Objective To evaluate 1*"H magnetic resonance spectroscopy (1H MRS) in the differentiating recurrent brain gliomas after radiation therapy from delayed cerebral necrosis. Methods Fifteen patients who had clinical and CT, MRI changes that suggested a diagnosis of delayed cerebral necrosis or recurrent brain tumor after radiation therapy and 5 patients who had a definite clinical diagnosis of delayed cerebral necrosis underwent single voxel MR spectroscopy simultaneously both in the lesion′s region and the contralateral side. Results Of the former 15 cases who proved by surgicopathology, 14 cases were gliomas,1case was delayed cerebral necrosis, and their etiologic diagnoses of 1*"H MRS were correct. (1)1H MRS in 14 cases with gliomas exhibited specific spectral peaks including prominent choline-containing compounds (Cho), decreased or absent acetylaspartate(NAA) and total creatine (Cr),and the metabolic ratios showed significantly increased Cho/Cr, decreased NAA/Cr. Twelve cases showed abnormal lactate (Lac). (2)Among 6 cases with delayed cerebral necrosis, 5 cases exhibited decreased or absent Cho, NAA, Cr, and abnormal Lipid, 1 case showed absent Cho, NAA, and Cr with a flat curve without Lac. Conclusion 1H MRS was positively claimed for differentiating recurrent brain gliomas after radiation therapy from delayed cerebral necrosis.

16?Gy) of STRS seems to reduce the incidence of rebleeding after radiosurgery. However,there is no histopathologic evidence of vascular obliteration in the resected CCA specimens after radiosurgery. The benefits and risks must be carefully balanced before the use of radiosurgery for cerebral cavernous hemangioma.

Objective To study the average ADC and eADC values in the C6 glioma regions and the contralateralnormal caudate nucleus of rat C6 glioma models on 3.0Tesla MR.Methods 32 healthy male Sprague-Dawley rats, weighted 250~300 g, were injected with C6 cells in right candate nucleus. All subjects were examined with MR imaging, including conventional and diffusion-weighted imaging with two b values ( 0 and 1000 s/mm~2 ) at 3.0T . ADC and eADC values were determined on ADC and eADC maps . Results The average ADC values in the C6 glioma regions and the contralateral normal caudate nucleus were(0.805?0.12)?10~ -3 mm~2/s and( 0.666?0.13 )?10~ -3 mm~2/s respectively ; the average eADC values in the C6 glioma regions and the contralateral normal caudate nucleus were (0.451?0.06) and (0.519?0.08) respectively. The difference of average ADC and eADC value between C6 glioma region and the contralateral normal caudate nucleus is significant. Conclusion It is feasible to do DWI in rat C6 glioma model with 3.0T MR and the ADC and eADC values measured in C6 glioma model can be used for reference in future studies.

Objective To study the correlations between MR imaging and histological classification of intracranial meningiomas.Methods MR imaging findings of 128 cases of intracranial meningiomas proved by operation and pathology were analyzed retrospectively.Results On T 1-weighted images,29(49%) meningothelial meningiomas were hypointense, 11(19%) were slightly hypointense and 17(29%) were isointense, while fibrours meningiomas were respectively in 23(59%),5(13%) and 9(23%). On T 2-weighted images, 34(58%) meningothelial meningiomas were hyperintense, 15(25%) were slightly hyperintense and 10(17%) were isointense, while fibrours meningiomas were in 2(5%),8(20.5%) and 11(28%) respectively. Most of the intracranial meningiomas such as meningothelial, fibrours and transitional were iso- and hypo-intense to the cortex on T 1-weighted imaging. On T 2-weighted imaging, meningothelial, angiomatous and transitional were hyperintense or slightly hyperintense, while fibrous tended to be hypointense or slightly hypointense. Conclusion The signals of meningiomas of different histologic type on T 1-weighted images are no significant different.On T 2-weighted images,there are significant correlation between signal intensity and tumor histology.

