Evaluation of Preoperative and Intraoperative Mobile Gamma Camera Imaging in Sentinel Lymph Node Biopsy for Melanoma Independent of Preoperative Lymphoscintigraphy.

INTRODUCTION: Sentinel lymph node biopsy (SLNB) is a standard practice for staging cutaneous melanoma. High false-negative rates have an increased interest in adjunctive techniques for localizing SLNs. Mobile gamma cameras (MGCs) represent potential tools to enhance SLNB performance. METHODS: An institutional review board approval was obtained for this study (ClinicalTrials.gov ID NCT01531608). After obtaining informed consent, 20 eligible melanoma patients underwent 99mTc sulfur colloid injection and standard lymphoscintigraphy with a fixed gamma camera (FGC). A survey using a 20 cm square MGC, performed immediately preoperatively by the study surgeon, was used to establish an operative plan while blinded to the FGC results. Subsequently, SLNB was performed using a gamma probe and a novel 6 cm diameter handheld MGC. RESULTS: A total of 24 SLN basins were detected by FGC. Prior to unblinding, all 24 basins were identified with the preoperative MGC and the operative plan established by preoperative MGC imaging was confirmed accurate by review of the FGC images. All individual sentinel lymph nodes were identified during intraoperative MGC imaging, and in 5/24 (21%) cases, surgeon-reported additional clinically useful information was obtained from the MGC. CONCLUSIONS: Preoperative MGC images provide information consistent with FGC images for planning SLNB and in some cases provide additional information that aided in surgical decision-making.

An Exploratory Study of Neoadjuvant Cetuximab Followed by Cetuximab and Chemoradiotherapy in Women With Newly Diagnosed Locally Advanced Cervical Cancer.

OBJECTIVES: This study explored the feasibility of cetuximab with chemoradiation in women with cervical carcinoma and evaluated fluorine-18 fluorodeoxyglucose-positron emission tomography/computed tomography (18F-FDG-PET/CT) to assess early response to cetuximab (NCT00292955). PATIENTS AND METHODS: Eligible patients with International Federation of Gynecology and Obstetrics (FIGO) stage IB-IVB invasive carcinoma of the uterine cervix were treated on 1 of 3 dose levels (DL). DL1 consisted of neoadjuvant cetuximab, then concurrent radiotherapy with cetuximab 250 mg/m2/cisplatin 40 mg/m2, followed by weekly cetuximab. DL2 consisted of radiotherapy with cetuximab 200 mg/m2 and cisplatin 30 mg/m2. DL3 consisted of radiotherapy with cetuximab 250 mg/m2 and cisplatin 30 mg/m2. Patients underwent 18F-FDG-PET/CT before treatment, after neoadjuvant cetuximab, and at the end of treatment. RESULTS: Of the 21 patients enrolled, 9, 3, and 9 were treated in DL1, DL2, and DL3, respectively. DL1 required dose reductions due to gastrointestinal toxicities. DL2 and 3 were tolerated with 1 dose-limiting toxicity (grade 4 renal failure) at DL3. Following 3 weekly treatments of neoadjuvant cetuximab in DL1, 7 patients had maximum standardized uptake value changes on 18F-FDG-PET/CT consistent with response to cetuximab. Of the 12 patients with locally advanced disease, eleven evaluable patients had no evidence of disease on 18F-FDG-PET/CT at treatment end. Five-year progression-free survival and overall survival rates for all patients were 57.5% and 58.5%, respectively. CONCLUSIONS: Cetuximab with cisplatin 30 mg/m2 and radiotherapy was tolerated. 18F-FDG-PET/CT demonstrated early evidence of response to neoadjuvant cetuximab. With advances in precision oncology and the recent approval of pembrolizumab in metastatic cervical cancer, dual-target inhibition with an epidermal growth factor receptor inhibitor may be a promising treatment in the future.

Diffuse large B-cell lymphoma relapse presenting as extensive neurolymphomatosis.

