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Objective:To evaluate the spatial position and functional parameters of 18F-FDG PET-CT and diffusion-weighted imaging (DWI) before and during radiotherapy (RT) based on the medium of 3DCT in patients with esophageal cancer and to explore whether the high-signal area derived from DWI can be used for individualized definition of the volume in need of dose-escalation for esophageal cancer. Methods:Thirty-two patients with esophageal cancer treated with concurrent chemoradiotherapy or neoadjuvant chemoradiation sequentially underwent repeated 3DCT, 18F-FDG PET-CT and enhanced MRI scans before RT and at the 15 th time of RT. All images were fused with the 3DCT images by deformable registration. The gross tumor volume (GTV) was delineated based on PET Edge on the first and second 3DCT, PET-CT and DWI and corresponding T 2-weighted MRI (T 2W-MRI) fused images, and defined as GTV CTpre and GTV CTdur, GTV PETpre, GTV PETdur, GTV DWIpre and GTV DWIdur, respectively. SUV (SUV max, SUV mean, SUV peak), MTV, TLG, ADC (ADC min and ADC mean) values and △SUV (△SUV max, △SUV mean, △SUV peak), △MTV, △TLG, △ADC (△ADC mean and △ADC min) of lesions were measured before and during RT. Results:The differences in SUV (SUV max, SUV mean, SUV peak), MTV, TLG, ADC mean and ADC min of the GTV before and during RT were statistically significant (all P<0.001). The tumor ADC and SUV values before and during RT showed no significant correlation, and there was no correlation between △ADC and △SUV (both P>0.05). The conformity index (CI) of GTV PETpre to GTV DWIpre was significantly higher than that of GTV PETdur to GTV DWIdur ( P<0.001). The shrinkage rate of maximum diameter (△LD DWI)(24%) and the shrinkage rate of tumor volume (VRR DWI)(60%) based on DWI during RT were significantly greater than the corresponding PET-based △LD PET (14%) and VRR PET (41%)( P=0.017 and P<0.001). Conclusions:The location of high residual FDG uptake based on PET-CT yields poor spatial matching compared with the area with residual high signal based on DWI during RT. Tumor ADC and SUV values may play complementary roles as imaging markers for prediction of patterns of failure and for definition of the volume in need of dose-escalation. In addition, the shrinkage rates of tumor maximum diameter/volume based on DWI during RT are significantly faster than those based on PET-CT. Therefore, the feasibility of selecting boosting of the high signal area derived from DWI for individualized definition of the volume for esophageal cancer is not clear.
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Objective@#To investigate the predictive value of 18F-FDG PET-CT scan for occult lymph node metastasis in patients with stage ⅠA lung adenocarcinoma.@*Methods@#The image and pathological data of 272 patients with stage ⅠA lung adenocarcinoma from October 2006 to September 2015 were retrospectively analyzed. All patients underwent preoperative 18F-FDG PET-CT scan followed by lobectomy and systematic lymph node dissection. The correlation between occult lymph node metastasis and the maximum standardized uptake value (SUVmax) of primary tumor as well as other clinicopathological factors was analyzed to screen the risk factors of occult lymph node metastasis in stage ⅠA lung adenocarcinoma.@*Results@#Occult lymph node metastasis was detected in 50 patients (18.4%), with 24 (8.8%) patients of pN1 involvement and 26 (9.6%) of pN2 involvement. Among the 272 patients enrolled, 39 had pure ground glass nodule, 59 had part-solid nodule and 174 had solid nodule. All patients with pure ground glass nodule or nodule≤1 cm were pN0. For the 233 patients with part-solid and solid nodule, no lymph node metastasis was found in T1a stage (tumor length ≤1 cm). Primary tumor SUVmax (Z=-5.663, P<0.001), nodule type (χ2=21.586, P<0.001), tumor location (χ2= 12.790, P< 0.001), histological grade (χ2= 22.784, P< 0.001) and visceral pleural invasion (χ2=5.357, P=0.021) showed significant differences between occult lymph node metastasis group (pN+ ) and non-lymph node metastasis group (pN0). With SUVmax=2.405 as cut-off value, the sensitivity and specificity for predicting occult lymph node metastasis were 90.0% and 61.7%, the area under curve was 0.761(95%CI=0.700~0.823), and the negative predictive value was 95.8%. Multivariate analysis revealed that SUVmax >2.405 (P<0.001), central location (P=0.030) and higher histological grade (P=0.024) were independent predictors of occult lymph node metastasis.@*Conclusions@#For clinical stage ⅠA adenocarcinoma, primary tumor SUVmax > 2.405, central location and higher histological grade were independent risk factors for occult lymph node metastasis. Systematic lymph node dissection may be avoided in lung adenocarcinoma with pure ground glass density, tumor length ≤1 cm or SUVmax ≤ 2.405, due to the very low probability of nodal involvement.
