Clinical characteristics of Coronavirus Disease 2019 and development of a prediction model for prolonged hospital length of stay.

BACKGROUND: The epidemic of Coronavirus Disease 2019 (COVID-19) has become a global health emergency, but the clinical characteristics of COVID-19 are not fully described. We aimed to describe the clinical characteristics of COVID-19 outside of Wuhan city; and to develop a multivariate model to predict the risk of prolonged length of stay in hospital (ProLOS). METHODS: The study was conducted in a tertiary care hospital in Zhejiang province from January to February 20, 2020. Medical records of all confirmed cases of COVID-19 were retrospectively reviewed. Patients were categorized into the ProLOS and non-ProLOS groups by hospital length of stay greater and less than 14 days, respectively. Conventional descriptive statistics were applied. Multivariate regression model was built to predict the risk of ProLOS, with variables selected using stepwise approach. RESULTS: A total of 75 patients with confirmed COVID-19 were included for quantitative analysis, including 25 (33%) patients in the ProLOS group. ProLOS patients were more likely to have history of traveling to Wuhan (68% vs. 28%; P=0.002). Patients in the ProLOS group showed lower neutrophil counts [median (IQR): 2.50 (1.77-3.23) ×109/L vs. 2.90 (2.21-4.19) ×109/L; P=0.048], higher partial thrombin time (PT) (13.42±0.63 vs. 13.10±0.48 s; P=0.029), lower D-Dimer [0.26 (0.22-0.46) vs. 0.44 (0.32-0.84) mg/L; P=0.012]. There was no patient died and no severe case in our cohort. The overall LOS was 11 days (IQR, 5-15 days). The median cost for a hospital stay was 7,388.19 RMB (IQR, 5,085.39-11,145.44). The prediction model included five variables of procalcitonin, heart rate, epidemiological history, lymphocyte count and cough. The discrimination of the model was 84.8% (95% CI: 75.3% to 94.4%). CONCLUSIONS: Our study described clinical characteristics of COVID-19 outside of Wuhan city and found that the illness was less severe than that in the core epidemic region. A multivariate model was developed to predict ProLOS, which showed good discrimination.

CYP2E1 Rsa Ι/Pst Ι polymorphism and lung cancer susceptibility: A meta-analysis involving 10,947 subjects.

The above article, published in the Journal of Cellular and Molecular Medicine on 14 September 2016 in Wiley Online Library (wileyonlinelibrary.com), and in Volume 19, pp. 2136-2142, has been retracted by agreement between the authors, the journal Editor in Chief, Stefan Constantinescu, and John Wiley & Sons Ltd. The retraction has been agreed due to unattributed overlap of the language used in the "Materials and method" and "Discussion" sections of this study and the following article published in Lung Cancer: "CYP2E1 Rsa I/Pst I polymorphism is associated with lung cancer risk among Asians" by Ping Zhan, Jing Wang, Yu Zhang, Li-Xin Qiu, Su-feng Zhao, Qian Qian, Shu-Zhen Wei, Li-Ke Yu and Yong Song, Volume 69, 2010, pages 19-25. REFERENCE Shen Z-T, Wu X-H, Li B, Shen J-S, Wang Z, Li J, Zhu X-X. CYP2E1 Rsa Ι/Pst Ι polymorphism and lung cancer susceptibility: a meta-analysis involving 10,947 subjects. J Cell Mol Med. 2015;19:2136-2142. https://doi.org/10.1111/jcmm.12579.

Mechanical synthesis of chemically bonded phosphorus-graphene hybrid as high-temperature lubricating oil additive.

Red phosphorus (P) was covalently attached to graphene nanosheets (Gr) using high-energy ball-milling under a nitrogen atmosphere. Benefiting from the formation of phosphate and P-O-C bonds on graphene surfaces, the resulting phosphorus-graphene (P-Gr) hybrids exhibited excellent dispersion stability in polyalkylene glycol (PAG) base oil compared with graphene. Moreover, tribological measurement indicated that addition of 1.0 wt% P-Gr into PAG resulted in significant reduction in friction coefficient (up to about 12%) and wear volume (up to about 98%) for steel/steel contact at 100 °C, which was likely due to the formation of a boundary lubrication film on the sliding surfaces during the friction and wear processes. XPS analysis demonstrated that the tribofilm is composed of FeO, Fe3O4, FeOOH, FePO4, and the compounds containing C-O-C and P-O bonds.

