Jonathan M. Morris

Percutaneous Cryoablation of Musculoskeletal Oligometastatic Disease for Complete Remission

PURPOSE To assess the safety and effectiveness of percutaneous cryoablation to treat limited metastases to the musculoskeletal system, with the goal of complete disease remission. MATERIALS AND METHODS In a single-institution retrospective study of data from December 2003 to October 2011, 43 consecutive patients underwent initial cryoablation of limited (five or fewer) musculoskeletal metastases with the goal of complete disease remission (ie, no clinical or radiographic evidence of disease). Three patients were lost to follow-up. As a result, the present report describes 40 patients who underwent 40 cryoablation procedures to treat 52 tumors. RESULTS Local control was achieved in 45 of 52 tumors (87%; 95% confidence interval [CI], 75%-93%) at a median follow-up of 21 months (range, 4-62 mo). Thirteen of 19 treated bone metastases (68%) and 32 of 33 soft-tissue metastases (97%) showed local control (P = .007). One- and 2-year overall survival rates were 91% (95% CI, 75%-97%) and 84% (95% CI, 65%-93%), respectively. Median overall survival was 47 months (95% CI, 26-62 mo). One- and 2-year disease-free survival rates were 22% (95% CI, 11%-37%) and 7% (95% CI,<1% to 26%), respectively. Median disease-free survival was 7 months (95% CI, 5-10 mo). Two of 40 procedures (5%) were associated with major complications. CONCLUSIONS Percutaneous cryoablation is a safe and effective treatment to achieve local tumor control and short-term complete disease remission in patients with limited metastatic disease to the musculoskeletal system.

The Noninferiority of the Nonparticulate Steroid Dexamethasone vs the Particulate Steroids Betamethasone and Triamcinolone in Lumbar Transforaminal Epidural Steroid Injections

OBJECTIVE To assess whether a nonparticulate steroid (dexamethasone, 10 mg) is less clinically effective than the particulate steroids (triamcinolone, 80 mg; betamethasone, 12 mg) in lumbar transforaminal epidural steroid injections (TFESIs) in subjects with radicular pain with or without radiculopathy. DESIGN Retrospective observational study with noninferiority analysis of dexamethasone relative to particulate steroids. SETTING Single academic radiology pain management practice. SUBJECTS Three thousand six hundred forty-five lumbar TFESIs at the L4-5, L5-S1, or S1 neural foramina, performed on 2,634 subjects. METHODS/OUTCOME MEASURES Subjects were assessed with a pain numerical rating scale (NRS, 0-10) and Roland-Morris disability questionnaire (R-M) prior to TFESI, and at 2 weeks and 2 months follow-up. For categorical outcomes, successful pain relief was defined as either ≥50% reduction in NRS or pain 0/10; functional success was defined as ≥40% reduction in R-M score. Noninferiority analysis was performed with δ = -10% as the limit of noninferiority. Continuous outcomes (mean NRS, R-M scores) were analyzed for noninferiority with difference bounds of 0.3 for NRS scores and 1.0 for R-M scores. RESULTS With categorical outcomes, dexamethasone was demonstrated to be noninferior to the particulate steroids in pain relief and functional improvement at 2 months. Using continuous outcomes, dexamethasone was demonstrated to be superior to the particulate steroids in both pain relief and functional improvement at 2 months. CONCLUSION This retrospective observational study reveals no evidence that dexamethasone is less effective than particulate steroids in lumbar TFESIs performed for radicular pain with or without radiculopathy.

Aβ-related angiitis: Comparison with CAA without inflammation and primary CNS vasculitis