A 56-year-old woman with a history of diffuse large B-cell non-Hodgkin lymphoma (DLBCL-NHL) in remission for two years presented with weight loss and multifocal sensory/motor symptoms. Magnetic resonance imaging (MRI) of the neuraxis and whole-body FDG PET/CT led to a diagnosis of secondary neurolymphomatosis (NL). MRI demonstrated extensive thickening and enhancement of multiple cranial nerves and peripheral nerve plexuses with corresponding elevated metabolism on FDG PET/CT. Treatment with chemotherapy resulted in complete response on FDG PET/CT and subsequently she underwent autologous stem cell transplantation. NL is a rare manifestation of lymphoma affecting the peripheral nervous system. Nonspecific neuropathic symptoms make clinical diagnosis difficult. Though nerve biopsy is considered the gold standard, MRI and FDG PET/CT are accepted alternatives for making the diagnosis. We review imaging findings in NL, describe the differential diagnosis, and discuss the limitations of the imaging modalities.

Lateral ectopic thyroid mimics carotid body tumor on Indium-111 pentetreotide scintigraphy.

A 34-year old woman with past history of anxiety, depression, and hypothyroidism resulting from prior total thyroidectomy for multinodular goiter presented with complaints of palpitations, sweating, and tachycardia. Clinical examination revealed a painless right lateral neck mass. USG/CT of the neck revealed the soft tissue mass located at the right carotid bifurcation. A subsequent Indium-111 pentetreotide somatostatin receptor scintigraphy (SRS) demonstrated tracer uptake in the mass. Hence, secretory carotid body tumor/paraganglioma was strongly suspected. However, post-surgical histopathological specimen revealed only benign thyroid follicles indicative of lateral ectopic thyroid with no evidence of neuroendocrine cells or malignancy. This case highlights the importance of considering lateral ectopic thyroid, a very rare entity, in the differential diagnosis for carotid bifurcation masses. Also highlighted is the false positivity from normal but ectopic thyroid tissue on Indium-111 pentetreotide SRS mimicking a paraganglioma.

FDG PET/MRI Coregistration Helps Predict Response to Gamma Knife Radiosurgery in Patients With Brain Metastases.

OBJECTIVE: The purpose of this study was to determine whether relative standardized uptake value (SUV) measurements at FDG PET/MRI coregistration are predictive of local tumor control in patients with brain metastases treated with stereotactic radiosurgery (SRS). MATERIALS AND METHODS: A retrospective review was conducted of the images and clinical characteristics of a cohort of patients with brain metastases from non-CNS neoplasms treated with gamma knife radiosurgery (GKRS) who underwent posttherapy FDG PET because of MRI findings concerning for progression. The PET and contrast-enhanced MR images were fused. Relative SUV measurements were calculated from ROIs placed in the area of highest FDG uptake within the enhancing lesion and in the contralateral normal-appearing white matter. Relative SUV was defined as the ratio of maximum SUV in the tumor to maximum SUV in healthy white matter. Two independent readers evaluated response to GKRS using serial posttherapy MRI performed at least 3 months after GKRS completion. The relation between relative SUV and local tumor progression was evaluated with respect to treatment effect. RESULTS: Eighty-five patients (48 [56.5%] women, 37 [43.5%] men; mean age at diagnosis, 60.5 ± 11.3 years) met the inclusion criteria. Thirty-three (38.8%) lesions progressed after SRS. There was a significant association between relative SUV and local tumor control (p = 0.035). Relative SUV provided a diagnostic ROC AUC of 0.67 (95% CI, 0.55-0.79). CONCLUSION: Quantitative relative SUV at posttherapy FDG PET serves as a biomarker of response to SRS in patients with brain metastases in cases in which lesion growth is identified at follow-up MRI. This prognostic data may affect management, supporting the need for further therapeutic actions for selected patients.

Unenhanced MRI as an Alternative to 99mTc-Labeled Dimercaptosuccinic Acid Scintigraphy in the Detection of Pediatric Renal Scarring.