Long-term survival in gliosarcoma with radiation-induced meningeal sarcomas: Case report and molecular features.

Gliosarcoma is a rare primary malignant tumor of the central nervous system with poor prognosis. The median survival time of this disease ranges from 6 months to 14.8 months. However, a computer literature search indicated few long-term survivors. We investigated a case of a survivor of gliosarcoma with radiation-induced meningeal sarcomas, who showed no indication of recurrence for more than 9 years. A battery of molecular studies was performed to develop a molecular profile of this unique patient. We also reviewed the distinct clinical and molecular features of the tumor.

[Ionizing Radiation Reduces TKI Resistance Caused by T790M Mutation in NSCLC Cell Lines].

BACKGROUND AND OBJECTIVE: Epidermal growth factor receptor-tyrosine kinase inhibitor (EGFR-TKI), which targets EGFR, plays an important role in non-small cell lung cancer (NSCLC) treatment. Patients with somatic activating mutations in the EGFR gene exhibit significant initial response but eventually develop resistance to TKI. The second mutation (T790M) of the EGFR gene is the possible main cause of drug resistance. The aim of this study is to investigate the effect of ionizing radiation on EGFR-TKI resistance caused by T790M mutation in NSCLC cell lines. METHODS: We selected H1975 and H3255 as research subjects and tested the mutation states by real-time PCR analysis. Radiosensitivity was determined by clone-forming test, and drug resistance was detected in different groups by MTT assay. RESULTS: H1975 is an EGFR double mutant (L858R plus T790M), whereas H3255 is an EGFR single mutant (L858R). The cell survival fractions of H1975 and H3255 did not vary in different treatment groups (P=0.952). Thus, T790M mutation did not affect the radiosensitivity of NSCLC cell lines. The IC50 of H1975 in the 2.5 Gy group [(0.678; 2±0.373) µmol/L] was statistically significant compared with that in the 0 Gy normal control group [(3.520±0.821) µmol/L] (P=0.008). The drug tolerance of the H1975 cell line by 89.5 dropped to 39.2 times. CONCLUSIONS: Ionizing radiation can reduce TKI resistance caused by T790M mutation in NSCLC cell lines. Our results provide a research basis for future in vivo and clinical studies. Radiotherapy combined with EGFR-TKI treatment can be a promising strategy to overcome T790M-mediated drug resistance.
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CYP2E1 Rsa Ι/Pst Ι polymorphism and lung cancer susceptibility: a meta-analysis involving 10,947 subjects.

Many studies have examined the association between the CYP2E1 Rsa Ι/Pst Ι (rs3813867) polymorphism gene polymorphisms and lung cancer risk in various populations, but their results have been inconsistent. The PubMed and CNKI database was searched for case-control studies published up to October 2013. Data were extracted and pooled odds ratios (OR) with 95% confidence intervals (CI) were calculated. In this meta-analysis, we assessed 23 published studies involving comprising 4727 lung cancer cases and 6220 controls of the association between CYP2E1 Rsa Ι/Pst Ι polymorphism and lung cancer risk. For the homozygote c2/c2 and c2 allele carriers (c1/c2 + c2/c2), the pooled ORs for all studies were 0.73(95% CI = 0.62-0.84; P = 0.005 for heterogeneity) and 0.84 (95% CI = 0.77-0.92; P = 0.001 for heterogeneity) when compared with the homozygous wild-type genotype (c1/c1). In the stratified analysis by ethnicity, the same significantly risks were found among Asians and mixed population for both the c2 allele carriers and homozygote c2/c2. However, no significant associations were found in Caucasian population all genetic models. This updated meta-analysis suggests that CYP2E1 Rsa Ι/Pst Ι c2 allele is a decreased risk factor for the developing lung cancer among Asians and mixed population.

Clinical outcomes of cyberknife stereotactic radiosurgery for lung metastases.

