Objective To investigate the relationship between the absorbed dose to the thyroid remnant and the outcome of m I ablation in patients after operation for DTC.Methods Seventy-two patients (14 males,58 females; age range:16-67 years,average age:(41±16) years) with DTC,prepared for thyroid remnant ablation,were prospectively recruited from September 2009 to September 2011.Scintigraphic images of the head and neck were serially acquired after oral administration of 3.7 GBq of 131I to assess the biokinetics of this tracer in thyroid remnant.Ultrasound was used to measure the mass of the thyroid remnant.Calculation of absorbed dose to thyroid remnant was based on the Medical Internal Radiation Dosimetry formula of the Society of Nuclear Medicine.The outcome of 131 I ablation was evaluated on the basis of stimulated Tg measurements and neck ultrasound at 6-9 months after ablation.Patients with stimulated Tg levels less than 1 μg/L and with no detectable thyroid tissue on neck ultrasound were considered successful ablation of thyroid remnant.Two-sample t test was used to analyze the data.Results The 131I uptake ratios at 24 h were 0.9％-6.3％ in 72 patients and the effective half-lives of 131I were 12.0-146.4 h.The thyroid remnant masses were 1.0-6.9 g; absorbed doses were 23-2 197 Gy,and absorbed dose rates at 24 h were 0.5-8.1 Gy/h.No significant difference was observed in absorbed doses to thyroid remnants in 43 patients having successful ablation and 29 patients having unsuccessful ablation ((363± 148) Gy vs (341± 167) Gy,t =15.097,P＞0.05).However,the absorbed dose-rates of thyroid remnants at 24 h were significantly higher in patients with successful ablation than those in patients with unsuccessful ablation ((3.7±2.1) Gy/h vs (2.9±1.6) Gy/h,t=7.908,P＜0.05).Conclusion A successful ablation is strongly dependent on the absorbed dose-rate of thyroid remnant.

Objective To compare the value of fine-needle aspiration cytology (FNAC),Tg,TgAb and ultrasonography (US) for the differential diagnosis of lymph node metastasis in patients with DTC after operation and radioactive iodine remnant ablation.Methods A total of 61 DTC patients with enlarged lymph nodes detected by US or physical examination after operation and radioactive iodine remnant ablation were included.FNAC was performed on the lymph nodes under US guidance within one week and the results were compared with those of Tg,TgAb and US.Final results were confirmed by comprehensive FNAC,posttreatment whole,body scan (Rx-WBS) and clinical follow-up.x2 test and Fisher's exact test were performed.Resuits Fifty-eight DTC patients had successful FNAC results,and 40 patients were confirmed as malignant and 18 as benign after overall assessment.FNAC identified 39 malignant and 19 benign cases.The coincidence rates of FNAC with postoperative pathological diagnosis and Rx-WBS for malignant cases were 100％ (20/20) and 78.9％ (15/19),respectively.For the benign cases,the coincidence rates of FNAC with clinical follow-up and Rx-WBS were 93.3％ (14/15)and 4/4,respectively.The sensitivity,specificity and accuracy were 97.5％(39/40),100％(18/18) and 98.3％(57/58) for FNAC; 87.5％(35/40),55.6％(10/18) and 77.6％(45/58) for US; 92.5％(37/40),72.2％(13/18) and 86.2％(50/58) for Tg combined with TgAb (Tg/TgAb).The accuracy of FNAC was higher than that of US and Tg/TgAb(x2 =4.336,11.697,both P＜0.05),while US and Tg/TgAb showed no significant difference (x2 =1.450,P＞0.05).Tg/TgAb and US results were consistent in 39 cases with a diagnostic accuracy of 97.4％ (38/39) verified by FNAC,while the other 19 cases with inconsistent Tg/TgAb and US results were verified as malignant in 4 cases and benign in 15 cases.Conclusions FNAC is superior to US and Tg/TgAb in the evaluation of lymph node metastasis in DTC patients after operation and radioactive iodine remnant ablation.FNAC should be recommended particularly when Tg/TgAb and US had inconsistent results.

