Contemporary Diagnosis of Very Low-risk Prostate Cancer in a Multihospital Health Care System

The National Comprehensive Cancer Network (NCCN) very low risk (VLR) category for prostate cancer (PCa) represents clinically insignificant disease, and detection of VLR PCa contributes to overdiagnosis. Greater use of magnetic resonance imaging (MRI) and biomarkers before patient selection for prostate biopsy (PBx) reduces unnecessary biopsies and may reduce the diagnosis of clinically insignificant PCa. We tested a hypothesis that the proportion of VLR diagnoses has decreased with greater use of MRI-informed PBx using data from our 11-hospital system. From 2018 to 2023, 351/3197 (11%) men diagnosed with PCa met the NCCN VLR criteria. The proportion of VLR diagnoses did not change from 2018 to 2023 (p = 0.8) despite an increase in the use of MRI-informed PBx (from 49% to 82%; p < 0.001). Of patients who underwent combined systematic and targeted PBx and were diagnosed with VLR disease, cancer was found in systematic PBx regions in 79% of cases and in targeted PBx regions in 31% of cases. When performing both systematic and targeted PBx, prebiopsy MRI-based risk calculators could limit VLR diagnosis by 41% using a risk threshold of >5% for Gleason grade group ≥3 PCa to recommend biopsy; the reduction would be 77% if performing targeted PBx only. These findings suggest that VLR disease continues to account for a significant minority of PCa diagnoses and could be limited by targeted PBx and risk stratification calculators. PATIENT SUMMARY: We looked at recent trends for the diagnosis of very low-risk (VLR) prostate cancer. We found that VLR cancer still seems to be frequently diagnosed despite the use of MRI (magnetic resonance imaging) scans before biopsy. The use of risk calculators to identify men who could avoid biopsy and/or biopsy only for lesions that are visible on MRI could reduce the overdiagnosis of VLR prostate cancer.

Increased Grades of Rectal Intussusception: Role of Decline in Pelvic Floor Integrity and Association With Dyssynergic Defecation

INTRODUCTION

The natural history of rectal intussusception (RI) is poorly understood. We hypothesized that decline in pelvic floor integrity and function leads to increasing RI grades.

METHODS

Retrospective analysis of a registry of patients with defecatory disorders with high-resolution anorectal manometry and magnetic resonance defecography was performed. Association of risk factors on increasing RI grades was assessed using logistic regression.

RESULTS

Analysis included a total of 238 women: 90 had no RI, 43 Oxford 1-2, 49 Oxford 3, and 56 Oxford 4-5. Age ( P = 0.017), vaginal delivery ( P = 0.008), and prior pelvic surgery ( P = 0.032) were associated with increased Oxford grades. Obstructive defecation symptoms and dyssynergic defecation were observed at relatively high rates across groups. Increased RI grades were associated with less anal relaxation at simulated defecation yet, higher rates of normal balloon expulsion ( P < 0.05), linked to diminished anal sphincter. Indeed, increased RI grades were associated with worsening fecal incontinence severity, attributed to higher rates of anal hypotension. Levator ani laxity, defined by increased levator hiatus length and its excessive descent at straining, was associated with increasing RI grades, independent of age, history of vaginal delivery, and pelvic surgeries and could independently predict increased RI grades. Concurrent anterior and posterior compartments, and visceral prolapse were associated with higher Oxford grades.

DISCUSSION

Our data suggest that decline in pelvic floor integrity with abnormal levator ani laxity is associated with increased RI grades, a process that is independent of age, history of vaginal deliveries, and/or pelvic surgeries, and perhaps related to dyssynergic defecation.

Locoregional Therapies for Hepatocellular Carcinoma prior to Liver Transplant: Comparative Pathologic Necrosis, Radiologic Response, and Recurrence

PURPOSE

To compare pathologic tumor necrosis rates after locoregional therapies (LRTs) for hepatocellular carcinoma (HCC) prior to liver transplantation and evaluate radiologic-pathologic correlation along with posttransplant HCC recurrence.

MATERIALS AND METHODS

Consecutive patients with solitary HCC bridged or downstaged with LRT from 2010 to 2022 were included. LRTs were transarterial chemoembolization (TACE), radioembolization (yttrium-90 [90Y]), ablation, and stereotactic body radiotherapy (SBRT). Upfront combination therapy options were TACE/ablation and TACE/SBRT. Subsequent therapy crossover due to local recurrence was allowed. Posttreatment imaging closest to the time of transplant, explant histopathologic necrosis, and tumor recurrence after transplant were reviewed.

RESULTS

Seventy-three patients met inclusion criteria, of whom 5 (7%) required downstaging. 90Y alone (n = 36) and multimodal therapy (pooled upfront combination and crossover therapy, n = 23) resulted in significantly greater pathologic necrosis compared with TACE alone (n = 14; P = .01). High dose 90Y radiation segmentectomy (≥190 Gy; n = 27) and TACE/ablation (n = 7) showed highest rates of complete pathologic necrosis (CPN)-63% (n = 17) and 71% (n = 5), respectively. Patients with CPN had a mean lesion size of 2.5 cm, compared with 3.2 cm without CPN (P = .04), irrespective of LRT modality. HCC recurrence was more common in patients without CPN (16%, 6/37) than in those with CPN (3%, 1/36; P = .11). Using Liver Imaging Reporting and Data System (LI-RADS), a nonviable imaging response was 75% sensitive and 57% specific for CPN.

CONCLUSIONS

Radiation segmentectomy and multimodal therapy significantly improved CPN rates compared with TACE alone. A LI-RADS treatment response of nonviable did not confidently predict CPN.

Imaging Genomics and Multiomics: A Guide for Beginners Starting Radiomics-Based Research

Radiomics uses advanced mathematical analysis of pixel-level information from radiologic images to extract existing information in traditional imaging algorithms. It is intended to find imaging biomarkers related to the genomics of tumors or disease patterns that improve medical care by advanced detection of tumor response patterns in tumors and to assess prognosis. Radiomics expands the paradigm of medical imaging to help with diagnosis, management of diseases and prognostication, leveraging image features by extracting information that can be used as imaging biomarkers to predict prognosis and response to treatment. Radiogenomics is an emerging area in radiomics that investigates the association between imaging characteristics and gene expression profiles. There are an increasing number of research publications using different radiomics approaches without a clear consensus on which method works best. We aim to describe the workflow of radiomics along with a guide of what to expect when starting a radiomics-based research project.