OBJECTIVE: The purpose of this study was to determine whether unenhanced MRI without sedation is a feasible substitute for dimercaptosuccinic acid (DMSA) scintigraphy in the detection of renal scars in pediatric patients. SUBJECTS AND METHODS: Patients scheduled for 99mTc-labeled DMSA scintigraphy for assessment of possible renal scars were recruited to undergo unenhanced MRI (free-breathing fat-suppressed T2-weighted single-shot turbo spin-echo and T1-weighted gradient-echo imaging, 13 minutes' total imaging time). Scintigraphic and MRI studies were evaluated by two independent blinded specialty-based radiologists. For each imaging examination, readers identified scars in upper, middle, and lower kidney zones and rated their diagnostic confidence and the quality of each study. The scintigraphic readers' consensus score opinion for the presence of scars was considered the reference standard. RESULTS: DMSA scintigraphy showed scarring in 19 of the 78 (24.4%) evaluated zones and MRI in 18 of the 78 (23.1%). The two MRI readers found mean sensitivities of 94.7% and 89.5%, identical specificities of 100%, and diagnostic accuracies of 98.7% and 97.4%. Interobserver agreement was 98.7% for MRI and 92.3% for DMSA scintigraphy. The MRI readers were significantly more confident in determining the absence rather than the presence of scars (p = 0.02). MRI readers were more likely to rate study quality as excellent (84.6%) than were the scintigraphic readers (57.7%) (p = 0.024). CONCLUSION: Unenhanced MRI has excellent sensitivity, specificity, diagnostic accuracy, and interobserver agreement for detecting renal scars in older children who do not need sedation. It may serve as a substitute modality, especially when DMSA is not available.

Earlier seizure onset and longer epilepsy duration correlate with the degree of temporal hypometabolism in patients with mesial temporal lobe sclerosis.

OBJECTIVE: To study the relationship of glucose metabolism and volume of the temporal lobes with age at epilepsy onset, epilepsy duration, and seizure frequency in patients with mesial temporal sclerosis (MTS). METHODS: We evaluated the pre-surgical 18F-fluoro-deoxyglucose (FDG) positron emission tomography (PET) and magnetic resonance imaging (MRI) of 18 patients with epilepsy and MRI findings of MTS, who were seizure-free for at least 2-years after temporal lobectomy. We calculated the volume of the hippocampi and amygdalae on MRI. On PET we studied their mean standard uptake values (SUV), and relative metabolic activity as compared to normal subjects in terms of Z-scores. We compared the PET and MRI metrics in the bilateral structures using the Wilcoxon sign rank test. We studied the relationship between the imaging metrics and age of epilepsy onset, epilepsy duration, and seizure frequency via Spearman correlation analyses. RESULTS: Younger age at onset correlated with decreased hippocampal glucose metabolism (rs=0.64, p=0.008). Longer epilepsy duration correlated with decreased hippocampal glucose metabolism (rs=-0.55, p=0.024). There was no correlation between age at onset of epilepsy, epilepsy duration, or seizure frequency and volumetrics. Z-score in the sclerotic hippocampus (-3.51±2.2vs -0.7±1.7) and amygdala (-3.26±2.3 vs -0.68±1.8) was smaller than the contralateral (p<0.001). The diseased hippocampus (2.84±0.49 vs 3.52±0.4ml) and ipsilateral amygdala (1.49±0.24 vs 1.72±0.3ml) were significantly smaller than the contralateral (p<0.02). SIGNIFICANCE: Earlier epilepsy onset correlated with hippocampal hypometabolism. Longer epilepsy duration correlated with amygdalar hypometabolism suggesting an ongoing progressive disease in MTLE.

MIBG Localization of a Subclinical Paraganglioma of the Bladder.

Urinary bladder paragangliomas are very rare, and the majority are hormonally active. Nonfunctioning paragangliomas are even rarer and more difficult to diagnose because of absence of catecholamine secretion. We present a 27-year-old woman with an asymptomatic paraganglioma of the urinary bladder discovered incidentally in a patient with prior resection of a functional pararenal paraganglioma. Metabolic profiles and cystoscopy were nondiagnostic. We demonstrate the increased sensitivity of I-MIBG SPECT/CT compared with planar scintigraphy for detection of a nonfunctional paraganglioma of the urinary bladder, which makes it valuable in evaluation of functional and nonfunctional paragangliomas.

FDG PET/MR Imaging Coregistration Helps Predict Survival in Patients with Glioblastoma and Radiologic Progression after Standard of Care Treatment.

