed target dose of 95% and 100%in HT, IMRT and 3D-CRT groups were 99.13%and 95.87%,97.80%and 94.05%,96.37%and 87.29%.respectively.The CI and HI in HT.IMRT and 3D-CRT groups were 0.80±0.10 and 1.09 ±0.03,0.65±0.07 and 1.14±0.02,0.40±0.08 and 1.17±0.04,respectively V5,V10 and V20 of the heart were the lowest at 3D-CRT than HT and lM RT.V5 of the diseased lung was the lowest at 3D-CRT compared to HT and IMRT.V5 and V10 of the healthy lung were the lowest at 3 D-CRT compared to other groups.Conclusions Compared with IMRT and 3D-CRT.HT technique in treating breast cancer had the best conformity index and homogeneity index as well as steeper dose gradient.Irradiated doses and volume at the heart was the lowest at 3D- CRT and the highest at IMRT.Irradiated doses and volume of the heart and healthy lung as well as the diseased lung were the lowest at 3D-CRT compared to HT and IMRT groups.

Objective To quantifying the urine human cytomegalovirus(HCMV)DNA from the HCMV infection infants and its corresponding liver function indications,and investigate the relationship between their concentrations.Methods The u-rine samples were collected from HCMV infection infants.HCMV DNA was measured by fluorescence quantitative polymer-ase chain reaction (FQ-PCR).Serum ALT,AST,ALP,GGT,T-Bil and D-Bil liver function indications were detected and the positive rate was analyzed,simultaneously.The correlation between the logarithm urine HCMV DNA (log HCMV DNA) concentration and ALT,AST,ALP,GGT,T-Bil and D-Bil were analyzed by Spearman correlation analysis.Results The dis-tribution range ofurine log HCMV DNA in 444 HCMV infection infants was <2.70~7.90;the positive rate of serum ALT, AST,ALP,GGT,T-Bil and D-Bil were 24.8%,59.0%,95.7%,31.1%,16.7% and 16.3%,respectively.The urine log HC-MV DNA was associated with GGT and the correlation coefficient was 0.099 (P < 0.05),but no associated with ALT, AST,ALP,T-Bil and D-Bil.Conclusion The positive rate of liver function indications will rise in HCMV infection infants, the urine log HCMV DNA was associated with GGT,but not associated with other liver function indications.

Objective To investigate the serum concentration of 25-hydroxyl vitamin D in the common autoimmune diseases and whether the differences of the 25-hydroxyl vitamin D level exist in different autoimmune diseases.Methods 137 cases of autoim-mune diseases,including 71 cases of rheumatoid arthritis(RA),36 cases of systemic lupus erythematosus(SLE),16 cases of Sjogren syndrome(SS)and 14 cases of ankylosing spondylitis(AS),in our hospital from January 2012 to April 2013 were selected as the re-spondents.The serum samples were collected for detecting the 25-hydroxyl vitamin D level by the electrochemiluminescence method and comparing the differences of the 25-hydroxyl vitamin D level among different autoimmune diseases.At the same time whether the differences in the proportion of the normal level,insufficiency and lack of 25-hydroxyl vitamin D exist among different kinds of disease.Results The serum 25-hydroxyl vitamin D concentration had statistically significant difference among the patients with dif-ferent autoimmune diseases(P =0.006),which in the RA group was significantly higher than that in the other groups;the propor-tion of 25-hydroxyl vitamin D insufficiency in RA,SLE,SS and AS were 29.6%,52.8%,62.5% and 57.1% respectively,which in the SLE,SS and AS groups was significantly higher than that in the RA group(P <0.05).Conclusion The 25-hydroxyl vitamin)D insufficiency is general in common autoimmune diseases,the vitamin D supplements needs to be strengthened.

To investigate the patient-specific dose verification method using ArcCHECK for total marrow irradiation (TMI) with Volumetric Modulated Arc Therapy (VMAT) and Helical Tomotherapy (HT). The kVCT images collected from 8 patients were respectively designed for RapidArc and Tomotherapy plans in total marrow irradiation. ArcCHECK was used for dose verification for the head-neck, chest-abdomen and pelvic. The merging function of ArcCHECK was used in VMAT and the method of double plans (reference and delivery plans) were used in HT. The γ-analysis passing rates for the head-neck, chest-abdomen, pelvic were 98.9% ± 1.9%, 98.4% ± 1.8%, 97.4% ± 2.1% for VMAT plans and 94.3% ± 1.5%, 96.5 ± 1.2%, 94.1% ± 1.9% for HT plans. The results show that using the merging function of ArcCHECK can achieve the dose verification well for VMAT plans with TMI. The method of double plans was done for the dose verification of HT plans with TMI as well as the plans with the targets keeping away from the set-up center.
Bone Marrow ; radiation effects ; Humans ; Radiotherapy Dosage ; Radiotherapy Planning, Computer-Assisted ; Radiotherapy, Intensity-Modulated

Objective: Quality assurance (QA) of intensity modulated radiotherapy (IMRT) dosimetry is a laborious task. The goal of this work is to evaluate the dosimetric characteristics of a new 2D diode array and assess the role it can play in routine MRT QA. Methods: A diode array, MapCHECK~(TM) and MapPHAN phantom from Sun Nuclear corporation (USC) were used for verifying the dose distribution of 10 tomotherapy IMRT plan cases. The combined phantom was set up to measure the dose distribution from coronal and sagittal orientations. After MVCT registration, the measured dose distributions of the coronal and sagittal planes were compared with those from calculation in the planning system. The results were evaluated by the absolute doses. The feasibility of the different measuring methods were studied. Results: The dose distribution measured by the MapCHECK~(TM) 2D array was well consistent with that calculated by tomotherapy planning system. In the comparison of the MapCHECK~(TM) measured versus planning system calculated using the 3mm/3% and 4mm/4% γ criteria, the number of detectors with γ parameter ≤ 1 was 96.8%/99.38% and 96.99%/99.49% average of the 10 cases respectively, for coronal and sagittal orientations. The acceptance criteria which is the combined 3mm/3% analysis would be introduced. And the number of points required to pass was generally 90%. Conclusions: MapCHECK~(TM) with MapPHAN phantom has been successfully tested for HT dose verification, and offers users an accurate and convenient rotational dosimetry solution.