Intravascular large B-cell lymphoma presenting with diffusely increased pulmonary fluorodeoxyglucose uptake without corresponding CT abnormality.

A 60-year-old male presented with complaints of dyspnea, intermittent fever, and 40 pounds of weight loss over the previous 9 months and was admitted for acute hypoxemic respiratory failure. Labs demonstrated elevated inflammatory markers, mild anemia, and thrombocytopenia. Fluorodeoxyglucose-positron emission tomography scan demonstrated diffusely increased pulmonary fluorodeoxyglucose uptake without corresponding abnormality on CT images. Excisional lung biopsy demonstrated intravascular large B-cell lymphoma (IV-LBCL). Presentation, imaging findings, and diagnosis of IV-LBCL will be discussed, as well as differential considerations for pulmonary involvement by IV-LBCL.

Patterns of lymph node positivity on 11C-acetate PET imaging in correlation to the RTOG pelvic radiation field for prostate cancer.

PURPOSE: 11C-acetate positron emission tomography (PET) imaging allows for the detection of occult metastatic disease that may otherwise go undetected with standard imaging for prostate cancer (PCa). The aim of this study was to evaluate lymph node coverage of the standard Radiation Therapy Oncology Group (RTOG) whole pelvic radiation therapy (WPRT) field in patients found to have node-positive PCa determined by 11C-acetate PET imaging. METHODS AND MATERIALS: A retrospective analysis was conducted on 125 PCa patients who underwent 11C-acetate PET scans at our institution between 2007 and 2014. Patients were included if they had evidence of nodal disease without distant metastatic cancer. Individual lymph nodes were characterized by location, size, and relationship to the RTOG WPRT field. RESULTS: A total of 55 11C-acetate PET scans (from 54 men) met criteria for inclusion in the study. Median age at diagnosis was 61 years. Median prostate-specific antigen values at diagnosis and at the time of the scan were 9.2 and 8.1 ng/mL, respectively. A total of 159 positive lymph nodes were identified, 78% of which were smaller than 1 cm. The most frequently involved lymphatic regions were the external iliacs (38.4%), para-aortics (19.5%), and common iliacs (16.3%). Additionally, 10.1% of positive nodes were identified as nodes of Cloquet. Of the positive nodes, 51.6% were determined to reside outside of the radiation field and, of those, the most common sites were para-aortic (36.9%), proximal common iliac (17.8%), distal external iliac (17.8%), and nodes of Cloquet (17.8%). CONCLUSIONS: Based on 11C-acetate PET imaging in patients with PCa, the standard RTOG WPRT field may miss more than one-half of all positive lymph nodes. Clinicians should be aware of the potential for insufficient nodal coverage when using the standard RTOG WPRT field in patients with node-positive PCa. 11C-acetate PET imaging may be useful in defining target volumes for these patients.

Prostate Cancer Metastases to Inguinal Lymph Nodes Detected by Attenuation-Corrected 11C-Acetate PET/CT.

The inguinal lymph nodes are an unusual site of metastases for prostate adenocarcinoma. We present a case in which a 61-y-old man with biochemically recurrent prostate cancer underwent attenuation-corrected (11)C-acetate PET/CT, which demonstrated multiple foci of increased activity in the left inguinal, left iliac chain, and right inguinal regions. The attenuation-corrected CT portion of the scan also showed anterior wall thickening of the rectum. The imaging findings were suggestive of metastatic involvement of the rectum below the dentate line with subsequent spread to the inguinal lymph nodes.

Effect of atrial fibrillation ablation on gastric motility: the atrial fibrillation gut study.