Purpose To determine the correlation between metabolic activity at fluorine 18 fluorodeoxyglucose (FDG) positron emission tomography (PET) and survival in patients with glioblastoma and suspected progression at posttherapy magnetic resonance (MR) imaging. Materials and Methods The authors retrospectively examined the relationship between metabolic activity at FDG PET in the residual lesion identified at brain MR imaging and survival time in 56 patients with glioblastoma who were treated with postoperative concurrent radiation and temozolomide therapy and who underwent FDG PET/computed tomography because of radiologic deterioration at follow-up MR imaging between 2006 and 2015. A normalized metric of metabolic activity in the residual lesion (standardized uptake value ratio [SUVr]) was calculated as the maximum standardized uptake value (SUVmax) in the tumor relative to that in healthy white matter. The primary end point of the study was survival time from PET. Patients were stratified according to SUVr. Comparisons of risk for death between subgroups were made with the log-hazard ratio of the Cox proportional hazard model. Results There was a significant association between overall survival and SUVr in the residual lesion (P = .006), and a survival benefit was observed in patients with SUVr of less than 1.7, who had a median survival time of 23.1 months (95% confidence interval [CI]: 12.7, 38.9), which was significantly longer than that in patients with an SUVr of 2.0 to less than 2.5 and those with an SUVr of at least 2.5, who had a median survival time of 10.1 (95% CI: 2.4, 15.9; P = .008) and 7.5 (95% CI: 3.9, 9.7; P < .001) months, respectively. Conclusion Patients with glioblastoma whose posttherapy MR images showed a residual lesion with high relative metabolic activity at FDG PET had a shorter survival time than did those with low activity at FDG PET. © RSNA, 2016.

Primary osteogenic osteosarcoma of the ethmoid sinus in an adolescent: case report.

Osteosarcomas of the craniofacial bones account for fewer than 10% of all osteosarcomas. Primary osteosarcomas of the nasal cavity and paranasal sinus are rare (0.5-8.1% of the osteosarcomas occur in this location). Because of the rarity of this presentation, we report a case of osteogenic osteosarcoma arising de novo from the ethmoid bone in a 13 year old male who presented with discharge from the right eye and headaches. We describe the imaging features of this rare tumor and provide a brief review of the literature.

Active herpes zoster infection with cutaneous manifestation and adenopathy on FDG PET/CT.

We report a patient with history of Hodgkin lymphoma. Six months after treatment, 2-deoxy-2-[18F]fluoro-d-glucose positron emission tomography and/or computed tomography ([18F] FDG PET/CT) scan showed abnormal uptake in right axillary lymph nodes concerning for recurrence. In addition, PET/CT showed a new hypermetabolic skin lesion overlying the right scapula. Clinical evaluation was consistent with shingles, and the patient was treated with valacyclovir. Subsequent PET/CT scan was normal with no evidence of lymphoma. Although there have been reported cases of abnormal FDG in nodes or in skin due to herpes zoster, our case is unique in the literature in that the PET/CT demonstrates abnormalities involving both the skin and associated lymph nodes. The possibility of false positive uptake, not because of recurrent malignancy, must always be considered when abnormal FDG uptake is noted in the follow-up of oncology patients. Careful review of the scan and correlation with clinical findings can avoid false positive interpretation and facilitate patient management.

Sialadenitis following low dose I-131 diagnostic thyroid scan with Thyrogen® (recombinant human thyroid stimulating hormone--thyrotropin alfa).

Salivary dysfunction and sialadenitis are well known complications of radioiodine treatment for thyroid cancer. The parotid gland is more frequently affected and the salivary gland injury is dose related. The symptoms may develop shortly after therapeutic Iodine 131(I-131) administration or months later and progress with time. The development of unilateral parotiditis following a low dose, diagnostic I-131 scan performed following Thyrogen stimulation in a patient without prior history of sialadenitis is rare in our experience, and has not been reported in the medical literature.

Indium-111 Capromab Pendetide (ProstaScint(®)) Demonstrates Renal Cell Carcinoma and Aortocaval Nodal Metastases from Prostate Adenocarcinoma.