Pancreatic Cancer and Its Mimics

Pancreatic ductal adenocarcinoma (PDAC) is the most common primary pancreatic malignancy, ranking fourth in cancer-related mortality in the United States. Typically, PDAC appears on images as a hypovascular mass with upstream pancreatic duct dilatation and abrupt duct cutoff, distal pancreatic atrophy, and vascular encasement, with metastatic involvement including lymphadenopathy. However, atypical manifestations that may limit detection of the underlying PDAC may also occur. Atypical PDAC features include findings related to associated conditions such as acute or chronic pancreatitis, a mass that is isointense to the parenchyma, multiplicity, diffuse tumor infiltration, associated calcifications, and cystic components. Several neoplastic and inflammatory conditions can mimic PDAC, such as paraduodenal "groove" pancreatitis, autoimmune pancreatitis, focal acute and chronic pancreatitis, neuroendocrine tumors, solid pseudopapillary neoplasms, metastases, and lymphoma. Differentiation of these conditions from PDAC can be challenging due to overlapping CT and MRI features; however, certain findings can help in differentiation. Diffusion-weighted MRI can be helpful but also can be nonspecific. Accurate diagnosis is pivotal for guiding therapeutic planning and potential outcomes in PDAC and avoiding biopsy or surgical treatment of some of these mimics. Biopsy may still be required for diagnosis in some cases. The authors describe the typical and atypical imaging findings of PDAC and features that may help to differentiate PDAC from its mimics. ©RSNA, 2023 Online supplemental material is available for this article. Quiz questions for this article are available through the Online Learning Center. See the invited commentary by Zins in this issue.

An Atypical Presentation of Hepatocellular Carcinoma with Multisite Metastasis following a Curative Liver Transplant

Hepatocellular carcinoma (HCC) is the most common primary liver malignancy, and liver transplantation is usually curative. HCC recurrences are rare after curative treatment options, although they are prevalent depending on various risk factors. We present a 71-year-old female patient with an unusual pattern of disease progression following a curative liver transplant with a metastatic presentation in the absence of alpha-fetoprotein elevation after 3 years of disease-free clinical presentation. We present this case to emphasize the importance of intermittent cross-sectional imaging in addition to ultrasound screening in HCC surveillance.

Application of vaginal tampon as an alternative to nasal swabs for higher recovery of DNA from sheep and goats for PCR based diagnosis of bovine tuberculosis

A study was conducted to find the applicability of vaginal tampons as an alternative to regular cotton swabs as a nasal secretion collection tool for the higher recovery of DNA. Nasal secretions were collected from sheep and goats using regular cotton swab and tampon swab. The mean yield and purity of the DNA extracted from tampon were significantly higher than that of the DNA extracted from cotton swab. The tampon swabs resulted higher DNA recovery than the cotton swabs after they were allowed to absorb M. bovis culture. The tampon swab was also found to be more sensitive in detecting M. bovis by PCR. This study concluded that vaginal tampons are having a higher absorption capacity with more DNA yield and can be used as a nasal swab in the diagnosis of bovine tuberculosis.

Rare Columnar Cell Variant Papillary Thyroid Carcinoma with Metastasis to Pancreas and Lungs at Initial Presentation: A Case Report and Review of Literature

Papillary thyroid cancer (PTC) is the most common endocrine malignancy, accounting for 85% of differentiated thyroid cancers. A small percentage of PTC variants are considered more aggressive, such as the tall cell variant associated with the V600E mutation in the BRAF gene and the rarer columnar variant, which is described in only 0.2% of cases and has a poor prognosis. Although locoregional metastases to neck lymph nodes are common, distant metastases of PTC are rare at presentation with only 5 to 7% reported in the literature. We present a very rare case of columnar cell variant PTC with synchronous metastasis to the lungs and indolent focus in the pancreas at initial diagnosis, which has never been reported in the literature. Our patient presented with non-radioactive iodine (RAI) responsive PTC with diffuse metastases to the lungs and one synchronous focal metastatic lesion in the pancreas. After multidisciplinary discussions, pancreatectomy/metastasectomy was deferred due to the disseminated PTC with multiple metastases to the lungs, lack of pancreas-related symptoms in the patient, and inherent complication risks. The patient was treated with systemic therapy using a tyrosine kinase inhibitor (lenvatinib), which is the standard of care for non-RAI responsive PTC and showed a complete radiologic resolution of the pancreatic lesion, however, with partial yet nonprogressive metastatic disease in the lungs.

Rare primary pulmonary angiosarcoma with aberrant neuroendocrine differentiation

Angiosarcomas are aggressive, malignant endothelial cell tumors derived from the vascular or lymphatic epithelium. Angiosarcomas makes up less than 1% of all soft tissue sarcomas. Primary pulmonary angiosarcoma is a rare tumor that most commonly presents as metastatic disease and carries a grim prognosis. The disease rarity and low index of suspicion make the diagnosis problematic. In this report, we present a case of primary pulmonary angiosarcoma with aberrant neuroendocrine differentiation. The diagnostic images, pathology and management strategy are discussed in this case with overall longer survival. The unique neuroendocrine pathologic subtype may contribute to the overall longer survival, however, there are only a few limited cases published. Further recognition and investigation of primary pulmonary angiosarcoma with aberrant neuroendocrine differentiation is warranted to further characterize diagnostic markers, determine more effective treatment strategies, and establish a possible link to improved survival.

Postpolypectomy coagulation syndrome - an uncommon complication of colonoscopy

Colonoscopy is the most sensitive and specific test for detecting colon cancer and is a common procedure performed in over 19 million people annually in the United States as of 2017. Though the incidence of complications from colonoscopy is low, there are several important complications that may require surgical intervention including bowel perforation, bleeding, splenic injury, and diverticulitis. Post-polypectomy coagulation syndrome (PPCS) is an uncommon complication of colonoscopy however, clinical presentation mimics bowel perforation and the differentiation between the two is vital as the management differs. Herein we present a case of a 43-year-old female with abdominal pain after undergoing colonoscopy and developed PPCS.

ProsRegNet: A deep learning framework for registration of MRI and histopathology images of the prostate

Magnetic resonance imaging (MRI) is an increasingly important tool for the diagnosis and treatment of prostate cancer. However, interpretation of MRI suffers from high inter-observer variability across radiologists, thereby contributing to missed clinically significant cancers, overdiagnosed low-risk cancers, and frequent false positives. Interpretation of MRI could be greatly improved by providing radiologists with an answer key that clearly shows cancer locations on MRI. Registration of histopathology images from patients who had radical prostatectomy to pre-operative MRI allows such mapping of ground truth cancer labels onto MRI. However, traditional MRI-histopathology registration approaches are computationally expensive and require careful choices of the cost function and registration hyperparameters. This paper presents ProsRegNet, a deep learning-based pipeline to accelerate and simplify MRI-histopathology image registration in prostate cancer. Our pipeline consists of image preprocessing, estimation of affine and deformable transformations by deep neural networks, and mapping cancer labels from histopathology images onto MRI using estimated transformations. We trained our neural network using MR and histopathology images of 99 patients from our internal cohort (Cohort 1) and evaluated its performance using 53 patients from three different cohorts (an additional 12 from Cohort 1 and 41 from two public cohorts). Results show that our deep learning pipeline has achieved more accurate registration results and is at least 20 times faster than a state-of-the-art registration algorithm. This important advance will provide radiologists with highly accurate prostate MRI answer keys, thereby facilitating improvements in the detection of prostate cancer on MRI. Our code is freely available at https://github.com/pimed//ProsRegNet.

