Deep generative modeling of the human proteome reveals over a hundred novel genes involved in rare genetic disorders

Identifying causal mutations accelerates genetic disease diagnosis, and therapeutic development. Missense variants present a bottleneck in genetic diagnoses as their effects are less straightforward than truncations or nonsense mutations. While computational prediction methods are increasingly successful at prediction for variants in known disease genes, they do not generalize well to other genes as the scores are not calibrated across the proteome1-6. To address this, we developed a deep generative model, popEVE, that combines evolutionary information with population sequence data7 and achieves state-of-the-art performance at ranking variants by severity to distinguish patients with severe developmental disorders8 from potentially healthy individuals9. popEVE identifies 442 genes in patients this developmental disorder cohort, including evidence of 123 novel genetic disorders, many without the need for gene-level enrichment and without overestimating the prevalence of pathogenic variants in the population. A majority of these variants are close to interacting partners in 3D complexes. Preliminary analyses on child exomes indicate that popEVE can identify candidate variants without the need for inheritance labels. By placing variants on a unified scale, our model offers a comprehensive perspective on the distribution of fitness effects across the entire proteome and the broader human population. popEVE provides compelling evidence for genetic diagnoses even in exceptionally rare single-patient disorders where conventional techniques relying on repeated observations may not be applicable.

ProteinGym: Large-Scale Benchmarks for Protein Design and Fitness Prediction

Predicting the effects of mutations in proteins is critical to many applications, from understanding genetic disease to designing novel proteins that can address our most pressing challenges in climate, agriculture and healthcare. Despite a surge in machine learning-based protein models to tackle these questions, an assessment of their respective benefits is challenging due to the use of distinct, often contrived, experimental datasets, and the variable performance of models across different protein families. Addressing these challenges requires scale. To that end we introduce ProteinGym, a large-scale and holistic set of benchmarks specifically designed for protein fitness prediction and design. It encompasses both a broad collection of over 250 standardized deep mutational scanning assays, spanning millions of mutated sequences, as well as curated clinical datasets providing high-quality expert annotations about mutation effects. We devise a robust evaluation framework that combines metrics for both fitness prediction and design, factors in known limitations of the underlying experimental methods, and covers both zero-shot and supervised settings. We report the performance of a diverse set of over 70 high-performing models from various subfields (eg., alignment-based, inverse folding) into a unified benchmark suite. We open source the corresponding codebase, datasets, MSAs, structures, model predictions and develop a user-friendly website that facilitates data access and analysis.

Deep generative modeling of the human proteome reveals over a hundred novel genes involved in rare genetic disorders

Identifying causal mutations accelerates genetic disease diagnosis, and therapeutic development. Missense variants present a bottleneck in genetic diagnoses as their effects are less straightforward than truncations or nonsense mutations. While computational prediction methods are increasingly successful at prediction for variants in known disease genes, they do not generalize well to other genes as the scores are not calibrated across the proteome. To address this, we developed a deep generative model, popEVE, that combines evolutionary information with population sequence data and achieves state-of-the-art performance at ranking variants by severity to distinguish patients with severe developmental disorders from potentially healthy individuals. popEVE identifies 442 genes in a cohort of developmental disorder cases, including evidence of 119 novel genetic disorders without the need for gene-level enrichment and without overestimating the prevalence of pathogenic variants in the population. By placing variants on a unified scale, our model offers a comprehensive perspective on the distribution of fitness effects across the entire proteome and the broader human population. popEVE provides compelling evidence for genetic diagnoses even in exceptionally rare single-patient disorders where conventional techniques relying on repeated observations may not be applicable. Interactive web viewer and downloads available at pop.evemodel.org.

A - 84 Neuropsychological Phenotypes of FDG-PET Identified Corticobasal Degeneration Pathology

OBJECTIVE

Corticobasal degeneration (CBD), a rare neurodegenerative disorder, can present with diverse clinical phenotypes. This qualitative case series examines clinical progression of neuropsychological findings associated with CBD identified pathology on fluorodeoxyglucose-positron emission tomography (FDG-PET).

METHOD

Three clinically referred older adults underwent neuropsychological assessment prior to and after FDG-PET. All patients reported subjective memory complaints. Patient A: 67-year-old female with swallowing difficulty. Patient B: 83-year-old male with decreased balance. Patient C: 77-year-old male with gait disturbance. Neuropsychological re-evaluations occurred at 64, 19, and 17 months, respectively. Radiological interpretations of FDG-PET hypometabolism were reviewed. Clinically significant changes were defined as >1 standard deviation discrepancy from baseline performance.

RESULTS

Patients A & C had predominant right hemisphere hypometabolism, and Patient B had predominantly left hemisphere hypometabolism. Patient A: hypometabolism for R > L frontoparietal, right temporal and occipital regions. Neuropsychological declines in left fine motor control/speed, attention, visual memory, and semantic fluency. Patient B: hypometabolism for left temporal, frontal, parietal, and occipital regions. Neuropsychological declines in semantic fluency and set-shifting. Patient C: hypometabolism for diffuse right hemisphere, including thalamus and basal ganglia. Neuropsychological declines in verbal learning and memory. There were no significant neuropsychological improvements for Patients A or C. Significant neuropsychological improvement for Patient B was evident for verbal memory and naming.

CONCLUSIONS

The present case series highlights the diverse clinical presentation associated with CBD identified pathology on FDG-PET. Further studies are needed to characterize clinical phenotypes of CBD as they relate to quantitative FDG-PET pathology.

A conformal TOF-DOI Prism-PET prototype scanner for high-resolution quantitative neuroimaging

BACKGROUND

Positron emission tomography (PET) has had a transformative impact on oncological and neurological applications. However, still much of PET's potential remains untapped with limitations primarily driven by low spatial resolution, which severely hampers accurate quantitative PET imaging via the partial volume effect (PVE).

PURPOSE

We present experimental results of a practical and cost-effective ultra-high resolution brain-dedicated PET scanner, using our depth-encoding Prism-PET detectors arranged along a compact and conformal gantry, showing substantial reduction in PVE and accurate radiotracer uptake quantification in small regions.