Objective To prospectively investigate the optimal setting for sentinel lymph node biopsy (SLNB) in patients with breast cancer by comparing the effects of different preparation methods and injection sites of 99Tcm-SC in sentinel lymph node (SLN) mapping and detection.Methods Two batches of 99Tcm-SC were prepared by boiling for 3 min (radiotracer 1) and 5 min (radiotracer 2),respectively.Radioactive chemical purity (RCP) and size of colloid particles were measured at 10 min,1 h,2 h and 4 h after the preparation.One hundred and forty-seven patients with breast cancer were involved and randomly divided into 3 groups.Group A consisted of 40 patients with periareolar injection of radiotracer 1,group B of 40 patients with periareolar injection of radiotracer 2,and group C of 67 patients with peritumoral injection of radiotracer 2.Lymphatic mapping was performed for all patients using SPECT/CT preoperatively and blue dye was subdermally injected over the tumor.The detection rate of the axillary and internal mammary SLN was recorded.One-way analysis of variance,independent two-sample t and x2 tests were used to analyze the data.Results There was no significant difference of RCP between the two radiotracers at 10 min,1 h,2 h and 4 h after preparation (t =-0.267,-0.794,0.826 and-0.977,all P＞0.05).Compared with radiotracer 1,the percentage of particles smaller than 100 nm in radiotracer 2 reduced significantly ((73.72±2.36) ％ vs (65.25±3.56)％,t=6.436,P＜0.05) and the mean effective particle size was significantly larger ((45.27±6.42) nm vs (75.59t7.04) nm,t=7.315,P＜0.05).In groups A,B and C,the detection rate of the internal mammary SLN was 70.0％ (28/40),47.5％ (19/40) and 17.9％ (12/67),respectively,with significant difference (x2=29.525,P＜0.05).In groups A,B and C,the detection rate of the axillary SLN was 100％ (40/40),95.0％ (38/40) and 97.0％ (65/67),respectively,without significant difference (x2 =2.686,P＞ 0.05).Conclusion For SLNB of patients with breast cancer,the axillary and internal mammary SLN could be better detected by SPECT/CT lymphatic mapping using radiotracer prepared with a shorter boiling time,via periareolar injection,and combined with subdermal injection of blue dye.

Objective To compare the diagnostic efficacy of the V/Q scan and CT pulmonary angiography (CTPA) for the detection of acute pulmonary embolism (PE) in elderly patients.Methods Fortyfour patients (age ≥60 years old) with suspected acute PE underwent V/Q scan and CTPA.The diagnosis of PE by V/Q scan was based on the criteria of prospective investigation of PE diagnosis (PIOPED) Ⅱ and the prospective investigative study of acute PE diagnosis (PISA-PED).The final diagnosis was made clinically.The sensitivities,specificities and accuracies of PIOPED Ⅱ,PISA-PED,CTPA and Wills score were calculated and compared using x2 and Fisher's exact tests.Kappa analysis was used to analyze the diagnostic accordance rate of PIOPED Ⅱ and PISA-PED.Results The sensitivities of PIOPED Ⅱ,PISA-PED and CTPA in the diagnosis of PE were 70.00％ (14/20),84.62％ (22/26) and 65.22％ (15/23),respectively (x2 =0.069-1.545,all P＞0.05).The sensitivity of Wills score was significantly lower (23.08％,3/13).The specificity of CTPA (93.75％,15/16) was significantly higher than those of PIOPED lⅡ and PISAPED (80.00％,12/15 and 61.11％,11/18,both P＜0.05).The accuracies of PIOPED Ⅱ,PISA-PED and CTPA were 74.29％ (26/35),75.00％ (33/44) and 76.92％ (30/39),respectively (x2 =0.005-0.070,all P＞0.05).The accuracy of Wills score was significantly lower (52.17％,12/23).The diagnostic accordance rate of PIOPED Ⅱ and PISA-PED criteria was 77.14％(27/35),Kappa=0.547,P＜0.05.Conclusion V/Q scan and CTPA have no significant difference for the diagnosis of PE in the elderly patients.