A 62-year-old male with a history of radical prostatectomy for a Gleason 9 (4 + 5) pT3N0Mx prostate cancer presented with rising prostate-specific antigen of 9.0 ng/dl. A contrast-enhanced computerized tomography (CT) revealed an enhancing left upper pole renal mass and aortocaval lymph nodes. Indium (In)-111 Capromab Pendetide (ProstaScint(®)) single-photon emission computerized tomography-CT showed abnormal increased uptake in left renal mass and aortocaval lymph nodes with no uptake in the prostate bed or pelvic lymph nodes. He underwent left radical nephrectomy and dissection of aortocaval lymph nodes. Pathology showed renal clear cell carcinoma and metastatic prostate adenocarcinoma involving aortocaval lymph nodes. Our case demonstrates a rare combination of two different malignancies, prostate cancer and clear cell renal cell cancer, showing In-111 ProstaScint(®) uptake. Though ProstaScint(®) uptake in renal cell carcinoma and in metastatic aortocaval lymph nodes from prostate cancer may be seen in clinical practice, this combination has not been reported previously.

AIDS Presenting as Granulomatous Amebic Encephalitis: PET and MR Imaging correlation.

Granulomatous amebic encephalitis (GAE) is a rare and oftentimes fatal disease in immune compromised patients caused by free living amebae Acanthamoeba and Balamuthia. We report a patient in whom GAE secondary to Acanthamoeba was the initial presentation of acquired immunodeficiency syndrome in a 41-year-old male, and discuss the FDG positron emission tomography (PET) and magnetic resonance imaging findings that preceded the pathological diagnosis. The PET results provided complementary information when coupled with the MR brain findings. Improved understanding of the clinical and imaging findings of this deadly disease is the best hope for early diagnosis and treatment of this uncommon but deadly disease.

Recombinant human thyrotropin use resulting in ovarian hyperstimulation: an unusual side effect.

A 43-year-old female was administered recombinant human thyrotropin-α (Thyrogen®; Genzyme Corp., Cambridge, Mass., USA) before a fluorodeoxyglucose positron emission tomography/computed tomography (PET/CT) scan as part of an evaluation of thyroid cancer recurrence. She was administered two doses of Thyrogen only 4 weeks before for stimulated thyroglobulin measurement. The PET/CT scan demonstrated enlarged ovaries which on subsequent conservative follow-up resolved. This transient hyperstimulated state of the ovaries was presumed to be related to Thyrogen injections received twice within a space of a month. Thyrogen is being increasingly used for raising the level of thyroid-stimulating hormone (TSH), besides thyroid hormone withdrawal for suspected recurrence of differentiated thyroid carcinoma. Ovarian hyperstimulation has been reported as an iatrogenic complication for in vitro fertilization with the presence of human chorionic gonadotropin being invariably associated. Transient gestational thyrotoxicosis has been reported to be related to promiscuous activation of the thyrotropin receptor by chorionic gonadotropin. In our case it is possible that due to the promiscuous stimulation, thyrotropin caused a follicle-stimulating hormone (FSH)-like action resulting in ovarian hyperstimulation. The reason behind this could be the shared sequence identity of the hormone-binding domains of TSH and FSH receptors, or some mutation in the FSH receptor. In conclusion, our case highlights a potential side effect of administering Thyrogen in females of the reproductive age group.

FDG Positron Emission Tomography and Computed Tomography Demonstration of Carcinoma Arising in an Epiphrenic Diverticulum.

Esophageal carcinoma arising within an epiphrenic diverticulum is rare. We describe a case of a carcinoma in a long-standing epiphrenic diverticulum in a 62-year-old patient. Fluorine-18-2-Fluoro-2-Deoxy-D-Glucose Positron Emission Tomography and Computed Tomography, and endoscopic ultrasound revealed a hypermetabolic mass within the diverticulum. A preoperative diagnosis was made via endoscopic biopsy. The patient underwent Ivor-Lewis esophagectomy. He remains well and free of recurrence 18 months after surgery.

Prosthetic vascular graft infection imaging.

