18F-DCFPyL PSMA PET/CT Tracheobronchial Uptake in Patients with Prostate Cancer: Incidence and Etiology.

We evaluated the incidence and potential etiology of tracheobronchial uptake in patients being evaluated by 18F-DCFPyL PET/CT for prostate cancer (PCa). Methods: The study included a consecutive 100 PCa patients referred for 18F-DCFPyL PET/CT. The PET/CT scans were retrospectively reviewed. The presence or absence of physiologic tracheobronchial uptake on PET/CT was recorded. To further evaluate tracheal prostate-specific membrane antigen (PSMA) expression, immunohistochemistry was performed on tracheal samples taken from 2 men who had surgical resection of lung cancer. Results: Tracheal uptake was present in 31 of 100 patients (31%). When tracheal uptake was present, the SUVmax was significantly higher in the left main bronchus (mean, 2.7) than in the right (mean, 2.3) (P < 0.001). Histopathologic testing of tracheobronchial samples showed PSMA expression in bronchial submucosal glands. Conclusion: In PCa patients undergoing 18F-DCFPyL PET/CT, tracheobronchial uptake occurred in 31% of patients. This is attributed to normal physiologic PSMA expression in bronchial submucosal glands.

Evaluating appropriateness of 18F-fluciclovine PET/CT relative to standard of care imaging guidelines and the impact of ADT on positivity: a prospective study in 62 Veterans Administration patients at a single institution.

BACKGROUND: According to the National Comprehensive Cancer Network Guidelines, 18F-fluciclovine PET/CT is considered appropriate after negative standard of care (SOC) imaging. OBJECTIVE: To prospectively compare 18F-fluciclovine to SOC imaging, investigate whether it should be done when SOC imaging is (+), and evaluate its detection rate in patients receiving androgen deprivation therapy. METHODS: We recruited 57 prostate cancer patients with biochemical recurrence with 18F-fluciclovine PET/CT and SOC imaging within 30 days. Prostate-specific antigen (PSA) level, Gleason score (GS), history of radical prostatectomy (RP), radiation therapy (RT) or hormone therapy (HT) were reviewed. RESULTS: The 57 patients had a median PSA of 2.6 and average GS of 7.4; 27 (47.4%) had RP, 28 (49.1%) had RT, 1 (1.75%) had HT and 1 (1.75%) observation only. 18F-fluciclovine identified disease recurrence in 45/57 patients (78.9%), including oligometastasis in 18/45 (40%). SOC imaging identified recurrent disease in 12/57 patients (21.1%) while 18F-fluciclvoine identified additional sites of disease in 11/12 (91.7%). The (+) 18F-fluciclovine studies had a median PSA 2.6 ng/ml compared to 6.0 ng/ml in the (+) SOC studies. CONCLUSION: 18F-fluciclovine was superior to SOC imaging for lesion detection, identification of oligometastasis and identification of additional sites of disease.

Incidence of 99Tc-MDP uptake in the external occipital protuberance in the pediatric population: the new normal?

BACKGROUND: Children and young adults have a vast array of electronics at their fingertips. While it can provide endless hours of entertainment and education, we are also seeing a structural consequence. Children are using these devices with their head tilted down with poor posture resulting in increased stress on the skull from attached structures which can lead to a bone spur (exostosis) at the external occipital protuberance (EOP). While typically painless, it can progress to necessitate surgical intervention. OBJECTIVES: The purpose of this study is to understand the prevalence of exostosis at the EOP and how the finding can affect the nuclear medicine bone scan. MATERIALS AND METHODS: 43 pediatric patients who underwent a whole-body bone scan over a period of 1 year were included in the study (10-19 years old). Images were reviewed by 2 board-certified Nuclear Medicine physicians to assess for uptake midline in the occipital skull. Suspected cases were followed up with all available clinical and radiographic reports and images. RESULTS: Bone scan demonstrated an occipital focus of uptake in 7 (16%) of the 43 patients (5 males and 2 females with a mean age of 15 years; range 10-19). Of these, 5/7 (71%) were confirmed by additional imaging. CONCLUSION: The rapidly advancing technology is leading to increased screen time in children and young adults. Our study shows that 16% of the pediatric population imaged at our facility between the ages of 10-19 years have signs of exostosis at the EOP. It is particularly important for clinicians to be aware of this entity when reading bone scans to avoid false positive interpretations.