DTC in pediatric and adolescent patients has lower incidence and is generally reported to have better prognosis.However,compared with DTC in adults,it is more aggressive and the recurrence rate is higher.Surgery and adjuvant radioiodine therapy can minimize the risk of recurrence.Total or near total thyroidectomy combined with central compartment lymph node dissection is the preferred surgical procedure for most of these patients.Radioiodine therapy for ablation of thyroidal remnant or residual disease is recommended in order to reduce the risk of tumor recurrence,but there is slight chance of increased risk of a sec ond primary malignancy (SPM).Long-term follow-up is therefore recommended for the pediatrics and adolescents with DTC after treatment.Multi-disciplinary collaborative management is needed to optimize treatment efficacy and to minimize adverse effects.

MicroRNAs (miRNAs) are a novel class of small noncoding RNAs that regulate gene expression by targeting mRNAs for either cleavage or translational repression.Accumulated studies show that miRNAs aberrantly expressed in tumors are closely related with tumorogenesis and could be potential tumor biomarkers.It will be helpful in the diagnosis,prognosis and(or) predicting treatment response of tumor by imaging miRNAs expression.Several molecular imaging methods,including the optical imaging,radionuclide imaging and multimodality imaging,have been successfully used to visualize miRNAs,miRNAs,a new molecular imaging target,may explore a new field for tumor diagnosis and therapy.

For patients with DTC,the side effect of 131I therapy on fertility and offspring is an important issue since genital tissues are highly sensitive to radiation.Exposure to 131 I radiation may result in transient impairment of gonadal function in male patients caused by elevated levels of serum follicle stimulating hormone and luteinizing hormone,low sperm count and motility.In female patients,exposure to 131I radiation may be complicated with delay of menstruation,oligomenorrhea and transient cessation of menstrual period.Most of these symptoms may resolve within one year after 131 I therapy.A slightly earlier menopause is the only reported long-term side effect of 131I therapy on ovarian function.Currently available data do not indicate that exposure to 131I may cause permanent infertility in male patients with DTC.For female patients with DTC,131 I therapy does not affect fertility or pregnancy outcomes beyond one year.

Objective To investigate the relationship between V-raf murine sarcoma viral oncogene homolog B1 (BRAF)v600E mutation and radioactive iodine (RAI) uptake in distant metastases from papillary thyroid cancer(PTC).Methods From January 2011 to December 2012,40 PTC patients (21 males,19 females,average age 39.8 years) with distant metastases were recruited and divided into mutation group and wild group according to the BRAFv600E mutation in primary lesions.The clinical,pathological and serological differences were compared between the two groups.The relationship between BRAFv600E mutation and RAI uptake capability in distant metastases from PTC,as well as its relationship with Tg change after 131I treatment were investigated.Statistical analysis was performed with two-sample t test,x2 test or Fisher exact test.Results The BRAFv600E mutation rate was 30.0％ (12/40) in patients with metastases from PTC.There was no significant difference in clinical,pathological and serological features between mutation group (n =12) and wild group (n=28; t:from-0.533 to 1.728,x2:from-1.951 to 1.088,all P＞0.05).Twelve PTC patients had no RAI uptake in the distant metastases,of which 10 belonged to mutation group (83.3％,10/12) and 2 belonged to wild group (7.1％,2/28; x2=19.734,P＜0.05).BRAFv600E mutation group was more likely to have no RAI uptake in the distant metastases.Tg change after 131I treatment in 30 patients were analyzed.In the wild group,Tg level decreased in 66.7％ (14/21) patients,stabilized in 19.0％ (4/21)and increased in 14.3％ (3/21)patients.While there was no decrease of Tg in the mutation group (0/9).Two patients had increased Tg level and 7 patients (with no RAI uptake) kept stable in mutation group.Conclusions Due to poor RAI uptake capability in PTC patients with BRAFv600E mutation,both primary and metastatic sites may have poor response to 131I treatment.Molecular detection of BRAFv600E mutation might be helpful for choosing PTC with distant metastases and predicting the effect of 131 I treatment.