Objective To investigate the value of MR perfusion-weighted imaging(PWI)in the evaluation of therapeutic effect of brain metastases with gamma knife.Methods Treatment by gamma knife before and after that 3 months or 6 months PWI studies were penformed respectively in 22 patients with brain metastases .Maps of relative regional blood volume(rCBV)and mean transit time(MTT)were obtained.The ratios of rCBV and MTT of lesions were analyzed.Results rCBV of tumors in 22 cases was increased.The ratios of maximum rCBV of the lesions and opposite side were 6.16?3.12 and 1.18?0.17 respectively.The ratios of MTT of the tumors was 1.44?0.53.After gamma knife treatment,9 of 22 cases appeared decreased rCBV,but the ratios of MTT were no changing,of them,3 cases presented cerebral necrosis.13 of 22 cases,the ratios of rCBV were increased in varied degree after treatment by gamma knife,and 6 cases presented brain radionecrosis.Conclusion PWI is a significant method in evaluating the therapeutic effect of brain metastases with gamma knife

Objective To explore the value of MR spectroscopy in preoperative grading of astrocytic tumors.Methods 52 cases with astrocytomas proved by pathology,including 20 diffuse astrocytomas,14 anaplastic astrocytomas and 18 glioblastomas,underwent MR spectroscopy with multi-voxel PRESS sequence.Results ①Astrocytic tumors were characterized by increased Cho and decreased NAA,while Lipids were present in high-grade astrocytic tumors;②Cho/Cr(r＝0.656,P=0.000),Lip1.3/Cr(r＝0.559,P=0.001) and Glx/Cr(r＝0.482,P=0.005) in the solitary tumor's regions had a significant positive correlation with the grading of astrocytic tumors, while Cho/NAA(r＝0.395,P=0.025),Lip0.9/Cr(r＝0.386,P=0.029) had a positive correlation with the tmor grading;③When Cho/Cr＝2, the sensitivity, specificity,positive predictive value and negative predictive value for diagnosis of WHO4 astrocytic tumors were 94.4%,64.3%,77.3% and 90% respectively;④When Lip1.3/Cr＝0.526, the sensitivity, specificity,positive predictive value and negative predictive value for diagnosis of WHO4 astrocytic tumors were 88.9%,92.9%,94.1% and 86.7% respectively. Conclusion MR spectroscopy is helpful in preoperative grading of astrocytic tumors.

Objective:To study the pathological changes of nasopharyngeal carcinoma cases after the treat-ment of stereotactic radiosurgery. Method: 15 cases with recurrent or residual squamous cell carcinoma of na-sopharynx diagnosed as T1～4 N0M0 were selected,which had undergone previous radiotherapy. The patients weretreated by Gamma Knife while the isodose curve was 50％00 and the margin dose was 20 Gy. The nasopharynxbiopsy was performed before the treatment and 1,3,6,12 months after the treatment. The biopsy specimen wastaken to make a pathological examination. Result:①Before the Gamma Knife treatment, carcinoma cell could beseen in the tissue;②1～3 months after the treatment, cell necrosis and acute inflammation cell infiltration couldbe seen in the target ;③6～12 months after the treatment ,infiltration of chronic inflammation cell ,proliferation offibrous tissue and capillary could be found in the target. Conclusion:This research implies that the short-termpathological changes after the treatment of stereotactic radiosurgery can be defined as two phases ..The first phaseoccurs from 1 to 3 months after the treatment called necrosis period. The second phase occurs from 6 to 12months after the Gamma Knife treatment named as absorption period.

