Stereotactic radiotherapy for the treatment of acoustic neuromas.
ABSTRACT The authors sought to assess the safety and efficacy of stereotactic radiotherapy when using a linear accelerator equipped with a micromultileaf collimator for the treatment of patients with acoustic neuromas.
Fifty patients harboring acoustic neuromas were treated with stereotactic radiotherapy between September 1997 and June 2003. Two patients were lost to follow-up review. Patient age ranged from 20 to 76 years (median 59 years), and none had neurofibromatosis. Forty-two patients had useful hearing prior to stereotactic radiotherapy. The fifth and seventh cranial nerve functions were normal in 44 and 46 patients, respectively. Tumor volume ranged from 0.3 to 19.25 ml (median 2.51 ml). The largest tumor dimension varied from 0.6 to 4 cm (median 2.2 cm). Treatment planning in all patients included computerized tomography and magnetic resonance image fusion and beam shaping by using a micromultileaf collimator. The planning target volume included the contrast-enhancing tumor mass and a margin of normal tissue varying from 1 to 3 mm (median 2 mm). All tumors were treated with 6-MV photons and received 54 Gy prescribed at the 90% isodose line encompassing the planning target volume. A sustained increase greater than 2 mm in any tumor dimension was defined as local relapse. The follow-up duration varied from 6 to 74 months (median 36 months). The local tumor control rate in the 48 patients available for follow up was 100%. Central tumor hypodensity occurred in 32 patients (67%) at a median of 6 months following stereotactic radiotherapy. In 12 patients (25%), tumor size increased 1 to 2 mm at a median of 6 months following stereotactic radiotherapy. Increased tumor size in six of these patients was transient. In 13 patients (27%), tumor size decreased 1 to 14 mm at a median of 6 months after treatment. Useful hearing was preserved in 39 patients (93%). New facial numbness occurred in one patient (2.2%) with normal fifth cranial nerve function prior to stereotactic radiotherapy. New facial palsy occurred in one patient (2.1 %) with normal seventh cranial nerve function prior to treatment. No patient's pretreatment dysfunction of the fifth or seventh cranial nerve worsened after stereotactic radiotherapy. Tinnitus improved in six patients and worsened in two.
Stereotactic radiotherapy using field shaping for the treatment of acoustic neuromas achieves high rates of tumor control and preservation of useful hearing. The technique produces low rates of damage to the fifth and seventh cranial nerves. Long-term follow-up studies are necessary to confirm these findings.
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ABSTRACT: IntroductionMost previous reports indicate that traditional bilateral kyphoplasty improves patient function and restores height of collapsed vertebral bodies, but limited data about the effects of unilateral kyphoplasty on clinical and radiological outcome are available. Material and methodsOne hundred five patients were treated by unilateral kyphoplasty between January 2004 and December 2006. These patients underwent 105 operations to treat 132 vertebral compression fractures between T8 and L5. Sagittal alignment was analyzed from standing radiographs. Clinical outcomes were determined by comparison of preoperative and postoperative data from patient-reported index (visual analogue pain scale score). Radiographs were assessed as to percent vertebral collapse, vertebral height restoration and local kyphosis correction. ResultsMean length of follow-up was 15.3 months (range 3-36 months); improved height 2.3 and 4.0 mm in the anterior and medial columns, respectively (P>0.05); Cobb angle increased 3.0° (P<0.05), visual analogue pain scale score improved from 8.7 ±1.4 before surgery to 2.3 ± 0.9 (P < 0.05); no adverse medical or procedural complications; 6.8% (9/132) cement leakage rate. ConclusionUnilateral transpedicular kyphoplasty improves physical function, reduces pain, and may correct kyphotic deformity associated with vertebral compression fractures. This result shows comparable to traditional bilateral kyphoplasty procedure.12/2007: pages 157-160;
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ABSTRACT: IntroductionRadiosurgery evolved from brain to spine. Mechanical and computer advances in linear accelerator (LINAC) radiosurgery apply precise single/fractional stereotactic radiation to multiple pathologies. MethodsDuring a 10-year span the senior author used proton-beam radiosurgery in over 300 lesions, followed by gamma-knife, adapted and dedicated LINACS, including cyber-knife, in another 700 patients. The last 10 years, experience was accumulated with the Novalis in over 3,000 patients. Novalis uses a beam-shaper in a high-speed delivery LINAC. It operates using conventional circular arc, conformai static beam, dynamic conformai or intensity modulated modes. Patients treated with Novalis at the UCLA since 1997 were evaluated regarding effectiveness, complications and failure. These results were compared with previous 1997 data. ResultsOver 4,000 patients with trigeminal neuralgia/intractable pain, arteriovenous malformations/angiomas, métastases, ependymomas, gliomas, meningiomas hemangiopericytomas, schwannomas, adenomas, hemangioblastomas, and chordoma were treated. Spinal lesions were treated with frameless stereotaxis and on-line precision checks. Treatment was expeditious, comfortable and with reduced complications. Success is similar or superior to published data. Reduced treatment time of complex lesions and highly homogeneous dose compares favorably to other radiosurgery. ConclusionsThe senior author’s experience validates the novel shaped-beam approach. Long-term follow-up supports safety and effectiveness and capability to treat brain and spine.12/2007: pages 163-168;
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ABSTRACT: Analysis of the results of the various methods for treatment of typical trigeminal neuralgia (TN) based on the literature and personal experience. The personal experience includes 847 cases: total thyzotomy in the posterior fossa 17 cases; rhyzotomy in the posterior fossa sparing the intermediate fibers 16 cases; microvascular decompression (MVD) 141 cases; controlled thermorhizotomy (PTR) 54 cases; Fogarty Balloon compression (FBC) 223 cases; glycerol ganglyolis (PGG) 12 cases; miscellaneous 48 case; medical treatment only 310 cases; cyberknife radiosurgery (CKR) 46 cases. The follow-up in this series is 1–32 years. MVD of the Vth cranial nerve in posterior fossa gives the best results in term of long-term pain relief without collateral effects in drug-resistant TN. Percutaneous techniques (PTR, PGG, FBC) are indicated in patients either without neurovascular conflict or with excessive surgical risk. Stereotactic radiosurgery (SRS) and CKR might be considered an improvement of percutaneous and surgical techniques, but contrary to the expectations, the rate of complete pain relief at long term is lower. SRS and CKR are less effective than MVD which, in spite of the risks it entails, remains the choice treatment for typical trigeminal neuralgia.12/2007: pages 27-33;