The Lateral C1-C2 Puncture: Indications, Technique, and Potential Complications.

OBJECTIVE: Lateral C1-C2 puncture can be used for CSF collection, contrast agent injection for myelography, and access for cordotomy. The objective of this article is to describe the indications, technique, and potential complications of this procedure. CONCLUSION: Radiologists performing lumbar puncture or myelography should be comfortable gaining access to the subarachnoid space via the lateral C1-C2 approach when indicated. Familiarity with the technique and its potential complications is essential for a safe and efficient procedure.

Change in the cross-sectional area of the thecal sac following balloon kyphoplasty for pathological vertebral compression fractures prior to spine stereotactic radiosurgery.

OBJECTIVEPercutaneous vertebral augmentation procedures such as vertebroplasty and kyphoplasty are often performed in cancer patients to relieve mechanical axial-load pain due to pathological collapse deformities. The collapsed vertebrae in these patients can be associated with varying degrees of spinal canal compromise that can be worsened by kyphoplasty. In this study the authors evaluated changes to the spinal canal, in particular the cross-sectional area of the thecal sac, following balloon kyphoplasty (BKP) prior to stereotactic radiosurgery (SRS).METHODSThe authors retrospectively reviewed the records of all patients with symptomatic vertebral compression fractures caused by metastatic disease who underwent kyphoplasty prior to single-fraction SRS. The pre-BKP cross-sectional image, usually MRI, was compared to the post-BKP CT myelogram required for radiation treatment planning. The cross-sectional area of the thecal sac was calculated pre- and postkyphoplasty, and intraprocedural CT imaging was reviewed for epidural displacement of bone fragments, tumor, or polymethylmethacrylate (PMMA) extravasation. The postkyphoplasty imaging was also evaluated for evidence of fracture progression or fracture reduction.RESULTSAmong 30 consecutive patients, 41 vertebral levels were treated with kyphoplasty, and 24% (10/41) of the augmented levels showed a decreased cross-sectional area of the thecal sac. All 10 of these vertebral levels had preexisting epidural disease and destruction of the posterior vertebral body cortex. No bone fragments were displaced posteriorly. Minor epidural PMMA extravasation occurred in 20% (8/41) of the augmented levels but was present in only 1 of the 10 vertebral segments that showed a decreased cross-sectional area of the thecal sac postkyphoplasty.CONCLUSIONSIn patients with preexisting epidural disease and destruction of the posterior vertebral body cortex who are undergoing BKP for pathological fractures, there is an increased risk of further mass effect upon the thecal sac and the potential to alter the SRS treatment planning.

Nonenhancing Leptomeningeal Metastases: Imaging Characteristics and Potential Causative Factors.

The diagnosis of leptomeningeal metastasis (LM) has increased in frequency, as new therapies have lengthened the survival of patients with cancer. Early diagnosis and intervention help improve quality of life and prevent further neurological deterioration in LM. The detection of LM is often established by magnetic resonance imaging examinations, cerebrospinal fluid analysis, or both. We present a series of cases where LM was identified on fluid-attenuated inversion recovery or T2-weighted image but was nonenhancing on the traditionally more sensitive postcontrast T1-weighted sequences. Nonenhancing LM is unusual and not yet fully understood but should be considered in the appropriate clinical context and may become more common with increased utilization of antiangiogenic therapies.

Sacroplasty for cancer-associated insufficiency fractures.

BACKGROUND: Tumor-associated sacral insufficiency fractures (SIF) present a significant clinical challenge. As survival increases for many malignancies, sacral fractures associated with metastases, sacral or extended pelvic radiation, and paraneoplastic osteoporosis are increasingly common and yet remain difficult to treat in the setting of the potentially significant morbidity of open sacral surgery. OBJECTIVE: To describe our prospective experience with sacroplasty for tumor-associated lesions, including the largest series to date of radiation-induced SIF. METHODS: Twenty-five patients with symptomatic SIF underwent 31 percutaneous fluoroscopy-guided sacroplasties with a median 5.8 mL of polymethyl methacrylate or a ceramic-resin composite under fluoroscopic guidance and with concurrent biopsy acquisition. Eighteen patients had fractures related to previous sacral or pelvic radiation; 4 had viable lytic lesions; and 2 had oncology-related osteoporosis. Postoperative pain reduction, procedural morbidity, and functional outcomes were recorded. RESULTS: Twenty of 25 patients (80%) had reduction in their visual analog pain score at a median follow-up of 6.5 months; no patients worsened. The mean visual analog scale score decreased from 8.8 to 4.7 postprocedurally (P < .001), with significant reductions regardless of the underlying pathology (P < .001 to P < .05). Six of 13 patients with pretreatment ambulatory impairment required fewer ambulatory aids and 3 were newly ambulatory. Extravertebral cement migration was noted in 18 procedures; however, no instance was clinically relevant. Six repeat or contralateral procedures were performed. No morbidity was encountered. CONCLUSION: Sacroplasty is a safe and effective option for the palliation of sacral fractures in the oncologic population.