68Ga-PSMA PET/CT in early relapsed prostate cancer patients after radical therapy.

Biochemical recurrence (BCR) of prostate cancer (PCa) occurs in about 25% of patients treated with radical prostatectomy (RP) and up to 45% in patients who receive external beam radiotherapy (RT). Early diagnosis of PCa recurrence is of high importance for successful salvage therapy. The aim of the present study is to analyze the efficacy of 68 Ga-PSMA PET/CT in detecting the presence of local and/or systemic disease in patients with a history of PCa who have BCR. A total of 52 PCa patients with BCR referred for 68 Ga-PSMA PET/CT were recruited from the American University of Beirut Medical Center between November 2017 and December 2019. We compared the performance of PSMA PET/CT to the results and clinical factors based on follow up: PSA, PSA kinetics, primary treatment, and Gleason score. The relationship between the PET/CT findings and clinical indicators of disease were assessed by univariate and multivariate logistic regression. From a total of 52 patients, 34 (65.4%) had positive PSMA-PET/CT scans. Among those, 8/34 (23.5%) received primary RT. For all patients with a positive PSMA-PET: the detection rate was 2/4 (50%) for PSA < 0.2, 5/10 (50%) for PSA 0.2-0.49, 3/6 (50%) for PSA 0.5-0.99, 6/12 (50%) for PSA 1-1.99, 8/9 (88.9%) for PSA 2-3.99, and 10/11 (90.9%) for PSA 4-10.PSMA-PET/CT positivity was significantly associated with PSA level at time of PET scan, PSA doubling time, Gleason score and TNM staging. However, it did not show a significant correlation with radiotherapy as primary treatment, ongoing androgen deprivation therapy (ADT), time to relapse, and initial PSA before therapy. In our single center prospective trial, 68 Ga-PSMA PET/CT successfully detected the recurrence of PCa in patients with BCR. Scan positivity was significantly associated with PSA level at time of PET scan, PSA doubling time, Gleason score, and TNM staging. PSMA- PET/CT is a highly promising modality in the work up of patients with PCa in the setting of BCR for earlier detection of disease recurrence.

Reducing Radiation Exposure from PET Patients.

This study measured the typical emitted radiation rate from the urinary bladder of PET patients after their scan and investigated simple methods for reducing the emitted radiation before discharge. Methods: The study included 83 patients (63 18F-FDG and 20 18F-NaF patients). Emitted radiation from the patients' urinary bladder was measured with an ionization survey meter at a 1-m distance, presuming the urinary bladder to be the primary source of radiation. The measurements were taken at different time points after PET image acquisition: immediate (prevoid 1), voided (postvoid 1), after waiting 30 min in the uptake room while drinking 500 mL of water (prevoid 2), and voided again (postvoid 2). Results: For 18F-FDG patients, the reduction of emitted radiation due to drinking water and voiding alone from prevoid 1 to decay-corrected postvoid 2 was an average of 22.49% ± 7.48% (13.65 ± 3.42 µSv/h to 10.48 ± 2.37 µSv/h, P < 0.001). For 18F-NaF patients, the reduction was an average of 25.80% ± 10.03% (9.83 ± 2.01 µSv/h to 7.23 ± 1.49 µSv/h, P < 0.001). Conclusion: In addition to the physical decay of the radiotracers, using the biologic clearance properties resulted in a significant decrease of the emitted radiation in this study. Implementing additional water consumption to facilitate voiding with 30 min of wait time before discharging certain 18F-FDG and 18F-NaF patients who need to be in close contact with others, such as elderly, caregivers, and inpatients, might facilitate lowering their emitted radiation by an average of 22%-25% due to voiding, not counting in the physical decay that should add an additional 17% reduction.

