| Part ?MR Fluoroscopy-Guided Brain Biopsy using 1.0 T Open MRI ScannerIntroductionThe accurate diagnosis of the brain lesion is an important prerequisite for optimized treatment.At present,there are four major types of procedures for brain biopsy:frame-based,frameless,intraoperative MRI.and CT-guided brain biopsy.Although frame-based stereotactic brain biopsy has been the most commonly used method,there are limitations to this technique,of which mainly is the absence of real-time image feedback during biopsy procedure.During operation,the accurate location of needle and biopsy target can not be visualized,which may lead to false negative result and intraoperative morbidity.Real-time MRI-guided brain biopsy overcomes this limitation and provides high diagnostic yield and lower rate of serious complications.Most of the reported procedures were performed using a closed-bore MR scanner without a larger open access.In closed-bore scanner,the patient access can be restricted to some extent.In addition,the biopsy procedure requires also auxiliary apparatus;and the procedure is complicated leading to longer procedural time.Larger open access and simpler procedure are of great significance for biopsy of brain lesions.High-field open MR has the above two characteristics,and has anticipated application value.MR fluoroscopy technique in 1.0 T open MR has been utilized in guidance of biopsy procedures and interventional therapy,such as liver biopsy,breast biopsy,radiofrequency ablation,etc.Recent studies have shown that real-time technique in 1.0 T open MR provides a time-efficient,simplified,and accurate approach for biopsy guidance.However,to the best of our knowledge,1.0 T open MR has not been used in brain biopsy at present.In our study,we used a 1.0 T open MRI scanner and fluoroscopy technique for brain biopsy.The aim of this study was to evaluate the safety,feasibility and diagnostic performance of using 1.0 T open MRI scanner with MR fluoroscopy technique in brain biopsy.ObjectiveTo study the feasibility,safety and diagnostic performance of 1.0 T open MR and MR fluoroscopy technique-guided brain biopsy.Materials and MethodsOne hundred and twelve cases of brain biopsy guided by 1.0 T open MR scanner and MR fluoroscopy technique were analyzed retrospectively.Patient demographics,imaging data,surgical characteristics,and histopathological diagnosis were retrospectively reviewed.All cases were divided into two groups of larger than 1.5 cm and smaller than or equal to 1.5 cm according to the size of lesions.Criteria for selected cases(1)pathological diagnosis is needed before surgical operation;(2)pathological diagnosis must be obtained before radiotherapy or chemotherapy;(3)it is difficult to differentiate recurrence of tumors from radiation necrosis and gliosis;(4)patients with non-neoplastic lesions who did not have good response to the medical treatment,and further diagnosis is needed to make the treatment strategy.Criteria for exclusive cases(1)Patients with contraindications for MR examination;(2)severe coagulation dysfunction(activated partial thromboplastin time twice more than the normal time,or international standard ratio INR>1.5,or platelet count<50 X ×09/L);(3)intracranial vascular lesions;(4)unconsciousness patients;(5)cerebral hernia.Preoperative preparation Patients were placed on the operating table of the MR scanner in a suitable position.A receive-type flexible surface loop coil was wrapped around the patient's head.The position of the patient was fixed by a vacuum bag.A fish oil capsule marker was placed on the surface of scalp in the area of interest.Biopsy procedure Patients underwent enhanced MR imaging(T1W-TSE)to determine the entry point and puncture trajectory.A twist-drill hole was made at the entry point.The fluoroscopy sequence(T1W-FFE,T1W-TSE,T2W-TSE)was selected according to the enhancement characteristics of the lesion.With the guidance of the fluoroscopy images,the operator punctured the needle into the target of the lesion.The position and depth of the needle were identified by T1W or T2W fast sequence imaging.Sampling procedure was performed with an semi-automated cutting needle.Any complications occurred were recorded.Postoperative follow-up Postoperative pathological results of patients who underwent surgical treatment after needle biopsy were recorded.Patients who did not undergo surgical treatment were followed up for more than one year.The postoperative pathological results and follow-up results were identifed as the final diagnosis.Statistical analysis The diagnostic accuracy,sensitivity,specificity,positive predictive value(PTV)and negative predictive value(NPV)were calculated.Two-tailed Fisher's exact test was used to compare diagnostic accuracy,sensitivity,specificity,PTV and NPV in two groups(maximum diameter<1.5cm,maximum diameter>1.5 cm).Statistics analysis was performed by