3D Registration of pre-surgical prostate MRI and histopathology images via super-resolution volume reconstruction

The use of MRI for prostate cancer diagnosis and treatment is increasing rapidly. However, identifying the presence and extent of cancer on MRI remains challenging, leading to high variability in detection even among expert radiologists. Improvement in cancer detection on MRI is essential to reducing this variability and maximizing the clinical utility of MRI. To date, such improvement has been limited by the lack of accurately labeled MRI datasets. Data from patients who underwent radical prostatectomy enables the spatial alignment of digitized histopathology images of the resected prostate with corresponding pre-surgical MRI. This alignment facilitates the delineation of detailed cancer labels on MRI via the projection of cancer from histopathology images onto MRI. We introduce a framework that performs 3D registration of whole-mount histopathology images to pre-surgical MRI in three steps. First, we developed a novel multi-image super-resolution generative adversarial network (miSRGAN), which learns information useful for 3D registration by producing a reconstructed 3D MRI. Second, we trained the network to learn information between histopathology slices to facilitate the application of 3D registration methods. Third, we registered the reconstructed 3D histopathology volumes to the reconstructed 3D MRI, mapping the extent of cancer from histopathology images onto MRI without the need for slice-to-slice correspondence. When compared to interpolation methods, our super-resolution reconstruction resulted in the highest PSNR relative to clinical 3D MRI (32.15 dB vs 30.16 dB for BSpline interpolation). Moreover, the registration of 3D volumes reconstructed via super-resolution for both MRI and histopathology images showed the best alignment of cancer regions when compared to (1) the state-of-the-art RAPSODI approach, (2) volumes that were not reconstructed, or (3) volumes that were reconstructed using nearest neighbor, linear, or BSpline interpolations. The improved 3D alignment of histopathology images and MRI facilitates the projection of accurate cancer labels on MRI, allowing for the development of improved MRI interpretation schemes and machine learning models to automatically detect cancer on MRI.

Aligning the Implicit Curriculum with the Explicit Curriculum in Radiology

Physician education occurs through two mechanisms that operate in tandem: the explicit and the implicit curriculum. The explicit, or formal, curriculum is the official version that is usually taken as the one-and-only curriculum and which is detailed in official documentation; however, an implicit curriculum exists, comprised of subtle messaging about professional norms, values, and beliefs that are tacitly communicated through both positive and negative role modeling. Both contribute to the overall education of the medical student and physician-in-training. Despite its well-documented influence in medical education, much of the teachings of the implicit curriculum occurs in the shadows, unspoken and unarticulated, and outside the awareness of both teacher and student. As panel members of the The Implicit Curriculum in Radiology Task Force of the Association of University Radiologists-Radiology Research Alliance (AUR-RRA), we present a review of the implicit curriculum, exploring its origin and impact on medical education, and on the overall professional development of medical students, post-graduate medical trainees and practicing physicians. Strategies for recognizing and contending with the implicit curriculum in radiology training are discussed, with a special emphasis on opportunities to leverage its potential through positive role modeling.

Variables Influencing Radiology Volume Recovery During the Next Phase of the Coronavirus Disease 2019 (COVID-19) Pandemic

The coronavirus disease 2019 (COVID-19) pandemic has reduced radiology volumes across the country as providers have decreased elective care to minimize the spread of infection and free up health care delivery system capacity. After the stay-at-home order was issued in our county, imaging volumes at our institution decreased to approximately 46% of baseline volumes, similar to the experience of other radiology practices. Given the substantial differences in severity and timing of the disease in different geographic regions, estimating resumption of radiology volumes will be one of the next major challenges for radiology practices. We hypothesize that there are six major variables that will likely predict radiology volumes: (1) severity of disease in the local region, including potential subsequent "waves" of infection; (2) lifting of government social distancing restrictions; (3) patient concern regarding risk of leaving home and entering imaging facilities; (4) management of pent-up demand for imaging delayed during the acute phase of the pandemic, including institutional capacity; (5) impact of the economic downturn on health insurance and ability to pay for imaging; and (6) radiology practice profile reflecting amount of elective imaging performed, including type of patients seen by the radiology practice such as emergency, inpatient, outpatient mix and subspecialty types. We encourage radiology practice leaders to use these and other relevant variables to plan for the coming weeks and to work collaboratively with local health system and governmental leaders to help ensure that needed patient care is restored as quickly as the environment will safely permit.

Dynamic nuclear polarization studies of nitroxyl spin probes in agarose gel using Overhauser-enhanced magnetic resonance imaging

Agarose is a tissue-equivalent material and its imaging characteristics similar to those of real tissues. Hence, the dynamic nuclear polarization studies of 3-carboxy-2,2,5,5-tetramethyl-pyrrolidine-1-oxyl (carboxy-PROXYL) in agarose gel were carried out. The dynamic nuclear polarization parameters such as spin lattice relaxation time, longitudinal relaxivity, leakage factor, saturation parameter and coupling parameter were estimated for 2 mM carboxy-PROXYL in phosphate-buffered saline solution and water/agarose mixture (99 : 1). From these results, the spin probe concentration was optimized as 2 mM, and the reduction in enhancement was observed for carboxy-PROXYL in water/agarose mixture (99 : 1) compared with phosphate-buffered saline solution. Phantom imaging was also performed with 2 mM concentration of carboxy-PROXYL in various concentrations of agarose gel at various radio frequency power levels. The results from the dynamic nuclear polarization measurements agree well with the phantom imaging results. These results pave the way for designing model system for human tissues suited to the biological applications of electron spin resonance/Overhauser-enhanced magnetic resonance imaging.

Retroperitoneal extrarenal angiomyolipoma at the surgical bed 8 years after a renal angiomyolipoma nephrectomy: A case report and review of literature

Retroperitoneal extrarenal angiomyolipoma (RERAML) are rare and close mimickers of retroperitoneal liposarcoma on both imaging and histopathology. However, imaging findings including heterogeneity, hyperdensity on unenhanced computed tomography, intralesional hemorrhage, absence of calcifications, low signal intensity on T2-weighted magnetic resonance imaging, and dilated intratumoral vessels can lead to the diagnosis of RERAML. Diagnosis of RERAML can avoid unnecessary surgery since conservative medical management with continued surveillance has been proven to be effective for RERAML whereas surgical resection is the treatment for liposarcoma. Imaging and laboratory follow-up for at least 5 years has been recommended in patients who underwent surgical resection of angiomyolipoma (AML). We present a case of RERAML in an asymptomatic patient whose AML recurred in the surgical bed 8 years after an ipsilateral nephrectomy for renal AML.

Concentration dependence of nitroxyl spin probes in liposomal solution: electron spin resonance and overhauser-enhanced magnetic resonance studies

In this work, the detailed studies of electron spin resonance (ESR) and overhauser-enhanced magnetic resonance imaging (OMRI) were carried out for permeable nitroxyl spin probe, MC-PROXYL as a function of agent concentration in liposomal solution. In order to compare the impermeable nature of nitroxyl radical, the study was also carried out only at 2 mM concentration of carboxy-PROXYL. The ESR parameters were estimated using L-band and 300 MHz ESR spectrometers. The line width broadening was measured as a function of agent concentration in liposomal solution. The estimated rotational correlation time is proportional to the agent concentration, which indicates that less mobile nature of nitroxyl spin probe in liposomal solution. The partition parameter and permeability values indicate that the diffusion of nitroxyl spin probe distribution into the lipid phase is maximum at 2 mM concentration of MC-PROXYL. The dynamic nuclear polarization (DNP) parameters such as DNP factor, longitudinal relaxivity, saturation parameter, leakage factor and coupling factor were estimated for 2 mM MC-PROXYL in 400 mM liposomal dispersion. The spin lattice relaxation time was shortened in liposomal solution, which leads to the high relaxivity. Reduction in coupling factor is due to less interaction between the electron and nuclear spins, which causes the reduction in enhancement. The leakage factor increases with increasing agent concentration. The increase in DNP enhancement was significant up to 2 mM in liposomal solution. These results paves the way for choosing optimum agent concentration and OMRI scan parameters used in intra and extra membrane water by loading the liposome vesicles with a lipid permeable nitroxyl spin probes in OMRI experiments.

