Total-body Positron Emission Tomography Research Articles

Assessing tumor metabolic heterogeneity of non-small cell lung cancer with total body PET-CT imaging on the uExplorer: Analysis of dynamic changes of 18F-FDG uptake.

e20549 Background: Total body positron emission tomography (PET) of uExplorer enables imaging of highly quantitative parameters beyond the standardized uptake value (SUV). The aim of this prospective study is to assess the dynamic changes of 2-deoxy-2-[18F]fluoro-D-glucose ([18F]FDG) uptake in characterizing tumor heterogeneity of non-small cell lung cancer (NSCLC). Methods: Sixteen NSCLC patients were prospectively enrolled in a prospective study (NCT04654234, GASTO-1067) between September 2020 and December 2020. All patients underwent a dynamic total-body 18F-FDG PET/CT scan before any treatment. The primary lung tumor, metastatic regional lymph node and inflammatory lymph node were manually delineated by a nuclear medicine physician and a radiation oncologist. Total Body PET was acquired between 0 – 60 mins after the injection of FDG from the subject’s feet. We compared lesion heterogeneity and different image-derived PET metrics including the SUV-mean, Patlak-derived influx rate constant (Ki) and distribution volume (DV). Results: The SUV-mean and Ki-mean of primary lung tumor and metastatic lymph node were significantly higher than inflammatory lymph node (p < 0.001), while there was no significantly different of DV(p > 0.05). By the scatter plot of SUV-mean and Ki-mean of primary lung tumor, 9 patients had been separated into high dynamic FDG metabolic (H-DFM) group and 7 in low DFM(L-DFM) group. The SUV-mean(p = 0.0002) and Ki-mean(p = 0.0002) of primary lung tumor were significantly higher in H-DFM group, whereas there is no difference in metastatic lymph node of both group. Interestingly, the SUV-mean and Ki-mean of primary lung tumor were higher than that of metastatic lymph node(p = 0.0002) in H-DFM group. On the contrast, the SUV-mean and Ki-mean of primary lung tumor were lower than that of metastatic lymph node(p = 0.05) in L-DFM group. There is no significant difference of DV-mean among primary lung tumor, metastatic lymph node and inflammatory lymph node in both arms. Conclusions: The results demonstrated that dynamic parameters from total body PET scan has the potential of providing complementary information of tumor heterogeneity in NSCLC than conventional static SUV imaging. The characteristics of H-DFM and L-DFM group could be taken into account for evaluation of further treatment response.

PET image reconstruction with deep progressive learning

Convolutional neural networks (CNNs) have recently achieved state-of-the-art results for positron emission tomography (PET) imaging problems. However direct learning from input image to target image is challenging if the gap is large between two images. Previous studies have shown that CNN can reduce image noise, but it can also degrade contrast recovery for small lesions. In this work, a deep progressive learning (DPL) method for PET image reconstruction is proposed to reduce background noise and improve image contrast. DPL bridges the gap between low quality image and high quality image through two learning steps. In the iterative reconstruction process, two pre-trained neural networks are introduced to control the image noise and contrast in turn. The feedback structure is adopted in the network design, which greatly reduces the parameters. The training data come from uEXPLORER, the world’s first total-body PET scanner, in which the PET images show high contrast and very low image noise. We conducted extensive phantom and patient studies to test the algorithm for PET image quality improvement. The experimental results show that DPL is promising for reducing noise and improving contrast of PET images. Moreover, the proposed method has sufficient versatility to solve various imaging and image processing problems.

Ultra-low-activity total-body dynamic PET imaging allows equal performance to full-activity PET imaging for investigating kinetic metrics of 18F-FDG in healthy volunteers.