METHODS

The decagon-shaped prototype scanner has a long diameter of 38.5 cm, a short diameter of 29.1 cm, and an axial field-of-view (FOV) of 25.5 mm with a single ring of 40 Prism-PET detector modules. Each module comprises a 16 × 16 array of 1.5 × 1.5 × 20-mm3 lutetium yttrium oxyorthosillicate (LYSO) scintillator crystals coupled 4-to-1 to an 8 × 8 array of silicon photomultiplier (SiPM) pixels on one end and to a prismatoid light guide array on the opposite end. The scanner's performance was evaluated by measuring depth-of-interaction (DOI) resolution, energy resolution, timing resolution, spatial resolution, sensitivity, and image quality of ultra-micro Derenzo and three-dimensional (3D) Hoffman brain phantoms.

RESULTS

The full width at half maximum (FWHM) DOI, energy, and timing resolutions of the scanner are 2.85 mm, 12.6%, and 271 ps, respectively. Not considering artifacts due to mechanical misalignment of detector blocks, the intrinsic spatial resolution is 0.89-mm FWHM. Point source images reconstructed with 3D filtered back-projection (FBP) show an average spatial resolution of 1.53-mm FWHM across the entire FOV. The peak absolute sensitivity is 1.2% for an energy window of 400-650 keV. The ultra-micro Derenzo phantom study demonstrates the highest reported spatial resolution performance for a human brain PET scanner with perfect reconstruction of 1.00-mm diameter hot-rods. Reconstructed images of customized Hoffman brain phantoms prove that Prism-PET enables accurate radiotracer uptake quantification in small brain regions (2-3 mm).

CONCLUSIONS

Prism-PET will substantially strengthen the utility of quantitative PET in neurology for early diagnosis of neurodegenerative diseases, and in neuro-oncology for improved management of both primary and metastatic brain tumors.

Extensive Nonsegmental Pulmonary Perfusion Defects on SPECT/CT as an Early Sign of COVID-19 Infection

We describe a hospitalized patient with confirmed coronavirus disease 2019 in whom the initial chest computed tomography (CT) was negative, while subsequent perfusion single-photon emission computed tomography/computed tomography imaging revealed extensive nonsegmental perfusion defects in addition to newly developing parenchymal densities. Possible reasons for these findings and their relationship to the multisystem severe acute respiratory syndrome coronavirus 2 infection are discussed in this article.

High-resolution and high-sensitivity PET for quantitative molecular imaging of the monoaminergic nuclei: A GATE simulation study

PURPOSE

Quantitative in vivo molecular imaging of fine brain structures requires high-spatial resolution and high-sensitivity. Positron emission tomography (PET) is an attractive candidate to introduce molecular imaging into standard clinical care due to its highly targeted and versatile imaging capabilities based on the radiotracer being used. However, PET suffers from relatively poor spatial resolution compared to other clinical imaging modalities, which limits its ability to accurately quantify radiotracer uptake in brain regions and nuclei smaller than 3 mm in diameter. Here we introduce a new practical and cost-effective high-resolution and high-sensitivity brain-dedicated PET scanner, using our depth-encoding Prism-PET detector modules arranged in a conformal decagon geometry, to substantially reduce the partial volume effect and enable accurate radiotracer uptake quantification in small subcortical nuclei.

METHODS

Two Prism-PET brain scanner setups were proposed based on our 4-to-1 and 9-to-1 coupling of scintillators to readout pixels using1.5 × 1.5 × 20 $1.5 \times 1.5 \times 20$  mm3 and0.987 × 0.987 × 20 $0.987 \times 0.987 \times 20$  mm3 crystal columns, respectively. Monte Carlo simulations of our Prism-PET scanners, Siemens Biograph Vision, and United Imaging EXPLORER were performed using Geant4 application for tomographic emission (GATE). National Electrical Manufacturers Association (NEMA) standard was followed for the evaluation of spatial resolution, sensitivity, and count-rate performance. An ultra-micro hot spot phantom was simulated for assessing image quality. A modified Zubal brain phantom was utilized for radiotracer imaging simulations of 5-HT1A receptors, which are abundant in the raphe nuclei (RN), and norepinephrine transporters, which are highly concentrated in the bilateral locus coeruleus (LC).

RESULTS

The Prism-PET brain scanner with 1.5 mm crystals is superior to that with 1 mm crystals as the former offers better depth-of-interaction (DOI) resolution, which is key to realizing compact and conformal PET scanner geometries. We achieved uniform 1.3 mm full-width-at-half-maximum (FWHM) spatial resolutions across the entire transaxial field-of-view (FOV), a NEMA sensitivity of 52.1 kcps/MBq, and a peak noise equivalent count rate (NECR) of 957.8 kcps at 25.2 kBq/mL using 450-650 keV energy window. Hot spot phantom results demonstrate that our scanner can resolve regions as small as 1.35 mm in diameter at both center and 10 cm away from the center of the transaixal FOV. Both 5-HT1A receptor and norepinephrine transporter brain simulations prove that our Prism-PET scanner enables accurate quantification of radiotracer uptake in small brain regions, with a 1.8-fold and 2.6-fold improvement in the dorsal RN as well as a 3.2-fold and 4.4-fold improvement in the bilateral LC compared to the Biograph Vision and EXPLORER, respectively.

CONCLUSIONS

Based on our simulation results, the proposed high-resolution and high-sensitivity Prism-PET brain scanner is a promising cost-effective candidate to achieve quantitative molecular neuroimaging of small but important brain regions with PET clinically viable.

“Low Dose MR” Dixon Technique for Imaging FDG PET-MR Lymphoma

Introduction  Hybrid PET-MR is a relatively new imaging modality with its major strength being the MR component offering superior soft tissue contrast. While PET/MRI offers the inherent advantage of reduced radiation dose, it has been shown to result in a markedly prolonged examination time becoming a challenge in children and sick patients. "Low dose MRI" is a term used in the nuclear medicine community to describe fast acquired PET-MR scan protocols that rely heavily on PET images for diagnosis. In this study, we sought to determine if the Dixon sequences obtained for attenuation correction could be used as a diagnostic sequence for interpreting PET-MRI lymphoma cases, potentially reducing scan time.

