Isabelle M. Germano

Intrathecal baclofen for dystonia: benefits and complications during six years of experience.

Fourteen patients with primary or secondary dystonia received intrathecal baclofen (ITB) through an implanted pump following a trial dose. Patients were selected for ITB trial if they had clinically unsatisfactory responses to oral antidystonic medications, including oral baclofen. Patients were rated using the Burke‐Fahn‐Marsden rating scale by a blinded rater after the dose of ITB was optimized. Five patients experienced improvement in symptoms as determined by a change in rating scale scores, although only two had a clear clinical benefit. Etiology of dystonia did not determine the efficacy of ITB therapy, as benefit or failure was seen in both primary and secondary dystonia.

Intracerebral hemorrhage occurring remote from the craniotomy site.

OBJECTIVEnThe purpose of this study was to analyze the available clinical data on postoperative intracerebral hemorrhages that occur in locations remote from the sites of craniotomy.nnnMETHODSnThe findings of 37 cases of postoperative intracerebral hemorrhages occurring remote from the craniotomy sites were reviewed (5 from our records and 32 from the literature).nnnRESULTSnRemote postoperative intracerebral hemorrhages presented within the first few hours postoperatively in 78% of the patients and were not related to the types of lesions for which the craniotomies were performed. Supratentorial procedures that produced infratentorial hemorrhages involved operations in the deep sylvian fissure and paraclinoid region in 81% of the patients and hemorrhages in the cerebellar vermis in 67% of the patients. Infratentorial procedures that produced supratentorial hemorrhages were performed with the patient in the sitting position for 87% of the patients. The remote supratentorial hemorrhages that occurred were superficial and lobar in 84% of the patients, as opposed to deep and basal ganglionic, which are classic locations for hypertensive hemorrhages. Remote intracerebral hemorrhages occurring after craniotomies were not associated with hypertension, coagulopathy, cerebrospinal fluid drainage, or underlying occult lesions. These hemorrhages commonly led to significant complications; 5 of 37 patients (14%) were left severely disabled, and 12 of 37 patients (32%) died.nnnCONCLUSIONSnRemote intracerebral hemorrhage is a rare complication of craniotomy with significant morbidity and mortality. Such hemorrhages likely develop at or soon after surgery, tend to occur preferentially in certain locations, and can be related to the craniotomy site, operative positioning, and nonspecific mechanical factors. They do not seem to be related to hypertension, coagulopathy, cerebrospinal fluid drainage, or underlying pathological abnormalities.

Clinical Evaluation of Multimodality Registration in Frameless Stereotaxy

Computer-assisted frameless neurosurgery bases its accuracy and reliability on registration. The aim of this prospective study was to compare the clinical accuracy of different registration techniques used for computer-assisted frameless neurosurgery. Ninety-eight registrations in 44 patients were used to compare the clinical accuracy of self-adhesive marker (MR) and facial landmark (FR) registrations used alone or in conjunction with surface-fit registration (MR/SR and FR/SR, respectively) for cranial neurosurgery. The computer estimated error (CEE) of each registration was compared to the real error (RE). This was obtained by holding the frameless pointer at the center of three different markers and measuring the distance from the real-time representation on the computer three-planar images to the center of the marker on the screen. The most accurate registration was obtained using MR; the RE of MR was 1.6 +/- 0.1 mm compared to 3.4 +/- 0.4 mm for FR. Although the smallest CEE error was obtained using MR/SR, this was not sustained by the RE. Furthermore, the RE of FR/SR was significantly larger than the CEE (Student t test, p <.001). This study corroborates previous results showing that, in the clinical setting, self-adhesive marker registration is more accurate than facial landmark registration. Furthermore, although surface-fit registration can be used in conjunction with self-adhesive marker registration, this does not improve the degree of real accuracy for cranial registration.

Clinical outcome of vertebral compression fracture after single fraction spine radiosurgery for spinal metastases.

AbstractnVertebral compression fracture (VCF) occurs after stereotactic body radiation therapy (SBRT) for spine metastasis. Recently, single fraction radiosurgery (sfSRS) is used more frequently. The aim of this study is to determine the clinical outcome of VCF after sfSRS. Spinal instability neoplastic score (SINS) criteria were used to retrospectively score 143 consecutive vertebral segments in 79 patients treated with SRS. Follow-up MRI, pain, and neurologic assessments obtained every 3–6xa0months. Pain also scored at 7, 14, and 30xa0days after sfSRS. Follow up was 16xa0±xa018xa0months ±SD, range 3–78. Long-term radiographic control occurred in 94xa0% of cases. Pain improvement resulted within 7xa0days in 100xa0% of cases with severe pain and sustained long-term in 95xa0%. VCF occurred in 21xa0% of segments: 30xa0% were de novo VCF. The overall 1xa0year fracture free probability (1yFFP) was 76xa0%. Pre-existing VCF resulted in higher probability to progress: 1yFFP 90 versus 60xa0%. Symptoms presented in 6xa0% of cases with de novo VCF and 39xa0% with progressive. The former were treated with vertebral augmentation (VA), the latter with open surgery. Surgery/VA prior to SRS did not change risk of progressive VCF. Univariate but not multivariate analysis identified histology (colorectal), pre-existing VCF, and pain (severe) as significant predictors of VCF. In conclusion, sfSRS compares favourably to SBRT for radiographic and pain control with similar VCF risk. Patients with pre-existing VCF have a higher probability to progress, become symptomatic, and require surgery. These results may help discussing risk and benefits with patients undergoing sfSRS for spinal metastasis and developing new treatment algorithms.