BACKGROUND: Collateral damage to the vagal nerve and the upper gastrointestinal (UGI) system during atrial fibrillation ablation has not been systematically evaluated. METHODS AND RESULTS: We performed a prospective, observational study assessing the effect of atrial fibrillation ablation on the function of the vagus nerve/UGI system. All patients underwent esophageal manometry, gastric emptying study, and sham-feeding test (corresponding to esophageal, gastric, and small intestinal function evaluation, respectively) before ablation (baseline) and subsequently at 24 hours, 90 days, and 180 days after the procedure. In addition, UGI symptom assessment using the patient assessment of upper gastrointestinal disorders-symptom severity index (PAGI-SYM) questionnaire was performed at baseline and during each of the subsequent evaluations. Of the 27 patients enrolled in the study, 9 (33%) patients had abnormal UGI function at baseline; defined as at least one of the 3 abnormal tests. At 24 hours after the radiofrequency catheter ablation, 20 (74%) patients had at least 1 new abnormality on the UGI function tests (P<0.001). New onset esophageal dysmotility, delayed gastric emptying time, and abnormal sham-feeding tests were observed in 13 (48%), 13 (48%), and 9 (33%) patients, respectively. Mean PAGI-SYM scores increased from 7.78±6.6 at baseline to 15.56±13.4 (P=0.002) at 24 hours. New onset abnormalities persisted in 9 (33%) patients at 3 months and normalized in all patients at 6 months. CONCLUSIONS: Atrial fibrillation ablation results in functional impairment of the UGI system, including the esophagus, stomach, and small intestine. This impairment is transient and is probably mediated by the injury to the components of the vagal nerve. CLINICAL TRIAL REGISTRATION: URL: http://clinicaltrials.gov. Unique Identifier: NCT01396356.

Prostate-specific antigen and prostate-specific antigen velocity as threshold indicators in 11C-acetate PET/CTAC scanning for prostate cancer recurrence.

PURPOSE: The aim of this study was to identify which patient characteristics are associated with the highest likelihood of positive findings on 11C-acetate PET/computed tomography attenuation correction (CTAC) (PET/CTAC) scan when imaging for recurrent prostate cancer. METHODS: From 2007 to 2011, 250 11C-acetate PET/CTAC scans were performed at a single institution on patients with prostate cancer recurrence after surgery, brachytherapy, or external beam radiation. Of these patients, 120 met our inclusion criteria. Logistic regression analysis was used to examine the relationship between predictability of positive findings and patients' characteristics, such as prostate-specific antigen (PSA) level at the time of scan, PSA kinetics, Gleason score, staging, and type of treatment before scan. RESULTS: In total, 68.3% of the 120 11C-acetate PET/CTAC scans were positive. The percentage of positive scans and PSA at the time of scanning and PSA velocity (PSAV) had positive correlations. The putative sensitivity and specificity were 86.6% and 65.8%, respectively, when a PSA level greater than 1.24 ng/mL was used as the threshold for scanning. The putative sensitivity and specificity were 74% and 75%, respectively, when a PSAV level greater than 1.32 ng/mL/y was used as the threshold. No significant associations were found between scan positivity and age, PSA doubling time, Gleason score, staging, or type of treatment before scanning. CONCLUSIONS: This retrospective study suggests that threshold models of PSA greater than 1.24 ng/mL or PSAV greater than 1.32 ng/mL per year are independent predictors of positive findings in 11C-acetate PET/CTAC imaging of recurrent prostate cancer.

Inflammatory response following neutrophil recovery postchemotherapy in acute myeloid leukemia cases without evidence of infection: role of homing of neutrophils.

Neutropenic sepsis is a common clinical entity occurring in postchemotherapy patients. Infection may not be the cause of fever in such patients after neutrophil-count recovery. Herein, we present two patients who developed fever during the neutropenic phase of induction chemotherapy and were treated with broad-spectrum antibiotics until they were no longer febrile and had recovered their neutrophil count. Being off antibiotics, they redeveloped fever within 48-72 hours. These fevers seemed to be secondary to postinfectious inflammatory response and not infection, supported by the fact that adequate antibiotic treatment was given and the collected fluid contained neutrophils but the cultures were negative. We hypothesize an explanation for this phenomenon based on the "homing of neutrophils" to bone marrow, which involves chemoattraction of CXC chemokine receptor (CXCR)-4 expressed on neutrophils towards the chemokine stromal cell-derived factor (SDF)-1 (CXCL12) expressed constitutively by bone marrow. Literature has shown that elevation of SDF-1 levels at injured/inflamed sites might create a similar gradient. This gradient results in the migration of neutrophils to the sites of previous injury/inflammation, leading to the formation of sterile abscesses. Based on our cases, we also conclude that antibiotics do not prevent the formation or treat such sterile "abscesses"; however, the drainage of these "abscesses" and treatment with anti-inflammatory agents are useful in such cases.

Positron-emission tomography pitfalls related to oral prosthesis.