SPSS 22.0 statistical software.P value<0.05 was considered to indicate significant difference.ResultsAll biopsy specimens were technically successfully obtained.Procedure duration was 39±4.6 minutes(range,29-49 minutes).All biopsy needles were placed with one pass.One hundred and eight procedures yielded definitive diagnoses in all procedures.The diagnostic accuracy,sensitivity,specificity,PTV and NPV were 96.4%(108/112),96.3%(79/82),96.7%(29/30),98.8%(79/80),90.6%(29/32),respectively.The diagnostic accuracy,sensitivity,specificity,PTV and NPV of lesions of smaller than or equal to 1.5cm were 96.6%(28/29),93.8%(15/16),100%(13/13),100%(15/15)and 92.9%(13/14)respectively.The diagnostic accuracy,sensitivity,specificity,PTV and NPV of lesions of larger than 1.5cm were 96.4%(80/83),97.0%(64/66),94.1%(16/17),98.5%(64/65)and 88.9%(16/18)respectively.There were no significant differences between the two groups;p value>0.05 by Fisher's exact test.No serious complications occurred.Minor complications included four cases of small amount of hemorrhage in biopsy procedure,including one case of epidural hemorrhage,three cases of cerebral hemorrhage.The amount of bleeding was about 2.3ml,8.7ml,0.6ml and 0.5ml,respectively.The complication rate was 3.6%(4/1 12).Conclusions1.1.0 T open MRI and fluoroscopy technique-guided brain biopsy is safe,feasible,and with good diagnostic performance.2.The procedure duration is shortened and biopsy work flow is simplified.It could be considered as an alternative for brain biopsy.Part ?Three-Dimensional Noncoplanar Template Combined with MR-Guided 125I Brachytherapy for Recurrent GlioblastomaIntroduction125I seed brachytherapy is one of the treatment strategies for recurrent glioblastoma.It is reported that patients with recurrent glioblastoma can benefit from 125I seeds implantation.Although this treatment has been developed earlier and proved effective,it has not been used widely in clinical practice.We analysed that besides the complexity of this technique,the difficulty in precise control of dose distribution is an important reason.Stereotactic 125I seed implantation is the most widely used implantation technology.Some scholars reported that the incidence of spatial displacement of 125I seeds under the guidance of stereotactic framework can reach 20%.Therefore,how to accurately achieve preoperative treatment plan is one of the keys to the succesful treatment of glioma with 125I brachytherapy.In recent years,the technique of three-dimentional non-coplanar printing templates(3DNPT)has been applied to assist 125I seed implantation for tumors in head and neck,chest,abdomen,etc.It has been shown that the application of 3DNPT in brachytherapy can improve the accuracy and conformity of 125I seed implantation.On the other hand,MR has excellent capabilities of soft tissue contrast,functional imaging and multi-planar imaging.It has significant advantages in target determination,intraoperative monitoring in craniocerebral surgery.Therefore,in this study,we used 3DNPT combined with high-field MR guidance in order to explore a new technique of 125I seed implantation for safety,accuracy,and dose standardization in the treatment of brain glioma.ObjectiveTo study the feasibility,safety,accuracy and clinical efficacy of a new technique of 125I seed implantation for recurrent glioma-three-dimensional non-coplanar template combined with 1.0 T open MR-guided 125I brachytherapy.Materials and MethodsTwenty patients of recurrent glioblastoma underwent permanent 125I brachytherapy in our department from August 2017 to October 2018 were analyzed retrospectively.The control group included 14 patients with recurrent glioblastoma who received bevacizumab treatment from January 2017 to November 2018.Criteria for selected cases(1)patients with glioblastoma who had previously undergone surgery and/or radiotherapy and temozolomide treatment;(2)recurrent glioblastoma was confirmed by pathology or imaging examination;(3)the predicted survival time was longer than 3 months;(4)the number of lesions<2.Criteria for exclusive cases(1)with contraindications for MR examination;(2)patients with unconsciousness;(3)severe coagulation dysfunction(activated partial thromboplastin time twice more than the normal time,or international standard ratio INR>1.5,or platelet count<50 × 109/L);(4)severe and uncontrolled hypertension,severe cardiac dysfunction or pulmonary dysfunction;(5)there was a history of arteriovenous thrombosis,intracranial hemorrhage in the past six months or craniotomy in the past month.Preoperative preparation Contrast-enhanced isovoxel T1-weighted images with slice thickness of 1mm were obtained for preoperative brachytherapy treatment planning.Gross Tumor Volume(GTV)was delineated according to the enhanced margin of tumor in each slice of the contrast-enhanced isovoxel T1-weighted images.Planning target volume(PTV)was 