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Objective:To determine the safety of prophylactic irradiation dose CTV 60Gy optimized to CTV 50Gy for II b region in patients with stage N 0-N 1 nasopharyngeal carcinoma (NPC) and the dose advantage and clinical value for parotid gland protection, and to understand the diagnostic value of PET-CT and diffusion-weighted imaging (DWI) for suspicious positive lymph nodes in the neck (5 mm≤maximum short diameter<10 mm). Methods:Clinical data of 157 patients with primary non-metastatic NPC (N 0-N 1) admitted to our hospital from June 2015 to March 2017 were retrospectively analyzed. 104 patients underwent II b clinical target volume optimization guided by multimodal imaging system. Survival analysis was performed by Kaplan - Meier method. Univariate/multivariate regression analysis was performed to analyze the pattern of cervical lymph node recurrence. Paired t-test was used to compare the differences in target volume and parotid gland dose parameters before and after dose optimization. Results:Sixty patients underwent single-neck optimization in stage N 1, 25 patients received double-neck optimization (only those with retropharyngeal lymph node metastasis), and 19 patients underwent double-neck optimization in stage N 0. Three patients had cervical regional recurrence, all in-field. The 5-year overall survival rate was 93.3%. The lymph node recurrence-free survival rate, local recurrence-free survival rate, distant metastasis-free survival rate and disease-free survival rate were 97.1%, 91.3%, 88.5% and 80.8%, respectively. Cervical lymph node recurrence was associated with local recurrence in the nasopharynx, regardless of retropharyngeal lymph node status. Fourteen patients had suspicious positive cervical lymph nodes in II b region, with a mean maximum short diameter of 7.1 (5~9) mm on the largest cross-sectional plane, and 11 of them were positive on PET-CT, with a mean SUV max of 2.96 (2.5~3.3). There was no significant difference in GTV after optimization ( P>0.05). D mean, D max, D 50% and V 26Gy of parotid gland were significantly lower than those of conventional plan (all P<0.01). Conclusions:It is safe to optimize CTV 60Gy to CTV 50Gy in II b region in patients with N 0-N 1 NPC, and the exposure dose to normal tissues around the parotid gland and neck is significantly reduced. For small lymph nodes that do not meet the diagnostic criteria, it needs to be individualized in combination with multimodality imaging systems, such as PET-CT and DWI.
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Objective To analyze the features and diagnostic value of 3.0T multiparametric MRI for prostate cancer(PCa).Methods The clinical and MRI data of 48 patients with PCa and 52 patients with benign prostatic hyperplasia (BPH)were analyzed retrospectively. All patients underwent plain MRI,DWI,DCE-MRI and MRS.Results The PCa were hyperintensity on DWI and hypointensity on ADC,respectively.There was significant difference in the ADC values between the benign and malignant lesions.DWI using the high b-value was sensitivitive to diagnosing the PCa.The distribution of the S-I T was significant difference between the two groups.The SI-T curves of the PCa were type Ⅲ in 40 cases,type Ⅱ in 5 cases and type Ⅰ in 3 cases.The SI-T curves of the BPH were type Ⅰ in 27 cases,type Ⅱ in 23 cases and type Ⅲ in 2 cases.The peak value of choline (Cho)increased and citrate (Cit)decreased on MRS.The ratio of (Cho+Cre)value/Cit value of the PCa was increased.Conclusion DWI,DCE-MRI and MRS can present the specific findings of PCa.The combining application of the three technics could increase the accuracy in diagnosing PCa.
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Objective To clarify the diagnostic value of diffusion-weighed imaging ( DWI) in the medial group of retropharyngeal lymph nodes in nasopharyngeal carcinoma, understand the clinical characteristics of retropharyngeal lymph nodes and explore the feasibility of optimizing the target volume of CT V60. Methods Clinical data of 437 patients with clinical stage Ⅰ-IVa nasopharyngeal carcinoma admitted to Jiangsu Cancer Hospital from 2011 to 2017 were retrospectively analyzed. All patients underwent magnetic resonance imaging (MRI),DWI (1 000 s/mm2) and enhanced CT scans to analyze the clinical characteristics of retropharyngeal lymph nodes and investigate the dosimetric advantage and safety of CT V60 lower margin on the upper margin of C2. Results The medial lymph nodes with a transverse diameter of 2. 0-19. 0 mm were detected 13 of 437 patients,and 53. 8% of the lymph nodes were measured 2-5 mm in transverse diameter. The medial lymph nodes were distributed between the superior margin of C1and 1/3 of C3.Its occurrence was related to N stage,double cervical lymph node metastases,especially the transverse diameter of cervical lymph node＞ 3 cm.The sensitivity of DWI,T2and enhanced CT were 100%,61. 5% and 23. 1%.After the special cases were excluded,the lower margin of CT V60on the superior margin of C2was separated. The radiation dose and volume of the swallowing structures were significantly decreased. The 5-year survival rate was 80% without recurrence in the optimized region. Conclusions The incidence of the medial group of retropharyngeal lymph nodes is low with a diameter of less than 5 mm. DWI possesses advantages in displaying the medial group of retropharyngeal lymph nodes. Isolating the lower margin of CT V60from the superior margin of C2is safe and feasible and has dosimetric advantages for protecting swallowing structure.