To investigate the feasibility of ultra-low-activity total-body positron emission tomography (PET) dynamic imaging for quantifying kinetic metrics of 2-[18F]-fluoro-2-deoxy-D-glucose (18F-FDG) in normal organs and to verify its clinical relevance with full-activity imaging. Dynamic total-body PET imaging was performed in 20 healthy volunteers, with eight using full activity (3.7MBq/kg) of 18F-FDG and 12 using 10× activity reduction (0.37MBq/kg). Image contrast, in terms of liver-to-muscle ratio (LMR), liver-to-blood ratio (LBR), and blood-to-muscle ratio (BMR) of radioactivity concentrations were assessed. A two-tissue compartment model was fitted to the time-to-activity curves in organs based on regions of interest (ROIs) delineation using PMOD, and constant rates (k1, k2, and k3) were generated. Kinetic constants, corresponding coefficients of variance (CoVs), image contrast, radiation dose, prompt counts, and data size were compared between full- and low-activity groups. All constant rates, corresponding CoVs, and image contrast in different organs were comparable with none significant differences between full- and ultra-low-activity groups. PET images in the ultra-low-activity group generated significantly lower effective radiation dose (median, 0.419 vs. 4.886mSv, P < 0.001), reduced prompt counts (median, 2.79 vs. 55.68 billion, P < 0.001), and smaller data size (median, 71.11 vs. 723.18GB, P < 0.001). Total-body dynamic PET imaging using 10× reduction of injected activity could achieve relevant kinetic metrics of 18F-FDG and comparable image contrast with full-activity imaging. Activity reduction results in significant decrease of radiation dose and data size, rendering it more acceptable and easier for data reconstruction, transmission, and storage for clinical practice.

Kinetic metrics of 18F-FDG in normal human organs identified by systematic dynamic total-body positron emission tomography.

To investigate the kinetic metrics of 2-[18F]-fluoro-2-deoxy-D-glucose (18F-FDG) in normal organs by using dynamic total-body (TB) positron emission tomography (PET). Dynamic TB-PET was performed for nine healthy volunteers. Time-to-activity curves (TACs) were obtained by drawing regions of interest in the organs. A two-tissue compartment model was fitted for each tissue TAC. Constant rates, including k1, k2, and k3, and the metabolic rate of FDG (MRFDG) were obtained. The parameter statistics, including the average, standard deviation, coefficient of variance, and inter-site and inter-individual variances, were compared. Constant rates and MRFDG varied significantly among organs and subjects, but not among sides or sub-regions within an organ. The mean k1 and k2 ranged from 0.0158min-1 in the right lower lung to 1.1883min-1 in the anterior wall of the left ventricle (LV) myocardium and from 0.1116min-1 in the left parietal white matter to 4.6272min-1 in the left thyroid, respectively. The k3 was lowest in the right upper area of the liver and highest in the septal wall of the LV myocardium. Mean MRFDG ranged from 23.1696μmol/100g/min in the parietal cortex to 0.5945μmol/100g/min in the lung. Four groups of organs with similar kinetic characteristics were identified: (1) the cerebral white matter, lung, liver, muscle, bone, and bone marrow; (2) cerebral and cerebellar cortex; (3) LV myocardium and thyroid; and (4) pancreas, spleen, and kidney. The kinetic rates and MRFDG significantly differed among organs. The kinetic metrics of FDG parameters in normal organs can serve as a reference for future dynamic PET imaging and research.

Depth of Interaction Measurements Based on Rectangular Light Sharing Window Technology and Nine-Crystals-to-One-SiPM Coupling Method

Depth of interaction (DOI) decoding capability shows great application potential for positron emission tomography (PET), especially for high-resolution small-animal PET or long axial field of view PET systems. On the basis of GATE optical simulation results, we presented a novel $9\times 9$ lutetium–yttrium oxyorthosilicate array with 10-mm rectangular light-sharing windows (RLSWs) and assembly the detector with nine crystals coupled to one silicon photomultiplier (SiPM) method; this caused DOI-related position shifts in the crystal decoding spots of the flood map. Homogeneous radiation was used to establish transfer functions to convert spot shifts into DOI measurements. The conventional collimated radiation experiments were used to assess the accuracy of the DOI measurements. Flood map results show that 81 segmented crystals can be clearly resolved, including 16 crystals adjacent to two RLSW windows (M-type), 40 crystals adjacent to one RLSW window (E-type), and 25 crystals not adjacent to any RLSW window (C-type). The mean absolute error of all DOI-capable crystals, M-type crystals, and E-type crystals are 2.15 ± 0.61, 1.95 ± 0.50, and 2.23 ± 0.63 mm, respectively. The novel nine-crystals-to-one-SiPM coupling technology is a low cost approach for constructing high-performance DOI detector modules. Detectors using nine-crystals-to-one-SiPM coupling technology are good candidates for high-resolution preclinical PET and for total-body PET.