ESR line width and line shape dependence of Overhauser-enhanced magnetic resonance imaging

Electron spin resonance and Overhauser-enhanced magnetic resonance imaging studies were carried out for various concentrations of ¹⁴ N-labeled 3-carbamoyl-2,2,5,5-tetramethyl-pyrrolidine-1-oxyl in pure water. Overhauser-enhancement factor attains maxima in the range of 2.5-3 mm concentration. The leakage factor showed an asymptotic increase with increasing agent concentration. The coupling parameter showed the interaction between the electron and nuclear spins to be mainly dipolar in origin. The electron spin resonance parameters, such as the line width, line shape and g-factor, were determined. The line width analysis confirms that the line broadening is proportional to the agent concentration, and also the agent concentration is optimized in the range of 2.5-3 mm. The line shape analysis shows that the observed electron spin resonance line shape is a Voigt line shape, in which the Lorentzian component is dominant. The contribution of Lorentzian component was estimated using the winsim package. The Lorentzian component of the resonance line attains maxima in the range of 2.5-3 mm concentration. Therefore, this study reveals that the agent concentration, line width and Lorentzian component are the important factors in determining the Overhauser-enhancement factor. Hence, the agent concentration was optimized as 2.5-3 mm for in vivo/in vitro electron spin resonance imaging and Overhauser-enhanced magnetic resonance imaging phantom studies. Copyright © 2016 John Wiley & Sons, Ltd.

Clinical and surgical correlation of hip MR arthrographic findings in adolescents

OBJECTIVE

The purpose of this study was to analyze the utility of MRA-H in adolescents by comparing the results of imaging with surgical findings and/or clinical outcome.

MATERIAL AND METHODS

After obtaining appropriate IRB approval, the Radiologic Information System database was queried for all patients 13-18 years of age who underwent MRA-H from 2004 through 2013. The electronic medical record was reviewed for clinical history, clinical examination findings, and operative notes. MRA-H images were reviewed for soft tissue abnormalities (labral tear, paralabral ganglion, articular cartilage loss, synovitis, ligament tears) and bony abnormalities (cam-type femoroacetabular impingement (FAI), pincer-type FAI, hip dysplasia). MRA-H findings were correlated with surgical findings and with clinical outcomes.

RESULTS

Twenty-six patients with labral tears by MRA-H were included in study and grouped as follows: Group I) patients who underwent surgical management (n=10); group II) patients managed non-surgically (medication, intra-articular injection, physical therapy) (n=9); group III) patients lost to follow up after being advised to have surgery (n=7). With regard to presenting symptomatology, 87.5% of patients with labral tear had groin pain. Of those patients who were diagnosed with a labral tear, 52% were categorized as idiopathic labral tears, 26% as secondary tears (secondary to abnormal bony morphology), and 22% as traumatic labral tears. The labral tears were found to be anterior in 61% and posterior in 22%. Associated articular cartilage lesions were found in 29% of patients. In group I (surgical patients), MRA-H labral findings were confirmed at surgery in 9/10. Seventy percent of labral tears in our study had some form of abnormal bony morphology. Nine of the 12 patients with bone abnormalities were derived from group I patients. Six out of 7 patients with cam-type FAI had a labral tear.

CONCLUSION

Labral tears diagnosed by MRA-H in the adolescent population correlated well with clinical examination and surgical findings. Also, MRA-H contributed by defining bony morphology that was directly applied to surgical management. Non-surgical management of labral tears diagnosed on MRA-H had a generally favorable outcome.

Gastrocnemius tendinosis--A frequent finding on MRI knee examination

OBJECTIVE

Gastrocnemius tendinosis (GT) is one potential cause for posterior knee pain, commonly overlooked on clinical examinations and imaging. This study assesses the frequency of GT on MR imaging in a convenience sample based on a database search and associations with other articular pathologies and clinical findings.

SUBJECTS AND METHODS

With IRB approval, retrospective review was completed on 300 randomly selected MR knee exams performed from February 2009 to June 2010. Following de-identification, axial T2 and sagittal PD images, with or without fat suppression, were reviewed by 2 radiologists. The gastrocnemius tendon femoral attachments were graded as normal, mild (few cysts, thickening, intermediate signal) or severe GT (multiple cysts, marrow edema, tear). Select associated MR findings of internal derangement were documented. Clinical charts were reviewed for clinical presentation, physical exam findings, and select demographics.

RESULTS

The inter-observer reliability for presence/grading of GT was very high (kappa statistic=0.97). Frequency of GT was 50.33%, most frequently involving medial head of gastrocnemius (63.6%). Grades of GT were 41.7% and 17.2% for mild and severe respectively. Univariate analysis showed statistically significant relationship between grade of GT with arthrosis (p=0.05) and clinical joint effusion (p=0.02). Multivariate analysis showed higher odds of severe GT for individuals with medial plus lateral GT. Statistical significance was noted for presence of both GT and ACL tear (13.9%; p=0.02).

CONCLUSION

Significant findings of our analysis included GT presented with predominant involvement of medial head of gastrocnemius tendon, mild in severity, strong association with ACL tear, presented frequently as posterior knee pain, limited joint motion and clinical joint effusion. However, there was no statistically significant association between demographic features and medical comorbidities in the patients. Increased understanding of frequency of GT allows more accurate reporting of MR knee exam and systematic search for associated abnormalities.

Dynamic nuclear polarization properties of nitroxyl radical in high viscous liquid using Overhauser-enhanced Magnetic Resonance Imaging (OMRI)

The dynamic nuclear polarization (DNP) studies were carried out for (15)N labeled carbamoyl-PROXYL in pure water and pure water/glycerol mixtures of different viscosities (1.8cP, 7cP and 14cP). The dependence of DNP parameters was demonstrated over a range of agent concentration, viscosities, RF power levels and ESR irradiation time. DNP spectra were also recorded for 2mM concentration of (15)N labeled carbamoyl-PROXYL in pure water and pure water/glycerol mixtures of different viscosities. The DNP factors were measured as a function of ESR irradiation time, which increases linearly up to 2mM agent concentration in pure water and pure water/glycerol mixtures of different viscosities. The DNP factor started declining in the higher concentration region (∼3mM), which is due to the ESR line width broadening. The water proton spin-lattice relaxation time was measured at very low Zeeman field (14.529mT). The increased DNP factor (35%) was observed for solvent 2 (η=1.8cP) compared with solvent 1 (η=1cP). The increase in the DNP factor was brought about by the shortening of water proton spin-lattice relaxation time of solvent 2. The decreased DNP factors (30% and 53%) were observed for solvent 3 (η=7cP) and solvent 4 (η=14cP) compared with solvent 2, which is mainly due to the low value of coupling parameter in high viscous liquid samples. The longitudinal relaxivity, leakage factor and coupling parameter were estimated. The coupling parameter values reveal that the dipolar interaction as the major mechanism. The longitudinal relaxivity increases with the increasing viscosity of pure water/glycerol mixtures. The leakage factor showed an asymptotic increase with the increasing agent concentration. It is envisaged that the results reported here may provide guidelines for the design of new viscosity prone nitroxyl radicals, suited to the biological applications of DNP.