This case report describes false-positive positron-emission tomography/computed tomography (PET/CT) findings related to oral prostheses and its implications in cancer surveillance. In head and neck cancer management, F18-flurodeoxyglucose (FDG) PET/CT is widely accepted for evaluating treatment response and detecting recurrence. Interpretation of FDG PET/CT images in this setting is often challenging due to various prostheses and reconstruction methods. Following surgery for squamous cell carcinoma of the maxillary alveolus, a 61-year-old female had a FDG PET/CT scan on a 7-month follow-up that showed high FDG uptake along the resection site. Clinical examination showed no signs of inflammation or recurrence. Repeat FDG PET/CT without the prosthesis was normal. The PET/CT attenuation-corrected images demonstrated high FDG uptake (standardized uptake value: 11.6) along the resection site corresponding to contrast-enhanced CT images of the lesion. PET/CT nonattenuation-corrected images also confirmed increased activity. Repeat PET/CT without the prosthesis was normal. FDG is not tumor specific; it can accumulate in inflammation, infection, and post-therapy settings. Metallic and high-density prostheses show radial artifacts on CT and falsely elevated FDG uptake on PET/ CT in adjacent areas. Salivary pooling may concentrate FDG. The presence of oral prostheses has not been described as a cause of this high level of activity. PET/CT images that demonstrate intense activity corresponding to dense structures should be viewed with caution. A detailed history and physical exam as well as knowledge of artifacts are pertinent for the managing physician. Laryngoscope, 2012.

Prostate imaging modalities that can be used for complementary and alternative medicine clinical studies.

This article provides an overview of imaging modalities that aid in diagnosing, staging, and assessing therapeutic response in prostate cancer. Prostate cancer is the second most common type of cancer in American men and the second leading cause of cancer death among men. Prostate cancer is difficult to diagnose in early stages, and advanced disease often recurs after treatment. To localize sites of recurrence many imaging modalities have been used with varying success. This article presents case studies of PET scanning using carbon 11 acetate and discusses intravenously infused ascorbate, a complementary and alternative medicine therapy for prostate cancer.

Optimizing the diagnostic power with gastric emptying scintigraphy at multiple time points.

BACKGROUND: Gastric Emptying Scintigraphy (GES) at intervals over 4 hours after a standardized radio-labeled meal is commonly regarded as the gold standard for diagnosing gastroparesis. The objectives of this study were: 1) to investigate the best time point and the best combination of multiple time points for diagnosing gastroparesis with repeated GES measures, and 2) to contrast and cross-validate Fisher's Linear Discriminant Analysis (LDA), a rank based Distribution Free (DF) approach, and the Classification And Regression Tree (CART) model. METHODS: A total of 320 patients with GES measures at 1, 2, 3, and 4 hour (h) after a standard meal using a standardized method were retrospectively collected. Area under the Receiver Operating Characteristic (ROC) curve and the rate of false classification through jackknife cross-validation were used for model comparison. RESULTS: Due to strong correlation and an abnormality in data distribution, no substantial improvement in diagnostic power was found with the best linear combination by LDA approach even with data transformation. With DF method, the linear combination of 4-h and 3-h increased the Area Under the Curve (AUC) and decreased the number of false classifications (0.87; 15.0%) over individual time points (0.83, 0.82; 15.6%, 25.3%, for 4-h and 3-h, respectively) at a higher sensitivity level (sensitivity=0.9). The CART model using 4 hourly GES measurements along with patient's age was the most accurate diagnostic tool (AUC=0.88, false classification=13.8%). Patients having a 4-h gastric retention value>10% were 5 times more likely to have gastroparesis (179/207=86.5%) than those with ≤10% (18/113=15.9%). CONCLUSIONS: With a mixed group of patients either referred with suspected gastroparesis or investigated for other reasons, the CART model is more robust than the LDA and DF approaches, capable of accommodating covariate effects and can be generalized for cross institutional applications, but could be unstable if sample size is limited.

Regression of internal melanoma metastases following application of topical imiquimod to overlying skin.

The prognosis for metastatic melanoma is grim, and treatment options are limited. Imiquimod is a topically applied immune modulator that has been used to treat superficial cutaneous melanoma, but has not been reported to treat metastatic melanoma. We report a patient whose liver and iliac fossa melanoma metastases regressed after topical application of imiquimod cream to overlying skin. This supports further investigation of the potential use of imiquimod for metastatic melanoma.

FDG-PET staging and importance of lymph node SUV in head and neck cancer.