Monitoring Individual Occupational Radiation Exposure at Multiple Institutions.

Within a few years of its' discovery, ionizing radiation demonstrated adverse effects on biological systems. Since that time great strides were made in both radiation protection, detection, and personnel monitoring. Monitoring occupational radiation dose to individuals is enforced by several regulatory agencies in the United States (U.S.) and is referenced in numerous sections of the Code of Federal Regulations (CFR). A literature review with an examination of regulatory guidelines and a Radiation Safety Officers (RSO) survey was conducted to evaluate how often radiation dose exposure is monitored when an individual receives occupational radiation dose at more than one facility. The length of time an RSO has overseen the radiation safety program at his/her institution can impact if dosimetry reports are requested for individuals that work at multiple places. Despite having safer equipment and occupational radiation exposure standards, there is no universal mechanism to track and record exposure for individuals working at more than one institution.

Intra-patient comparison of physiologic 68Ga-PSMA-11 and 18F-DCFPyL PET/CT uptake in ganglia in prostate cancer patients: a pictorial essay.

BACKGROUND: Recent studies reported metabolic uptake in at least one of the evaluated ganglia in 98.5% of patients undergoing 68Ga -PSMA-11 and in 96.9% of patients undergoing 18F-DCFPyL PET/CT examination. We have observed different patterns of ganglion visualization with 18F-DCFPyL compared to 68Ga-PSMA-11. This includes more frequent visualization of cervical and sacral ganglia, which may be attributable to better imaging characteristics with 18F PET imaging. CASE PRESENTATION: This pictorial essay is to illustrate and compare, in the same patient, various representative cases of 68Ga-PSMA-11 and 18F-DCFPyL PET/CT uptake in ganglia at different anatomic locations, with different patterns and distribution of metabolic activity. CONCLUSION: Reading physicians should be aware of the frequently encountered and occasionally different physiologic uptake of 68Ga-PSMA-11 and 18F DCFPyL in different ganglia.

FDG PET/CT for tumoral and systemic immune response monitoring of advanced melanoma during first-line combination ipilimumab and nivolumab treatment.

PURPOSE: We aimed to investigate the role of FDG-PET/CT in monitoring of response and immune-related adverse events (irAEs) following first-line combination-immune checkpoint inhibitor (combination-ICI) therapy for advanced melanoma. METHODS: We retrospectively reviewed outcomes in patients who had (1) first-line nivolumab plus ipilimumab; (2) pre- and post-treatment FDG-PET/CT scans (pre-FDG-PET/CT and post-FDG-PET/CT) within 2 and 4 months of starting ICI, respectively; and (3) at least one lesion assessable by PET response criteria in solid tumors (PERCIST). Extracranial response was monitored by 3 monthly FDG-PET/CT. Whole-body metabolic tumor volume (wbMTV) was measured pre- and post-treatment and correlated with outcome. FDG-PET/CT manifestations of irAE were defined as new increased non-tumoral uptake on post-FDG-PET/CT and were correlated with clinical presentation. RESULTS: Thirty-one consecutive patients, median age 60 years (range, 30-78), were identified from 2016 to 2018. The median number of combination-ICI cycles to the first post-FDG-PET/CT response assessment was 3 (interquartile range (IQR), 2-4). The best-overall responses were complete metabolic response (CMR) in 25 (80%), partial metabolic response (PMR) in 3 (10%), and progressive metabolic disease (PMD) in 3 (10%) patients. Patients with PMD had significantly higher pre-treatment wbMTV (p = 0.009). At a median follow-up of 21.5 months, 26 (84%) patients were alive with median progression-free and overall survival not reached. Secondary progression occurred in 9/31 (29%) patients at a median of 8.2 months (IQR, 6.9-15.5), of those majority (78%) was detected by FDG-PET/CT. Of 36 findings on post-FDG-PET/CT suggestive of irAE, 29 (80%) had clinical confirmation. In 3 (7%), the FDG-PET/CT findings preceded clinical presentation. The most common FDG-PET/CT detectable irAEs were endocrinopathies (36%) and enterocolitis (35%). CONCLUSION: FDG-PET/CT response evaluation predicts the long-term outcome of patients treated with first-line combination-ICIs. Long-term treatment response monitoring for detection of extracranial secondary progression is feasible by FDG-PET/CT. Beyond response assessment, FDG-PET/CT frequently detects clinically relevant irAEs, which may involve multiple systems contemporaneously or at various time-points and may precede clinical diagnosis.