Synchronization and Calibration of the 24-Modules J-PET Prototype With 300-mm Axial Field of View

Research conducted in the framework of the J-PET project aims to develop a cost-effective total-body positron emission tomography scanner. As a first step on the way to construct a full-scale J-PET tomograph from long strips of plastic scintillators, a 24-strip prototype was built and tested. The prototype consists of detection modules arranged axially forming a cylindrical diagnostic chamber with the inner diameter of 360 mm and the axial field-of-view of 300 mm. Promising perspectives for a low-cost construction of a total-body PET scanner are opened due to an axial arrangement of strips of plastic scintillators, wchich have a small light attenuation, superior timing properties, and the possibility of cost-effective increase of the axial field-of-view. The presented prototype comprises dedicated solely digital front-end electronic circuits and a triggerless data acquisition system which required development of new calibration methods including time, thresholds and gain synchronization. The system and elaborated calibration methods including first results of the 24-module J-PET prototype are presented and discussed. The achieved coincidence resolving time equals to CRT = 490 $\pm$ 9 ps. This value can be translated to the position reconstruction accuracy $\sigma(\Delta l) =$ 18 mm which is fairly position-independent.

Seeing Is Believing: Nuclear Imaging of HIV Persistence.

A major obstacle to HIV eradication is the presence of infected cells that persist despite suppressive antiretroviral therapy (ART). HIV largely resides outside of the peripheral circulation, and thus, numerous anatomical and lymphoid compartments that have the capacity to harbor HIV are inaccessible to routine sampling. As a result, there is a limited understanding of the tissue burden of HIV infection or anatomical distribution of HIV transcriptional and translational activity. Novel, non-invasive, in vivo methods are urgently needed to address this fundamental gap in knowledge. In this review, we discuss past and current nuclear imaging approaches that have been applied to HIV infection with an emphasis on current strategies to implement positron emission tomography (PET)-based imaging to directly visualize and characterize whole-body HIV burden. These imaging approaches have various limitations, such as the potential for limited PET sensitivity and specificity in the setting of ART suppression or low viral burden. However, recent advances in high-sensitivity, total-body PET imaging platforms and development of new radiotracer technologies that may enhance anatomical penetration of target-specific tracer molecules are discussed. Potential strategies to image non-viral markers of HIV tissue burden or focal immune perturbation are also addressed. Overall, emerging nuclear imaging techniques and platforms may play an important role in the development of novel therapeutic and HIV reservoir eradication strategies.

Advances in PET Diagnostics for Guiding Targeted Cancer Therapy and Studying In Vivo Cancer Biology.

We present an overview of recent advances in positron emission tomography (PET) diagnostics as applied to the study of cancer, specifically as a tool to study in vivo cancer biology and to direct targeted cancer therapy. The review is directed to translational and clinical cancer investigators who may not be familiar with these applications of PET cancer diagnostics, but whose research might benefit from these advancing tools. We highlight recent advances in 3 areas: (1) the translation of PET imaging cancer biomarkers to clinical trials; (2) methods for measuring cancer metabolism in vivo in patients; and (3) advances in PET instrumentation, including total-body PET, that enable new methodologies. We emphasize approaches that have been translated to human studies. PET imaging methodology enables unique in vivo cancer diagnostics that go beyond cancer detection and staging, providing an improved ability to guide cancer treatment and an increased understanding of in vivo human cancer biology.

