The technique of stereotactic I125 brachytherapy (permanent implants) of brain tumors in Vienna

Methods of stereotactic target localisation are used in brachytherapy of brain tumors for many years. Since 1987 eight patients with inoperable astrocytomas grade I to III were treated at the Neurosurgical Clinic and Clinic for Radiotherapy of the University Vienna by permanent stereotactic I125-seed implantation. For that purpose a newly developed applicator was used. Preliminary results confine the low risk of operation, but the follow-up time is too short for evaluation of the treatment success. Principal problems of brain brachytherapy are discussed in the light of international data. In general, I125 brachytherapy is a useful and well tolerated way of treatment of low grade astrocytomas, the risk is low, which is especially important for children and old patients.     

192Ir核素脑胶质瘤间质内放疗的研究及其临床应用

为观察用＾１９２Ｉｒ后装治疗脑胶质瘤间后内放疗的有效性及其并发症,用皮荷瘤鼠和脑荷瘤鼠模型行间质内放疗实验,证明在内照射后可抑制肿瘤生长及延长鼠的生存期的可靠基础上,对７２例脑胶质瘤采用＾１９２Ｉｒ后装机行瘤间后内近距离照射,取得良好疗效。手术无何严重并发症,无死亡。术后随访１－５年,生存率分别为９２％、８２％、７２％、５６％及３２％,表明生存期显著延长。结论脑深部胶质瘤用＾１９２Ｉｒ核素瘤间持     

Iodine-125 Brachytherapy of Brain Stem Tumors

PURPOSE: To report on iodine-125 ((125)I) interstitial irradiation in the treatment of brain stem tumors. PATIENTS AND METHODS: Two patients with brain stem tumors were treated with CT- and image fusion-guided (125)I stereotactic brachytherapy. RESULTS: By March 2003, the patients had been followed up for 47 and 13 months, respectively. In case 1, the tumor volume was 1.98 cm(3) on the control CT, indicating a 65.5% shrinkage as compared to a target volume of 5.73 cm3 at the time of brachytherapy. In case 2, shrinkage was more distinct. After irradiation, the cyst volume was 0.16 cm(3) on the control MRI, indicating a 97.4% shrinkage as compared to a target volume of 6.05 cm(3) at the time of brachytherapy, i. e., the metastasis had virtually disappeared. CONCLUSION: CT- and image fusion-guided (125)I stereotactic brachytherapy can be performed during the biopsy session. The procedure can be well planned dosimetrically and is surgically precise.     

Interstitial iridium-192 implantation for malignant brain tumours. Part I: Techniques of dosimetry planning

Interstitial implants for brain tumours with removable iridium-192 radioactive seeds have been performed using a Brown-Roberts-Wells stereotactic frame. A simple and accurate computed-tomography-guided dosimetry pre-planning technique and procedure prior to implant have been developed and are discussed.     

Intraoperative brachytherapy for resected brain metastases

Brain metastases are the most common intracranial malignancies in adults. Surgical resection is the preferred treatment approach when a pathological diagnosis is required, for symptomatic patients who are refractory to steroids, and to decompress lesions causing mass effect. Radiotherapy is administered to improve local control rates after surgical resection. After a brief review of the literature describing the treatment of brain metastases using whole-brain radiotherapy, postoperative stereotactic radiosurgery, preoperative radiosurgery, and brachytherapy, we compare patient-related, technical, practical, and radiobiological considerations of each technique. Finally, we focus our discussion on intraoperative brachytherapy, with an emphasis on the technical aspects, benefits, efficacy, and outcomes of studies utilizing permanent Cs-131 implants.     