Objective To establish a novel TRFIA for the measurement of heparanase (HPA) in serum samples,and investigate its clinical application.Methods The micro-pore plate wells were first coated with partially recombinant murine anti-human HPA monoclonal antibody.Biotin-labeled recombinant HPA protein was then used to compete with HPA in serum samples,and the prepared europium (III)-labeled streptavidin (Eu3+-SA) was used as signal readout for establishing the BSA-TRFIA assay.Using this assay,the serum HPA levels in healthy subjects (n=32) and tumor patients (n=54) were measured.The results of BSA-TRFIA were compared with those of ELISA.Two-sample t test (or t' test),and linear correlation analysis were used to analyze the data.Results The sensitivity of BSA-TRFIA for measuring HPA was 0.33 ug/L.The CV values for intra-batch and inter-batch were 5.29% and 7.54%,respectively.The average recovery rate was 105.5%.The standard curve range was 0-1 000 ug/L.The serum HPA level measured by the BSA-TRFIA method in healthy subjects was (2.03_+ 1.47) Iug/L.In tumor patients,the HPA level was significantly higher:(22.13_+7.38) ug/L (t'=19.388,P

Objective To synthesize 99Tcm-TP5-3 and evaluate its biodistribution and kinetics as a molecular probe for the detection of apoptosis,and evaluate tumor apoptosis after a single dose of paclitaxel chemotherapy in MDA-MB-231 breast tumor model.Methods TP5-3 was labeled with 99Tcm directly,and analyzed with HPLC.The radioactivity in tissues was measured and expressed as ％ID/g and T/NT (tumor/muscle).The mice bearing MDA-MB-231 breast tumor were divided into two groups:the treatment group which was given a single dose of paclitaxel (40 mg· kg-1,via tail vein),and the control group which was injected with the same volume of normal saline.After therapy,99Tcm-TP5-3 was injected via tail vein in both groups (100 μ1 for each mouse).MicroSPECT/CT was performed at 3 h postinjection.Radioactivity in different tissues was determined after imaging.Apoptotic cells were measured with flow cytometry.The morphological changes of the apoptotic cells were observed by light microscopies.One-way analysis of variance,two-sample t test and linear correlation analysis were used to analyze the data.Results The radiolabeling efficiency was ＞ 95％ and the radiochemical purity of 99Tcm-TP5-3 was (96.0± 1.5)％ at room temperature for 4 h.The predominant uptake was found in the kidneys at 30 min postinjection ((8.48± 1.07) ％ID/g),with rapid tracer clearance from the circulation.By comparison with activity at 5 min postinjection ((13.74± 4.21) ％ID/g),85％ of the initial activity reduced in blood at 4 h ((2.07±0.35) ％ID/g; F=11.310,P＜ 0.05).99Tcm-TP5-3 was mainly accumulated in the kidneys,liver and stomach,and excreted via the kidneys.T/NT in the treated group was 4.21±0.06,which was significantly higher than that of the control group (1.57±0.67; t =12.820,P＜0.05).The radioactivity of tumor tissue in the treatment group was much higher than that in the control group (4.82±0.54) ％ID/g vs (1.44±0.38) ％ID/g,t=0.679,P＜0.05).The tumor uptake of 99Tcm-TP5-3 in the treatment group positively correlated well with the apoptotic cells (r =0.985,P＜0.05).Histopathology further confirmed that a large number of apoptosis had occurred in the tumor after paclitaxel treatment.Conclusion 99Tcm-TP5-3 appears to have potential to be a useful molecular probe for imaging tumor cell apoptosis.