Development of Simple Methods to Reduce the Exposure of the Public to Radiation from Patients Who Have Undergone 18F-FDG PET/CT.

At a time when reducing the radiation dose to patients and the public has become a major focus, we assessed the radiation exposure rate from patients after an 18F-FDG PET/CT scan and evaluated different interventions to reduce it. Methods: We enrolled 100 patients, divided into 2 groups. For both groups, the radiation dose rate was measured with an ionization survey meter immediately after the scan. For group 1, the patients then voided and their dose rate was measured again. For group 2, the patients waited 30 min before voiding, and we measured the dose rate before (group 2A) and after (group 2B) they voided. Results: In total, 74 of the 100 patients exceeded the 20 µSv/h (2 mR/h) threshold immediately after the scan. In group 1, the mean dose rate decreased by 20.0% from the postscan measurement, with 12 of 36 remaining at or above 20 µSv/h. In group 2A, the mean dose rate decreased by 23% from the postscan measurement, with 9 of 38 remaining at or above 20 µSv/h. In group 2B, the mean dose rate decreased by 35% from the postscan measurement, with 1 of 38 remaining at 20 µSv/h. Conclusion: Nearly 75% of patients undergoing an 18F-FDG PET/CT scan exceed 20 µSv/h when leaving the imaging facility. The most effective method to reduce radiation exposure was to have the patient void 30 min after the examination.

Pediatric Nasopharyngeal Carcinoma as Seen on 18F-FDG PET/CT.

Pediatric nasopharyngeal carcinoma is a rare malignancy strongly associated with Epstein-Barr virus infection. Patients typically present with non-specific symptoms of epistaxis or serous otitis from eustachian tube obstruction and therefore diagnosis is often delayed. We present a case of a previously healthy 17 year old female who initially complained of migraines which was resistant to oral medication. Symptoms progressed and she saw a dental surgeon for concern of a dental infection and was prescribed antibiotics with no relief. Her symptoms continued to progress until an otolaryngologist visualized a large mass along the floor of the left nasal cavity. Subsequent imaging showed a large mass in the posterior left nasal cavity and biopsy was consistent with nasopharyngeal carcinoma.

Chemotherapy-induced coronary arteries calcium score deterioration as detected with unenhanced CT portion of FDG PET/CT.

This study aims to detect the potential impact of chemotherapy on the coronary calcium scoring (CCS) in lymphoma patients undergoing FDG-PET/CT at baseline and for therapy response using the CT portion of the exam to calculate the CCS. One hundred twelve lymphoma patients were included in the study based on having both baseline and at least 2 post-chemotherapy scans. The unenhanced CT portions of the scans were reviewed to measure the CCS which was then extracted using the Toshiba Vital Program. Agatston scores were assessed as category 1 with zero CCS unit and categories 2 to 5 having more than >1, 11, 101, and 400 CCS units respectively. For statistical analysis, paired T-Tests were used to compare results. The overall changes in total coronary artery calcium (CAC) from baseline to last treatment showed a statistically significant increase in CAC with an average increase of at least 35% in the CAC score. We also compared the overall changes in CAC with patients having category 1 and 2 Agatston at baseline and found no statistical increase in CAC post-chemotherapy. Additionally, we compared the overall changes in CAC with patients having category 3 and 4 Agatston at baseline and found statistically significant increase in CAC post-chemotherapy. In lymphoma patients, chemotherapy may cause worsening of CCS and this can serve as an early indicator of chemotherapy-induced cardiac toxicity. When present, such CCS deterioration can be detected by the unenhanced CT portion of routine oncologic FDG PET/CT scans.