Materials and Methods  We retrospectively identified 40 patients who underwent ⁸⁸ FDG PET-MR body imaging studies for staging or restaging lymphoma. A radiologist and nuclear medicine physician initially reviewed top of the head to mid thigh PET images, attenuation correction coronal Dixon MRI sequences, and PET-MR fusion with Dixon sequence. The same physicians reviewed the PET images, multi-sequence MR including the attenuation correction Dixon, and multi-sequence PET-MR fusion images The lesions were further characterized based on their imaging characteristics, size, SUVmax, and malignant potency. A consensus read followed.

Results   All patients were adults with an average study age of 43.8 years. Our study consisted of 40 females and 48 males out of which 7 were for staging and 81 were for re-staging. All patients had systemic lymphoma. Thirty-seven of the studies had active lymph nodes on Dixon PET-MR that agreed with multi-sequence PET-MR which identified 33 positive cases (89.1%) having an average SUV 10.2 ± 7.74 SD. Four Dixon PET-MR cases did not detect lesions, with an average SUV 2.3 ± 0.55 SD, which was read as minimal residual activity. Multi-sequence MR identified 11 patients with enlarged lymph nodes without FDG uptake, which were not seen on Dixon MR. All 5 studies with bones lesions were detected by Dixon PET-MR as well as 2 soft tissue organ lesions. Multi-sequence MR identified 1 patient with non-active, healed bone lesion. Fifty-five of these studies were true negatives. Compared to multi-sequence PET-MR, Dixon PET-MR demonstrated 89.2% sensitivity, 100% specificity with no false positive studies.

Conclusion   The present study investigated the diagnostic potential of a fast protocol for integrated PET/MRI used for dedicated tumor staging of patients with lymphoma. In this retrospective study, Dixon PET-MR was shown to be sensitive and specific compared to multi-sequence PET-MR in the detection of lymphoma. The low number of these cases not detected had minimally active lymph nodes that resolved on subsequent imaging and probably were not clinically important.

Metabolic positron-emission tomography/magnetic resonance imaging in primary progressive aphasia and frontotemporal lobar degeneration subtypes: Reassessment of expected [18F]-fluorodeoxyglucose uptake patterns

Clinical assessment of frontotemporal lobar degeneration (FTLD)/primary progressive aphasia (PPA) patients is challenging, given that common cognitive assessments rely extensively on language. Since asymmetry in neuroimaging biomarkers is often described as a central finding in these patients, our study evaluated [¹⁸F]-fluorodeoxyglucose (FDG) uptake patterns in patients meeting clinical and imaging criteria for FTLD, with emphasis on PPA. Fifty-one subjects underwent brain [¹⁸F]-FDG positron-emission tomography/magnetic resonance imaging (PET/MRI) as part of their routine clinical workup for dementia and neurodegenerative disease. Images were obtained using a Siemens Biograph mMR integrated 3T PET/MRI scanner. PET surface maps and fusion fluid-attenuated inversion recovery-PET images were generated utilizing MIMneuro software. Two board-certified neuroradiologists and one nuclear medicine physician blinded to patient history classified each FTLD/PPA subtype and assessed for left- versus right-side dominant hypometabolism. Qualitative and semiquantitative assessment demonstrated 18 cases of PPA, 16 behavioral variant frontotemporal dementia (bvFTD), 12 corticobasal degeneration, and 5 progressive supranuclear palsy. Among the 18 PPA subjects (11 svPPA, 5 lvPPA, and 2 agPPA), 12 (67%) demonstrated left-dominant hypometabolism and 6 (33%) right-dominant hypometabolism. While existing literature stresses left-dominant hypometabolism as a key imaging feature in the PPA subtypes, a third of our cases demonstrated right-dominant hypometabolism, suggesting that emphasis should be placed on the functionality of specific brain regions affected, rather than left versus right sidedness of hypometabolism patterns.

Regenerative Endodontic Therapy using a New Antibacterial Root Canal Cleanser in necrotic immature permanent teeth: Report of two cases treated in a single appointment

A case of regenerative endodontics: (a) before treatment; (b) post-treatment Xray; (c) follow-up at 6 months; (d) follow-up at 12 months.

(18F)-Fluorodeoxyglucose positron emission tomography/magnetic resonance imaging assessment of hypometabolism patterns in clinical phenotypes of suspected corticobasal degeneration

Corticobasal degeneration (CBD) is a rare neurodegenerative disorder presenting with atypical parkinsonian symptoms that characteristically involves the frontoparietal region including the primary sensorimotor cortex, ipsilateral basal ganglia, and thalamus, typically in an asymmetric pattern. We aim to evaluate the metabolic and volumetric abnormalities in patients with clinically suspected CBD phenotypes utilizing hybrid ¹⁸F-fluorodeoxyglucose (FDG) positron emission tomography–magnetic resonance (PET/ MR) brain imaging. A retrospective analysis was performed on 75 patients (mean age 74 years, 31 males and 44 females) who underwent ¹⁸F-FDG PET/MR imaging (MRI) as part of their clinical dementia workup. Images were obtained using an integrated Siemens mMR 3T PET/MRI scanner. Two board-certified neuroradiologists and a nuclear medicine physician evaluated the metabolic and volumetric data of each hemisphere to assess for symmetric or asymmetric involvement of regions of interest in the subset of patients with suspected CBD. Of the 75 patients, 12 were diagnosed with suspected CBD based on a combination of clinical symptoms, neurocognitive testing, and hybrid neuroimaging findings. Ten of 12 patients (87%) demonstrated asymmetrically decreased FDG uptake involving a single cerebral hemisphere and ipsilateral subcortical structures, whereas two of 12 patients (13%) demonstrated striking hypometabolism of the bilateral sensorimotor cortices. Our study highlights two characteristic patterns of hypometabolism in patients with clinical and neuroimaging findings suggestive of the underlying CBD. The first pattern is asymmetric hypometabolism and volume loss, particularly within the frontoparietal and occipital cortices with involvement of ipsilateral subcortical structures, including the basal ganglia and thalamus. The second, more atypical pattern, is symmetric hypometabolism with striking involvement of the bilateral sensorimotor cortices.