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Charged particle radiation is one of the most precise approaches for external radiation right now. With a characteristic inverted depth?dose profile and a high?dose Bragg peak at the end of the range, charged particle radiation therapy can deliver a high dose of radiation to tumor without damages in tissue around the tumor. However, a shift of Bragg peak would result in severe consequences. Therefore, it is extremely important to monitor the radiation beam. Application of position emission tomography ( PET) in proton and heavy?ion radiation therapy makes it possible to get accurate radiation range and position of the particle beam, which improves the treatment accuracy of charged particle therapy. This paper introduces the current application of PET in position verification of charge particle range radiation therapy.
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Objective At present,nasopharyngeal carcinoma (NPC) is a head and neck cancer with special geographical distribution and biological behavior.Studies have shown that 18 F-FDG PET/CT parameters have certain prognostic values in patients with NPC in high-incidence areas.The aim of this study is to investigate the prognostic values of 18 F-FDG PET/CT parameters in patients with NPC in low-incidence areas.Methods The clinical data of 83 NPC patients who were diagnosed and treated in Beth Israel Medical Center, Albert Einstein Medical College from January 2003 to December 2013 were analyzed retrospectively.Based on 18 F-FDG PET/CT images,gross tumor volume (GTV) was delineated using the gradient method to obtain 18 F-FDG PET/CT parameters:maximum standardized uptake value (SUVmax ), metabolic tumor volume ( MTV),and total lesion glycolysis ( TLG).Results The number of patients followed was 37 at 3-years time.For all patients,the 3-year failure-free survival,locoregional relapse-free survival,and metastasis-free survival rates were 74%,88%,and 85%,respectively.The univariate analysis showed that SUVmax of the primary tumor (P=0.004) and TLG (P=0.014) were prognostic factors for 3-year locoregional relapse-free survival rate,and SUVmax of the primary tumor (P=0.024) and TLG (P=0.033) were prognostic factors for 3-year failure-free survival rate.The multivariate analysis showed that SUVmax of the primary tumor was the independent prognostic factor for 3-year failure-free survival rate. Conclusion SUVmax of the primary tumor before treatment is the independent prognostic factor for failure-free survival in patients with NPC.
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Objective To investigate the differences in position and volume between planning target volumes (PTV) based on positron emission tomography?computed tomography (PET?CT) images with an standardized uptake value ( SUV) no less than 2?5, 20% of the maximum SUV ( SUVmax ), or 25% of SUVmax , three?dimensional ( 3D ) CT, and four?dimensional ( 4D ) CT in thoracic esophageal cancer. Methods Eighteen patients with thoracic esophageal cancer sequentially received chest 3DCT, 4DCT, and [18F]fluoro?2?deoxy?D?glucose (FDG) PET?CT scans. PTV3D was obtained by conventional expansion of 3DCT images;PTV4D was obtained by fusion of target volumes from 10 phases of 4DCT images. The internal gross tumor volumes ( IGTV) , IGTVPET2.5 , IGTVPET20%, and IGTVPET25%, were generated based on PET?CT images with an SUV no less than 2?5, 20% of SUVmax , and 25% of SUVmax , respectively. These IGTVs were expanded longitudinally by 3?5 cm and radically by 1 cm to make PTVPET2.5 , PTVPET20%, and PTVPET25%, respectively. Results PTV3D was significantly larger than both PTV4D and PTVPET(P=0?000 -0?044), while there was no significant difference between PTV4D and PTVPET ( P= 0?216 -0?633 ) . The mutual degrees of inclusion ( DIs ) between PTV3D and PTV4D were 0?70 and 0?95, respectively, which were negatively correlated with 3D?Vector ( P=0?039). The mutual DIs between PTVPET2.5, PTVPET20%, and PTVPET25% were 0?74, 0?72, 0?78, 0?73, 0?77, and 0?70, respectively, which showed no correlation with 3D?Vector (P=0?150 -0?822). The mutual DIs between PTV3D and PTVPET were 0?86, 0?84, 0?88, 0?63, 0?67, and 0?59, respectively. Conclusions It is difficult to achieve complete volumetric overlap of PTVs based on 3DCT, 4DCT and PET?CT in thoracic esophageal cancer due to different target volume information. PET scan during free breathing should be used with caution to generate PTVs in thoracic esophageal cancer.
