MR imaging-guided laser-induced thermotherapy

Summary

Interstitial laser-induced thermotherapy (LITT) is a recently developed, minimally invasive technique for local tumour destruction within solid organs. The purpose of this study was to evaluate the potential of MR-guided laser-induced thermotherapy (LITT) for the treatment of recurrent head and neck and liver tumours in a prospective study. In the head and neck study 12 patients with recurrent head and neck tumours were treated using MR-con-trolled laser-induced thermotherapy. In the liver study 76 patients with in total 171 histologically-proven liver metastases of colorectal carcinoma, oesopha-geal, gastric, pharyngeal, testicular and Pancoast tumours were treated with LITT. A total of 527 applications were performed. All procedures were tolerated under local anaesthesia with no clinically relevant side effects. MR thermome-try clearly demonstrated an area of signal loss with a radius of up to 15 mm in the vicinity of the laser tip. Dynamic gadolinium-enhanced MRI is suitable for early and late follow-up studies for lesions treated with LITT. Follow-up studies indicate that the laser-induced effects lead to reliable palliation in recurrent head and neck tumours. Our data prove a high tumour response in liver metastases smaller than 20mm in diameter. Technical innovations and increasing experience in combination with the multi-applicator technique improve the results in larger diameter lesions.     

Laser-induced thermoablation of tumours of the head and neck under MR tomographic control

Summary

This study evaluates the potential of MR-guided laser-induced thermotherapy for the treatment of recurrent head and neck tumours, as a stand-alone method, or in combination with radiotherapy. 15 patients with recurrent head and neck tumours (recurrent squamous cell carcinoma n=13, recurrent pleomorphic adenoma n=2) were treated, using MR-controlled laser-induced thermotherapy. 18 lesions were treated with 25 laser applications. MR thermometry was performed, using a temperature-sensitive TurboFLASH (TR/TE/TI = 7/3/400; flip angle = 8d`) and FLASH-2D (TR/TE/flip angle = 102/8/70d`) sequence for monitoring thermal-induced changes in signal and morphology. T₁ weighted (TR/TE=700/15) sequences, plain and contrast-enhanced, were used for follow-up. 14 patients tolerated the procedure well. In one patient, with a recurrent squamous cell carcinoma and infiltration of the sublingual gland, the treatment had to be stopped after 5 min due to pain. No long-term side effects related to treatment were observed. We were able to induce coagulative necrosis in all patients. The 4 year MR-control study of one patient with a pleomorphic adenoma showed no recurrent tumour. Clinically-relevant improvement of symptoms was observed in 11 patients. MR-guided LITT is an excellent method of treating a local tumour recurrence in the head and neck region. MR-thermometry allowed monitoring of laser-induced heating during LITT.     

Diary of forthcoming events

Summary

Interstitial laser photocoagulation (ILP) is currently limited by deficient per-procedural monitoring. The purpose of this study was to evaluate MR control of ILP of hepatic metastases. Twenty-two laser activations were used to treat eight metastases in seven patients under local anaesthesia and sedation. Laser energy was delivered via optical fibres positioned in the tumour under ultrasound guidance. T1-weighted FLASH and spin-echo sequences were used to monitor the procedure. Enhanced CT was performed at 24 h to assess thermal necrosis. FLASH imaging showed an enlarging area of signal change during ILP. The final extent of this correlated closely with the extent of tissue necrosis on CT. Spin-echo imaging was disappointing because of poor contrast between the treated tissue and normal liver/untreated tumour. Per-procedural MR imaging accurately and reliably depicts ILP-induced necrosis. MR control may permit more widespread application of ILP to the treatment of hepatic tumours.     

Radiofrequency ablation of brain tumours using MR guidance

Summary

MR-guided stereotactic thermal ablation was developed as a minimally invasive brain tumour treatment. Eighteen primary or metastatic brain tumours were treated in 15 patients. The entire procedure was performed under local anaesthesia in an MR suite. The outcome was analysed with 13-30 months of clinical follow-up. Local control was achieved in nine tumours in eight patients. Among them four patients with five tumours were disease-free for more than 22 months after the treatment. Four patients died from systemic disease or primary cancer while metastatic brain tumours were locally controlled. Local recurrence was seen in hypervascular metastatic tumours and a glioblastoma multiforme. For metastatic and primary brain tumours, MR provides not only accurate localization of brain tumour but also near real time thermal monitoring of acute tissue changes. This immediate imaging feedback facilitates safe and complete coagulation of the brain tumour. Based on our limited sample experiences, it is hoped that relatively long-term local control can be obtained in non-hypervascular metastases. MR-guided stereotactic RF thermal ablation is an attractive and promising technique, offering a potential treatment alternative for patients with previously treated brain tumour or systemic illness preventing other more conventional therapies.     