Percutaneous CT-guided biopsy of osseous lesion of the spine in patients with known or suspected malignancy.

BACKGROUND AND PURPOSE: CT-guided spinal biopsy (CTGSB) is considered a safe and accurate procedure. Our goal was to determine the accuracy of a CTGSB of osseous spinal lesions in patients with known or suspected underlying malignancy in reference to major variables such as the radiographic appearance of the biopsied lesion and its location within the spinal column. METHODS: We retrospectively reviewed results of 410 consecutive percutaneous CTGSB procedures of osseous spinal lesions. Biopsy was determined to be adequate if diagnostic tissue was obtained (n = 401) or unsatisfactory (n = 9) if only blood without cellular elements was present on final pathologic-cytologic examination. RESULTS: The level of spinal biopsy was cervical in nine patients (2%), thoracic in 123 (31%), lumbar in 164 (42%), and sacral in 96 (25%). The overall diagnostic accuracy of CTGSB was 89%, with a false-negative rate of 11%. Biopsy of lytic lesions yielded an accurate diagnosis in 93% (220 of 236). Despite technical challenges inherent to biopsy of sclerotic lesions, diagnostic accuracy was 76% (63 of 83), although more importantly, 24% (20 of 83) of the results in sclerotic lesions were falsely negative. CONCLUSION: CTGSB of osseous spinal lesions is an important tool in the workup of patients with known or suspected underlying neoplastic disease. However, a negative result must be confirmed with either close follow-up or, preferably, open biopsy, especially in cases of sclerotic lesions for which diagnostic accuracy is decreased and the false-negative rate is high.

Pharmacokinetics of Nisoldipine Coat--Core Formulation in Subjects with Liver Cirrhosis.

The pharmacokinetics of a controlled-release formulation (coat--core) of the calcium channel blocker nisoldipine was investigated in eight subjects with biopsy-proved liver cirrhosis and eight healthy subjects. In Stage I, subjects received a single 10-mg dose to determine if this dose would be safely tolerated in the subjects with cirrhosis. Because all subjects in both groups tolerated the dose without difficulty, all were continued to Stage II. In Stage II, subjects received a once-daily dose of 10-mg coat-core tablets for 7 days. Serial plasma samples were assayed for nisoldipine in both stages. The C(max) and AUC of nisoldipine were approximately fourfold to fivefold higher (p < 0.01) in subjects with cirrhosis as compared to healthy subjects; however, there was overlap in the range of pharmacokinetic parameters between the two groups. The accumulation factor following multiple dosing was similar in both groups. Results suggest that nisoldipine dose should be optimized by monitoring of a pharmacodynamic end point, such as effect on blood pressure. It is likely that dose requirements for patients with liver disease will be lower.

Insufficiency fractures of the sacrum following stereotactic body radiotherapy for sacral tumors.

INTRODUCTION: There is little data on sacral insufficiency fracture(SIF) incidence following pelvic radiotherapy, with existing studies based on conventional fractionation. Stereotactic body radiotherapy (SBRT), characterized by dose escalation with hypofractionation, may pose even greater risks to sacral integrity. This study aims to define SIF incidence and risk factors following SBRT. METHODS: Records of 43 consecutive patients who underwent sacral SBRT from September 2005-May 2009 were reviewed. Baseline patient information (age, gender, menopausal status, body mass index, use of bone-thinning agents, presence of osteoporosis), tumor characteristics (histology, lesion appearance and extent) and treatment parameters (dose/fractionation, prior radiation/surgery) were documented. Primary end-point was development of new fractures or progression of pre-existing fractures. Secondary end-points included pain scores, analgesic use, functional ability, and local tumor control. RESULTS: Median follow-up was 17months. Common histologies included sarcoma, renal cell, and prostate carcinoma; 47% of lesions were lytic, 37% sclerotic and the remainder mixed. Doses ranged from 18-24Gy/1fraction to 30Gy/5fractions with 45% receiving single fractions.14% had prior radiation (median dose: 30Gy/10fractions).Five patients developed SIF. In four, fractures occurred in the context of controlled local disease. Median time to SIF was 8.2months. Symptoms varied from minimal pain requiring no intervention to severe pain impacting on function. Two patients underwent sacroplasty due to intractable pain, with both obtaining good analgesia. Low event numbers precluded meaningful univariate/multivariate analyses. One-year local tumor control rates were excellent (91.7%). CONCLUSION: In this study, actuarial SIF incidence at one year was 8.2%, suggesting that SIF risk from sacral SBRT is low. However, larger prospective studies with longer follow-up are needed. In addition, novel therapies such as sacroplasty need further study to determine safety, efficacy and indications for use.