SERS investigations on orientation of 2-bromo-3-methyl-1,4-dimethoxy-9,10-anthraquinone on silver nanoparticles

Silver nanoparticles (Ag NPs) were prepared by solution combustion method with urea as fuel. Silver nanoparticles were characterized by UV-visible spectroscopy, X-ray diffraction (XRD) and scanning electron microscopy (SEM) techniques. Surface-enhanced Raman scattering (SERS) of 2-bromo-3-methyl-1,4-dimethoxy-9,10-anthraquinone (BMDMAQ) adsorbed on silver nanoparticles was investigated. The orientation of BMDMAQ on silver nanoparticles was inferred from nRs and SERS spectral features. Density functional theory (DFT) calculation was also performed to study the theoretical performance. The observed spectral features such as the high intensity of C-H out-of-plane bending mode and ring C-C stretching mode revealed that BMDMAQ adsorbed on silver surface through 'stand-on' orientation. Anthraquinone (AQ) derivatives have wide biomedical application which includes laxatives, antimalarials and antineoplastics used in the treatment of cancer. This present study would help to identify the interaction of drug molecules with DNA.

Biopsy versus conservative management of sonographically benign-appearing solid breast masses in adolescents

OBJECTIVES

To determine whether the size of palpable solid breast masses in adolescents at initial sonography and their growth at follow-up sonography could be used to decide between conservative management and tissue biopsy.

METHODS

This retrospective study included 37 adolescent female patients with 45 palpable benign-appearing solid breast masses on initial sonography. They were grouped as follows: group I, masses undergoing follow-up sonography with subsequent biopsy (n = 9); group II, masses undergoing biopsy without follow-up sonography (n = 13); and group III, masses undergoing follow-up sonography without biopsy (n = 23). The largest dimension, volume, volume change per month, and change in the sonographic appearance were analyzed to predict the need for biopsy. A combination of a largest dimension greater than 3 cm and volume change per month greater than 16% was used to assess the need for biopsy. Sonograms of 22 masses were correlated with histopathologic diagnoses.

RESULTS

None of the masses that underwent follow-up sonography showed changes in their sonographic appearance. All masses that underwent biopsy were benign on histopathologic analysis. There was no significant difference in the largest dimension among the groups at initial sonography or between groups I and III at follow-up sonography. The volume change was smaller for fibroadenomas (n = 7; mean, 22.67%) than benign phyllodes tumors (n = 2; mean, 45.30%) in group I, but the difference was not significant (P = .384). However, the volume change for groups I and III showed a significant difference (P = .026). Neither size greater than 3 cm nor volume change greater than 16% predicted pathologic outcomes.

CONCLUSIONS

If the combined criteria for assessing benignity of palpable breast masses had been used, biopsy could have been reduced by 89% in group I and deemed not necessary in 96% of group III breast masses.

Spectroscopic studies on sidewall carboxylic acid functionalization of multi-walled carbon nanotubes with valine

The valine functionalized multi-walled carbon nanotubes (MWCNTS) were prepared and characterized by using XRD, UV-Vis, FT-IR, EPR, SEM, and EDX, spectroscopic techniques. The enhanced XRD peak (002) intensity was observed for valine functionalized MWCNTs compared with oxidized MWCNTs, which is likely due to sample purification by acid washing. UV-Vis study shows the formation of valine functionalized MWCNTs. FT-IR study confirms the presence of functional groups of oxidized MWCNTs and valine functionalized MWCNTs. The ESR line shape analysis indicates that the observed EPR line shape is a Gaussian line shape. The g-values indicate that the systems are isotropic in nature. The morphology study was carried out for oxidized MWCNTs and valine functionalized MWCNTs by using SEM. The EDX spectra revealed that the high purity of oxidized MWCNTs and valine functionalized MWCNTs. The functionalization has been chosen because, functionalization of CNTs with amino acids makes them soluble and biocompatible. Thus, they have potential applications in the field of biosensors and targeted drug delivery.

Vibrational spectroscopic and DFT calculation studies of 2-amino-7-bromo-5-oxo-[1]benzopyrano [2,3-b]pyridine-3 carbonitrile

The vibrational spectra of 2-amino-7-bromo-5-oxo-[1]benzopyrano [2,3-b]pyridine-3 carbonitrile were recorded using fourier transform-infrared and fourier transform-Raman spectrometer. The optimized structural parameters, vibrational frequencies, Mulliken atomic charge distribution, frontier molecular orbitals, thermodynamic properties, temperature dependence of thermodynamic parameters, first order hyperpolarizability and natural bond orbital calculations of the molecule were performed using the Gaussian 09 program. The vibrational frequencies were assigned on the basis of potential energy distribution calculation using the VEDA 4.0 program. The calculated first order hyperpolarizability of ABOBPC molecule was obtained as 6.908×10(-30) issue, which was 10.5 times greater than urea. The nonlinear optical activity of the molecule was also confirmed by the frontier molecular orbitals and natural bond orbital analysis. The frontier molecular orbitals analysis shows that the lower energy gap of the molecule, which leads to the higher value of first order hyperpolarizability. The natural bond orbital analysis indicates that the nonlinear optical activity of the molecule arises due to the π→π(∗) transitions. The Mulliken atomic charge distribution confirms the presence of intramolecular charge transfer within the molecule. The reactive site of the molecule was predicted from the molecular electrostatic potential contour map. The values of thermo dynamic parameters were increasing with increasing temperature.

Adsorption of N-(1-(2-bromophenyl)-2-(2-nitrophenyl)ethyl)-4-methylbenzenesulfonamide on silver nanoparticles: SERS investigation

SERS provides essential data regarding the interaction of molecules in drugs with DNA. In the present study silver nanoparticles were synthesized using a solution combustion method with urea as fuel. The prepared silver nanoparticles are rod like structure. Surface-enhanced Raman scattering (SERS) of N-(1-2-bromophenyl)-2-(2-nitrophenyl)ethyl)-4-methylbenzenesulfonamide (BrS) adsorbed on the silver nanoparticle was studied. The nRs and Raman spectral analysis reveal that the BrS adsorbed tilted orientation on the silver surface. Vibrational modes of nRs along with HF calculations are also performed to study the HOMO and LUMO behavior and vibrational features of BrS.