Mini EXPLORER II: a prototype high-sensitivity PET/CT scanner for companion animal whole body and human brain scanning

As part of the EXPLORER total-body positron emission tomography (PET) project, we have designed and built a high-resolution, high-sensitivity PET/CT scanner, which is expected to have excellent performance for companion animal whole body and human brain imaging. The PET component has a ring diameter of 52 cm and an axial field of view of 48.3 cm. The detector modules are composed of arrays of lutetium (yttrium) oxyorthosilicate (LYSO) crystals of dimensions 2.76 × 2.76 × 18.1 mm3 coupled to silicon photomultipliers (SiPMs) for read-out. The CT component is a 24 detector row CT scanner with a 50 kW x-ray tube. PET system time-of-flight resolution was measured to be 409 ± 39 ps and average system energy resolution was 11.7% ± 1.5% at 511 keV. The NEMA NU2-2012 system sensitivity was found to be 52–54 kcps MBq−1. Spatial resolution was 2.6 mm at 10 mm from the center of the FOV and 2.0 mm rods were clearly resolved on a mini-Derenzo phantom. Peak noise-equivalent count (NEC) rate, using the NEMA NU 2-2012 phantom, was measured to be 314 kcps at 9.2 kBq cc−1. The CT scanner passed the technical components of the American College of Radiology (ACR) accreditation tests. We have also performed scans of a Hoffman brain phantom and we show images from the first canine patient imaged on this device.

Performance assessment of a software-based coincidence processor for the EXPLORER total-body PET scanner

Coincidence processing in positron emission tomography (PET) is typically done during acquisition of the data. However, on the EXPLORER total-body PET scanner we plan, in addition, to store unpaired single events (i.e. singles) for post-acquisition coincidence processing. A software-based coincidence processor was developed for EXPLORER and its performance was assessed. Our results showed that the performance of the coincidence processor could be significantly impacted by the type of data storage (Peripheral Component Interconnect Express (PCIe)-attached solid state drive (SSD) versus RAID 6 hard disk drives (HDDs)) especially when multiple data files were processed in parallel. We showed that a 48-thread computer node with dual Intel Xeon E5-2650 v4 central processing units (CPUs) and a PCIe SSD was sufficient to process approximately 120 M singles s−1 at an incoming singles rate of approximately 150 Mcps. With two computer nodes, near real-time coincidence processing became possible at this incoming singles rate.

Estimating the NEMA characteristics of the J-PET tomograph using the GATE package

A novel whole-body positron emission tomography (PET) system based on plastic scintillators is developed by the J-PET Collaboration. It consists of plastic scintillator strips arranged axially in the form of a cylinder, allowing the cost-effective construction of the total-body PET system. In order to determine the properties of the scanner prototype and optimize its geometry, advanced computer simulations were performed using the GATE (Geant4 application for tomographic emission) software.The spatial resolution, sensitivity, scatter fraction and noise equivalent count rate were estimated according to the National Electrical Manufacturers Association norm, as a function of the length of the tomograph, the number of detection layers, the diameter of the tomographic chamber and for various types of applied readout. For the single-layer geometry with a diameter of 85 cm, a strip length of 100 cm, a cross-section of 4 mm × 20 mm and silicon photomultipliers with an additional layer of wavelength shifter as the readout, the spatial resolution (full width at half maximum) in the centre of the scanner is equal to 3 mm (radial, tangential) and 6 mm (axial). For the analogous double-layer geometry with the same readout, diameter and scintillator length, with a strip cross-section of 7 mm × 20 mm, a noise equivalent count rate peak of 300 kcps was reached at 40 kBq cc−1 activity concentration, the scatter fraction is estimated to be about 35% and the sensitivity at the centre amounts to 14.9 cps kBq−1. Sensitivity profiles were also determined.