SU‐E‐T‐584: Dosimetric Comparison Between Static IMRT and VMAT for a Four‐ Lesion Brain Treatment

PURPOSEnSparing brain volume is the goal when designing plans for multiple brain tumors. We compared dose distributions for tumor and normal tissues using VAMT and static IMRT.nnnMETHODSnA patient presented with recurrent meningioma with 4 lesions identified. The greatest dimensions for the tumors were 0.4 to 2.0 cm. The tumor sizes and locations can be treated with a single plan with 1.8 Gy/fraction, 30 fractions. A 6-field non-coplanar IMRT with the gantry(G) and couch(C) in IEC scale were used: G0C0, G45C0, G330C0, G240C0, G50C90, and G120C90. IMRT was performed using iPlan sliding-window. For VMAT, four arcs were used; two using 350 degree from G175 to G185 and the other two using 175 degree from G0 to G175. Two arcs were designed with couch=0 and the rest two using couch=90 degree. VMAT was designed with Eclipse system. Tumors and normal brain were contoured in the iPlan and then exported to Eclipse to maintain identical volume. DVH for normal brain was compared for the same tumor coverage from the two plans.nnnRESULTSnEither static IMRT or VMAT generated an acceptable coverage for these four tumors. The conformity of tumor coverage was better in VMAT than that using IMRT; the range of min.-max. doses were: 57.5-63.5 Gy from VMAT vs. 54.1-64.9 Gy from IMRT. For normal brain, DVH did not show a clear difference between the two plans. For doses 5-15 Gy, VMAT delivered 1- 10% more brain volume (1040 cc) but 1-2 % less volume in 30-40 Gy than that from static IMRT.nnnCONCLUSIONSnEither static IMRT or VMAT can adequately be used to treat multiple lesions with a single isocenteric treatment. VMAT plan demonstrated improved tumor coverage, spared 1- 2% brain tissue at 30-40 Gy but irradiated up to 10% more brain in 2-7 Gy. The patient was treated with VMAT.

SU-E-T-893: A Standardized 11-Field Treatment Plan for Radiosurgery to Spinal Lesions

Purpose: A single high radiation dose is effective to reduce pain caused by tumors adjacent to the spine. This study was to investigate optimal treatment angles and field numbers to create a standardized treatment for spine radiosurgery. Methods: 20 patients with thoracic and lumbar lesions treated in the past two years were redesigned. IMRS treatment plans were performed using iPlan planning system and patients were treated with 18 Gy. Dose constraints were: less than 10% of spinal cord volume received 10 Gy; mean kidneydose less than 7 Gy, and <10 Gy for esophagus. Field number of 7, 9, and 11 were used for the comparisons. Gantry angle from various arrangements were studied. Results: Excellent clinical outcomes were observed without any normal tissue complication. With the same cord dose constraint (i.e., 10 Gy to less than 10% cord volume), the PTV received better dose coverage in 11‐fields plans compared with the 9‐fields, and PTV coverage was better in 9‐fields plans than in the 7‐fields. Using 11‐field treatments, the effect of gantry angle is not significant. In our standardized 11‐filed IMRS plans, 18 Gy covers 85 to 95 % of the PTV volume, 16 Gy covers 96–100%, and 13 Gy covers 100% of PTV. The under dose regions were found at the interface between cord and lesions, which is necessary for safety margin. The range of total MU was around 10000 and the planning time was about 1.5 hours for the 11‐field standardized plan. Conclusions: Spinal lesions require urgent treatments; usually within 2–4 days including QA. With large field numbers (e.g., 11 fields), the selection of gantry angle is not important and plan can be designed in 1.5 hours. It may be relatively difficult to design a good plan if field number is less than 7 for the spine radiosurgery.

Gadopentetate-Induced status epilepticus

Abstract Gadopentetate dimeglumine (gadolinium) is the most commonly used magnetic resonance imaging contrast medium. This medium has an excellent safety record, although it has been associated with occasional serious adverse events, including seizures. We present the first reported case of gadopentetate-induced status epilepticus, and discuss some of the possible risk factors for gadopentetate-associated reactions.