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Objective To investigate the value of 18F-FDG PET-CT in detection and accurate staging of extranodal non-Hodgkin lymphoma (NHL).Methods The results of PET-CT of 94 patients with NHL were retrospectively analyzed.The consistency of checking out lesions and accurate staging by PET-CT were compared with those by other imaging examination in extranodal NHL.Results 432 lesions were checked out by PET-CT, including 319 (73.8 ％) lymphoid tissues and organs with the average SUVmax of 13.4 (3.4-33.4), and 113 (26.2 ％) extranodal lesions with the average SUVmax of 13.5 (3.1-55.0).The detection consistent rate between CT and PET-CT for lymphoid tissues and lymph organ lesions was 95 ％, while the consistent rate of the extranodal lesions was only 54.9 ％.The detection rates of PET-CT for soft tissue, bone and gastrointestinal lesions were higher than those of CT, but the detection rate for the bone marrow lesion was lower than that for the bone marrow cytology.According to the results of PET-CT, the stages of 29 patients (31.0 ％) were re-adjusted, including up-regulated for 75.9 ％ (22/29) because of high detection rates of PET-CT for soft tissue and skeletal lesions, and down-regulated for 24.1％ (7/29) mainly due to the strong resolution capability of PET-CT for detection of non-neoplastic lymph nodes and spleen increasing or effusion.Conclusion 18F-FDG PET-CT can improve the detection rate of NHL extranodal lesions, especially for diffuse non-mass lesions in bone and soft tissues, which facilitates the accurate lymphoma staging.
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With the increase of the incidence and the refinement of clinical treatment,the clear preoperative staging and the assessment of tumor recurrence and metastasis of cervical cancer is particular important.Different results may be explained in the same tumor applied different methods of imaging examination,which influences the clinical diagnosis and treatment.So imaging examination plays a more and more important role in the assessment of preoperative staging and tumor recurrence.
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Objective To investigate the value of 18 F-fluorodeoxyglucose FDG) positron emission tomography (PET)-computed tomography (CT) in predicting the progression-free survival (PFS)and overall survival (OS) of patients with esophageal squamous cell carcinoma (ESCC) after threedimensional (3D) radiotherapy.Methods A retrospective analysis was performed on 98 ESCC patients,who underwent FDG PET-CT before 3D radiotherapy from 2004 to 2010,to investigate their 1-,3-,and 5-year PFS and OS rates.The relationship of maximum standard uptake value (SUVmax),mean SUV (SUVmean),metabolic target volume (MTV),length of primary tumor on PET-CT before radiotherapy,and number of tumors on PET with PFS and OS were analyzed.The SUVs and clinical data were analysed by independent samples t-test or Hotelling T2 test; the Kaplan-Meier method was used for calculating PFS and OS rates,and the Logrank test was used for survival difference analysis;the prognostic factors were analysed using the Cox proportional hazard model.Results The follow-up rate was 100％ ;56 patients were followed up for at least 3 years,and 27 for at 5 years.The SUVmax SUVmean and MTV of primary tumor,length of primary tumor on PET-CT before radiotherapy,and number of tumors on PET were correlated with PFS and OS (x2 =8.99-41.82,all P ＜ 0.01).The Cox regression analysis showed that PFS could be well predicted based on SUVmean (x2 =4.41,P =0.036,RR =1.398) and number of tumors on PET (x2 =6.79,P =0.009,RR =3.650) and that OS could be well predicted based on number of tumors on PET (x2 =5.03,P =0.025,RR =3.740).Conclusions When estimating the long-term response to precise radiotherapy in patients with ESCC,SUV mean and number of tumors on PET may be used to predict PFS,and number of tumors on PET may be used to predict OS.