BACKGROUND: Cyberknife stereotactic radiosurgery is an emerging noninvasive technique for treating oligometastatic cancer. The aim of this study is to evaluate the efficacy and tolerability of cyberknife for the treatment of patients with lung metastases. MATERIALS AND METHODS: A total of 134 lung metastases in 95 patients were treated with cyberknife in the radiotherapy center of our hospital from March 2009 to March 2013. The number of lung metastases per patient ranged from one to four (single lesions in 63 patients, 66.3%). The average tumor volume was 14.6 cm(3) and the prescribed radiation dosage ranged from 30  to 60 Gy, fractionated one to five times with a 60% to 88% isodose line. The primary end point was local control (LC); secondary end points were survival and toxicity. RESULTS: The median follow-up was 17 months (ranging from 4 to 46 months). The 1-year LC rate was 97.6%, the 2-year LC rate was 90.6%, and the 3-year LC rate was 87.0%. The median survival time was 38.0 months and the median progression-free survival (PFS) time was 14.0 months. The 2-year PFS rate was 29.0% and the overall survival (OS) rate was 61.3%. No grade 4 or higher toxicity was encountered. CONCLUSIONS: Cyberknife is safe and effective treatment for patients with lung metastases.

Effect of miR-18a overexpression on the radiosensitivity of non-small cell lung cancer.

The aim of the present study is to investigate whether there is a relationship between miR-18a expression and radiosensitization of non-small-cell lung caner (NSCLC). The relationship between miR-18a expression and clinicopathological characteristics was investigated. To determine whether the miR-18a expression levels were associated with radiotherapeutic efficacy, therapeutic response was evaluated by radiologic Response Evaluation Criteria in Solid Tumors (RECIST). To determine whether miR-18a was required for lung cancer cell radioresistance, A549 cells were treated with different doses of ionizing radiation, following transfection with inhibitor miR-18a or inhibitor NC. We found that the level of miR-18a in NSCLC was strongly correlated with tumor differentiation (P = 0.026), regional lymph node metastasis (P = 0.013) and clinical TNM stage (P = 0.005). According to RECIST, miR-18a expression level was significantly associated with therapeutic response, exhibiting higher expression level in non-responsive patients. Furthermore, the depletion of miR-18a increased A549 cell radiosensitivity. In conclusion, we provide the evidence that down-regulation of miR-18a sensitizes NSCLC to radiation treatment, and it may help to develop a new approach to sensitizing radioresistant lung cancer cells by targeting miR-18a.

Clinical outcomes of CyberKnife stereotactic body radiotherapy for peripheral stage I non-small cell lung cancer.

The aim of this study was to evaluate the clinical outcome of CyberKnife stereotactic body radiotherapy (SBRT) for patients with stage I non-small cell lung cancer (NSCLC). Fifty patients with peripheral stage I NSCLC who refused surgery or were medically inoperable were treated with 48-60 Gy (median dose: 57 Gy) in three divided doses. Histopathology was available in 86% of patients. Thirty patients had a T1 tumor, and 20 patients had T2 tumors. More than 95% of the target volume was covered by the 72% isodose surface. Fiducials were implanted in or near the tumors in all patients to track tumor movement and breathing patterns. The median follow-up time was 35 months (3-45 months). Based on computed tomography scans, 40 patients achieved complete remission, six patients achieved partial remission, two patients exhibited stable disease, and two patients had progressive disease. The local control rate (CR + PR) was 92%, and the 2-year disease control rate (CR + PR + SD) was 96%. Overall survival for the whole group was 86% at 1 year and 74% at 2 years. Grade III toxicity occurred in two patients (4%) after marker placement. Treatment-related late grade III toxicity occurred in five patients (10%). Toxicities greater than grade III were not observed. CyberKnife SBRT achieves a high rate of local control and long-term curative effect with acceptable toxicity for patients with inoperable stage I NSCLC. However, long-term follow-up is necessary to evaluate survival and late toxicity.

CyberKnife Treatment for Kaposiform Hemangioendothelioma of the Ilium in an adult: case report and review of the literature.

BACKGROUND: Kaposiform hemangioendothelioma (KHE) is a rare vascular neoplasm that mainly affects infants. KHE rarely develops in adolescents and adults. These tumors tend to be locally invasive, but are not known to produce distant metastases. Numerous treatment modalities are available for KHE, but the optimal therapy is unknown. CASE REPORT: A 51-year-old woman was diagnosed with KHE of the ilium in September 2005. The lesion recurred within 5 years of local excision, and was subsequently treated with CyberKnife. Within 1 month of CyberKnife therapy, pain intensity was significantly reduced and the patient's quality of life was significantly improved. Since January 2011, she has remained pain-free and has had no signs of recurrence or metastasis for more than 2 years following CyberKnife therapy. CONCLUSION: We report the first CyberKnife treatment of an adult with KHE of the bone without accompanying cutaneous changes and Kasabach-Merritt syndrome. CyberKnife treatment could be a useful temporizing measure for bone KHE.