MR Guided Laser-Induced Thermotherapy (LITT)of Malignant Liver and Soft Tissue Tumours

Objective: Presentation of MR guided laser-induced thermotherapy (LITT) for percutaneous interstitial thermotherapy of malignant liver tumours and soft tissue lesions.Material and methods:MR-guided LITT is carried out by means of catheter systems that can be implanted percutaneously. CT or open MRI technologies are used as the control method for inserting the catheter. Irrigated application systems are available for LITT.Findings:Percutaneous LITT currently permits local tumour control of 97.2% for localised liver metastases without an extrahepatic manifestation pattern. In a patient population of 729 patients median survival times of 45.0 months for liver metastases, 42.6 months for patients with colorectal liver metastases have been documented. In the treatment of soft tissue tumours in the head and neck and pelvis MRI guided LITT allows an excellent local tumour control rate and reduces clinical symtoms in a palliative manner.Conclusions:Percutaneous MR-guided LITT permits a high level of tumour control in the case of liver metastases and soft tissue tumours smaller or equal to 5 cm and a maximum number of 5 lesions with an improvement of survival data.     

MR-guided ablation of head and neck tumors

Interstitial laser-induced thermotherapy (LITT) is a minimally invasive technique for local tumor destruction within solid organs using optical fibers to deliver a high-energy laser to the target lesion. MR imaging is used both for placement of the laser in the tumor and for monitoring progress of thermocoagulation caused by the laser The success of LITT is dependent on the delivery of the optical fibers to the target area, real-time monitoring of the effects of the treatment, and subsequent evaluation of the extent of thermal damage. The key to achieving these objectives is the imaging methods used. The thermosensitivity of certain MR sequences is the key to real-time monitoring, allowing accurate estimation of the extent of thermal damage.     

The potential of laser-induced interstitial thermotherapy to treat liver metastases

Summary

Laser-induced interstitial thermotherapy (LITT) is a method which has become a promising alternative for the palliative treatment of non-resectable metastases. At an early stage, a bare fibre was inserted, e.g. into liver metastases. Sophisticated applicators, with an integrated cooling system, are now used to increase the coagulated volume. The applicators can be introduced via laparotomy and laparoscopy under US-control, or percutaneously under CT- or MR-control. Most often, the Nd:YAG laser is used as the energy source, because of its good penetration properties in biological tissue. There is a simultaneous increase of the temperature in the whole volume reached by the laser radiation. This is a great advantage over cryotherapy and other thermal procedures, which are purely based on heat conduction. However, the maximal diameter treated is limited by the blood perfusion, that takes away a large amount of heat. Coagulation volumes of 35 mm in diameter can be reached. The coagulation zone can be controlled by US- CT- or MR-imaging. A cooled application system was designed and evaluated in an animal experiment with pigs. The tissue repair reaction after coagulation is early fibrosis. In the weeks following the treatment, the surrounding scar capsule, consisting of fibrocytes, biliary ductules and collagen fibres, continuously enlarges. Complications, such as bleeding, infection and liver failure, are not as frequent after LITT as after surgical resection. Since the coagulation process is non-ablative, even the area around big vessels can be treated. Due to the large heat transport by the blood flow, the wall of the vessel is not affected by thermal radiation. Therefore, even metastases close to the vena cava or the portal vein are treatable. It has been shown that metastases can principally be destroyed with this method. Randomised studies are needed to evaluate this method clinically and determine survival time and quality of life.     