Normalized Subtraction of Serial Brain Magnetic Resonance Images and Fludeoxyglucose-Positron Emission Tomography Images for Tumor Treatment Monitoring: Case Report and Method Description.

A 60-year-old Caucasian male with a long history of cigarette smoking was diagnosed with epidermal growth factor receptor-mutation negative lung adenocarcinoma. The single cerebral metastasis in the right frontal lobe was treated with stereotactic radiosurgery and systemic chemotherapies. Normalized subtraction (NS) method was used to evaluate the serial brain magnetic resonance (MR) and fludeoxyglucose-positron emission tomography (FDG-PET) findings retrospectively, and the potential benefit of concurrent NS of serial MR images (MRIs) and PET images was demonstrated. MIM 4.1 (MIM Software Inc., Cleveland, OH) was used to co-register MRI with PET data and to perform NS on the serial MRI and PET data. MIM 4.1 provides fully automated alignment of imaging data by maximization of mutual information. Cortical regions distant from the brain lesion were used to adjust for the intensity differences between scans, so the voxel differences in normal brain regions were near zero in the NS images. A difference of 15% or greater in voxel densities was used for both MRI and PET, above or below which a change in MR signal intensity and FDG avidity was considered significant. The use of NS, in this case, allowed for an enhanced correlation of morphologic and functional information, which may have added value in the early treatment monitoring of brain tumors and help distinguish recurrent tumor from postradiation changes.

Impact of Renal Failure on F18-FDG PET/CT Scans.

OBJECTIVE: The current guidelines for 2-deoxy-2-[18F]fluoro-d-glucose PET/CT scanning do not address potential inaccuracies that may arise due to patients with renal failure. We report a retrospective analysis of standard uptake values (SUVs) in patients with and without renal failure in order to warrant a protocol adjustment. METHODS: Patients were matched based on age, gender, and BMI all of which are potential effectors on observed SUV. Thirty patients were selected with clinically diagnosed renal failure, of which 12 were on dialysis. All 30 patients had age, gender, and BMI control matches. Blood urea nitrogen and creatinine levels were measured within 1 month of the scan to assess renal failure. PET/CT scans for both the renal failure patients and controls were performed 60 min after FDG injection. SUVs were measured by placing circular regions of interest in the right hepatic lobe (LSUV) and left psoas muscle (PSUV). RESULTS: For the 30 renal failure patients, the mean LSUV was 2.77 (SD = 0.57) and PSUV was 1.43 (SD = 0.30) while the controls had mean LSUV 2.74 (SD = 0.50) and PSUV 1.42 (SD = 0.37). The SUVs from both the liver and psoas muscle were not significantly different between the renal failure patients and the normal controls with p values >0.05. In addition, dialysis and gender also had no effect on SUVs. CONCLUSION: Our data suggest that renal failure patients do not require an adjustment in protocol and the standard protocol times should remain.

Detection of Synchronous Primary Malignancies with 68Ga-Labeled Prostate-Specific Membrane Antigen PET/CT in Patients with Prostate Cancer: Frequency in 764 Patients.

We evaluated the incidence of synchronous primary malignancies in patients undergoing 68Ga-labeled prostate-specific membrane antigen PET/CT for prostate cancer (PC). Methods: Reports for 764 PC patients were reviewed. Incidental lesions atypical for PC metastases and suggestive of a synchronous primary malignancy were identified. Follow-up was obtained to confirm etiology. Results: Lesions atypical for PC metastases were found in 49 (6.4%) of 764 patients, and a synchronous primary malignancy was confirmed in 5 patients (0.7%; 2 lung, 1 lymphoma, 1 thyroid, and 1 base of tongue). In 8 patients (1.0%), lesions were proven to be atypical metastases from PC. In 24 patients (3.1%), lesions had a benign etiology. Follow-up was not available in 12 patients (1.6%). Conclusion: Synchronous 68Ga-labeled prostate-specific membrane antigen-avid malignancies were rare (0.7%) in PC patients; atypical lesions were more commonly unusual PC metastases (1.0%) or benign (3.1%).