CyberKnife radiotherapy for malignant fibrous histiocytoma of the chest wall: A case report and review of the literature.

Malignant fibrous histiocytoma (MFH) is the most common type of soft tissue sarcoma, but rarely originates in the chest wall. Surgical resection is considered to be the most reliable treatment, however, no consensus has been reached concerning the best treatment for unresectable MFH. The current study presents the case of a 77-year-old male with MFH of the chest wall. The patient developed a painless mass and intermittent fever over a four-month period. A computed tomography scan demonstrated a large inhomogeneous lesion in the right chest wall, which was subsequently diagnosed via biopsy as a MFH. Since the tumor was an unresectable mass, CyberKnife® radiotherapy was conducted. Following the treatment, a marked reduction in the tumor size was observed with a tolerable level of toxicity. The sequencing analysis also revealed an in-frame deletion (delE746-A750) in exon 19 of the epidermal growth factor receptor gene. Based on this result, gefitinib was administered to the patient at a dose of 250 mg/day.

Gefitinib combined with stereotactic radiosurgery in previously treated patients with advanced non-small cell lung cancer.

BACKGROUND: Disease progression remains the major challenge in the management of advanced (stage IIIb or IV) non-small cell lung cancer (NSCLC) after the failure of first-line or second-line chemotherapy, or even of targeted therapies such as gefitinib. The current study evaluated the tolerability and efficacy of stereotactic body radiation therapy (SBRT) in combined with gefitinib as a second-line or third-line treatment in patients with advanced NSCLC. METHODS: Fourteen advanced NSCLC patients showing disease progression after platinum-based chemotherapy regimens were recruited. Eligible patients started taking gefitinib (250 mg/d) 7 days before SBRT and continued for 1 year until disease progression, unacceptable toxicity or withdrawal of consent. SBRT was delivered in median 3 fractions within 3 to 5 days. Treatment-associated toxicity was assessed according to the Common Terminology Criteria for Adverse Events (v.3.0). Local control was assessed according to the Response Evaluation Criteria in Solid Tumors criteria and symptom assessments were measured by the Functional Assessment of Cancer Therapy-Lung instrument (V4.0). RESULTS: With an overall median follow-up of 15.5 months (range, 4 to 27 mo), most patients were well tolerated with common side effects from grade 1 to 2. No grade 4 or higher toxicity was encountered. The clinical disease-related symptom improvement rate was reached 57.1% with the median duration of symptom improvement of 8.0 months. The 1-year local control and overall survival (OS) rates were 83.9% and 69.6%, respectively. The median progression-free survival and OS were 7.0 and 19.0 months, respectively. CONCLUSIONS: The SBRT combined with gefitinib is a promising treatment strategy for advanced (stage IIIb or IV) NSCLC after the failure of previously chemotherapy. This method improves local control and disease-related symptoms with tolerated toxicity, and even increases the progression-free survival and OS.

Treating adrenal tumors in 26 patients with CyberKnife: a mono-institutional experience.

BACKGROUND: CyberKnife (CK) is a novel stereotactic radiosurgery system for treating tumors in any part of the body. It is a non-invasive or minimally invasive tumor treatment modality that can deliver high doses of spatially precise radiation and minimize exposure to neighboring healthy tissues or vital organs. The purpose of this study was to investigate the safety and efficacy of CK in the treatment of adrenal tumors. METHODS AND RESULTS: We performed a retrospective analysis of 26 patients with adrenal tumors who had been treated with CK in the radiotherapy center of our hospital between March 2009 and March 2012. Eight patients had primary adrenal tumors and 18 patients had metastatic adrenal tumors. In addition to CK, 4 patients received chemotherapy and 2 patients received immunotherapy. The average tumor volume was 72.1 cm(3) and the prescribed radiation dosage ranged from 30 to 50 Gy and was fractionated 3 to 5 times with a 58% to 80% isodose line. Abdominal CT was performed between 1 to 3 months after the CK treatment to evaluate the short-term efficacy with follow-up examinations once every 3 months. Three patients had complete remission, 12 patients had partial remission, 5 patients had stable disease, and 6 patients had progressive illness. The effective rate of pain relief was 93.8% and the disease control rate was 77% with a median overall survival of 17 months and a median progression-free survival of 14 months. Treatment Related toxicity was well-tolerated, but preventative measure need to be taken for radiation enteritis. CONCLUSIONS: CK is safe and effective for treating adrenal tumors with few adverse reactions. Nonetheless, its long-term effects requires further follow-up.