Microwave hyperthermia radiosensitized iridium-192 for recurrent brain malignancy

Twenty-one patients whose solitary detectable biopsy proven recurrent brain malignancies produced Central Nervous System (CNS) symptoms warranting further intervention received 60-minute 43 degrees C (180 degree-minute) interstitial 2450 MHz microwave hyperthermia fractions. All received brain teletherapy prior to recurrence. The first 15 received no brachytherapy and served as a toxicity pilot. All 15 enjoyed neurologic improvement, 12 symptomatic improvement, and 12 objective response as mass reduction and/or tumor necrosis. The next 6 patients were selected with more favorable Karnofsky performance status, no known active malignancy elsewhere, and received afterloading Ir-192 interstitial implantation juxtaposed to radiosensitizing hyperthermia. Volume dose varied from 1000 to 2245 rad, and dose rate from 40 to 100 rad/hr. Dose selected varied as a function of pre-recurrence teletherapy dose, general condition, histologic type, and volume. Neurosurgical debulking, if technically indicated through no additional aperture or trauma, was permitted if consistent with preservation of neurological function. Six enjoyed neurologic improvement, symptom reduction, and objective tumor response; three remain alive, and one experienced transient improvement. Complications, histologic subtypes, autopsy findings, stereotactic approach, thermal monitoring methods and CT follow-up of objective response are presented along with computer dosimetry and isotherm chart. Our microtraumatic universal catheter technique for CT guided stereotactic biopsy, aspiration, decompression, thermal sensory loop, thermalization antennae, and brachytherapy without multiple trauma nor changing catheters is stressed. The rationale for combined modes peculiar to the CNS will be outlined.2+ Proposal for incorporating controlled-release ARA-C chemotherapy polymer micro-rods into the interstitial format will be offered. The preceeding is an FDA-approved controlled clinical trial.(ABSTRACT TRUNCATED AT 250 WORDS)     

Preoperative mapping of cortical language areas in adult brain tumour patients using PET and individual non-normalised SPM analyses

In patients scheduled for the resection of perisylvian brain tumours, knowledge of the cortical topography of language functions is crucial in order to avoid neurological deficits. We investigated the applicability of statistical parametric mapping (SPM) without stereotactic normalisation for individual preoperative language function brain mapping using positron emission tomography (PET). Seven right-handed adult patients with left-sided brain tumours (six frontal and one temporal) underwent 12 oxygen-15 labelled water PET scans during overt verb generation and rest. Individual activation maps were calculated for P<0.005 and P<0.001 without anatomical normalisation and overlaid onto the individuals' magnetic resonance images for preoperative planning. Activations corresponding to Broca's and Wernicke's areas were found in five and six cases, respectively, for P<0.005 and in three and six cases, respectively, for P<0.001. One patient with a glioma located in the classical Broca's area without aphasic symptoms presented an activation of the adjacent inferior frontal cortex and of a right-sided area homologous to Broca's area. Four additional patients with left frontal tumours also presented activations of the right-sided Broca's homologue; two of these showed aphasic symptoms and two only a weak or no activation of Broca's area. Other frequently observed activations included bilaterally the superior temporal gyri, prefrontal cortices, anterior insulae, motor areas and the cerebellum. The middle and inferior temporal gyri were activated predominantly on the left. An SPM group analysis ( P<0.05, corrected) in patients with left frontal tumours confirmed the activation pattern shown by the individual analyses. We conclude that SPM analyses without stereotactic normalisation offer a promising alternative for analysing individual preoperative language function brain mapping studies. The observed right frontal activations agree with proposed reorganisation processes, but they may also reflect an unspecific recruitment of the right-sided Broca's homologue in the effort to perform the task.     

Accuracy of 3-D Needle Navigation in Interstitial Brachytherapy in Various Body Regions

BACKGROUND: Precise immobilisation of a patient during extracranial stereotactic 3-D navigation is essential in order to minimize the patient's movement during CT data recording and needle application. In this paper we report the first results of needle positioning accuracy in various body regions, using a 3-D navigation system for brachytherapy and a new patient immobilisation system. PATIENTS AND METHODS: Six patients with different manifestations of neoplastic diseases were immobilized by a special vacuum system and treated with stereotactic 3-D navigational interstitial brachytherapy. RESULTS: The comparison of the simulated stereotactic needle positions with the actual needle positions resulted in a mean positioning deviation varying from 3.4 to 6.5 mm for 29 needles. The maximum positioning deviation lay between 5.7 and 13 mm. CONCLUSION: The results of our study show that, despite effective patient immobilisation, an increase in needle positioning accuracy is limited by the method of stereotactic 3-D navigation. Effects such as modification of body shape caused by the needle application morphologic alterations, and inherent inaccuracies within the navigation system have an important influence upon accuracy, which it is not yet possible to calculate.     