Non-invasive 3d magnetic resonance thermal mapping: determination of the lesion size during laser-therapy in ex vivo tissues

Object Developments in open magnetic resonance imaging (MRI) magnets have made possible the use of reproducible thermosensitive sequences to determine temperature distribution inside biological tissue. This study aimed to compare MR thermal mapping during laser-induced interstitial thermal therapy (LITT) with macroscopically observed thermal lesions in order to estimate the 3D size of the coagulative necrosis. Materials and methods Laser irradiation was performed ex vivo with a 980-nm laser in pig liver in an open low-magnetic field (0.2 T) scanner. Laser light was transmitted through a 1,040/600 μm (outer/core diameter) bare-tipped silica fiber. Laser energy was applied in a pulsed mode (10 s laser-on, 10 s laser-off) for 12 min, power 6 W, energy 2,160 J. Gradient-echo images acquired during laser irradiation were used for real-time temperature mapping by the MR-T1 method. The method was then validated by a comparison between calculated 60°C isotherm and macroscopic lesion size. Results Temperature accuracy was 2.2°C, temporal resolution was 20 s. and spatial resolution was 2.5 × 2.5 × 2.5 mm³ (0.8% of the mean volume of coagulative necrosis). The mean lesion volume was 1830 mm³ ± 189 (standard error), σ (standard deviation) = 499 and range (min = 1281; max = 2591) mm³. Volumes calculated from MRI isotherms were correlated (correlation coefficient r ² = 0.70) significantly (P = 0.08) to lesion size determined from macroscopic measurements. Conclusion Using fast gradient-echo sequence, laser monitoring is achieved efficiently with fast temperature mapping. T1-weighted images appear promising in monitoring lesion size evolution in future low magnetic field in vivo studies.     

Interstitial laser irradiation of cerebral gliomas

The most common type of the primary brain tumor is the glioma. For patients unsuited for open surgery, local tumor ablation may be employed as an alternative palliative option. For laser irradiation, we used a specially designed light guide (LITT Standard Applicator, Trumpf Medizintechnik, Umkirch, Germany). The light guide possesses an optical diffusion, tip which is characterized by a homogeneous spherical or ellipsoid emission profile. The light guide was introduced into an appropriate protecting sheath (Somatex, Rietzneuendorf/b Berlin, Germany). As laser light source, we used a continuous wave Nd:YAG Laser (; cw; 4060n; Dornier Medizintechnik, Germering, Germany). Laser irradiation was performed under general anaesthesia in a 0.5 T open configuration MR system (Signa SP, GE, Milwaukee, Wisconsin, USA). Heretofore, the tip of the light guide was positioned in the center of the tumor using the built-in localization system (Flashpoint 3000, IGT, Boulder, CO, USA) in combination with a specially designed navigation system (Localite™, Bonn, Germany) if appropriate. The position of the light guide was then controlled using multiplanar reconstructions of T1-weighted sequences. For on-line control, temperature monitoring was performed using an experimental software package based on the temperature-dependent shift of the MR signal. Laser irradiation was ceased when the temperature monitoring revealed a steady-state temperature profile within the heated tissue.The first clinical long term results seem to be promising even in patients with bad clinical conditions and in patients with gliomas in unfavorable locations like in corpus callosum gliomas.

Zusammenfassung

Die Prognose von Patienten mit Hirntumoren in Form von diffus wachsenden Gliomen ist bekanntermaßen schlecht. Trotz Einführung multimodaler Therapieformen wird weiterhin nur eine Überlebenszeit zwischen Monaten und wenigen Jahren erreicht. Zur Zytoreduktion bei Gliomen wurden interstitielle Laserbestrahlungen (LITT) durchgeführt.Zur Laserbestrahlung wurde ein Neodym-YAG Laser (, cw, 4060 N, Dornier Medizintechnik, Germering, Deutschland) verwendet. Das Laserlicht wurde über eine Lichtfaser mit einem optischen Diffusor am Faserende (LITT Standard Applikator, Trumpf, Umkirch, Deutschland) übertragen. Für die stereotaktische Positionierung der flexiblen Faser wurde ein im offenen MRT (Signa SP/i, GE Milwaukee, WI, USA) eingebautes Navigationssystem (Flash point 3000, IGT, Boulder, CO, USA) verwendet. Mit Hilfe der ‘‘Phase Shift”—Technik wurde die Laser-induzierte Thermotherapie in der Echtzeit farbkodiert dargestellt. In den MRT-Verlaufskontrollen konnte in allen Fällen eine Abnahme des Tumorvolumens im Bereich der Lase-behandelten Areale nachgewiesen werden.     