Nedaplatin concurrent with three-dimensional conformal radiotherapy for treatment of locally advanced esophageal carcinoma.

AIM: To evaluate the efficacy and toxicity of nedaplatin (NDP) concurrent with radiotherapy in the treatment of locally advanced esophageal carcinoma. METHODS: Sixty-eight patients with locally advanced esophageal carcinoma were randomized into either a NDP group (n = 34) or a cisplatin (DDP) group (n = 34). The NDP group received NDP 80-100 mg/m² iv on day 1 + leucovorin (CF) 100 mg/m² iv on days 1-5 + 5-fluorouracil (5-FU) 500 mg/m² iv on days 1-5. The DDP group received DDP 30 mg/m² iv on days 1-3 + CF 100 mg/m² on days 1-5 + 5-FU 500 mg/m² iv on days 1-5. The treatment was repeated every 4 wk in both groups. Concurrent radiotherapy [60-66 Gy/(30-33 f)/(6-7 wk)] was given during chemotherapy. RESULTS: There was no significant difference in the short-term response rate between the NDP group and DDP group (90.9% vs 81.3%, P = 0.528). Although the 1- and 2-year survival rates were higher in the NDP group than in the DDP group (75.8% vs 68.8%, 57.6% vs 50.0%), the difference in the overall survival rate was not statistically significant between the two groups (P = 0.540). The incidences of nausea, vomiting and nephrotoxicity were significantly lower in the NDP group than in the DDP group (17.6% vs 50.0%, P = 0.031; 11.8% vs 47.1%, P = 0.016; 8.8% vs 38.2%, P = 0.039). There was no significant difference in the incidence of myelosuppression, radiation-induced esophagitis or radiation-induced pneumonia between the two groups. CONCLUSION: NDP-based concurrent chemoradiotherapy is effective and well-tolerated in patients with locally advanced esophageal carcinoma. NDP-based regimen has comparable efficacy to DDP-based regimen but is associated with lower incidences of gastrointestinal and renal toxicity.

Interaction studies of aristolochic acid I with human serum albumin and the binding site of aristolochic acid I in subdomain IIA.

Optical spectroscopy and molecular docking methods were used to examine the binding of aristolochic acid I (AAI) to human serum albumin (HSA) in this paper. By monitoring the intrinsic fluorescence of single Trp214 residue and performing displacement measurements, the specific binding of AAI in the vicinity of Sudlow's Site I of HSA has been clarified. An apparent distance of 2.53nm between the Trp214 and AAI was obtained via fluorescence resonance energy transfer (FRET) method. In addition, the changes in the secondary structure of HSA after its complexation with the ligand were studied with circular dichroism (CD) spectroscopy, which indicated that AAI does not has remarkable effect on the structure of the protein. Moreover, thermal denaturation experiments clearly indicated that the HSA-AAI complexes are conformationally more stable. Finally, the binding details between AAI and HSA were further confirmed by molecular docking studies, which revealed that AAI was bound at subdomain IIA through multiple interactions, such as hydrophobic effect, van der Waals forces and hydrogen bonding.

Spectroscopic and molecular modeling evidence of clozapine binding to human serum albumin at subdomain IIA.

Various spectroscopy and molecular docking methods were used to examine the binding of Clozapine (CLZ) to human serum albumin (HSA) in this paper. By monitoring the intrinsic fluorescence of single Trp214 residue and performing Dansylamide (DNSA) displacement measurement, the specific binding of CLZ in the vicinity of Sudlow's Site I of HSA has been clarified. An apparent distance of 27.3 Å between the Trp214 and CLZ was obtained via fluorescence resonance energy transfer (FRET) method. In addition, the changes in the secondary structure of HSA after its complexation with CLZ ligand were studied with CD spectroscopy, which indicate that CLZ does not has remarkable effect on the structure of the protein. Moreover, thermal denaturation experiment shows that the HSA-CLZ complexes are conformationally more stable. Finally, the binding details between CLZ and HSA were further confirmed by molecular docking studies, which revealed that CLZ was bound at subdomain IIA through multiple interactions, such as hydrophobic effect, van der Waals forces and hydrogen bonding.