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Objective To compare gross tumor volume (GTV) of nasopharyngeal carcinoma (NPC) according to MRI and FDG PET/CT and to investigated four fixed threshold methods to delineate the GTV using FDG PET/CT.Methods Fifty patients with primary biopsy-proven NPC were prospectively were enrolled into the study.FDG PET/CT scans and MRI were carried out within one week prior to pretreatment,respectively.The GTV was named GTV-MRI (GTV were delineated according to MRI),GTV-PETvis,GTV-PET30,GTV-PET40,GTV-PET50 (GTV was delineated according to the PET-based GTVs obtained by visual interpretationor,by percentage of the SUVmax (30％,40％,50％) thresholds,respectively).The differences were compared among the GTV-MRI,GTV-PETvis,GTV-PET30,GTV-PET40 and GTV-PET50 in different by Wilcoxon test.Results Of 50 patients,the median of volume descending order were: GTV-MRI 27.8 cm3,GTV-PETvis 22.2 cm3,GTV-PET30 22.7 cm3,GTV-PET40 14.4 cm3 and GTV-PET50 9.0 cm3.However,there was no significant difference between GTV-PETvis and GTV-PET30 (Z=-0.05,P=0.958),as well as GTV-MRI and GTV-PETvis or GTV-PET30 in 25 patients who were T1-2 stage (Z =-0.93,-0.93,P=0.353,O.353),the other GTVs were all different in 50 patients' (Z=-5.74-2.09,P =0.000-0.037).Conclusions All the GTVs delineated by the different methods of using FDG PET/CT were less than the GTV delineated by MRI.The potential advantages with the GTV-PETvis or GTV-PET30 delineated by FDG PET/CT are reduction of biological metabolic tumor volume in GTV delineation and reduction of the size of the GTV in NPC patients.
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ObjectiveTo investigate the application of non-contrast and contrast-enhanced 18FDG PET/CT in the delineation of gross tumor volume ( GTV ) of pancreatic cancer.MethodsBetween Jan.2008 and Dec.2009,twenty-one patients with unresectable locally advanced pancreatic cancer or recurrent pancreatic cancer after surgery in our hospital had both non-contrast CT and PET images acquired at the same body position.Among the whole group,eleven patients also had contrast CT images.The image data sets were transferred to the treatment planning workstation for registration.Then gross tumor volumes ( GTV )were delineated independently using the information of PET images,contrast/non-contrast CT scan and contrast/non-contrast PET-CT fusion images.The differences of mean volume in these different sets of GTV were analyzed.Results For the whole group,the mean volume of non-contrast GTVCT,GTVPET,noncontrast GTVPET-CT were 76.9 cm3,47.0 cm3 and 44.5 cm3,respectively.The mean volume of non-contrast GTVPET-CT was significantly smaller than non-contrast GTVCT ( z =-3.91,P =0.000 ).For the eleven patients with contrast CT,the mean volume of contrast GTVCT,GTVPET,contrast GTVPET-CT were 64.1 cm3,45.1 cm3 and 49.3 cm3,respectively.The mean volume of contrast GTVPET-CT was significantly smaller than contrast GTVCT (z =-2.13,P =0.033 ).No significant differences were found between contrast PET-CT and non-contrast PET-CT (z =-0.80,P =0.424).ConclusionsCo-registration of PET and contrast/noncontrast CT information in pancreatic cancer may improve the accuracy of GTV delineation,and possibly reduce the adverse effect of irradiation.
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Purpose: The purpose of the study was to investigate the diagnostic value of SPECT, PET and PET/CT in the diagnosis of coronary artery disease, based on a systematic review. Material and Methods: A search of PubMed/Medline and Sciencedirect databases in the English-language literature published over the last 24 years was performed. Only studies with at least 10 patients comparing SPECT, PET or combined PET/CT with invasive coronary angiography in the diagnosis of coronary artery disease (50% stenosis) were included for analysis. Sensitivities and specificities estimates pooled across studies were analysed using a Chisquare test. Results: Twenty-five studies met the selection criteria and were included for the analysis. Ten studies were performed with SPECT alone; while another six studies were performed with PET alone. Five studies were carried out with both PET and SPECT modalities, and the remaining four studies were investigated with integrated PET-CT. The mean value of sensitivity, specificity and accuracy of these imaging modalities for the diagnosis of coronary artery disease was 82% (95%CI: 76 to 88), 76% (95%CI: 70 to 82) and 83% (95%CI: 77 to 89) for SPECT; 91% (95%CI: 85 to 97), 89% (95%CI: 83 to 95) and 89% (95%CI: 83 to 95) for PET; and 85% (95%CI: 79 to 90), 83% (95%CI: 77 to 89) and 88% (95%CI: 82 to 94) for PET/CT, respectively. The diagnostic accuracy of these imaging modalities was dependent on the radiotracers used in these studies, with ammonia resulting in the highest diagnostic value. Conclusion: Our review shows that PET has high diagnostic value for diagnosing coronary artery disease, and this indicates that it is a valuable technique for both detection and prediction of coronary artery disease.