Minimally invasive therapy in otorhinolaryngology and head and neck surgery

Summary

Minimally invasive surgery in ENT means replacement of the traditional, partially destructive, approaches to the area with new surgical techniques using the natural openings of the body. Such techniques require special instruments, optical aids such as the endoscope and microscope, specialized knowledge of surgical anatomy, and particularly in the region of the paranasal sinuses, a new concept of mucous membrane treatment. CO₂ laser surgery has become valuable for the treatment of inborn and acquired benign lesions of the upper aero-digestive tract in infants and adults. Laser surgery is especially useful for the management of vascularized tumours such as haemangiomas and papillomas and for stenosis since function can be preserved and tracheotomy avoided.

In recent years great advances have been made in curative and palliative laser treatment of malignant tumours of the oral cavity, oropharynx, hypo-pharynx and the larynx. Early malignant lesions can be treated by micro-endoscopically controlled laser surgery with excellent oncological results. Swallowing and vocal function can be preserved. Radical mutilating surgery for advanced stage tumours does not result in improved survival rates. Minimally invasive laser surgery is advocated where possible to avoid en bloc resection and subsequent defect repair while allowing similar survival rates with a better quality of life. Principles of minimally invasive surgery in the upper aero-digestive tract, in the paranasal sinuses and in the region of the medial orbital wall and optical nerve are presented.     

IMRT: is it Nirvana?

Abstract

Intensity modulated radiotherapy (IMRT) is a complex form of external beam radiation therapy, which is not called on commonly for palliative therapy. However, its use in day-to-day therapy is becoming more wide-spread with the increasing incorporation of new imaging and planning technologies into radiotherapy departments, together with the increasing availability of multileaf collimators and electronic portal imaging devices. In the clinical setting, IMRT is being used in a number of tumour settings where dose escalation is desirable or where there are dose-limiting organs in close proximity to the tumour. The clinical evidence and basis for treatment is discussed.     

Cellular immunotherapy for malignant gliomas

ABSTRACT

Introduction: Cancer immunotherapy has made much progress in recent years. Clinical trials evaluating a variety of immunotherapeutic approaches are underway in patients with malignant gliomas. Thanks to recent advancements in cell engineering technologies, infusion of ex vivo prepared immune cells have emerged as promising strategies of cancer immunotherapy.

Areas covered: Herein, the authors review recent and current studies using cellular immunotherapies for malignant gliomas. Specifically, they cover the following areas: a) cellular vaccine approaches using tumor cell-based or dendritic cell (DC)-based vaccines, and b) adoptive cell transfer (ACT) approaches, including lymphokine-activated killer (LAK) cells, γδ T cells, tumor-infiltrating lymphocytes (TIL), chimeric antigen receptor (CAR)-T cells and T-cell receptor (TCR) transduced T cells.

Expert opinion: While some of the recent studies have shown promising results, the ultimate success of cellular immunotherapy in brain tumor patients would require improvements in the following areas: 1) feasibility in producing cellular therapeutics; 2) identification and characterization of targetable antigens given the paucity and heterogeneity of tumor specific antigens; 3) the development of strategies to promote effector T-cell trafficking; 4) overcoming local and systemic immune suppression, and 5) proper interpretation of imaging data for brain tumor patients receiving immunotherapy.     

Combined cisplatinum and laser thermal therapy for palliation of recurrent head and neck tumors

In recent years endoscopically controlled laser-induced thermal therapy (LITT) has been increasingly accepted as a minimally invasive method for palliation of advanced or recurrent head and neck or gastrointestinal cancer. Previous studies have shown that adjuvant chemotherapy can potentiate endoscopic laser thermal ablation of obstructing tumors leading to improved palliation in advanced cancer patients. Eight patients with recurrent head and neck tumors volunteered to enroll as part of an ongoing phase II LITT clinical trial, and also elected to be treated with systemic chemotherapy (cisplatin, 80 mg/m(2)) followed 24 h later by palliative laser thermal ablation. Laser treatments were repeated in patients with residual disease or recurrence for a total of 27 LITT sessions. Four of the 8 patients treated with laser thermal chemotherapy remained alive after a median follow-up of 12 months. Of the 12 tumor sites treated, complete responses were located in the oral cavity (3), oropharynx (1), hypopharynx (1), maxillary sinus (1), and median survival for these patients was 9.5 months. This initial experience with cisplatinum-based laser chemotherapy indicates both safety and therapeutic potential for palliation of advanced head and neck cancer but this must be confirmed by longer follow-up in a larger cohort of patients.     