Hybrid imaging in dementia: A semi-quantitative (18F)-fluorodeoxyglucose positron emission tomography/magnetic resonance imaging approach in clinical practice

Neurodegenerative disorders may demonstrate typical lobar and regional patterns of volume loss with corresponding decreased glucose metabolism. In this retrospective study, we correlated semi-quantitative volumetric changes utilizing NeuroQuant morphometric analysis with decreased fluorodeoxyglucose (FDG) uptake age-matched calculated z-scores utilizing ¹⁸F-FDG positron emission tomography/magnetic resonance imaging (PET/MRI). Eighty-nine patients (mean age 71.4) with clinical findings suggestive of various subtypes of dementia underwent PET/MR brain imaging. Cases were categorized as follows: Alzheimer's dementia (AD), frontotemporal lobar degeneration (FTLD), dementia with Lewy bodies (DLB), and corticobasal degeneration (CBD). NeuroQuant software provided semi-quantitative assessment of lobar-specific patterns of volume loss compared to age-matched controls. MIMneuro software provided semi-quantitative FDG uptake data, with metabolic z-scores generated in comparison to age-matched controls. Volumetric and metabolic data were then correlated for statistical significance. In 29 AD cases, Pearson correlation coefficient between z-score and lobar volume was 0.3 (P = 0.120) and 0.38 (P < 0.05), for parietal and temporal lobes, respectively. In 34 FTLD cases, it was 0.35 (P = 0.051) and 0.02 (P = 0.916), for frontal and temporal lobes, respectively. In 14 DLB cases, it was 0.42 (P = 0.130), 0.5 (P = 0.067), and 0.22 (P = 0.447) for the occipital lobes, middle occipital gyrus, and parietal lobes, respectively. In 12 CBD cases, it was 0.58 (P < 0.05) for the superior parietal lobule. Semi-quantitative (F18)-FDG PET/MRI analysis demonstrated a positive relationship between volumetric loss and hypometabolism within certain lobar-specific regions, depending on neurodegenerative disorder subtype. Our findings may add diagnostic confidence in the accurate imaging diagnosis of neurodegenerative disease.

Fluorodeoxyglucose positron-emission tomography-magnetic resonance hybrid imaging: An emerging tool for staging of cancer of the uterine cervix

Positron-emission tomography-magnetic resonance imaging (PET-MRI) is an emerging hybrid imaging modality that utilizes the superior soft tissue resolution of MR with the metabolic data from PET. In this study, we sought to assess the clinical value of fluorodeoxyglucose (FDG) PET-MRI with dedicated pelvic PET-MR in the initial staging of cervical cancer. In this institutional-approved study, we identified 23 adult females who underwent FDG PET-MRI on hybrid camera for staging of primary uterine cervical cancer that included a dedicated PET-MR of the pelvis. A nuclear medicine physician and a radiologist reviewed the PET, MRI, and fusion-body and pelvis images alone and then with consensus read characterizing PET and MR abnormal findings. There were 23 patients who underwent FDG PET-MRI for initial staging of cervical cancer with an average age of 52.2 ± 14.0 years. A total of 23 suspected lymph nodes in eight different patients were detected within the pelvis with increased metabolic activity on PET. Both the dedicated pelvis and whole-body PET imaging detected the same corresponding pelvic lymph nodes, although the pelvic PET imaging had better lymph node uptake delineation due to longer acquisition time. Using a 10-mm short-axis criterion, MRI identified only 43.5% of the FDG avid lymph nodes. The average SUVmax on the pelvis PET sequences was higher with SUV 8.9 ± 5.2 compared to the whole-body PET with SUV 7.8 ± 5.4 but was not statistically significant (P > 0.05). Primary cervical cancer was identified in 18 patients on both PET imaging and MRI with dedicated MR pelvis providing better characterization. Based on our results of the patients with cervical cancer evaluated for initial staging, combining dedicated pelvic PET-MRI with whole-body PET/MR provides the most complete status of malignant disease in reference to delineation of primary tumor, involvement of surrounding tissues, and regional lymph nodes.

Incidental PET/CT Findings of Suspected COVID-19 in a Region of High Prevalence

We describe a case of suspected COVID-19 pneumonia in a 61-year-old male with known primary central nervous system diffuse large B-cell lymphoma (DLBCL) who underwent restaging PET/CT during the initial peak of infection of COVID-19 pneumonia within the New York region. At the time of his routine PET-CT to assess for disease progression, typical CT imaging features of COVID-19 pneumonia were identified. Upon further investigation, the patient was asymptomatic, and his infection status remained unknown. He was subsequently lost to follow-up with his COVID-19 status pending.

Initial Studies with 11C-Vorozole PET Detect Overexpression of Intratumoral Aromatase in Breast Cancer

Aromatase inhibitors are the mainstay of hormonal therapy in estrogen receptor-positive breast cancer, although the response rate is just over 50% and in vitro studies suggest that only two thirds of postmenopausal breast tumors overexpress aromatase. The goal of the present study was to validate and optimize PET with ¹¹C-vorozole for measuring aromatase expression in postmenopausal breast cancer in vivo. Methods: Ten newly diagnosed postmenopausal women with biopsy-confirmed breast cancer were administered ¹¹C-vorozole intravenously, and PET emission data were collected between 40 and 90 min after injection. Tracer injection and scanning were repeated 2 h after ingestion of 2.5 mg of letrozole. Mean and maximal SUVs and ratios to nontumor tissue in the contralateral breast were determined at baseline and after letrozole. Biopsy specimens from the same tumors were stained for aromatase using immunohistochemistry and evaluated for stain intensity and the percentage of immune-positive cells. Results: Seven of the 10 women (70%) demonstrated increased mean focal uptake of tracer (SUV ratio > 1.1) coinciding with the mammographic location of the lesion, whereas the other 3 women (30%) did not (SUV ratio ≤ 1.0). All patients with an SUV ratio above 1.1 had mean SUVs above 2.4, and there was no overlap (SUV ratio ≤ 1; SUV_mean, 0.8-1.8). The SUV ratio relative to breast around tumor was indistinguishable from the ratio to contralateral breast. Pretreatment with letrozole reduced tracer uptake in most subjects, although the percentage of blocking varied across and within tumors. Tumors with a high SUV in vivo also showed a high immunohistochemical staining intensity. Conclusion: PET with ¹¹C-vorozole is a useful technique for measuring aromatase expression in individual breast lesions, enabling noninvasive quantitative measurement of baseline and posttreatment aromatase availability in primary tumors and metastatic lesions.