Objective:To analyze the clinical findings, response to therapy, and outcomes of patients with cerebral vascular amyloid-&bgr; (A&bgr;) deposition with and without inflammatory vascular infiltration. Methods:We report 78 consecutive patients with cerebral vascular A&bgr; deposition examined at Mayo Clinic Rochester over 25 years (1987 through 2011). Specimens reviewed by a neuropathologist showed 40 with vascular A&bgr; peptide without inflammation (cerebral amyloid angiopathy [CAA]), 28 with granulomatous vasculitis (A&bgr;-related angiitis or ABRA), and 10 with perivascular CAA-related inflammation. We also matched findings in 118 consecutive patients with primary CNS vasculitis (PCNSV) without A&bgr; seen over 25 years (1983 through 2007). Results:Compared to the 40 with CAA, the 28 with ABRA were younger at diagnosis (p = 0.05), had less altered cognition (p = 0.02), fewer neurologic deficits (p = 0.02), and fewer intracranial hemorrhages (<0.001), but increased gadolinium leptomeningeal enhancement (p = 0.01) at presentation, and less mortality and disability at last follow-up (p < 0.001). Compared with PCNSV, the 28 patients with ABRA were older at diagnosis (p < 0.001), had a higher frequency of altered cognition (p = 0.05), seizures/spells (p = 0.006), gadolinium leptomeningeal enhancement (p < 0.001), and intracerebral hemorrhage (p = 0.02), lower frequency of hemiparesis (p = 0.01), visual symptoms (p = 0.04), and MRI evidence of cerebral infarction (p = 0.003), but higher CSF protein levels (p = 0.03). Results of treatment and outcomes in ABRA and PCNSV were similar. Conclusions:ABRA appears to represent a distinct subset of PCNSV.Objective: To analyze the clinical findings, response to therapy, and outcomes of patients with cerebral vascular amyloid-β (Aβ) deposition with and without inflammatory vascular infiltration. Methods: We report 78 consecutive patients with cerebral vascular Aβ deposition examined at Mayo Clinic Rochester over 25 years (1987 through 2011). Specimens reviewed by a neuropathologist showed 40 with vascular Aβ peptide without inflammation (cerebral amyloid angiopathy [CAA]), 28 with granulomatous vasculitis (Aβ-related angiitis or ABRA), and 10 with perivascular CAA-related inflammation. We also matched findings in 118 consecutive patients with primary CNS vasculitis (PCNSV) without Aβ seen over 25 years (1983 through 2007). Results: Compared to the 40 with CAA, the 28 with ABRA were younger at diagnosis (p = 0.05), had less altered cognition (p = 0.02), fewer neurologic deficits (p = 0.02), and fewer intracranial hemorrhages (<0.001), but increased gadolinium leptomeningeal enhancement (p = 0.01) at presentation, and less mortality and disability at last follow-up (p < 0.001). Compared with PCNSV, the 28 patients with ABRA were older at diagnosis (p < 0.001), had a higher frequency of altered cognition (p = 0.05), seizures/spells (p = 0.006), gadolinium leptomeningeal enhancement (p < 0.001), and intracerebral hemorrhage (p = 0.02), lower frequency of hemiparesis (p = 0.01), visual symptoms (p = 0.04), and MRI evidence of cerebral infarction (p = 0.003), but higher CSF protein levels (p = 0.03). Results of treatment and outcomes in ABRA and PCNSV were similar. Conclusions: ABRA appears to represent a distinct subset of PCNSV.

Biopsy validation of 18F-DOPA PET and biodistribution in gliomas for neurosurgical planning and radiotherapy target delineation: results of a prospective pilot study

BACKGROUND Delineation of glioma extent for surgical or radiotherapy planning is routinely based on MRI. There is increasing awareness that contrast enhancement on T1-weighted images (T1-CE) may not reflect the entire extent of disease. The amino acid tracer (18)F-DOPA (3,4-dihydroxy-6-[18F] fluoro-l-phenylalanine) has a high tumor-to-background signal and high sensitivity for glioma imaging. This study compares (18)F-DOPA PET against conventional MRI for neurosurgical biopsy targeting, resection planning, and radiotherapy target volume delineation. METHODS Conventional MR and (18)F-DOPA PET/CT images were acquired in 10 patients with suspected malignant brain tumors. One to 3 biopsy locations per patient were chosen in regions of concordant and discordant (18)F-DOPA uptake and MR contrast enhancement. Histopathology was reviewed on 23 biopsies. (18)F-DOPA PET was quantified using standardized uptake values (SUV) and tumor-to-normal hemispheric tissue (T/N) ratios. RESULTS Pathologic review confirmed glioma in 22 of 23 biopsy specimens. Thirteen of 16 high-grade biopsy specimens were obtained from regions of elevated (18)F-DOPA uptake, while T1-CE was present in only 6 of those 16 samples. Optimal (18)F-DOPA PET thresholds corresponding to high-grade disease based on histopathology were calculated as T/N > 2.0. In every patient, (18)F-DOPA uptake regions with T/N > 2.0 extended beyond T1-CE up to a maximum of 3.5 cm. SUV was found to correlate with grade and cellularity. CONCLUSIONS (18)F-DOPA PET SUV(max) may more accurately identify regions of higher-grade/higher-density disease in patients with astrocytomas and will have utility in guiding stereotactic biopsy selection. Using SUV-based thresholds to define high-grade portions of disease may be valuable in delineating radiotherapy boost volumes.