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Objectives: To determine the clinical, imaging and pathological findings of Paget’s disease of the breast. Materials and methods: Approval by Institutional Review Board was granted and informed consent was waived. Retrospective review of the pathological diagnosis of 2,361 women with breast carcinoma between January 2004 and April 2010 revealed 27 patients with Paget’s disease of the breast. The clinical, mammographic and ultrasonographic images were retrospectively reviewed. Results: The prevalence of Paget’s disease of the breast was 1.14% of all breast carcinoma at this institution. Of the 27 patients with Paget’s disease, only 16 had imaging studies and this group constituted the basis of this study. All 16 patients were women, with ages ranging from 36–68 years (mean age 50.31 years). Eleven patients presented with clinical findings suggestive of Paget’s disease of the breast. Seven of these 11 patients also had associated palpable mass(es). Four patients presented with a palpable mass alone and one presented with bloody nipple discharge alone. Mammography was performed in all 16 patients and ultrasonography (US) in 15 patients. Of the 16 mammographic studies, two were negative. Of the 15 US studies, three were negative. Of these three negative US studies, two also had negative mammography and one had pleomorphic microcalcifications on mammogram. US was helpful in detecting multifocality in two patients. Mammography was 100% positive in patients who presented with palpable breast mass(es) and bloody nipple discharge, but 50% positive in patients who had clinically suggestive Paget’s disease alone. Almost all patients (15/16) had underlying breast malignancies. Seven patients had multifocality or multicentricity. Modified radical mastectomy was performed in 13 patients, simple mastectomy in two, and wide local excision in one patient. Pathological findings were ductal carcinoma in situ (DCIS) (n = 3), invasive ductal carcinoma (IDC) (n = 10), metaplastic carcinoma (n = 1), invasive lobular carcinoma (ILC) (n = 1), and only Paget’s disease of the nipple without underlying breast carcinoma (n = 1). Conclusion: Patients with Paget’s disease of the breast have a high incidence of an underlying breast carcinoma. Most of the patients in this study presented late and were more likely to have positive mammograms. Mammography should be performed to identify the underlying breast carcinoma. Those who have only nipple areolar changes and no palpable mass have less positive mammography and less invasive carcinoma.
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ObjectiveTo investigate prognostic factors in Stage Ⅲ non-small cell lung cancer (NSCLC)treated with definitive radiation therapy (RT) with PET-CT-based radiotherapy planning. MethodsFifty nine patients with Stage Ⅲ NSCLC treated with radiation therapy of 60 Gy or more were enrolled into this study.The impact of prognostic factors on survival was evaluated by univariate and multivariate analyses. Results The following-up rate was 98％.Nineteen patients completed 2 years' followed-up. The overall l-year and 2-year survival rate was 66％ and 37％, respectively, with a median survival time of 17 months. At a univariate analysis, cigarette smoking status, T stage, radiation dose, the standardized uptake value, the gross tumor volume and clinical stage were significant prognostic factors ( x2 =7.46,7. 52,8.37,4. 97,5.82,4. 37, P =0. 006,0. 006,0. 004,0. 026,0. 016,0. 037, respectively ).At multivariate analyses, cigarette smoking status, radiation dose, gross tumor volume and clinical stage were significant prognostic factors ( x2 =6. 20, 9. 69, 6. 39, 10. 09, P =0. 013,0. 002, 0. 011,0. 001,respectively). Conclusions Cigarette smoking status, radiation dose, gross tumor volume and clinical stage are significant prognostic factors on survival in patients with Stage Ⅲ NSCLC treated with RT based on PET-CT radiotherapy planning.