Active video gaming improves body coordination in survivors of childhood brain tumours

Purpose: We investigated whether active video gaming (AVG) could bring about regular, enjoyable, physical exercise in children treated for brain tumours, what level of physical activity could be reached and if the children’s physical functioning improved.

Methods: Thirteen children, aged 7–17 years, were randomised to either AVG or waiting-list. After 10–12 weeks they crossed-over. Weekly Internet coaching sessions were used to sustain motivation and evaluate enjoyment. Energy expenditure (EE) levels were measured as Metabolic Equivalent of Task (MET), using a multisensory activity monitor. Single-blinded assessments of physical functioning were done, using the Bruininks–Osteretsky Test of Motor Performance, second edition, evaluating participants before and after the intervention period, as well as comparing the randomisation groups after the first period.

Results: All patients completed the study. AVG sessions (mean duration 47?minutes) were performed on 72% of all days. Mean EE level during AVG sessions was 3.0 MET, corresponding to moderate physical activity. The Body Coordination score improved by 15% (p?=?0.021) over the intervention period.

Conclusions: In this group of childhood brain tumour survivors, home-based AVG, supported by a coach, was a feasible, enjoyable and moderately intense form of exercise that improved Body Coordination.

• Implications for Rehabilitation

• Childhood brain tumour survivors frequently have cognitive problems, inferior physical functioning and are less physically active compared to their healthy peers.

• Active video gaming (AVG), supported by Internet coaching, is a feasible home-based intervention in children treated for brain tumours, promoting enjoyable, regular physical exercise of moderate intensity.

• In this pilot study, AVG with Nintendo Wii improved Body Coordination.

     

Tumour-Targeted Treatment Intensification for Prostate Cancer Using Magnetic Resonance Imaging Guidance

IntroductionLocal control in prostate cancer may be improved with targeted dose escalation to regions with high tumour burden. Multiparametric magnetic resonance imaging (mpMRI) combined with MRI-guided biopsies may aid in defining tumour-dense regions before radiation therapy. Deformable registration techniques may be used to map these tumour regions onto the radiotherapy planning MRI. Radiation therapy delivery techniques such as volumetric modulated arc therapy and high-dose-rate brachytherapy may allow for highly conformal dose escalation, and when coupled with image-guided radiation delivery (ie, cone beam computed technology and fiducial markers), may allow high-precision dose-escalated treatment.MethodsEligible prostate cancer patients were enrolled on a prospective trial of tumour dose escalation. Two strategies were investigated: (1) an integrated boost to external beam radiation for a total tumour dose of 95 Gy in 38 fractions or (2) a focal high-dose-rate boost of 10 Gy before 76 Gy in 38 fractions external beam radiation. Patients underwent MRI-guided biopsy with fiducial marker placement before therapy. mpMRI was acquired and used in conjunction with a non-endorectal coil T2 MRI and computed technology simulation images to define the gross tumour volume via a deformable registration approach for intraprostatic tumour dose escalation.ResultsA case example for each dose escalation strategy illustrates the tumour-targeted approach using MRI guidance.ConclusionsCombining mpMRI sequences with a deformable registration approach may aid in more accurate and reproducible definition of tumour-dense regions. This novel process coupled with daily image guidance may allow high-precision dose-escalated tumour-targeted radiotherapy for prostate cancer.     