Brown adipose tissue detected by PET/CT imaging is associated with less central obesity.

PURPOSE: This retrospective review was performed to determine whether patients with brown adipose tissue (BAT) detected by fluorine-18-fluorodeoxyglucose (F-FDG) PET/computed tomography (CT) imaging have less central obesity than BMI-matched control patients without detectable BAT. PATIENTS AND METHODS: Thirty-seven adult oncology patients with F-FDG BAT uptake were retrospectively identified from PET/CT studies from 2011 to 2013. The control cohort consisted of 74 adult oncology patients without detectable F-FDG BAT uptake matched for BMI/sex/season. Tissue fat content was estimated by CT density (Hounsfield units) with a subsequent noise removal step. Total fat and abdominal fat were calculated. An automated separation algorithm was utilized to determine the visceral fat and subcutaneous fat at the L4/L5 level. In addition, liver density was obtained from CT images. CT imaging was interpreted blinded to clinical information. RESULTS: There was no difference in total fat for the BAT cohort (34±15 l) compared with the controls (34±16 l) (P=0.96). The BAT cohort had lower abdominal fat to total fat ratio compared with the controls (0.28±0.05 vs. 0.31±0.08, respectively; P=0.01). The BAT cohort had a lower visceral fat/(visceral fat+subcutaneous fat) ratio compared with the controls (0.30±0.10 vs. 0.34±0.12, respectively; P=0.03). Patients with BAT had higher liver density, suggesting less liver fat, compared with the controls (51.3±7.5 vs. 47.1±7.0 HU, P=0.003). CONCLUSION: The findings suggest that active BAT detected by F-FDG PET/CT is associated with less central obesity and liver fat. The presence of foci of BAT may be protective against features of the metabolic syndrome.

Skeletal Metastasis as Detected by 18F-FDG PET with Negative CT of the PET/CT: Frequency and Impact on Cancer Staging and/or Management.

OBJECTIVES: The aim of our study is to assess the frequency of detection of PET-positive computed tomography (CT)-negative skeletal metastases (SM) and determine the impact of such detection on staging and/or management in patients who had FDG PET/CT as part of the cancer work-up. METHODS: We retrospectively reviewed 2000 18F-FDG PET/CT scans of known cancer patients. A log was kept to record cases of suspected SM with or without bone changes from the low-dose non-contrast CT. The presence or absence of SM was evaluated based on available pathological and clinical data. The impact of detection of such lesions on cancer staging and/or management was evaluated by a board certified oncologist. RESULTS: Of the 2000 cases, 18F-FDG PET/CT suggested SM in 146/2000 (7.3%). Of those 146 cases, 105 (72%) were positive on both PET and CT. The remaining 41 (28%) had PET-positive CT-negative bone lesions. SM was confirmed in 36/41 (88%) PET-positive/CT-negative cases. This was based on biopsy, imaging, or clinical follow-up. The detection of PET-positive CT-negative SM did not change staging or management in 7/36 (19.4%). However, staging and/or management was affected in 29/36 (80.6%). CONCLUSION: SM is not uncommon in 18F-FDG PET/CT, as it accounts for 146/2000 (7.3%) of cases. PET demonstrated FDG-avid SM without a CT abnormality in at least 36/146 (25%). Patients staging and/or management changed in 29/36 (80.5%). We concluded that 18F-FDG PET is sensitive in the detection of SM with significant impact on staging and/or management.

Are there radiographic, metabolic, and prognostic differences between cavitary and noncavitary nonsmall cell lung carcinoma? A retrospective fluorodeoxyglucose positron emission tomography/computed tomography study.