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Objective To analyse the long-term result and prognosis of 18 FDG PET/CT positioning three - dimensional conformal radiotherapy ( 3 DCRT ) for stage Ⅲ non - small cell lung cancer. Methods Sixty-four cases with stage Ⅲ non-small cell lung cancer (clinical stage Ⅲa- Ⅲb ) were randomly divided into two groups: PET/CT positioning three-dimensional conformal radiotherapy group (PET/CT group) and the conventional CT positioning three-dimensional conformal radiotherapy group (conventional CT group). In the PET/CT group, the target volume and critical organs were sketched according to PET/CT after fusion of the PET and the CT images; the treatment plan was worked out, then conventional fractionated 3DCRT ( total dosage around 40 Gy) followed by field-shrinked radiotherapy to a total dose of 65 Gy or sowas performed ;in the conventional CT group, the target volume and critical organs were sketched according to CT and 3DCRT were performed to the same total dose; All cases were treated with the TP scheme (paclitaxel 175 mg/m2,d1 ,cisplatin 40 mg,d2-4) adjuvant chemotherapy for 6 cycles after the radiotherapy. Results The followup rate was 100%. The number of patients who completed the 1-,2-and 5-year follow-up were 40,20 and 11 respectively ;The number of patients of the PET/CT group and conventional CT group were 23 and 17,11 and 9,7 and 4 respectively. Target volumes of 13 cases in the PET/CT group were changed. The complete remission and partial remission rates of the two groups were 13% 、66% and 19% 、53% (x2 = 0. 33, P =0. 564), respectively. The 1-,2-and 3-year local control rates of the PET/CT group and conventional CT group were84 % 、66% 、53 % an d72% 、59% 、44% ( x2 = 2.36, P = 0. 124 ) respectively. The1 -, 2-and 3-year survival rates were 72% 、34% 、22% and 53% 、28% 、13% (x2 =2. 46,P =0. 117) respectively. The level-1 and level-2 lungs' and trachea's late radiation injury of the PET/CT group and the conventional CT group were 28% and 53% ( x2 = 4. 14, P = 0. 042 ), respectively. The hilar and mediastinal lymph node recurrence rates of the PET/CT group were lower than those of the conventional CT group, were 3% ,25%(P = 0. 026) and 6%, 28% ( P = 0. 042 ), respectively. The main reason for treatment failure was distant metastasis both in the PET/CT group and conventional CT group,56% and 47% (x2 = 0. 56,P = 0. 453 ),respectively. Conclusions PET/CT, as a method of sketching the target of stage Ⅲ non-small cell lung cancer, can improve the radiation treatment plan, reduce the recurrence rate of hilar and mediastinal lymph nodes, meanwhile it can not improve the long-term survival rate; Distant metastasis was the main reason of failure.
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Objective To establish a optimal method and threshold of 3-deoxy-3-fluorothymidine (FLT) PET-CT in delineating the biological target length of gross tumor in esophageal carcinoma, and to compare FLT PET-CT with other imaging modalities including esophagoseopy, esophagography, CT and flu-orodeoxyglucose (FDG) PET-CT. Methods Twenty-four patients with esophageal squamous cell carcinoma treated with radical surgery were enrolled. Before surgery, all the patients underwent FLT PET-CT, esepha-goscopy and esophagography. Twenty-two patients also received FDG PET-CT scan. Gross tumor volumes (GTV) were delineated using seven different threshold of FLT PET-CT: visual interpretation, standardized uptake value (SUV) 1.3, SUV 1.4, SUV 1.5, 20% of maximum standard uptake value (SUV_(max)), 25% SUV_(max), and 30% SUV_(max). Three different thresholds of FDG PET-CT were used, including visual interpre-tation, SUV 2.5, and 40% SUV_(max). The length of tumors on FLT PET-CT scan were measured and recorded as L_(FLTvis), L_(FLT1.3), L_(FLT1.4), L_(FLT1.5), L_(FLT20%), L_(FLT25%), and L_(FLT30%), respectively. The length of tumors on FDG PET-CT scan were recorded as L_(FDGvis), L_(FDG2.5), and L_(FDG40%), respectively. The length of tumors on CT, esophagography and esophagoscopy were recorded as L_(CT), L_(X-ray) and L_(Scopy). All of these results were com-pared with the length of gross tumor in the