Catalytic thia-Sommelet-Hauser rearrangement: application to the synthesis of oxindoles.

A series of 3-arylthio-1,3-disubstituted-oxindoles were prepared in good yields by the reaction of α-diazocarbonyl compounds and sulfenamides. The reaction involves a Rh-catalyzed thia-Sommelet-Hauser-type rearrangement.

Preliminary efficacy of CyberKnife radiosurgery for locally advanced pancreatic cancer.

BACKGROUND AND OBJECTIVE: CybeKnife is a newly developed technology in the field of stereotactic radiosurgery/radiotherapy (SRS/SRT). Compared with conventional SRS/SRT, there are many advantages for CyberKnife in terms of treating tumors that move with respiration, being real-time image-guidance, frameless, high accurateness, and so on. Recently, it has been used to treat different types of malignant carcinoma including intracranial and caudomedial tumors. This study was designed to evaluate the short-term efficacy and toxicity of the CyberKnife radiotherapy for locally advanced pancreatic cancer. METHODS: A total of 20 patients with locally advanced (stage II-III) pancreatic cancer treated with CyberKnife were recruited between April 2009 and December 2009. Of 20 patients, 13 were with cancer located at the pancreatic head and 7 were located at the pancreatic body and tail. The planning target volume (PTV) was defined as gross tumor volume (GTV) plus 2-3 mm, and more than 95% PTV should be covered by 75% isodose surface. The median of PTV was 47 cm³ (26-64 cm³). The median total prescription dose was 40 Gy (32-55 Gy) at 3-6 fractions. During treatment delivery, X-Sight Spine Tracking System was used in 5 patients to track movement of the tumor. Other 15 patients were implanted fiducials in the tumors to track movement of the tumor and patient breathing patterns. RESULTS: The median follow-up time was 7 months (3-11 months). All patients had finished the treatment and 19 were alive by the last follow-up. Slight fatigue was the most common complain. Evaluated by CT scan, 6 were complete response, 9 were partial response, 3 were stable disease, and 1 was progression; 1 was dead. There were 6 patients with grade I granulocytopenia, 7 with grade I nausea, and 5 with grade II vomiting. CONCLUSIONS: The CyberKnife radiosurgery for the locally advanced pancreatic cancer shows a high rate of local control and minimal toxicity. Long-term follow-up is necessary to evaluate the survival and late toxicity.

[Impact of MRI-CT image registration on target delineation of postoperative radiotherapy for gliomas].

BACKGROUND & OBJECTIVE: Magnetic resonance imaging (MRI) can well distinguish soft tissue, but its usage in radiotherapy for brain tumors was limited by its image distortion and lack of electron density for dosage calculation. The registration of MRI with computed tomography (CT) could resolve this problem. This study was to investigate the registration accuracy of MRI-CT image, and compare the change of center position, clinical target volume (CTV) and volume of organs at risk (OARs). METHODS: Nine glioma patients were examined by MRI and CT after operation. The registration accuracy of MRI-CT was evaluated. The changes of CTV, volume of OARs, and center position were investigated by the method of volume and center of geometry (COG) respectively. COG was used to measure the distance between center positions on MRI-CT registration image and CT location image. The volume method was used to measure the percentage of the volume of registration area (VMRI-CT) to the total volume (VMRI+CT). RESULTS: The registration accuracy by the method of artificial landmarks was less than 1.5 mm, which reached the error requirement for brain tumors. No significant change of volume of OARs was found (P>0.05). Of the 9 patients, 8 had decreased CTV (by 13.85%-73.59%) on MRI-CT registration image and 1 had increased CTV (by 10.35%). The difference in mean CTV between the 2 groups was significant (P<0.05). The change of central position of CTV was the largest [(8.74+/-6.60) mm], those of 2 eyes were the next [(5.25+/-2.38) mm for the left eyeû (5.65+/-2.56) mm for the right eye], and that of the brain stem was the least [(1.83+/-1.06) mm]. CONCLUSIONS: By the method of artificial landmarks, MRI-CT has better registration accuracy. MRI-CT registration can reduce the uncertainty of CTV delineation in radiation treatment planning for glioma patients after operation.