[Diffusion studies of redox-sensitive nitroxyl spin probes through bilayer lipid membranes using 300 MHz electron spin resonance spectrometer]

Electron spin resonance (ESR) studies were carried out for 14N-labeled deuterated 3-methoxy-carbonyl-2,2,5,5-tetramethyl-pyrrolidine-1-oxyl (MC-PROXYL) and 3-carboxy-2,2,5,5-tetramethyl-1-pyrrolidin-1-oxyl (carboxy-PROXYL) in pure water and various concentrations of liposomal solutions by using 300 MHz ESR spectrometer. The ESR parameters such as the line width, hyperfine coupling constant, rotational correlation time, g-factor, partition parameter and permeability were reported for the samples. The line width broadening was observed for MC-PROXYL and carboxy-PROXYL in liposomal solution. The hyperfine coupling constant was observed for both nitroxyl spin probes. The permeable and impermeable nature of nitroxyl spin probes was demonstrated. The rotational correlation time increases with increasing concentration of liposome. The partition parameter increases with increasing concentration of liposome for MC-PROXYL, which indicates that the nitroxyl spin probes diffuse into lipid membrane. The permeability value decreases with increasing concentration of liposome, which reveals an increase in membrane permeability. The peaks corresponding to the lipid phase were observed for MC-PROXYL in liposomal solution, but not resolved for carboxy-PROXYL. These results confirm the permeable and impermeable nature of nitroxyl spin probes.

Spectroscopic studies on covalent functionalization of single-walled carbon nanotubes with glycine

Single-walled carbon nanotubes (SWCNTs) have a great potential in a wide range of applications, but faces limitation in terms of dispersion feasibility. The functionalization process of SWCNTs with the amino acid, glycine involves oxidation reaction using a mild aqueous acid mixture of HNO3 and H2SO4 (1:3), via ultrasonication technique and the resulted oxidized SWCNTs were again treated with the amino acid glycine suspension. The resulted glycine functionalized carbon nanotubes have been characterized by XRD, UV-Vis, FTIR, EPR, SEM, and EDX, spectroscopic techniques. The enhanced XRD peak (002) intensity was observed for glycine functionalized SWCNTs compared with oxidized SWCNTs, which is likely due to sample purification by acid washing. The red shift was observed in the UV-Vis spectra of glycine functionalized SWCNTs, which reveals that the covalent bond formation between glycine molecule and SWCNTs. The functional groups of oxidized SWCNTs and glycine functionalized SWCNTs were identified and assigned. EPR results indicate that the unpaired electron undergoes reduction process in glycine functionalized SWCNTs. SEM images show that the increase in the diameter of the SWCNTs was observed for glycine functionalized SWCNTs, which indicates that the adsorption of glycine molecule on the sidewalls of oxidized SWCNTs. EDX elemental micro analysis confirms that the nitrogen element exists in glycine functionalized SWCNTs. The functionalization has been chosen due to CONH bioactive sites in glycine functionalized SWCNTs for future applications.

Orientation of N-(1-(2-chlorophenyl)-2-(2-nitrophenyl)ethyl)-4-methylbenzenesulfonamide on silver nanoparticles: SERS studies

In the present study, the silver nanoparticles were synthesized using a solution combustion method with urea as fuel. The prepared silver nanoparticles show an FCC crystalline structure with particle size of 59nm. FESEM image shows the prepared silver is a rod like structure. The surface-enhanced Raman scattering (SERS) spectrum indicates that the N-(1-(2-chlorophenyl)-2-(2-nitrophenyl)ethyl)-4-methylbenzenesulfonamide (CS) molecule adsorbed on the silver nanoparticles. The spectral analysis reveals that the sulfonamide is adsorbed by tilted orientation on the silver surface. The Hatree Fock calculations were also performed to predict the vibrational motions of CS. This present investigation has been a model system to deduce the interaction of drugs with DNA.

DFT calculation and vibrational spectroscopic studies of 2-(tert-butoxycarbonyl (Boc) -amino)-5-bromopyridine

The molecular structure of 2-(tert-butoxycarbonyl (Boc) -amino)-5-bromopyridine (BABP) was optimized by the DFT/B3LYP method with 6-311G (d,p), 6-311++G (d,p) and cc-pVTZ basis sets using the Gaussian 09 program. The most stable optimized structure of the molecule was predicted by the DFT/B3LYP method with cc-pVTZ basis set. The vibrational frequencies, Mulliken atomic charge distribution, frontier molecular orbitals and thermodynamical parameters were calculated. These calculations were done at the ground state energy level of BABP without applying any constraint on the potential energy surface. The vibrational spectra were experimentally recorded using Fourier Transform-Infrared (FT-IR) and micro-Raman spectrometer. The computed vibrational frequencies were scaled by scale factors to yield a good agreement with observed experimental vibrational frequencies. The complete theoretically calculated and experimentally observed vibrational frequencies were assigned on the basis of Potential Energy Distribution (PED) calculation using the VEDA 4.0 program. The vibrational modes assignments were performed by using the animation option of GaussView 05 graphical interface for Gaussian program. The Mulliken atomic charge distribution was calculated for BABP molecule. The molecular reactivity and stability of BABP were also studied by frontier molecular orbitals (FMOs) analysis.

Sonographic features of physiologic neonatal breast enlargement

The varying presentations of neonatal breast enlargement on imaging have been underreported in the literature. Our case report profiles a 3-week-old female patient who presented with a history of left breast enlargement with redness and tenderness for 2 days, who was clinically diagnosed and managed for neonatal mastitis, which was actually a neonatal breast enlargement with adjacent cellulitis. Awareness that physiologic neonatal breast enlargement can be associated with adjacent cellulitis without mastitis can prevent unnecessary hospitalization and treatment with parenteral antibiotics.

Magnetic resonance imaging of diabetic muscle infarction: report of two cases

Diabetic muscle infarction (DMI) occurs as a rare complication of long standing or severe diabetes mellitus. The condition usually occurs spontaneously and patients usually present with acute pain and swelling of affected muscles which persists for weeks, and resolves spontaneously without intervention. Magnetic resonance (MR) imaging is the modality of choice in patients with suspected DMI based on appropriate clinical setting and plays a major role in the diagnosis, assessing the extent of involvement and differentiating DMI from other conditions. The DMI affected muscles are bulky and appear heterogeneous with hyperintense signals on T2-weighted and STIR sequences, hypo or isointense on T1-weighted images with loss of normal fatty intramuscular septae. Subcutaneous and perifascial edema can be present. On postgadolinium scans, there is diffuse heterogeneous enhancement with non-enhancing foci, which may represent areas of necrosis. Biopsy can be avoided as MR findings are highly sensitive and specific. Treatment is usually conservative. Surgical intervention is required only in patients who do not respond to conservative management. The common differential diagnosis includes cellulitis, abscess, necrotizing fasciitis and polymyositis. We present two cases below to highlight the clinical, MR imaging findings and differential diagnosis of DMI.

SERS investigations of 2,3-dibromo-1,4-naphthoquinone on silver nanoparticles

In the present study silver nanoparticles were synthesized using a solution combustion method with glycine as fuel. The prepared silver nanoparticles show an fcc crystalline structure with a particle size of 39 nm. Surface-enhanced Raman scattering (SERS) spectra of 2,3-dibromo-1,4-naphthoquinone (DBNQ) adsorbed on silver nanoparticles were investigated. The C-C stretching modes were enhanced and they were broaden in SERS spectrum with respect to normal Raman spectrum. The spectral analysis reveals that the DBNQ adsorbed flat-on orientation on the silver surface. DFT calculations are also performed to study the vibrational features of DBNQ.