reseeted specimen measured by pathological examination (L_(Path)), Results The L_(Path) was (4.90±2.14) cm. The Length of tumors delineated by different methods, being from short to long, were L_(FDG40%), L_(Scopy), L_(X-ray),L_(FLT1.5),L_(CT),L_(FLT30%),L_(FLTvis),L_(FLT1.4),L_(FLT25%), L_(FDG2.5),L_(FDGvis),L_(FLT1.3),L_(FLT20%). The mean values were (3.85±1.52), (4.46±2.23), (4.63± 2.37), (4.64±2.38),(4.69± 1.85),(4.75±2.19) ,(4.85±2.33),(4.87±2.35),(5.05±2.20), (5.08± 2.19) ,(5.10±2.22), (5.21±2.40) and (5.53±2.17) cm,respectively. The correlation coefficients were 0.91,0.93,0.88, 0.95, 0.90, 0.81,0.96, 0.96, 0.80, 0.99, 0.99, 0.95 and 0. 79 , respective-ly. All the P values were 0. 000. L_(FLT1.4) of FLT PET-CT and L_(FDG2.5) of FDG PET-CT were found more ap-proximate to L_(Path). There was no significant difference between L_(FLT1.4) and L_(FDG2.5) (1= 1.23, P = 0.232), and the correlation coefficient was 0.96 (P = 0. 000). Conclusions Thresholds of SUV 1.4 on FLT PET-CT and SUV 2.5 on FDG PET-CT could optimally estimate the tumor length measured by pathological examina-tion, and could be objective and simple methods for semiquantitative analysis.
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Objective To evaluate the prognostic value of fluorodeoxyglucose (FDG) standardized uptake value (SUV) of positron emission tomography (PET) before radiotherapy in non-small cell lung cancer (NSCLC) treated with three-dimensional conformal radiation therapy (3DCRT). Methods Seventy-three patients with stage Ⅲ NSCLC underwent PET to calculate SUV within 2 weeks before 3DCRT. The a-nalysis was carried out after the irradiation of 60 -66 Gy. The possible prognostic factors were assessed by Cox proportional hazards model. Results The mean SUV for squamous cell carcinoma, adenocarcinoma and others were 16.94, 14.40 and 6.33, respectively (F = 0. 51, P = 0. 604). The mean SUV for tumor volume less than and more than 50 cm~3 was 13.81 and 20.18 (F = 7.54, P = 0. 008). In the univariate analysis, a cutoff SUV of 17 and chemotherapy were correlated with the prognosis. In the multivariate analysis, SUV was the only independent prognostic factor (relative risk = 2.61). Conclusions SUV is a prognostic factor in patients with NSCLC treated by 3DCRT, which deserves further studies.
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Objective To investigate the value of PET-CT in TNM staging and three-conformal radiotherapy (3DCRT) in esophageal carcinoma. Methods From September 2007 to November 2008, 20 patients with pathologically confirmed esophageal carcinoma were enrolled, including 2 treated with surgery and 18 with 3DCRT. All the patients received PET-CT simulation before the treatment. The length and maximum transverse diameter of Grit based on esophagoscope, esophagography, CT, PET-CT_(SUV2.5) and PET-CT_(40%SUVmax) were compared. The TNM stages were compared based on CT and PET-CT images. Three treatment plans were produced and analyzed based on images of CT, PET-CT_(SUV2.5) and PET-CT_(40%SUVmax),respectively. Results The length of lesion on esophagoscope, esophagography, CT, PET-CT_(SUV2.5) and PET-CT_(40%SUVmax) was 4. 93 cm, 5.06 cm, 6. 67 cm, 5. 89 cm and 4. 84 cm, respectively. The corresponding maximum transverse diameter on the last 3 images was 4. 05 cm, 3.38 cm and 2. 95 cm, respectively. In all, 31, 21 and 14 positive lymph nodes were identified according to CT images, PET-CT images and the both. Five patients with CT diagnosed stage M_0 were found to have distant metastasis by PET-CT images, and 1 patient with CT diagnosed stage M_1 was excluded by PET-CT. The volumes of GTV_(CT) were similar with GTV_(SUV2.5) in 2 patients, smaller in 5 patients, and larger for the remaining 13 patients. For these 13 patients, the radiation dose of normal tissues based on GTV_(SUV2.5) was relatively lower. Conclusions The length of lesion based on PET -CT_(SUV2.5) matches the pathological length best , followed by esophagography. With PET-CT_(40%SUVmax) the actual lesion length may be underestimated. TNM stage might be changed by PET-CT, and then the target volumes and radiation doses of normal tissues might be reduced.