Objective:To evaluate the outcome and prognostic factors of conventional radiotherapy followed by intensity-modulated radiation therapy (IMRT) as a boost combined with chemotherapy in the treatment of high-grade gliomas (HGG). Methods:From Nov. 2004 to Nov. 2006, 112 HGG patients were treated with conventional radiotherapy followed by IMRT as a boost combined with chemotherapy. The radiotherapy regimen included first-course conventional radiotherapy and latE-course IMRT as a boost with the total radiation dosage of 57.5- 62.5Gy (27-29 fractions in 37-45 days). All the patients received chemotherapy. Sixty-three patients received temozolomidE-based chemotherapy and 49 patients received semustine plus teniposide chemotherapy. The treatment reaction was recorded. The overall survival rate and local progression-free survival rate were calculated. The prognostic factors were analyzed by using multivariate COX regression model. Results:The acute treatment toxicity was the most at grade 1 to grade 2 and no grade 4 adverse reaction was observed. Three cases had late radiation-induced brain necrosis. The overall 1-, 2-, and 3-year survival rates were 78.9%, 54.7%, and 30.8%, respectively. Multivariate analysis revealed that tumor location (P=0.001) and KPS score (P=0.011) were independent prognostic factors. The 1-, 2-, 3-year local progression-free survival rates were 63.8%, 38.9%, and 10.5%, respectively. Multivariate analysis revealed that tumor location (P=0.001), KPS score (P=0.001), and histologic type (P=0.005) were independent prognostic factors. Multivariate analysis did not reveal the significant correlation of temozolomide chemotherapy with the prognosis of the patients. Conclusion:Postoperative conventional radiotherapy followed by IMRT as a boost combined with chemotherapy has better short-term efficacy in the treatment of HGG and the adverse reaction is tolerable. KPS score, tumor location, and histologic type are important prognostic factors. Temozolomide chemotherapy is not associated with the prognosis of patients.

[Summary] 45 male SD rats with 4 week old were assigned to 3 groups after normal feedstuff for 2 weeks:control group(n=15), diabetic group(n=15), and calcitriol group(n=15).Diabetic rat model were induced using intraperitoneal injection with streptozotocin( STZ) after 12 h fasting.Calcitriol group and diabetic group were treated with calcitriol for 24 weeks.Femoral biomechanics indexes were measured at end of the study.Total 30 SD rats ( 10 rats of each groups) were analyzed.Compared to normal controls, the rats in diabetic group had lower body weight [(437.02±18.66vs267.93±15.64)g,P<0.05],decreasedserumcalciumconcentration[(2.89±0.31vs2.60 ±0.38) mmol/L, P<0.05], and increased serum phosphorus concentration[(2.21 ±0.35 vs 2.80 ±0.66) mmol/L, P<0.05].At the end of the study, the ultimate force[(98.07 ±2.94 vs 70.87 ±5.75) N, P<0.05], ultimate displacement[(0.66 ±0.02 vs 0.51 ±0.02) mm, P<0.05], Young′s modulus[(139 188.51 ±10 617.69 vs 81 969.06 ±6 393.21) N/mm2, P<0.05], and modulus for toughness[(22 492.59 ±2 429.15 vs 8 292.87 ± 1 291.43) N/mm2 , P<0.05 ] of diabetic group were significantly lower than normal control group.However, calcitrol could reverse these changes at some extent.SD rats with diabetes had significant disorder of bone metabolism and decreased bone strength.Calcitriol could improve the decreased bone strength in diabetic rats.

OBJECTIVETo explore the therapeutic alternatives and evaluate the related clinical results of patients with primary central nervous system lymphoma (PCNSL) treated with gamma knife radiosurgery (GKS).

METHODSFrom January 1995 to December 2001, 44 patients suffering from PCNSL, who had undergone stereotactic biopsy or craniotomy, and who had received a confirmed diagnosis through pathological examination, were treated with GKS. All cases were followed up for 1 - 46 months with an average postoperative period of 27 months. The clinical materials, image features, treatment methods and results of follow-up, were retrospectively reviewed.

RESULTSThe symptoms and signs of the patients were markedly improved within 1 - 3 weeks after GKS. The Kanofsky performance status was also improved from a preoperative average of 40% to a postoperative one of 90%. Thirty-eight patients (86.36%) were in complete remission (CR), the other six (13.63%) were in partial remission (PR). The local control rate reached 100%, and the median survival time was 26.5 months. The main side effect was brain edema, which can be treated with dexamethasone and mannitol.

CONCLUSIONGKS is a safe and effective method in multimodality treatment of PCNSL. A stereotactic biopsy coupled with GKS is the first choice for diagnosis and treatment. Adjuvant chemotherapy or radiotherapy should then be given according to the patient's condition.

Adult ; Aged ; Aged, 80 and over ; Brain Neoplasms ; surgery ; Combined Modality Therapy ; Female ; Humans ; Lymphoma ; surgery ; Male ; Middle Aged ; Radiosurgery ; Retrospective Studies ; Treatment Outcome