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Objective To explore the correlation between apparent diffusion coefficient (ADC) and pathological grading and staging of cervical carcinoma.Methods Among 311 patients diagnosed with squamous cell carcinoma,87 patients were met the criteria for inclusion.All the patients were performed routine MR and diffusion-weighted imaging(DWI) with b=1 000 s/mm2 before treatments,and recorded the pathological grading and staging.The ADC values of the lesions were measured on GE AW4.5 workstation,and were compared among the groups with different pathological grading and staging by using LSD and paired t-test.Results The mean ADC value was (0.77±0.079)×10-3 mm2/s in the poorly-differentiated group,(0.88±0.10)×10-3 mm2/s in the moderately-differentiated group,and (1.05±0.084)×10-3 mm2/s in the well-differentiated group.There were significant differences among the different groups (P0.05).Conclusion The increasing of the ADC values is correlated with the high levels of tumor cell differentiation, and not correlated with the pathological stages in cervical carcinoma.
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Purpose To explore the ADC value in distinguishing prostate cancer (PCa) and benign prostatic hyperplasia (BPH) by reviewing related articles. Materials and Methods The studies about the diffusion-weighted images in distinguishing the prostate cancer and benign prostatic hyperplasia were enrolled from the websites of Elsevier Science, PubMed, Springer-Link, Wiley Online Library, Medline and CNKI from 2000 to 2011, with DWI, prostate, cancer, carcinoma and hyperplasia as search terms. According to the uniform inclusion and exclusion criteria, the correct studies were chosen and the parameters including the mean values and standard deviations of ADC value were extracted. Meta-analysis was done by using Stata 11 software. Results A total of 7 studies met the inclusion criteria, including 4 English articles and 3 Chinese articles. The fixed-effect model was used due to no heterogeneity. The standardized mean difference (SMD) was-1.357 and 95%confidence interval (95%CI) was (-1.604,-1.109, P=0.000). Conclusion DWI can be helpful in distinguishing the prostate cancer from the benign prostatic hyperplasia, and the ADC value of PCa is lower than that of BPH.
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Purpose To investigate the correlation between the brain white matter changes of MR diffusion tensor imaging (DTI) and cognitive function in the patients with mild cognitive impairment. Materials and Methods The patients (40 cases) were classified into two groups:group A (20 patients with ischemic foci in the deep white matter ) and group B (20 patients without ischemic foci in the deep white matter), and 20 normal controls was enrolled. Conventional MRI, DTI, mini-mental state examination (MMSE) and montreal cognitive assessment (MoCA) were applied, then fractional anisotropy (FA) value and apparent diffusion coefficient (ADC) value were compared among three groups. The scores of MoCA was analyzed between the patient groups. Results The decreased FA value, increased ADC value and decreased MoCA scores was demonstrate in group A, and showed significant difference compared with group B (t=-4.229,-3.251,-7.533,-2.702,-2.660;P<0.05). The increased ADC value and decreased FA value in the frontal and hippocampus region were detected in group B compared with normal controls (t=-7.790,-2.785,-4.415,-5.164;P<0.05). Conclusion The early and special structural changes can be detected using DTI compared with conventional MRI. The severe white matter lesions can be demonstrated in the patients with ischemic foci in the deep white matter, who is prone to dementia.
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Purpose To explore the correlation between whole body magnetic resonance diffusion-weighted imaging (WB-DWI) quantitative parameters of healthy adults' bone marrow with gender, age, height, weight, body mass index, and sex hormone levels. Materials and Methods 108 healthy adult subjects in different age groups underwent WB-DWI scan using GE 1.5T MR scanner, among them estradiol and progesterone levels were measured in 60 subjects within 48 hours before or after the scan. Apparent diffusion coefficient (ADC) values of bone marrow and the signal to noise ratio (SNR) were compared among different gender and age groups. Partial correlation analysis was used to evaluate the correlation of skeletal system ADC values and SNR with sex, age, height, weight, body mass index, estradiol and progesterone levels in 60 subjects. Results ADC values and SNR of the female subjects were significantly higher than males (P<0.01);there were significantly differences for skeletal system ADC values and SNR in different age groups (P<0.01). Skeletal system ADC values was significantly negatively correlated (r=-0.642, P<0.01) with age, and were mildly positively correlated (r=0.278, 0.271, P<0.05) with estradiol and progesterone levels;SNR was significantly negatively correlated (r=-0.709, P<0.01) with age, and was mildly positively correlated (r=0.293, P<0.05) with estradiol levels;ADC values and SNR had no significant correlation with height, weight and body mass index. Conclusion Skeletal system ADC values are effected by gender, age and sex hormone levels, the skeletal system WB-DWI manifestations are different in different gender and age groups.