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Objective To determine the prognostic value of standardized uptake value(SUV)of fluorodeoxyglucose(FDG)by positron emission tomography and computed tomography(PET-CT)in nonsmall cell lung cancer(NSCLC).Methods Forty-eight patients(39 male,9 female)with stage ⅢNSCLC were reviewed.All patients had at least two repeated FDG PET-CT scans either before and after therapy and the maximum standardized uptake value(SUVmax)of the primary lung lesion was calculated. Resuits Of the 45 eligible patients,after a median follow-up of 22.5 months(rang,13 to 35 months),24 patients had local and regional recurrenee or metastasis and 21 remain disease-free.The mean SUVmax of patients who had local recurrence or metastasis before and after treatment was 12.30±3.17 and 5.35±2.29,respectively.The mean SUVmax of patients who had no loeal recurrence or metastasis before and after treatment was 8.46±3.00 and 2.82±0.63,respectively.Significant differences(tbefore=4.15,Pbefore＜0.01;Pafter=4.88,Pafter＜0.01)in SUVmax were observed either before and after treatment.However,the percent change of SUVmax between pretreatment and post-treatment were not significiantly different(t=1.99,P＞0.05).Using the SUVbefore of 9.0 yielded 92% sensitivity,62% specificity,73% positive predictive value and 87%negaffve Dredictive value in predicting regional recurrence or metastasis. While using the SUVafter of 4.3 yielded 71% sensitivity,100% specificity,100% positive predictive valne and 72% negative Dredictive value. Conclusions PET-CT may have the potientials to predict response to therapy and the SUVmax is a significant predictor for recurrent or metastasis in patients of NSCLC.
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Objective To evaluate the clinical value of 18-fluoro-deoxyglucose positron emission tomography-CT(~(18)FDG PET-CT) for recurrence and metastasis in treated esophageal carcinoma (EC). Methods A retrospective study is done on 37 previously treated EC patients who underwent PET-CT scans to detect recurrent or metastatic lesions.The diagnostic accuracy of ~(18)FDG PET-CT was assessed with the help of pathological finding as well as clinical or follow-up data.Results Fourty-six sites of recurrence were finally confirmed in 37 patients by cytology,pathology or follow-up data.The sensitivity,specificity and accuracy of PET-CT in detecting recurrence of all sites were 93.5% (43/46),76.9% (20/26) and 87.5% (63/72),respectively.Two false-positive findings were found both at the anastomosis and hilar nodes,which caused the decrease in the overall specificity,especially that locally.The analysis of standard uptake value (SUV) demonstrated that patients with recurrence or who died during follow-up had higher SU- Vs compared with the control group.Condusions ~(18)FDG PET-CT is highly effective in detecting recur- rence in previously treated EC patients despite the low specificity at local sites.The analysis of stardard up- take value(SUV) provides incremental value in prognosis for this patient cohart.
ABSTRACT
Objective Under different standard uptake value(SUV),to assess gross tumor volume (GTV) definition for non-small cell lung cancer(NSCLC) with 18-fluoro-deoxy-glucose positron emission tomography (~(18)FDG PET) both under definite threshold (42 percent threshold) and various relative threshold (threshold SUV/maximum SUV) derived from the linear regressive function,threshold SUV=0.307?(mean target SUV)+0.588,with computer tomography (CT).Methods Of 20 patients with non-small cell lung cancer,the CT GTV (GTV_(?)).PET GTV with 42 percents threshold (GTV_(42%)) and PET GTV with relative threshold (GTV_(?)) were obtained and compared.Results The mean GTV_(42%),,mean GTV_(?) and mean GTV_(CT) was (13 812.5?13 841.4),(24 325.3?22 454.7) and (28 350.9?26 079.8)mm~3,respectively,with the difference in mean GTV among these three methods significant (F =10,P＜0.01).The GTV_(42%) was smaller than the GTV_(?) and the GTV_(CT)(P＜0.01),with i(?)significant difference between GTV_(?) and GTV_(CT)(P=0.125).Conclusion The relative threshold is more suitable to define the gross tumor volume than the definite threshold.