OBJECTIVES: The role of positron emission tomography (PET) with fluoro-deoxy-glucose (FDG) in the staging of head and neck cancer (HNC) is unclear. The NCCN guidelines do not recommend FDG-PET as a part of standard workup. The purpose of this report is to examine the role of FDG-PET imaging in altering management and providing prognostic information for HNC. METHODS: Retrospective review of HNC patients who had a staging FDG-PET scan performed at either Thomas Jefferson University or University of Kansas Medical Center between the years 2001 and 2007. A total of 212 PET scans were performed in patients who went on to receive radiotherapy. RESULTS: The median follow-up time for all patients was 469 days. The PPV and NPV of PET imaging to correctly identify lymph node status was 94% and 89% respectively. Lymph nodes with extracapsular extension (ECE) had higher SUVs than nodes without ECE, 11.0 vs. 5.0 (p < 0.0007). Maximum SUV for the primary tumor > 8.0 was predictive of worse overall survival (p < 0.045), while the SUV of the lymph nodes was predictive for distant recurrence at one year--with a mean SUV value of 10.4 for patients with distant failure vs. 7.0 without (p < 0.05). CONCLUSIONS: FDG-PET staging in head and neck cancer has good positive and negative predictive values in determining lymph node status. The maximum SUV of the primary tumor is predictive of overall survival. This is the first report to find that the SUV of a lymph node is predictive for ECE and also for distant recurrence.

Leiomyosarcoma of the inferior vena cava: a case report and review of the literature.

A 68-year-old white female presented with two years of progressively worsening dyspnea. Echocardiography revealed a large right atrial mass and partial obstruction of the inferior vena cava. Further imaging revealed a cystic dense mass in the inferior vena cava and right atrium. Immunohistochemical stains were consistent with leiomyosarcoma. Intraoperatively, the tumor was noted to originate from the posterior aspect of the inferior vena cava. The patient underwent successful resection of the mass. Adjuvant radiation therapy was completed. The patient's dyspnea gradually improved and she continues to remain disease free five years post-resection.

Mechanisms of high-frequency electrical stimulation of the stomach in gastroparetic patients.

Previous studies have demonstrated that high frequency and low energy gastric electrical stimulation (GES) reduced nausea and vomiting in gastroparetic patients without improving gastric emptying. The mechanisms of action for this have not been clarified. The aim of our study was to investigate the effects of GES on autonomic function, gastric distention and tone, and central control mechanism in gastroparetics patients. 10 gastroparetic patients refractory to standard medical therapy participated in this study and data were collected at baseline session, within two weeks before surgery for implantation of GES system, and at follow-up sessions between 6 to 12 weeks after GES therapy. In each session, electrocardiogram and gastric barostat measurements were conducted before and after a caloric liquid meal. Positron Emission Tomography (PET) brain scans were performed on a separate day. Analysis of autonomic function was accomplished through power spectral analysis of heart rate variability which revealed that the sympthovagal balance was significantly decreased after GES therapy, indicating a significant increase in vagal activity. Results from gastric barostat measurements demonstrated that during GES there was a significant increase in the discomfort threshold for both pressure and volume. Quantitative analysis of PET imaged cerebral activity showed that chronic GES increased thalamic activity. This study suggests that the symptomatic efficacy achieved by GES may be partly attributed to enhanced vagal autonomic function, decreasing gastric sensitivity to volume distention which simulates a postprandial adaptation and the activation of central control mechanisms for nausea and vomiting through thalamic pathways during GES.

Imaging for suspected appendicitis.

Acute appendicitis is the most common reason for emergency abdominal surgery and must be distinguished from other causes of abdominal pain. Family physicians play a valuable role in the early diagnosis and management of this condition. However, the overall diagnostic accuracy achieved by traditional history, physical examination, and laboratory tests has been approximately 80 percent. The ease and accuracy of diagnosis varies by the patient's sex and age, and is more difficult in women of childbearing age, children, and elderly persons. If th diagnosis of acute appendicitis is clear from the history and physical examination, prompt surgical referral is warranted. In atypical cases, ultrasonography and computed tomography (CT) may help lower the rate of false-negative appendicitis diagnoses, reduce morbidity from perforation, and lower hospital expenses. Ultrasonography is safe and readily available, with accuracy rates between 71 and 97 percent, although it is highly operator dependent and difficult in patients with a large body habitus. While there is controversy regarding the use of contrast media and which CT technique is best, the accuracy rate of CT scanning is between 93 and 98 percent. Disadvantages of CT include radiation exposure, cost, and possible complications from contrast media.