Intraoperative and percutaneous iridium-192 high-dose-rate brachytherapy for previously irradiated lesions of the spine.

PURPOSE: Advances in stereotactic radiosurgery have improved local control of spine metastases, but local failure is still a problem and repeat irradiation is limited by normal tissue tolerance. A novel high-dose-rate (HDR) brachytherapy technique has been developed to treat these previously irradiated lesions. METHODS AND MATERIALS: Five patients with progressive disease at previously irradiated sites in the spine who were not amenable to further external beam radiation were treated. Catheters were placed intraoperatively in 2 patients and percutaneously implanted in 3 patients with image-guided techniques. Conformal plans were generated to deliver dose to target tissues and spare critical structures. Patients received single-fraction treatment using HDR iridium-192 brachytherapy. RESULTS: Median dose was 14 Gy (range, 12-18 Gy) with a median gross total volume D90 of 75% (range, 31-94%); spinal cord/cauda equina dose constraints were met. At a median followup of 9 months, no local progression of disease has been observed. Four patients had reduction in pain 1-4 weeks after treatment. No brachytherapy-related complications have been observed. CONCLUSIONS: Intraoperative and percutaneous iridium-192 HDR spine brachytherapy techniques were not associated with complications or acute toxicity. There has been no local progression at treated sites, and most patients experienced reduction in cancer-related pain.

Use of diffusion weighted magnetic resonance imaging in predicting early postoperative outcome of new neurological deficits after brain tumor resection.

OBJECTIVE: To study risk factors for the development of postoperative neurological deficits after brain tumor resection and to define prognostic factors for recovery. METHODS: We prospectively studied 82 brain tumor patients undergoing tumor resection. Pre- and postoperative neurological examination, functional and performance status, cancer treatment, cardiovascular risk factors, seizure history, and blood pressure and oxygen saturation were recorded perioperatively. Postoperative magnetic resonance imaging scans were obtained within 72 hours of surgery, and the radiologist was blinded to the patient's status. Abnormalities on magnetic resonance diffusion weighted images were classified as new if they extended beyond the tumor cavity margins and were absent before surgery. RESULTS: Of the 80 assessable patients, 24 had a new or increased postoperative deficit by at least one point on the National Institutes of Health Stroke Scale. Presence of preoperative neurological deficits predicted development of postoperative deficits, whereas a new diffusion weighted imaging lesion after craniotomy predicted incomplete recovery of a new postoperative deficit. CONCLUSION: Postoperative diffusion magnetic resonance imaging is useful in predicting early functional recovery from new deficits after brain tumor surgery.

Necrotizing vasculopathy of the CNS: case report.

A 62-year-old man with progressive cerebellar and brainstem dysfunction had gadolinium-enhancing lesions in basal ganglia and occipital lobe on MRI suggestive of primary CNS lymphoma (PCNSL). The patient, who had been treated with high-dose steroid hormones for several months, developed respiratory failure and expired before a histological diagnosis could be obtained. The postmortem examination showed Pneumocystis cariniiwas the cause of death. Pathology of the brain showed a necrotizing vasculopathy affecting the white matter of the cerebrum and cerebellum with involvement of the basal ganglia and the periventricular gray matter. Other organs such as liver, lung, and kidneys were spared. Necrotizing vasculopathy is a novel entity that should be considered in the differential diagnosis of PCNSL.

Favorable-biology neuroblastoma presenting with leptomeningeal metastases?: a case presentation.

Intrinsic biologic tumor features are critical prognosticators of survival in patients with neuroblastoma. Patients with localized neuroblastoma and favorable biologic parameters may be observed without treatment. Conversely, leptomeningeal metastases in patients with primary extracranial neuroblastoma are highly unusual and, despite aggressive multimodality therapies, invariably fatal. The authors describe a newly diagnosed infant with neuroblastoma and radiographic imaging suggestive of leptomeningeal metastases. The patient underwent partial surgical resection of the primary tumor. The primary tumor revealed favorable biologic characteristics. The patient was observed with no cytotoxic therapy and remained well with no evidence of disease progression more than 3 years since diagnosis. This case illustrates that some infants with favorable-biology neuroblastoma may be observed without treatment despite the advanced INSS stage.