PURPOSE: We are reporting our experience with imaging of vascular graft infections using computed tomography angiography (CTA), white blood cell (WBC) scintigraphy and software-based fusion imaging. MATERIAL AND METHODS: Institutional review board approval was obtained. We performed a retrospective review of patients who had clinical signs and symptoms of vascular graft infection in whom both WBC single photon emission computed tomography (SPECT) and CTA was performed between 2005 and 2010. We performed fusion imaging with available data using software coregistration technique and analyzed outcome of the patients. RESULTS: We had 20 patients; 11 had grafts of the aorta, five had peripheral vascular grafts, three had aortic and peripheral vascular grafts, and one had a thoracic aortic graft. WBC imaging was positive in 10 patients, negative in six patients and indeterminate in 4 patients. CTA was positive in six patients, negative in four patients and indeterminate in 10 patients. Sensitivity, specificity, accuracy, positive predictive value and negative predictive value (NPV) for WBC, CTA and WBC SPECT/CTA fusion were 75/100/80/100/50%, 88/50/80/88/50% and 94/50/85/88/67% respectively. CONCLUSION: The use of CTA, WBC scintigraphy, and image co-registration influenced the diagnostic confidence of graft infection and the outcome of the patients. Software-based fusion imaging of both modalities resulted in improved sensitivity, accuracy, and NPV.

18-Fluorodeoxyglucose positron emission tomography for tuberculosis diagnosis and management: a case series.

BACKGROUND: F-fluorodeoxyglucose positron emission tomography (FDG-PET) is increasingly used to investigate for malignancy in the evaluation of pulmonary nodules, yet both active tuberculosis (TB) and malignancy have high uptake of FDG. Definitive diagnosis of TB can be further hindered in patients without growth of the organism from sputum. CASE PRESENTATIONS: We describe a series of four representative cases of TB in varying disease state originally imaged by FDG-PET during evaluation for malignancy. Decisions regarding treatment for active TB in the presence of negative cultures and the evolving understanding of the spectrum of the TB disease state are discussed. CONCLUSIONS: FDG-PET may possess a role in the diagnosis of active TB infection in settings where conventional microbiological methods are unavaiable and holds particular promise for monitoring response to therapy in cases of unsettled treatment duration such as multidrug-resistant TB or in extrapulmonary TB.

Phase I trial of induction histone deacetylase and proteasome inhibition followed by surgery in non-small-cell lung cancer.

INTRODUCTION: Despite complete surgical resection survival in early-stage non-small-cell lung cancer (NSCLC) remains poor. On the basis of prior preclinical evaluations, we hypothesized that combined induction proteasome and histone deacetylase inhibitor therapy, followed by tumor resection, is feasible. METHODS: A phase I clinical trial using a two-staged multiple-agent design of bortezomib and vorinostat as induction therapy followed by consolidative surgery in patients with NSCLC was performed. Standard toxicity and maximum tolerated dose were examined. Pre- and post-treatment tumor gene-expression arrays were performed and analyzed. Pre- and post-treatment fluorodeoxyglucose-positron emission tomography imaging was used to assess tumor metabolism. Finally, serum 20S proteasome levels were analyzed with enzyme-linked immunosorbent assay, and selected intratumoral proteins were assessed by immunohistochemistry. RESULTS: Of the 34-four patients providing written consent to participate in the trial, 21 were enrolled. One patient withdrew early because of disease progression. The maximum tolerated dose was bortezomib 1.3 mg/m and vorinostat 300 mg twice daily. There were grade III dose-limiting toxicities of fatigue and hypophosphatemia, which were self-limited. There was no mortality. Thirty percent of patients (6 of 20) had more than 60% histologic necrosis of their tumor after treatment, with two having 90% or more tumor necrosis. Tumor metabolism, 20S proteasome activity, and specific protein expression did not demonstrate consistent results. Gene-expression arrays comparing pre- and post-therapy NSCLC specimens revealed robust intratumoral changes in specific genes. CONCLUSIONS: Induction bortezomib and vorinostat therapy followed by surgery in patients with operable NSCLC is feasible. Correlative gene-expression studies suggest new targets and cell-signaling pathways that may be important in modulating this combined therapy.

Radioiodine (131I) accumulation in bronchogenic cyst in the setting of thyroid carcinoma remission.

A 76-year-old woman had (131)I accumulation within the mediastinum in the setting of thyroid carcinoma remission. Extensive diagnostic imaging including computed tomography (CT), magnetic resonance imaging (MRI), endoscopic ultrasound, bronchoscopy, and subsequently a needle aspiration biopsy revealed that the mass was a bronchogenic cyst. Five-year clinical and laboratory follow-up showed that the patient was free from thyroid carcinoma recurrence.