[Myringoplasties for anterior tympanic perforations: Our surgical technique]

Anterior tympanic perforations are actually the most difficult to close and a number of different techniques exist. This article represents the author's surgical procedure for type I tympanoplasties (myringoplasties) for this kind of perforation using the tragal cartilage and the perichondrium after preparation (revival, cleaning) of the perforation edge with a laser. This technique does not use a skin incision of external auditory meatus, when this one is large.

[Reconstruction of bone defects in the earcanal with hydroxyapatite]

Traditional reconstruction methods of osseous defects within the tympanic frame, most often being the atticotomy, within the framework of chronic otitis media surgery, still do not produce stable or definitive results, usually due to displacement or partial lyse of the transplanted material (cartilage, bone ...). The reconstruction procedure with the aid of hydroxyapatite cement as presented by the authors, allows for a complete, stable and definitive reconstruction.

Tc-99m mebrofenin hepatobiliary scan in obstructive hepatobiliary disease: determining causes with early and late delayed imaging

Hepatobiliary radionuclide imaging is typically performed to detect cholecystitis. Infrequently, imaging reveals an obstructive pattern. Although delayed hepatobiliary imaging is commonly used to differentiate between intrahepatic (IH) and extrahepatic (EH) obstruction in the newborn; there is room to clarify the use of delayed imaging in the adult population. A retrospective review was performed of adult patients demonstrating a complete obstructive pattern on initial Tc-99m mebrofenin hepatobiliary imaging. Delayed imaging was divided into early delayed (ED) (<10 h) and late delayed (LD) (≥10 h) imaging. Two physicians qualified the presence of intestinal radiotracer (negative, low to high) on delayed images. Determination of EH or IH pathology was obtained from chart review. A total of 24 patients demonstrated an obstructive pattern using delayed Tc-99m mebrofenin hepatobiliary imaging, with delayed imaging ranging from 4 to 30 h. EH pathologies (choledocholithiasis, stricture, other) represented 63% of cases (n = 15), IH pathologies (cirrhosis, hepatitis, other) represented 33% cases (n = 8) and 1 case was indeterminate. 67% of EH cases showed intestinal activity on delayed imaging (67% on ED and 67% on LD imaging), whereas 63% of IH cases showed intestinal activity on delayed imaging (67% on ED imaging and 60% on LD imaging). The presence of intestinal activity on the both the early and delayed images did not differentiate between the IH and EH pathology groups. Subdividing the groups into ED imaging and LD imaging was also not predictive of determining location of obstructive pattern on the initial 1 h of imaging. This data suggests that delayed hepatobiliary scintigraphy has little or no role in determining the cause of obstructive pathology.

Fluorodeoxyglucose PET-CT Findings Following Bone Marrow Harvesting

Two patients demonstrated an unusual pattern of intense bone and surrounding soft tissue hypermetabolic uptake in the posterior pelvis on fluorodeoxyglucose positron emission tomography with computed tomography PET-CT scans. After further investigation, we found that both patients underwent uncomplicated autologous bone marrow harvesting several weeks before imaging. These two cases illustrate a distinctive PET-CT appearance following bone marrow harvesting that the radiologist needs to recognize to not confuse the findings with metastatic disease.

[Ossiculoplasty with hydroxyapatite bone cement]

OBJECTIVE

To analyze the results obtained with hydroxyapatite bone cement (HABC).

PATIENTS

A total of 73 ossiculoplasties with HABC were evaluated. Ears were divided into 4 groups: Group 1: Reinforcement of the incudo-stapedial joint with HABC; Group 2: Reconstruction of an incus long process defect with HABC; Group 3: Partial ossicular reconstruction between stapes and malleus handle with HABC; Group 4: Reconstruction of stapes with mobile or fixed footplate with moderate or extensive incus long process erosion using a titanium piston glued to the incus remnant using HABC.

RESULTS

The mean follow-up was 21 months. The percentage of postoperative average air-bone gap (ABG) < or = 20 dB for groups 1, 2, 3 and 4 were 100%, 95%, 83% and 91% respectively; for ABG < or = 10 dB: 90%, 71%, 50% and 50%. No complications related to HABC and extrusion occurred.

CONCLUSION

Today, the use of HABC seems to help us improve our functional results and also to avoid extrusion. In our experience, ossiculoplastie with HABC seems to provide better and more stable functional results. HABC is safe and easy to use. The use of cement with or without biocompatible ossicular prostheses allows us to repair different types of ossicular defects whilst trying to conserve an anatomical and physiological ossicular chain. Reconstruction of the incus long process or incudo-stapedial joint defect with cement is preferable rather than using partial ossicular reconstruction with HABC.

Racial disparity in estrogen receptor positive breast cancer patients receiving trimodality therapy

INTRODUCTION

We assessed racial differences in progression-free survival (PFS) and overall survival (OS) in relation to subtype in uniformly treated stage II-III breast cancer patients.

METHODS

We reviewed records of 582 patients receiving post-mastectomy radiation (PMRT) between 1/1999 and 12/2009 and evaluated the effect of demographic, tumor, and treatment characteristics on PFS and OS.