10mm out of the GTV.Low activity 1251 seeds of 0.8 mci were utilized.The prescribed dose was 120-160 Gy.A 3DNPT was printed by a 3D printer according to the brachytherapy treatment plan.The 3DNPT is comprised of a base plate and three movable plates that can be embedded in the base plate.125I seed implantation The 3DNPT was placed on the scalp coinciding with the reference points.Then the patient underwent enhanced MR imaging.After the position of the template confirmed by the MR images,the skull drilling and puncturing process were performed with the assistance of 3DNPT.After needles were in place,the direction and depth of the needles were displayed and confirmed by intraoperative MR imaging.The 125I seeds were then implanted into the tumor following the preoperative brachytherapy treatment plan.Postoperative dosimetry verification On the second day after the brachytherapy procedure,patients underwent CT scanning.CT and preoperative MR images were then fused and transferred to brachytherapy treatment planning system for postoperative dosimetry verification.Dose volume histogram and dosimetry parameters(D90,D100,V100,V150,V200,Cl,El)were obtained.Bevacizumab treatment regimen in the control group Bevacizumab(7.5 mg/kg)was given every three weeks for a cycle until the imaging evaluation confirmed the progression of tumor or unacceptable toxicity.Clinical follow-up and therapeutic evaluation Patients were followed up every 2 months.According to the response assessment in neuro-oncology(RANO),the objective remission rate(ORR)of the two groups was calculated.Median progression-free survival(PFS)and median overall survival(OS)were the main indicators in this study;6-month survival rate and 1-year survival rate were the secondary indicators.Complications and toxicity evaluation The intraoperative and postoperative complications of 125I brachytherapy group were recorded.The adverse drug reactions of two groups were evaluated according to CTCAE 4.0 standard.Statistical analysis Preoperative and postoperative dosimetry parameters were compared by nonparametric Wilcoxon test.Fisher's exact test was used to compare the ORR,6-month survival rate,1-year survival rate and the rate of adverse reactions above grade 3 of the two groups.PFS and OS of the two groups were calculated by Kaplan-Meier method and compared by Logrank test.Statistics analysis was performed by SPSS 22.0 statistical software.P value<0.05 was considered to indicate significant difference.Results1.The preoperative D90,D100,V100,V150,V200,CI and El were(146.5±11.8)Gy,(78.7±9.9)Gy,(91.7±1.1)%,(66.0± 4.6)%,(44.7±4.6)%,0.77±0.04 and(18.0±5.8)%respectively.The postoperative D90,D100,V100,V150,V200,CI and El were(145.9±12.5)Gy,(80.1±10.5)Gy,(91.6±1.3)%,(65.5±4.9)%,(44.2±5.0)%,0.76±0.04 and(19.0±6.3)%respectively.There were no significant differences between the above preoperative and postoperative dosimetry parameters(P>0.05).Preoperative planned number of 125I seeds was 46.1 ± 30.0,postoperative seed number was 47.2± 29.6;there was no significant difference between them(P=0.101).2.In 125I brachytherapy group,the ORR was 85.0%,the 6-month survival rate was 95.0%,1-year survival rate was 60.0%,the median PFS was 10.1 months,the median OS was 13.8 months.In bevacizumab group,ORR was 35.7%,the 6-month survival rate was 78.6%,1-year survival rate was 14.3%,the median PFS was 4.5 months,the median OS was 8.1 months.The 6-month survival rate of 125I brachytherapy group was higher than that of bevacizumab group,but there was no significant difference.The ORR,1-year survival rate,PFS,OS of 125I brachtherapy group were higher than those of bevacizumab group with significant differences between the two groups.3.Toxicity(1)125I brachytherapy group:there were 3 cases of brain edema requiring drug treatment,including one case of grade 3 brain edema,two cases of grade 2 brain edema.There was one case of grade 1 pain of upper limb.(2)Bevacizumab group:five cases of degree 1 or degree 2 fatigue,one case of degree 3 neutropenia,one case of degree 1 neutropenia,two case of degree 3 hypertension,one case of degree 2 hypertension.The rate of adverse reactions above grade 3 in 125I group was 5%(1/20)and that in bevacizumab control group was 21.4%(3/14).There was no significant difference between the two groups(P=0.283).Conclusions1.Three-dimensional non-coplanar template combined with 1.0 T open MR-guided 125I brachytherapy for recurrent glioblastoma is feasible,safe and accurate.Postoperative dosimetry matched the preoperative treatment plan.2.125I seed implantation with precise dose distribution can prolong PFS and OS for recurrent glioblastoma.3.This novel implantation technique simplifies the brachytherapy procedural workflow.It could be considered as an alternative technique for brachytherapy treatment of recurrent glioma. |
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