Interferon (IFN)-ß1a and IFN-ß1b Block IFN-?-Induced Disintegration of Endothelial Junction Integrity and Barrier

Recent clinical trials indicate the efficacy of interferon (IFN)-beta 1b in reducing relapse rate in relapsing-remitting multiple sclerosis (MS), whereas a surge of IFN-gamma precedes and provokes acute relapses. Disruption of the cerebral endothelial barrier and transendothelial migration of inflammatory cell migration into the brain play a significant role in pathogenesis of MS and may be driven by this surge in IFN-gamma. However, the molecular mechanisms underlying the beneficial effects of IFN-beta 1b against the deleterious effects of IFN-gamma on the barrier formed by the junctional proteins remain to be characterized. The authors investigated the effects of IFN-beta 1b, IFN-beta 1a, and IFN-gamma on the integrity of two endothelial junctional proteins, occludin and vascular endothelial-cadherin (VE-cadherin). Human umbilical vein endothelial cell (HUVEC) layers were treated with IFN-beta 1b, IFN-beta 1a, IFN-gamma, IFN-beta 1b plus IFN-gamma, or IFN-beta 1a plus IFN-gamma. IFN-beta 1b, IFN-beta 1a, and IFN-gamma effects on occludin and VE-cadherin integrity and electrical resistance were assessed by Western blotting and immunofluorescence. IFN-gamma significantly reduced occludin expression and produced gaps in endothelial monolayers. VE-cadherin expression was decreased to a lesser extent in endothelial cells exposed to IFN-gamma. IFN-beta 1b significantly attenuated the IFN-gamma-induced decrease in occludin and VE-cadherin expression. The protective effects of IFN-beta 1a on IFN-gamma-treated endothelial cells were similar to those of IFN-beta 1b. IFN-gamma also significantly reduced endothelial monolayer electrical resistance; this effect was blocked by either IFN-beta 1a or IFN-beta 1b. IFN-beta 1a and IFN-beta 1b effectively prevent the IFN-gamma-induced disintegration of the endothelial tight junctions and sustain barrier against the effects of IFN-gamma. The protective effects of IFN-beta on occludin and VE-cadherin stability appear to represent molecular mechanisms for the therapeutic effects of the IFN-beta on blood brain barrier in MS.

N-methyl-d-aspartate receptor activation in human cerebral endothelium promotes intracellular oxidant stress

Cerebral endothelial cells in the rat, pig, and, most recently, human have been shown to express several types of receptors specific for glutamate. High levels of glutamate disrupt the cerebral endothelial barrier via activation of N-methyl-d-aspartate (NMDA) receptors. We have previously suggested that this glutamate-induced barrier dysfunction was oxidant dependent. Here, we provide evidence that human cerebral endothelial cells respond to glutamate by generating an intracellular oxidant stress via NMDA receptor activation. Cerebral endothelial cells loaded with the oxidant-sensitive probe dihydrorhodamine were used to measure intracellular reactive oxygen species (ROS) formation in response to glutamate receptor agonists, antagonists, and second message blockers. Glutamate (1 mM) significantly increased ROS formation compared with sham controls (30 min). This ROS response was significantly reduced by 1) MK-801, a noncompetitive NMDA receptor antagonist; 2) 8-( N, N-diethylamino)- n-octyl-3,4,5-trimethoxybenzoate, an intracellular Ca2+antagonist; 3) LaCl3, an extracellular Ca2+channel blocker; 4) diphenyleiodonium, a heme-ferryl-containing protein inhibitor; 5) itraconazole, a cytochrome P-450 3A4 inhibitor; and 6) cyclosporine A, which prevents mitochondrial membrane pore transition required for mitochondrial-dependent ROS generation. Our results suggest that the cerebral endothelial barrier dysfunction seen in response to glutamate is Ca2+dependent and may require several intracellular signaling events mediated by oxidants derived from reduced nicotinamide adenine dinucleotide oxidase, cytochrome P-450, and the mitochondria.

Cell column chromatography: a new research tool to quantify cerebral cell volume changes following chemically-induced anoxia/re-oxygenation

OBJECTIVE

The roles of individual types of cerebral cells in contributing to brain edema are undefined. The objective of this study was to determine the role of cerebral cell-column chromatography in quantifying cell volumes of individual cerebral cell lines, under chemically-induced anoxia/re-oxygenation (A/R).

METHODS

Cerebral endothelial cells (4 experiments) or type II astrocytes (4 experiments) were cultured to confluence on microcarrier beads. A chromatographic cell-column of 1.5 cm height was filled with non-treated cell-covered beads. The column was perfused at 1 ml/min with a balanced perfusate for one hour (Baseline). The perfusate was then switched to that containing 5 mM thioglycolic acid for one hour (Anoxia). Then the column was perfused with the normal perfusate for another two hours (Re-oxygenation). The total free space in the column, reversely reflecting cell volumes, was determined by averaged transit time (TTa) of a non-permeable flow tracer blue dextran. Decreased TTa means that cells swell, and vice versa.

RESULTS

TTa in endothelial cell columns increased with a peak at 60 minutes of re-oxygenation. TTa in astrocyte columns decreased with a nadir at 30 minutes of re-oxygenation.

CONCLUSION

Cell column chromatography can be used to determine the cerebral cell volume changes following chemically-induced anoxia/re-oxygenation.

Breast cancer metastasis to the medulla oblongata: a case report

Breast cancer metastasis to the brain stem is uncommon. Because of the rarity of the condition, the clinical course of such patients is not known. The case of a 41-year-old woman with advanced-stage carcinoma of the breast involving the medulla oblongata is presented and the literature concerning management, including patient outcome, is reviewed.

Glutamate causes a loss in human cerebral endothelial barrier integrity through activation of NMDA receptor

l-Glutamate is a major excitatory neurotransmitter that binds ionotropic and metabotropic glutamate receptors. Cerebral endothelial cells from many species have been shown to express several forms of glutamate receptors; however, human cerebral endothelial cells have not been shown to express either the N-methyl-D-aspartate (NMDA) receptor message or protein. This study provides evidence that human cerebral endothelial cells express the message and protein for NMDA receptors. Human cerebral endothelial cell monolayer electrical resistance changes in response to glutamate receptor agonists, antagonists, and second message blockers were tested. RT-PCR and Western blot analysis were used to demonstrate the presence of the NMDA receptor. Glutamate and NMDA (1 mM) caused a significant decrease in electrical resistance compared with sham control at 2 h postexposure; this response could be blocked significantly by MK-801 (an NMDA antagonist), 8-(N,N-diethylamino)-n-octyl-3,4,5-trimethyoxybenzoate (an intracellular Ca2+ antagonist), and N-acetyl-L-cystein (an antioxidant). Trans(+/-)-1-amino-1,3-cyclopentanedicarboxylic acid, a metabotropic receptor agonist (1 mM), did not significantly decrease electrical resistance. Our results are consistent with a model where glutamate, at excitotoxic levels, may lead to a breakdown in the blood brain barrier via activation of NMDA receptors.