RESULTS

Median follow up was 44.7 months. 24% of patients were black and 76% white. All had mastectomy and PMRT; 98% had chemotherapy; Estrogen receptor (ER)+ patients received endocrine therapy. Black patients were more likely to have ER- (56% vs. 38%, p=0.0001), progesterone receptor (PR)- (69% vs. 54%, p = 0.002), and triple negative (TN) (46% vs. 24%, p < 0.0001) tumors. Overall, black patients had worse PFS (60.6% vs. 78.3%, p = 0.001) and OS (72.8% vs. 87.7%, p < 0.0001). There was no racial difference in PFS (p = 0.229 and 0.273 respectively) or OS (p = 0.113 and 0.097 respectively) among ER- or TN. Among ER+, black patients had worse PFS (55% vs. 81%, p < 0.001) and OS (73% vs. 91%, p < 0.0001). The difference in PFS was seen in the ER+/PR+/HER2- subgroup (p = 0.002) but not ER+/PR-/HER2- (p = 0.129), and in the post-menopausal ER+/HER2- subgroup (p = 0.004) but not pre/peri-menopausal ER+/HER2- (p = 0.150).

CONCLUSIONS

Black women had worse survival outcomes in this cohort. This disparity was driven by (1) a higher proportion of ER- and TN tumors in black women and (2) worse outcome of similarly treated black women with ER+ breast cancer. The underlying causes of racial disparity within hormone receptor categories must be further examined.

The effect of molecular subtype on survival in a racially diverse cohort of patients with high-risk breast cancer receiving trimodality therapy

156

Background: To understand the origins of racial disparities in breast cancer outcomes, the relative importance of race must be examined in the context of molecular subtype. We assessed racial differences in progression-free survival (PFS) and overall survival (OS) in relation to subtype in a cohort of uniformly treated stage II-III breast cancer patients.

Methods: We reviewed records of 582 consecutive patients receiving post-mastectomy radiation (PMRT) between 1/1999 and 12/2009 and evaluated the effect of demographic, tumor, and treatment characteristics on PFS and OS.

Results: Median follow-up 44.7 months. Patients: 24% black, 76% white, 55% pre/peri-menopausal. Disease: stage II 30%, stage III 70%. Treatment: all had mastectomy and PMRT; 98% had chemotherapy. All ER+ patients received endocrine therapy. Black and non-black patients were similar in age, menopause status, stage, and completion of trimodality therapy. Black patients were more likely to be ER- (56% vs 38%, p=0.0001), PR- (69% vs 54%, p=0.002), and triple negative (TN) (46% vs 24%, p<.0001). Among ER+, there were no differences in menopause or PR status by race. Black patients had worse PFS (60.6% vs 78.3%, p=.001) and OS (72.8% vs 87.7%, p<.0001). There was no racial difference in PFS (p=0.229 and 0.273 respectively) or OS (p=0.113 and 0.097 respectively) among ER- or TN. Among ER+, black patients had worse PFS (55% vs 81%, p<.001) and OS (73% vs 91%, p<.0001). The difference in PFS was seen in the ER+/PR+/HER2- (“luminal A”) subgroup (p=.002) but not ER+/PR-/HER2- (“luminal B”) (p=0.129), and in the post-menopausal ER+/HER2- subgroup (p=.004) but not pre/perimenopausal ER+/HER2- (p=.150). On multivariate analysis, racial differences in PFS (p=.055) and OS (p=.052) were maintained in the luminal A postmenopausal subgroup.

Conclusions: In a cohort of breast cancer patients black women had worse survival. This disparity was driven by (1) a higher proportion of ER- and TN tumors in the black women and (2) worse outcome of similarly treated post-menopausal black women with luminal A breast cancer. The efficacy of various types of endocrine therapy must be examined in the setting of racial diversity.

Phase II study of bevacizumab (B), camptosar (I), high-dose 24-hour continuous intravenous infusion of floxuridine (F) and leucovorin (L) in patients with previously untreated metastatic colon cancer. (B-IFL)

e15114

Background: In a previous study, IFL was used in patients (pt) with untreated metastatic colon cancer and a median overall survival (MOS) of 31 months (m). In the current study we added B to IFL to determine toxicity profiles (TP) and the response rate (RR) to the B-IFL regimen. The primary end-point is MOS Methods: Each cycle involved 6 weeks (wks) of treatment. The treatment cycle consisted of a 90 minute infusion of I (110 mg/m2), followed by a 24 hour infusion of F (120mg/kg) and L (500 mg/m2) on wks 1, 2, 4, 5. Pt received B (7.5mg/kg) over 90 minutes on wks 1 and 4 prior to IFL. No therapy was given on wks 3 and 6. Eligible pt received 2 cycles of B-IFL followed by CT scan. Quality of life data and thymidylate synthase expression in peripheral blood mononuclear cells was monitored Results: 22 pt with a median age of 57 (38–82), 11 males and 11 females were enrolled. Median KPS was 90% (50–100). 8 pt (36%) had bilobar liver disease and involvement of 1 other organ, 6 pt (27%) had bilobar liver disease with involvement of ≥ 2 other organs; 5 pt (23.5%) had bilobar liver disease; 2 pt (9%) had abdominal carcinomatosis; 1 pt (4.5 %) had involvement in one liver lobe. Grade (Gr) 4 toxicity: pulmonary embolus 1 pt (5%) incidental CT finding. Gr 3 occurred in 11 pt (50%); DVT, diarrhea (Drh) 3 pt (14%); fatigue (Ftg), infection, port site thrombosis (Pst), small bowel obstruction 2 pt (9%); wound dehiscence 1pt (5%); Gr 2 and 1: constipation; Drh; Ftg; nausea; neutropenia; Pst; alopecia; anorexia; mucositis. 17 pt remain alive with median follow up of 15 m (2–28). 5 pt have died due to progression of disease. The estimated median time to progression was 13 m with corresponding lower 95% confidence bound of 8.4 m. Kaplan-Meier estimate at 2 yr survival is 61% (95% CI 27–83%). RR in 21 pt was 67% (95% CI: 43–85%). Conclusions: B-IFL regimen has a manageable TP. RR and progression free interval were promising. Pt accrual is ongoing. Supported by Pfizer.