Three-dimensional Physical Modeling: Applications and Experience at Mayo Clinic

Radiologists will be at the center of the rapid technologic expansion of three-dimensional (3D) printing of medical models, as accurate models depend on well-planned, high-quality imaging studies. This article outlines the available technology and the processes necessary to create 3D models from the radiologists perspective. We review the published medical literature regarding the use of 3D models in various surgical practices and share our experience in creating a hospital-based three-dimensional printing laboratory to aid in the planning of complex surgeries.

Motor Evoked Potential Monitoring during Cryoablation of Musculoskeletal Tumors

PURPOSE To describe the use of intraprocedural motor evoked potential (MEP) monitoring to minimize risk of neural injury during percutaneous cryoablation of perineural musculoskeletal tumors. MATERIALS AND METHODS A single-institution retrospective review of cryoablation procedures performed to treat perineural musculoskeletal tumors with the use of MEP monitoring between May 2011 and March 2013 yielded 59 procedures to treat 64 tumors in 52 patients (26 male). Median age was 61 years (range, 4-82 y). Tumors were located in the spine (n = 27), sacrum (n = 3), retroperitoneum (n = 4), pelvis (n = 22), and extremities (n = 8), and 21 different tumor histologies were represented. Median tumor size was 4.0 cm (range, 0.8-15.0 cm). Total intravenous general anesthesia, computed tomographic guidance, and transcranial MEP monitoring were employed. Patient demographics, tumor characteristics, MEP findings, and clinical outcomes were assessed. RESULTS Nineteen of 59 procedures (32%) resulted in decreases in intraprocedural MEPs, including 15 (25%) with transient decreases and four (7%) with persistent decreases. Two of the four patients with persistent MEP decreases (50%) had motor deficits following ablation. No functional motor deficit developed in a patient with transient MEP decreases or no MEP change. The risk of major motor injury with persistent MEP changes was significantly increased versus transient or no MEP change (P = .0045; relative risk, 69.8; 95% confidence interval, 5.9 to > 100). MEP decreases were 100% sensitive and 70% specific for the detection of motor deficits. CONCLUSIONS Persistent MEP decreases correlate with postprocedural sustained motor deficits. Intraprocedural MEP monitoring helps predict neural injury and may improve patient safety during cryoablation of perineural musculoskeletal tumors.

3D C-Arm Conebeam CT Angiography as an Adjunct in the Precise Anatomic Characterization of Spinal Dural Arteriovenous Fistulas

BACKGROUND AND PURPOSE: Precise anatomic understanding of the vascular anatomy of SDAVFs is required before treatment. This study demonstrates the utility of C-arm conebeam CT to locate precisely the fistulous point in SDAVFs and the courses of their feeding arteries and draining veins. MATERIALS AND METHODS: This retrospective study reports 14 consecutive patients with SDAVFs who underwent DSA and C-arm conebeam CT angiography. SDAVF sites included 5 thoracic, 7 lumbar, and 2 sacral fistulas. Selective DSA initially identified the location and arterial supply of the SDAVF. C-arm conebeam CT angiography was then performed with selective injection into the feeding artery. Reconstructed images were reviewed at a workstation with the referring surgeon, in conjunction with the standard 2D DSA images. The value of C-arm conebeam CT in depicting the fistula and the relationship to adjacent structures was qualitatively assessed. RESULTS: In all 14 patients, C-arm conebeam CT angiography was technically successful and precisely demonstrated the site of the fistula, feeding arteries, draining veins, and the relationship of the fistula to adjacent osseous structures. Information obtained from the C-arm conebeam CT angiogram was considered useful in all surgically (12 patients) and endovascularly (2 patients) treated SDAVFs. CONCLUSIONS: 3D C-arm conebeam CT angiography is a useful adjunct to 2D DSA in the anatomic characterization of SDAVFs. The technique allowed improved visualization of the vascular anatomy of the SDAVFs and clearer definition of their spatial relationships to adjacent structures.