The value of intraoperative scans during CT-guided stereotactic procedures

Sumamry The accuracy stereotactic procedures performed during the pre-computed tomography (CT) era was confirmed by intraoperative X-ray pictures. With the availability of CT it is now possible to confirm the position of the probe-tip on an image of the target. For biopsy of small lesions in critical areas of the brain, permanent placement of radioactive seeds, or thalamotomy, it would be desirable to have confirmation of the site of the probetip prior to performing the main step of the procedure. Intraoperative CT was performed in 216 stereotactic procedures carried out on the scanner table including biopsies, aspiration of cysts, brachytherapy, aspiration of abscesses, thalamotomy, and evacuation of intracerebral hematoma. In 6 cases, inaccuracies were detected, which it was possible to correct so as to place the probe where desired.     

The blood tumour barrier in intracranial tumours studied with X-ray computed tomography and positron emission tomography using 68-Ga-EDTA

Summary Disruption of the blood brain barrier or rather blood tumour barrier in cerebral tumours was studied with CT after intravenous injection of contrast medium and with PET after intravenous administration of 68-Ga-EDTA. Histology from stereotactic biopsies or open surgery is compared with the radiologic findings and advantages of the respective methods are discussed. The material consisted of 47 patients mainly with supratentorial gliomas and a few miscellaneous tumours. Astrocytomas (Kernohan grade II) were found to have no disruption of blood tumour barrier while anaplastic astrocytomas and glioblastomas (Kernohan grade III and IV) had. PET is somewhat superior to CT in detection of disruption of the blood tumour barrier. It is concluded that the combination of CT and PET is of value in the assessment of intracranial tumours.     

Brachytherapy: A critical component of primary radiation therapy for cervical cancer: From the Society of Gynecologic Oncology (SGO) and the American Brachytherapy Society (ABS)

Brachytherapy is well-established as an integral component in the standard of care for treatment of patients receiving primary radiotherapy for cervical cancer. A decline in brachytherapy has been associated with negative impacts on survival in the era of modern EBRT techniques. Conformal external beam therapies such intensity modulated radiation therapy (IMRT) or stereotactic body radiation therapy (SBRT) should not be used as alternatives to brachytherapy in patients undergoing primary curative-intent radiation therapy for cervical cancer. Computed tomography or magnetic resonance image-guided adaptive brachytherapy is evolving as the preferred brachytherapy method. With careful care coordination EBRT and brachytherapy can be successfully delivered at different treatment centers without compromising treatment time and outcome in areas where access to brachytherapy maybe limited.     

立体定向近距离消融治疗概念的提出与实践

随着肿瘤近距离治疗和消融治疗技术的发展,临床疗效可以达到消融治疗的目的。本文首次提出立体定向近距离消融(stereotactic ablation brachytherapy,SABT)概念,同时将SABT分为两类:H-SABT和L-SABT。H-SABT是指高剂量率后装近距离消融治疗,L-SABT是指低剂量率近距离消融治疗,也就是临床常用的放射性粒子植入治疗。SABT具有大分割,短疗程;影像引导,精确性高;疗效确切,可以达到手术切除式的疗效;器官功能保留的特点。立体定向近距离消融治疗已逐渐形成了独立的微创治疗技术体系,未来在肿瘤治疗领域将占有一席之地。     

Head and neck tumors: fractionated frameless stereotactic interstitial brachytherapy-initial experience

The authors used a frameless stereotactic navigation system, the Vogele-Bale-Hohner head holder, and a targeting device to reproducibly position brachytherapy needles for fractionated interstitial brachytherapy in 12 patients with inoperable cancers of the head and neck. In all cases, deviations of the needle relative to the planned position were within 1-15 mm depending on the location of the tumor.     