Cauda equina compression in breast cancer--incidence and treatment outcome

PURPOSE

To determine the incidence and treatment outcome of compression of the cauda equina by metastatic disease in patients with breast cancer.

METHODS

A retrospective study of individuals diagnosed with breast cancer at a single institution during a 16-year period was undertaken.

RESULTS

Of the 1,283 patients studied, 15 (1.2%) developed cauda equina syndrome from metastatic disease. The median survival was eight months; ten (67%) survived for at least six months. Among the evaluable patients, pain was completely relieved in eight of ten women; complete resolution of neurologic deficits was observed in five of nine patients.

CONCLUSION

Metastatic breast cancer compression of the cauda equina and long-term survival of patients are infrequent occurrences. Beneficial responses can be mediated by radiotherapy.

Stereotactic radiosurgery for hemangioblastomas of the brain

OBJECTIVE

To assess the effectiveness of stereotactic radiosurgery in achieving tumor control and improving survival in patients with hemangioblastoma, we evaluated results from patients who were managed at the University of Pittsburgh and the Mayo Clinic.

PATIENTS AND METHODS

Twenty-seven patients with 29 hemangioblastomas had stereotactic radiosurgery over a 10 year interval. The mean patient age was 32 years (range, 14-75 years). The tumor volumes varied from 0.36 to 27 ml (mean, 3.2 ml), and the mean tumor margin dose was 16 Gy (range, 11.7-20). Clinical and neuroimaging follow-up was obtained for all patients between 0.5 and 9 years (mean, 4 years) after radiosurgery.

RESULTS

At this assessment, 21 patients (79%) were alive and six (21%) had died. The median survival after radiosurgery was 6.5 years (actuarial 5 year survival = 75.1 +/- 11.5%). The median survival from the initial diagnosis was 15 years. Twenty two of 29 evaluable tumors were controlled locally. The two-year actuarial control rate was 84.5 +/- 7.1% and at five years, 75.2 +/- 8.9%. Multivariate testing of factors affecting good outcome indicated that smaller tumor volume and higher radiosurgical dose (> 18 Gy) were significant.

CONCLUSION

For small to moderate size hemangioblastomas, multiple or recurrent tumors, and for patients who are not surgical candidates, radiosurgery is a safe and effective option to control disease and improve survival.

Imaging the trigeminal nerve and pons before and after surgical intervention for trigeminal neuralgia

OBJECTIVE

To study the various imaging changes occurring in the trigeminal nerve and brainstem in patients before or after trigeminal neuralgia surgery.

METHODS

During a 7-year period, 275 patients with trigeminal neuralgia underwent high-resolution, contrast-enhanced magnetic resonance imaging (MRI) of the pons during gamma knife radiosurgery. Ninety-seven patients had no previous surgical intervention for trigeminal neuralgia, and 178 patients had undergone one or more previous procedures. Two independent observers, one of whom was blinded to patients' clinical details, reviewed MRI scans retrospectively. The analysis of the independent observers was then correlated with all previous therapeutic interventions.

RESULTS

One hundred one MRI scans demonstrated no radiological changes related to trigeminal neuralgia, and 174 MRI scans exhibited some radiological abnormality. The average axial plane diameter of the nerve for all patients was 4 mm (range, 2-6 mm). In the group that had not undergone previous surgery, 65 patients (67%) exhibited vascular compression. In the 88 patients who had undergone previous microvascular decompression, 21 (24%) had evidence of a pontine infarction. Twenty-six patients experienced facial sensory loss, 22 (88%) of whom had undergone previous surgery with evidence of a pontine infarction (n = 11) or perineural scarring (n = 6).

CONCLUSION

The majority of patients who had undergone previous trigeminal neuralgia surgery demonstrated readily identifiable abnormalities of the trigeminal nerve or brainstem. The frequency of such changes correlated with the type and number of procedures. Evidence of vascular compression was detected in the majority of patients. Most patients with postoperative facial sensory loss demonstrate changes in the nerve or pons on MR images.

Adjuvant stereotactic radiosurgery for anaplastic ependymoma

OBJECT

The purpose of this retrospective study is to evaluate the role of stereotactic radiosurgery using the Gamma Knife as an adjuvant to other modalities used in the treatment of malignant ependymomas of both children and adults and to assess its efficacy in terms of tumor control and overall survival.

METHOD

Between 1987 and 1998, 22 patients in the age range of 1.5-65 years (mean age 22. 3) with progressive anaplastic ependymoma were treated by stereotactic radiosurgery using the 201 source Co-60 Leksell Gamma Knife at the University of Pittsburgh. The irradiated tumor volume varied from 0.84 to 36.8 cm(3) (mean 13.7). The median dose delivered to the tumor margin was 16.1 Gy (range 10-20), and the mean maximal dose was 32.2 Gy (range 20-40). The disease-free survival, the tumor control rate and the overall survival were recorded to evaluate the efficacy of radiosurgery. The median follow-up from radiosurgery was 21 months (range 4-84).

RESULTS

Median survival after radiosurgery was 2.2 years (46.6 +/- 12.1% 5-year actuarial). Median survival from the initial diagnosis was 10. 1 years (50.3 +/- 12.5% at 5 years, 37.7 +/- 14.4% at 10 years). Reduction or stabilization of the treated tumor was seen in 16 out of 22 (68%) patients. Forty-one percent of the patients eventually developed delayed distant cerebral recurrence outside the treated volume. The 5-year actuarial rates for local control and cranial control at any location were 62.3 +/- 13.6% and 32.4 +/- 10.8%, respectively. No complication occurred as a side effect of radiosurgery.

CONCLUSION

For patients with locally recurrent or progressive anaplastic ependymomas, Gamma Knife stereotactic radiosurgery proved to be safe and effective as a salvage adjuvant therapy to achieve local tumor control and improve survival.

A comparison of surgical approaches for the management of tremor: radiofrequency thalamotomy, gamma knife thalamotomy and thalamic stimulation

OBJECTIVE

Between April 1994 and January 1999, 39 stereotactic procedures for patients with intractable tremor were performed at the University of Pittsburgh Medical Center. A retrospective analysis of results of radiosurgical thalamotomy (n = 15), MR-guided stereotactic radiofrequency thalamotomy (n = 13), and deep brain thalamic stimulation (DBS; n = 11) was performed to study relative advantages and risks of these procedures.

METHODS

All options were discussed with the patients, but radiosurgery usually was performed in elderly patients with concurrent medical problems. Stereotactic thalamotomy and DBS was performed with MR guidance and macrostimulation. For radiosurgery, a median dose of 140 Gy (range 130-150 Gy) was delivered using a single 4-mm collimator.

RESULTS

Of the 13 patients who underwent radiofrequency thalamotomy, 5 had immediate complete arrest of tremor, 6 had a significant reduction and 2 had partial reduction. All 11 patients who underwent DBS had excellent control of tremor immediately after the procedure, and in longer-term follow-up 10/11 maintained excellent tremor control. Of the 12 evaluable radiosurgery patients, 10 noted excellent relief and 2 had partial relief.

CONCLUSION

Stereotactic procedures for tremor control are safe and effective. Each procedure has specific advantages and disadvantages that are important for patient selection.