AIMS: The prognosis of nonsmall cell lung cancer with cavitation (NSCLC-c) is not well-known. We compared the positron emission tomography/computed tomography (PET/CT) findings and survival data of patients with NSCLC-c patients with those without cavitation (NSCLC-nc). METHODS: Between 7/2004 and 6/2007, cavitary lung lesions were identified in 46/248 patients undergoing fluorodeoxyglucose (FDG) PET/CT for lung nodule characterization or lung cancer staging. Within the same period, 40 of 202 patients with NSCLC-nc were randomly selected for comparison. The primary was assessed by location, size, cell type, and standardized uptake value (SUV). Disease stage was determined according to American Joint Committee on Cancer guidelines for lung cancer. Kaplan-Meier method was used for survival analysis and Cox regression to assess the effect of clinical and imaging variables on survival. RESULTS: NSCLC-c was found in 87% of patients that had a cavitary lung lesion at PET/CT. Squamous cell carcinoma, primary size and primary-to-liver SUV ratio differed significantly between NSCLC-c and NSCLC-nc, whereas age, gender, primary location, primary SUV, type of treatment, and disease stage did not. Median survival and overall 5-year survival were 19 months and 24% for NSCLC-c, and 31 months and 31% for NSCLC-nc, P = 0.23. Disease stage was the only predictor of survival. CONCLUSION: Cavitary lung lesions in patients undergoing FDG PET/CT harbor a significant risk for cancer. NSCLC-c is associated with squamous cell carcinoma, larger size, and greater FDG metabolism compared with NSCLC-nc, although these variables may not be predictive of survival. Nonetheless, PET/CT contributes to accurate staging and has an indirect impact on prognosis.

Case 227: Endobronchial Carcinoid Tumor with Incidental Metastatic Breast Cancer Detected with Somatostatin Receptor Scintigraphy ((111)In Pentreotide).

HISTORY: A 30-year-old woman with polycystic ovarian syndrome who was undergoing hormone replacement therapy presented with a 6-month history of a nonproductive cough and a 1-day history of hemoptysis (approximately 20 mL). Intravenous contrast material-enhanced (100 mL of Omnipaque 350; GE Healthcare, Princeton, NJ) computed tomographic (CT) pulmonary angiography was performed to evaluate for pulmonary embolism. On the basis of the CT pulmonary angiographic findings, chromogranin A and 5-hydroxyindoleacetic acid levels were measured and were 7 nmol/L (343 µg/L) (high) and 2.9 mg per 24 hours (15.167 µmol/d) (normal), respectively. This patient underwent bronchoscopy and biopsy. After these tests, she was referred for whole-body scintigraphy, which revealed an unexpected finding that was further investigated with fluorine 18 ((18)F) flurodeoxyglucose (FDG) positron emission tomography (PET) and CT.

Image findings of cranial nerve pathology on [18F]-2- deoxy-D-glucose (FDG) positron emission tomography with computerized tomography (PET/CT): a pictorial essay.

This article aims to increase awareness about the utility of (18)F -FDG-PET/CT in the evaluation of cranial nerve (CN) pathology. We discuss the clinical implication of detecting perineural tumor spread, emphasize the primary and secondary (18)F -FDG-PET/CT findings of CN pathology, and illustrate the individual (18)F -FDG-PET/CT CN anatomy and pathology of 11 of the 12 CNs.

Sjögren Syndrome Complicated by Mucosa-Associated Lymphoid Tissue Lymphoma and Lymphocytic Interstitial Pneumonia.

Sjögren syndrome (SS) is an autoimmune disease with exocrine glands dysfunction and multiorgan involvement. It is associated with increased risk of lymphoproliferative disorders, especially B-cell marginal zone lymphoma. While the role of F-18 Fluorodeoxyglucose position emission tomography/computed tomography (F-18 FDG PET/CT) for evaluation of lymphoma has been established, its use in patients with a chronic history of SS to evaluate for possible lymphoproliferative disorders or multiorgan involvement is limited. We present a case of chronic SS in which F-18 FDG PET/CT demonstrated FDG avid intraparotid and cervical lymph nodes pathologically proven to be mucosa-associated lymphoid tissue lymphoma. In addition, the patient had bibasilar cystic changes consistent with lymphocytic interstitial pneumonia.