Update of radiosurgery at the Royal Adelaide Hospital

This is an update of the Royal Adelaide Hospital radiosurgery experience between November 1993 and December 2004 comprising 165 patients with 168 intracranial lesions. Including re-treatment, there were 175 treatment episodes (163 radiosurgery and 12 stereotactic radiotherapy) at an average of 1.3 per month. The commonest lesions were acoustic neuroma (65), arteriovenous malformation (58), solitary brain metastasis (23) and meningioma (14). The clinical features, treatment details and outcome are described. Our results continue to be well within the range reported in the published work. Radiosurgery provides an elegant, non-invasive alternative to neurosurgery and conventional external beam radiotherapy for many benign and malignant brain tumours.     

Stereotactic radiosurgery in neurosurgery

Gamma-knife stereotactic radiosurgery offers a broad spectrum armamentarium for the safe treatment of various lesions within the central nervous system. It is widely used for treatment of metastastic brain tumors, non respectable tumours, residual or recurrent benign and malignant tumors as well as for treatment of arteriovenous malformations, functional diseases and pain disorders. It is less invasive than most other surgical methods and also cost effective compared to surgical methods and other radiation treatments.     

Evaluation of l-3-[123I]iodo-α-methyltyrosine SPET and [18F]fluorodeoxyglucose PET in the detection and grading of recurrences in patients pretreated for gliomas at follow-up: a comparative study with stereotactic biopsy

. Based on the results of stereotactic biopsy, we evaluated in a prospective fashion the efficiency of l-3-[¹²³I]iodo-α-methyltyrosine-single-photon emission tomography (SPET) and [¹⁸F]fluorodeoxyglucose (FDG) positron emission tomography (PET) in the detection and grading of recurrences in patients previously treated for gliomas. The patient population comprised 30 individuals, nine with astrocytomas of grade II, ten with astrocytomas of grade IV, three with oligoastrocytomas of grade II, six with oligodendrogliomas of grade II and two with anaplastic oligodendrogliomas of grade III) suspected of recurrence and scheduled for further treatment. IMT SPET data were acquired using either by dual-or a triple-headed SPET camera, Multispect 2/3. FDG uptake was measured with an ECAT ART PET camera. Two independent observers classified PET and SPET images as positive or negative for tumour tissue. Uptake of FDG and IMT was evaluated visually and, in the case of IMT, also quantitatively by calculating the ratios between tracer accumulation in the lesion and the unaffected contralateral regions of reference using the region of interest (ROI) technique. The PET and SPET results were compared with the histopathological findings obtained either by stereotactic biopsy or in one case by open surgery. Glucose metabolism and amino acid uptake of recurrences of brain tumours as assessed by FDG-PET and IMT-SPET correlated highly with the histopathological findings. Based on the histopathological data, FDG-PET and IMT-SPET findings confirmed recurrence in all cases of high-grade gliomas (IV). A difference could be demonstrated in low-grade (II–III) tumour recurrences. True-positive IMT-SPET results were found in 86% of grade III and 75% of grade II recurrences, whereas FDG-PET yielded a sensitivity of 71% in tumours of grade III and 50% in those of grade II. With respect to the grade of malignancy of brain tumours at recurrence, IMT-SPET, in contrast to FDG-PET, does not permit adequate in vivo grading of non-mixed brain tumours of astrocytic or oligodendroglial origin. However, in this study FDG-PET did not permit discrimination between upgrading of low-grade oligoastrocytomas (II) into anaplastic oligodendrogliomas (III) and upgrading into glioblastomas (IV) The results of this study indicate that FDG-PET and IMT-SPET are equivalent to stereotactic biopsy in their ability to identify high-grade tumours at recurrence. IMT-SPET proved to be superior to FDG-PET in confirming low-grade recurrences. In the case of suspected progression of the grade of malignancy in ordinary gliomas, FDG-PET correlated significantly with the histopathological grading, whereas IMT-SPET did not. However, tumour grading by FDG-PET has a limitation in mixed brain tumours in that it is not possible to discriminate between progression of the oligo- versus the astrocytic tumour entity. In this case histopathological evaluation of the tumour grade remains necessary. Received 6 August and in revised form 2 November 1998     

MRA-guided stereotactic radiation treatment planning for cerebral angiomas.