Myelin-associated proteins are potential diagnostic markers in patients with primary brain tumour

IntroductionTaking into account the possibility of myelin-associated proteins having a role in brain tumour development, the study aimed to evaluate the diagnostic usefulness of myelin-associated proteins (Nogo-A, MAG, OMgp) released into extracellular space in patients with brain tumours.Patients and methodsProtein concentration in primary brain tumour (n = 49) and non-tumoural subjects (n = 24) was measured in cerebrospinal fluid (CSF) and serum by means of ELISA. Immunohistochemistry for IDH1-R132H was done on 5-μm thick formalin-fixed, paraffin-embedded tumour sections with the use of an antibody specific for the mutant IDH1-R132H protein.ResultsThe receiver operator characteristic curve analysis showed that CSF Nogo-A and serum MAG were useful in differentiating patients with primary brain tumour from non-tumoural individuals. This was also true in the case of the separate analysis of the astrocytic tumour versus non-tumoural groups and the meningeal tumour versus non-tumoural groups. Neither Nogo-A nor MAG or OMgp concentrations were significantly different, in serum or CSF, between IDH1 wild-type astrocytic brain tumour patients compared to IDH1 mutant patients.ConclusionsOur results indicated the potential usefulness of CSF Nogo-A and serum MAG evaluation as circulating biomarkers of primary brain tumours. Because blood is relatively easy to obtain, future research should be conducted to explicitly indicate the value of serum MAG concentration evaluation as a brain tumour biomarker.

Key messages

1. Myelin-associated proteins may be circulating brain tumour biomarkers.
2. Nogo-A and MAG proteins seem to be the most useful in brain tumour diagnosis.
3. Decreased CSF Nogo-A concentration is an adverse prognostic factor for patients’ survival.

     

The past,present and future of minimally invasive therapy in urology: A review and speculative outlook

Abstract

Introduction: Twenty-five years of SMIT represents an important date. In this article we want to elaborate the development of minimally invasive surgery in urology during the last three decades and try to look 25 years ahead. Material and methods: As classical scenarios to demonstrate the changes which have revolutionized surgical treatment in urology, we have selected the management of urolithiasis, renal tumour, and localized prostate cancer. This was based on personal experience and a review of the recent literature on MIS in Urology on a MEDLINE/PUBMED research. For the outlook to the future, we have taken the expertise of two senior urologists, middle-aged experts, and upcoming junior fellows, respectively. Results: Management of urolithiasis has been revolutionized with the introduction of non-invasive extracorporeal shock wave lithotripsy (ESWL) and minimally invasive endourology in the mid-eighties of the last century obviating open surgery. This trend has been continued with perfection and miniaturization of endourologic armamentarium rather than significantly improving ESWL. The main goal is now to get rid of the stone in one session rather in multiple non-invasive treatment sessions. Stone treatment 25 years from today will be individualized by genetic screening of stone formers, using improved ESWL-devices for small stones and transuretereal or percutaneous stone retrieval for larger and multiple stones. Management of renal tumours has also changed significantly over the last 25 years. In 1988, open radical nephrectomy was the only therapeutic option for renal masses. Nowadays, tumour size determines the choice of treatment. Tumours >4 cm are usually treated by laparoscopic nephrectomy, smaller tumours, however, can be treated either by open, laparoscopic or robot-assisted partial nephrectomy. For patients with high co-morbidity focal tumour ablation or even active surveillance represents a viable option. In 25 years, imaging of tumours will further support early diagnosis, but will also be able to determine the pathohistological pattern of the tumour to decide whether the patient requires removal, ablation or active surveillance. Management of localized prostate cancer underwent significant changes as well. 25 years ago open retropubic nerve-sparing radical prostatectomy was introduced as the optimal option for effective treatment of the cancer providing minimal side-effects. Basically, the same operation is performed today, but with robot-assisted laparoscopic techniques providing 7-DOF instruments, 3D-vision and tenfold magnification and enabling the surgeon to work in a sitting position at the console. In 25 years, prostate cancer may be managed in most cases by focal therapy and/or genetically targeting therapy. Only a few patients may still require robot-assisted removal of the entire gland. Discussion: There has been a dramatic change in the management of the most frequent urologic diseases almost completely replacing open surgery by minimally invasive techniques. This was promoted by technical realisation of physical principles (shock waves, optical resolution, master-slave system) used outside of medicine. The future of medicine may lie in translational approaches individualizing the management based on genetic information and focalizing the treatment by further improvement of imaging technology.     