No significant financial relationships to disclose.

High complete response (CR) rate in patients (pts) with esophageal carcinoma (EC) undergoing neoadjuvant combination of docetaxel and cisplatin (DC) ± cetuximab(DCE) chemoradiation therapy—a retrospective analysis

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Background: EC is a highly lethal disease with 5 year survival less than 15%. Surgery offers a chance for cure in early disease. Still, fewer than 20% of pts treated with surgery alone are alive at 5 years. Neoadjuvant chemoradiation offers the theoretical advantage of increasing R0 resections and reducing early local and distal metastases which may translate into improved survival. Several clinical trials have resulted in pathologic complete response (pCR) rates of 20–30%. Methods: Newly diagnosed pts with EC Stage 2A (T3) to 4 received weekly Docetaxel (D)25–30mg/m2 and Cisplatin (C)25–30mg/m2.for 6–8 weeks concurrently with radiation, 5040 cGy in 28 fractions. Cetuximab (E) 200mg/m2 was added after it became accepted treatment in head and neck cancers. Pts were scheduled 4 - 6 weeks later for surgery followed by the same chemotherapy for total of 16 weeks of treatment. Pts were assessed for time to progression, overall survival and toxicities. Results: Fifteen pts treated in 2005–6 underwent IRB approved evaluation; 11 male and 4 female, median age of 62(range 44–78) . Four had squamous cell (SCC) and 11 adenocarcinomas. Nine pts had Stage II, 4 pts stage III and 2 pts stage IV disease. Seven pts underwent surgery, all R0 resections. Four of them had pCR, one pPR (downstaged from T3 to T1) and two pts had stable disease. An additional 3 pts had radiological and endoscopic proven CR (medically not surgical candidates) for an objective response (CR+PR) in 8 out of 15 pts (3 SCC and 5 adenoca). Five out of 9 receiving DC had an objective response while 3 of 6 receiving DCE responded. Five pts progressed prior to surgery. Grade 3/4 neutropenia occurred in 2, nausea in 3, and 1 pt experienced Grade 3 dehydration. Four patients required dose reductions by 20%. Six patients had one cycle and 2 had 3 cycles delayed by one week each. Conclusions: Neoadjuvant chemoradiation treatment with weekly Docetaxel and Cisplatin ± Cetuximab is tolerable with high rate of CRs. There was no observed difference in response with the addition of cetuximab. A Phase III study is suggested.

No significant financial relationships to disclose.

Parietal Lobe Epileptic Focus Identified on SPECT-MRI Fusion Imaging in a Case of Epilepsia Partialis Continua

Epilepsia partialis continua, or "Kozhevnikov syndrome," is a rare condition characterized by persistent localized motor seizures usually localized in a distant limb. It is most often seen in children under 16 years old without gender preference. We report a 12-year-old girl with epilepsia partialis continua who presented to the emergency room after the onset of seizures. Routine electroencephalography (EEG) was performed with no clear ictal localization. Magnetic resonance imaging (MRI) was unremarkable. Ictal single photon emission computed tomography (SPECT) images with Tc-99m exametazime fused with MRI images revealed a parietal lobe epileptic focus within the superior segment of the postcentral gyrus. This case illustrates a rare disorder with an unusual epileptic localization identified by SPECT-MRI fusion.

Neoadjuvant and adjuvant chemotherapy without radiation for esophageal cancer

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Background: A Phase II trial to evaluate neoadjuvant (NAD) and adjuvant (AD) combination chemotherapy (CT) without radiation therapy (RT), for Stage III esophageal adenocarcinoma. Methods: Stage III disease by CAT scan or EUS and ECOG performance status 0–1. The CT cycles included Cisplatin, Taxol, FUDR and Leucovorin. The chemotherapy was given for 16 weeks prior to surgery, followed by adjuvant chemotherapy for patients whose pathology at the time of surgery demonstrated microscopic disease. Survival was estimated via Kaplan Meier. Results: 33 patients were enrolled: 28 completed NAD, 15 received AD. Of 33 pts given NAD, 16 had grade I/II toxicity and 14 had grade III/IV. In addition, 6 of 15 pts receiving AD had grade I/II toxicity and 3 had grade III/IV during that phase of treatment. Thirty-two (32) patients went to surgery, 30 patients were resected: 24 transhiatial and 6 transthoracic. Of the 28 patients who completed NAD, 19 (68%) demonstrated improvement in dysphagia; 11 (41%) gained weight, and 7 (26%) had no weight change. Pathologic response to NAD: 30 patients had partial response and 2 patients had progressive disease, one died prior to surgery, post carotid endarterectomy. Ten (10) patients showed no gross disease. Twenty-three (23) patients have expired, 17 disease related with distant metastasis, 1 with local recurrence and distant metastasis, 3 non-disease related and 2 unresectable cases. Kaplan-Meier estimates of overall survival at 1, 3, and 5 years were 73% (95% CI: 58 to 88%), 52% (95%CI: 34 to 69%), and 29% (95% CI: 13 to 45%), respectively. Median survival was 42 months (95% CI: 14 to 52 months). Ten (10) patients are alive after a median follow up of 73 months (range 45 to 89). Seven (70%) of the surviving patients received both NAD (2 cycles) and AD (1 to 2 cycles) and all had no evidence of disease as of last clinical and radiological evaluation. Conclusions: This regimen of combination CT for locally advanced esophageal adenocarcinoma is safe and comparable with those regimens that contain RT. There has been 1 local recurrence; 17 patients have recurred distantly. Omission of RT may allow for a more aggressive CT and reduction in the local complications post-surgery. This study needs to be confirmed in a larger phase II or in randomized phase III trial.

No significant financial relationships to disclose.