The metastatic spine disease multidisciplinary working group algorithms

The Metastatic Spine Disease Multidisciplinary Working Group consists of medical and radiation oncologists, surgeons, and interventional radiologists from multiple comprehensive cancer centers who have developed evidence- and expert opinion-based algorithms for managing metastatic spine disease. The purpose of these algorithms is to facilitate interdisciplinary referrals by providing physicians with straightforward recommendations regarding the use of available treatment options, including emerging modalities such as stereotactic body radiation therapy and percutaneous tumor ablation. This consensus document details the evidence supporting the Working Group algorithms and includes illustrative cases to demonstrate how the algorithms may be applied.

Use of preoperative magnetic resonance imaging T1 and T2 sequences to determine intraoperative meningioma consistency.

Background: Meningioma firmness is a critical factor that influences ease of resection and risk, notably when operating on tumors intimate with neurovascular structures such as the mesial sphenoid wing. This study develops a predictive tool using preoperative magnetic resonance imaging (MRI) characteristics to determine meningioma consistency. Methods: 101 patients with intracranial meningioma (50 soft/51 firm) were included. MRI characteristics of 38 tumors (19 soft/19 firm) were retrospectively reviewed to identify preoperative imaging features that were then correlated with intraoperative description of the tumor as either “soft and/or suckable” or “firm and/or fibrous”. Criteria were developed to predict consistency and then blindly applied to the remaining 63 meningiomas (31 soft/32 firm). Results: The overall sensitivities for detecting soft and firm consistency were 90% and 56%, respectively (95% CI = 73–97% and 38–73%; P < 0.001). Compared to gray matter, meningiomas that were T2 hypointense were almost always firm. Soft meningiomas were hyperintense on T2 and hypointense on T1. Soft meningiomas were slightly larger and less likely to be associated with edema. There was a slight preponderance of firm meningiomas in the infratentorial compartment. Grade of meningioma was not predictive. Contrast enhancement, diffusion restriction, changes in overlying bone, intratumoral cysts, and angiographic features were not predictable. Conclusions: This tool using T1 and T2 series predicts meningioma consistency. Such knowledge should assist the surgeon in preoperative planning and counseling.

Cryoablation of Recurrent Sacrococcygeal Tumors

PURPOSE To review the safety and efficacy of cryoablation of recurrent sacrococcygeal tumors. MATERIALS AND METHODS The radiology departmental ablation database was retrospectively searched for cases of cryoablation performed to treat recurrences of sacrococcygeal tumors between January 1, 2010, and August 1, 2011. Patient demographics, procedure technical parameters, and patient outcomes were reviewed. RESULTS Five cases of recurrent chordoma and one recurrent myxopapillary ependymoma were treated with cryoablation in six patients whose ages ranged from 31 to 80 years. The tumors measured 14-39 mm in maximal dimension. Cryoablation was performed with the use of computed tomography guidance (n = 5) or a combination of ultrasound and magnetic resonance imaging guidance (n = 1). Sterile fluid was instilled to displace adjacent bowel and/or vagina in four cases, and electromyography monitoring was performed in two cases with adjacent nerve roots. Two patients with recurrent chordoma were treated for palliation of pain, with complete pain relief in one patient (pain recurred after 6 wk) and immediate reduction in pain from a score of six to a score of two on a 10-point scale in the other (pain recurred after 7 mo). Four tumors were treated for local control, with no evidence of recurrence on follow-up imaging at 3, 6, 12, and 15 months. No serious complication occurred. CONCLUSIONS Limited results suggest cryoablation to be a safe and relatively effective means of treating recurrent sacrococcygeal neoplasms for local control or palliation of pain in this small series with short-term follow-up.