瘤周区的rADC值测定在高级胶质瘤与单发脑转移瘤鉴别诊断中的价值

目的探讨弥散加权成像(difusion weighted imaging,DWI)的rADC值测量在高级胶质瘤与单发脑转移瘤鉴别诊断中的应用价值.方法对经手术病理证实的27例高级胶质瘤与19例脑转移瘤,在术前接受了常规MRI检查及DWI.分别测定感兴趣区ROI的ADC值,并计算其rADC值.结果高级胶质瘤瘤体的rADC值(1.27±0.17)与单发脑转移瘤瘤体的rADC值(1.23±0.18)间无显著性差异(P＞0.10);高级胶质瘤远瘤周区的rADC值(2.37±0.34)与单发脑转移瘤上述区域的rADC值(2.48±0.44)间亦无显著性差异(P＞0.10);但高级胶质瘤近瘤周区的rADC值(1.41±0.21)与单发脑转移瘤上述区域的rADC值(2.25±0.17)间存在显著的差异(P＜0.001).结论测定高级胶质瘤与单发脑转移瘤瘤体及远瘤周区的rADC值在二者鉴别诊断中的价值不大,测定二者近瘤周区的rADC值在二者鉴别诊断中具有一定的价值.     

Laser-induced thermotherapy of malignant liver tumors: general principals, equipment(s), procedure(s)--side effects, complications and results.

PURPOSE: To prospectively evaluate the therapeutic potential of MR-guided and ultrasound-guided laser-induced thermotherapy (LITT) in patients with liver metastases and oligonodular hepatocellular carcinoma (HCC). MATERIAL AND METHODS: Between June 1993 and June 2000 a total of 1608 LITT sessions was performed to treat 1914 lesions in 676 consecutive patients. The Nd-YAG laser fiber was introduced with a percutaneously positioned cooled application set. Qualitative and quantitative ultrasound and magnetic resonance (MR) parameters, as well as clinical data were evaluated. RESULTS: All patients tolerated the procedure well under local anesthesia; no relevant clinical complications were observed. The mean laser power was 25 W and the mean duration was 25 min. MR proved to be superior over computed tomography and ultrasound due the thermosensitivity of the MR sequences allowing a better visualization of the volume of laser-induced changes and their relation to the neighboring geographical structures. The ultrasound-guided LITT should be restricted for patients with contraindications for MR imaging monitoring and for selected patients with low diameter oligonodular HCC. In 95% of cases, we achieved a complete necrosis of the tumor and a 5-mm safety margin, resulting in a complete destruction of the tumor without local recurrences. Mean survival in this group was 35 months (calculated with the Kaplan-Meier method). CONCLUSION: MR-guided, or ultrasound-guided, LITT appears to be a safe and effective treatment protocol for liver metastases and oligonodular HCC.     

体素内不相干运动成像用于脑胶质瘤分级:Meta分析

目的 以Meta分析方法评价体素内不相干运动（IVIM）成像参数真性扩散系数（D）、假性扩散系数（D^*）及灌注分数（f）鉴别高、低级别脑胶质瘤的价值。方法 检索EMbase、PubMed、中国生物医学文献数据库、中国知网、万方医学网和维普数据库中自建库至2020年2月关于IVIM各参数鉴别诊断高、低级别脑胶质瘤的相关文献,依据纳入及排除标准筛选文献。以Metadisc 1.4及STATA 15.1软件行Meta分析。结果 共13篇文献（中文8篇,英文5篇）纳入研究,包括590例患者,其中350例高级别、240例低级别脑胶质瘤患者。D、D^*、f对分级诊断高、低级别脑胶质瘤无明显阈值效应（r=0.609、-0.387、-0.091,P=0.074、0.214、0.790）。异质性分析结果显示文献间无明显异质性,故采用固定效应模型进行分析。D、D^*及f鉴别诊断高、低级别脑胶质瘤的合并敏感度分别为0.86[95%CI（0.81,0.89）]、0.81[95%CI（0.76,0.85）]及0.80[95%CI（0.75,0.84）],合并特异度分别为0.74[95%CI（0.67,0.80）]、0.75[95%CI（0.69,0.81）]及0.80[95%CI（0.74,0.85）];综合受试者工作特征（SROC）曲线结果示D、D^*及f的曲线下面积（AUC）分别为0.898、0.860级0.874。结论 IVIM参数D、D^*、f值对鉴别诊断高、低级别脑胶质瘤均有一定临床应用价值,且三者诊断效能相当。