Low doses of alcohol substantially decrease glucose metabolism in the human brain

Moderate doses of alcohol decrease glucose metabolism in the human brain, which has been interpreted to reflect alcohol-induced decreases in brain activity. Here, we measure the effects of two relatively low doses of alcohol (0.25 g/kg and 0.5 g/kg, or 5 to 10 mM in total body H2O) on glucose metabolism in the human brain. Twenty healthy control subjects were tested using positron emission tomography (PET) and FDG after placebo and after acute oral administration of either 0.25 g/kg, or 0.5 g/kg of alcohol, administered over 40 min. Both doses of alcohol significantly decreased whole-brain glucose metabolism (10% and 23% respectively). The responses differed between doses; whereas the 0.25 g/kg dose predominantly reduced metabolism in cortical regions, the 0.5 g/kg dose reduced metabolism in cortical as well as subcortical regions (i.e. cerebellum, mesencephalon, basal ganglia and thalamus). These doses of alcohol did not significantly change the scores in cognitive performance, which contrasts with our previous results showing that a 13% reduction in brain metabolism by lorazepam was associated with significant impairment in performance on the same battery of cognitive tests. This seemingly paradoxical finding raises the possibility that the large brain metabolic decrements during alcohol intoxication could reflect a shift in the substrate for energy utilization, particularly in light of new evidence that blood-borne acetate, which is markedly increased during intoxication, is a substrate for energy production by the brain.

PET Findings in Pulmonary Dirofilariasis

This case demonstrates hypermetabolic activity in a pulmonary round infarct secondary to dirofilariasis. This case further illustrates that pulmonary dirofilariasis, like other infectious causes of pulmonary nodules, can be PET positive.

Gastric carcinoids: a temporal increase with proton pump introduction

BACKGROUND

Recent reports have indicated a rising incidence of gastric carcinoids. This study aimed to evaluate the incidence pattern of gastric carcinoids in two large population-based cancer registries.

METHODS

The Florida Cancer Data System (FCDS), Florida's statewide cancer registry, and the Surveillance, Epidemiology, and End Results (SEER) program were used. The study population was defined as all cases of gastric carcinoid identified in either database from January 1981 to December 2000. Descriptive statistics and age-adjusted incidence rates were calculated.

RESULTS

There were 326 (FCDS) and 594 (SEER) cases of invasive gastric carcinoid during the 20-year study period. The mean age of the patients was 65 years (range, 21-96 years), and the male:female ratio was 1:1. The age-adjusted incidence rate in FCDS increased from 0.04 (per 100,000 age-adjusted to the 2000 U.S. standard population) to 0.18 in the year 2000. The estimated annual percentage change in incidence was 8.17 in FCDS and 9.17 in SEER (p < 0.05). A decrease in gastric cancer was noted during this same period (from 8.64 to 11.14 cases per 100,000 in FCDS and from 11.14 to 8.06 cases per 100,000 in SEER).

CONCLUSIONS

This study documented a statistically significant eight- or ninefold increase in the incidence of gastric carcinoids in two large databases. The temporal increase in incidence correlates with the introduction and widespread use of proton pump inhibitors since the late 1980s. Other explanations include improved detection with wider application of upper endoscopy. Further epidemiologic studies are warranted.

Comparison of monoamine oxidase a in peripheral organs in nonsmokers and smokers

Smokers have reduced levels of brain monoamine oxidase A (MAO A) leading to speculation that MAO A inhibition by tobacco smoke may underlie some of the neurophysiologic effects of smoking. Because smoking exposes peripheral organs as well as the brain to MAO A-inhibitory compounds, we determined whether smokers would also have reduced MAO A in peripheral organs.

METHODS

We measured MAO A in peripheral organs in a group of 9 smokers and compared it with a group of nonsmokers studied previously. MAO A was measured using PET and serial scans with the MAO A-specific radiotracers (11)C-clorgyline and deuterium-substituted (11)C-clorgyline ((11)C-clorgyline-D2) using the deuterium isotope effect to assess binding specificity. The time course of radiotracer in the arterial plasma was also measured and data from the tissue time-activity curves and the arterial input function were analyzed using a 3-compartment model to estimate k(3), which represents the rate-limiting step for the irreversible binding of labeled clorgyline to MAO A.

RESULTS

Tracer uptake at plateau was reduced with deuterium substitution for the heart, lungs, and kidneys, indicating specificity for MAO. There was no difference in organ uptake at plateau between nonsmokers and smokers though, for the smokers, the efflux of tracer from peak uptake to plateau was slower for the lungs. The area under the time-activity curve for the arterial plasma was also significantly reduced for smokers versus nonsmokers and the reduction occurred in the first few minutes after radiotracer injection. Smokers had an approximately 50% reduction in k(3) when compared with nonsmokers; however, k(3) did not differ for nonsmokers and smokers for the heart and the kidneys.

CONCLUSION

Because MAO A breaks down serotonin, norepinephrine, dopamine, and tyramine, and because the lung is a major metabolic organ in degrading some of these substances, reduced lung MAO A may contribute to some of the physiologic effects of smoking. This study also revealed that the concentration of the radiotracers in the arterial plasma is significantly lower for the smoker versus the nonsmoker and that this appears to be caused in part by retention of the radiotracer in lungs. If this is generally true for other substances that are administered intravenously, then this needs to be considered as a variable that may contribute to different short-term behavioral responses to intravenously administered drugs for nonsmokers versus smokers.

Abdominal Muscle Uptake on FDG PET Secondary to Multiple Rib Fractures and Use of Accessory Muscles of Respiration

A 69-year-old man with a history of lung cancer was referred for FDG whole body positron emission tomography (PET) with computed tomography (CT) fusion. Three days before the study, the patient was involved in a motor vehicle accident (MVA). In addition to hypermetabolic lesions representing metastatic lung cancer, PET scan showed marked anterior and lateral abdominal muscle uptake. Multiple focal abnormalities were seen on the PET scan that corresponded to multiple rib fractures on the CT scan that were secondary to the MVA. When the patient was interviewed, he stated that he had thoracic wall pain that prevented him from breathing properly. This case illustrates an unusual pattern of increased anterior and lateral abdominal muscle uptake as a result of pain while breathing.