Stereotactic neurosurgical interventions are characterized by a high risk of rupturing intracranial vessels or damaging vital brain structures. By MRI and MRA, the anatomic information necessary for stereotactic treatment planning may be assessed with a single modality as a high-resolution digital image volume. The adequacy of MR as a modality for stereotactic guidance is demonstrated by the example of the radiosurgical treatment of cerebral angiomas. An optimized acquisition protocol, a stereotactic apparatus, a distortion correction and minimization method, and a 3D treatment planning workstation are elements of a proposed preoperative approach which in a clinical study met with good acceptance.     

Understanding the underutilization of cervical brachytherapy for locally advanced cervical cancer

PurposeTo understand the reasons behind current low utilization of brachytherapy for locally advanced cervical cancer in the United States.Methods and MaterialsA 17-item survey was e-mailed to the American Brachytherapy Society (ABS) listserv of active members in 2018. Responses of attending physicians in the United States were included in the analysis.ResultsAmong a total of 135 respondents, 81 completed the survey. Eighty-four percent agree/strongly agree that cervical brachytherapy is underutilized, and 46.9% disagree/strongly disagree that residents are receiving adequate training for brachytherapy; 75.3% agree/strongly agree that inadequate maintenance of brachytherapy skills is a major obstacle to brachytherapy use; and 71.6% agree/strongly agree that increased time requirement constitutes a major obstacle. Over 97% will recommend brachytherapy for most patients with cervical cancer if given access/time; 72.8% always perform their own brachytherapy, whereas 29.6% reported some type of barrier exists in performing brachytherapy themselves, with time required to perform brachytherapy (9.9%) being a leading factor. A quarter (24.7%) routinely refer to other radiation oncologists for brachytherapy. Even among ABS members, 37.0% reported that they would perform an intensity-modulated radiation therapy or stereotactic body radiation therapy boost in specific scenarios in potentially curable patients. The most common scenario is inability to place a uterine tandem (56.7%).ConclusionsThe underutilization of brachytherapy in cervical cancer is widely recognized by ABS members with inadequate training during residency and inadequate maintenance of skills being possible major contributing factors. Even among ABS members, there are identifiable barriers. Continued advocacy and future initiatives in enhancing access to brachytherapy training and efficiency are needed.     

Use of MR angiography for stereotactic planning.

With the introduction of MR angiography (MRA) into clinical routine MR protocols, it has become possible now to image flowing as well as stationary tissue with excellent contrast using a single modality. This has opened up new perspectives for planning stereotactic approaches, which are characterized by high risks for damaging intracerebral vessels or vital brain structures. In this article we present an MRA based planning method for the treatment of arteriovenous malformations by stereotactic radiosurgery. It includes flow compensated gradient echo pulse sequences for the acquisition of angiographic MR datasets, a stereotactic MR marker system, an algorithm for the correction of geometric distortion of MR image data, and a three-dimensional workstation system for the creation and evaluation of treatment plans. The latter is based on the concept of simultaneously displaying both MR slice and angiographic projection images. This allows the evaluation of intracerebral vasculature together with brain anatomy. The MRA guided planning approach was tested and compared to a conventional X-ray angiographic technique in a clinical study. Our satisfactory results suggest that MRA is a technique that can be used advantageously for stereotactic planning.     

Computer tomography-guided stereotaxic biopsy of intracranial lesions. Simple technic for the calculation of coordinates; method for the reduction of operative risk in the critical areas of the brain

The authors describe an original technique to calculate the coordinates for CT-guided stereotactic biopsies of brain lesions. On the basis of simple trigonometric formulas it is possible to get an accuracy of +/- 1 mm. By means of the standard software of a high precision CT and with a CT-compatible stereotactic apparatus the x, y, and z coordinates are obtained in a quick and reliable way. A further development of the trigonometric approach to the stereotactic calculations is the "double target technique". It allows to preset the path of the biopsy-device through a selected point, to reach the final target: in this way a valuable reduction of the surgical risk is afforded especially in critical areas of the brain (brain stem, pineal region etc.).