An extremely rare neoplasm, histiocytic sarcoma: A report of two cases with an aggressive clinical course

Abstract Histiocytic sarcoma (HS) is an extremely rare malignant neoplasm accounting for less than 1% of all hemato-lymphoid neoplasms. Sixty percent of all cases are metastatic at presentation and the prognosis is poor. Two cases of HS with an aggressive clinical course are presented. The first case was a 58-year-old man admitted to our hospital with back pain and paresthesia of the lower extremities. Magnetic resonance imaging (MRI) of the thoracic spine revealed a mass measuring 48 × 15 mm between the T2‒T5 paravertebral area, entering the spinal channel via the neural foramen and compressing the spinal cord. The mass was completely resected and pathological and immunohistochemical staining confirmed the diagnosis of HS. After three cycles of cyclophosphamide, doxorubicin, vincristine, and prednisone (CHOP) and two cycles of carboplatin/paclitaxel, the patient died due to disease progression after 9 months. The second case is a 48-year-old man who presented with fever and weight loss, and complained of back pain for 2 months. Thoracic vertebral MRI revealed a lesion destructing the T6, T7 and T9 vertebral corpus and a mass measuring 2.5 × 2 cm near the T6‒T7 transverse process. Total-body fluorodeoxyglucose positron emission tomography (FDG-PET) imaging revealed bilateral inguinal hypermetabolic lymph nodes measuring 10 × 14 mm and osteolytic destructive bone lesions on the vertebral colon and pelvic bones. Pathological and immunohistochemical staining of bone marrow aspirate confirmed the diagnosis of HS. After three cycles of ifosfamide, carboplatin, etoposide (ICE) chemotherapy, the patient died due to disease progression after 3 months. Conclusions HS is an extremely rare malignant neoplasm of the monocytic/macrophage lineage, with no standardized chemotherapy regimen for multisystemic disease. Metastatic patients have a more aggressive clinical course than those with unifocal disease.

Total-body imaging: Transforming the role of positron emission tomography.

The first total-body positron emission tomography (TB-PET) scanner represents a radical change for experimental medicine and diagnostic health care.

Treatment of Classic Kaposi's Sarcoma Showing a Discretely Scattered Distribution with Intralesional Vinblastine Injections

Dear Editor: Classic Kaposi's sarcoma (CKS) is one of clinical types of Kaposi's sarcoma (KS)1,2. Treatment options for CKS vary depending on clinical features such as age, number and distribution of lesions, and tumor depth3. It is essential, therefore, that treatment is tailored to the individual. Although many therapeutic strategies from systemic to local treatments are available for CKS, those treatments tend not to be suitable for cases with a discretely scattered distribution. Therefore, we report on a case of discretely scattered CKS treated successfully with intralesional vinblastine injections, which have previously proved effective and well-tolerated in acquired immune deficiency syndrome-related patients with localized oral KS lesions4. A 58-year-old Korean woman presented with a 5-year history of a skin lesion on her chin. Since that time of the initial skin lesion having appeared, subsequent lesions developed slowly on the upper and lower extremities. The patient was immunocompetent. Her past medical history was unremarkable except for the use of medication for dyslipidemia. A physical examination revealed multiple non-tender, round to elongated, red-purple papules and plaques (Fig. 1A), scattered over the chin, right hand, left forearm, and left shoulder. A skin biopsy of the chin was performed with immunohistochemistry stains (Fig. 2). Laboratory test results, including a complete blood cell count, thyroid function test, and anti-human immunodeficiency virus test, were all reported within normal limits. There was no evidence of metastasis on chest or abdominal computed tomography or on total body positron emission tomography imaging. We diagnosed this case as a discretely scattered CKS without visceral involvement. Although the patient had multifocal lesions on the head and limbs, the total number and size of the lesions had not changed in the last 3-months. To minimize the complications and considerable toxicities associated with the use of systemic chemotherapy or radiotherapy, we opted to treat our patient with intralesional vinblastine administration instead. All skin lesions were treated with intralesional vinblastine injections at a dose of 0.1 mg/cm2 using a 0.1 mg/ml solution of vinblastine sulfate in sterile saline4. After 5 weeks of treatment the tumors had completely regressed with no significant side effects except for a slight postinflammatory hyperpigmentation response (Fig. 1B). The patient was kept on regular follow-up and showed no signs of recurrence of CKS 6-months after treatment. Fig. 1 Clinical presentation of a discretely scattered classic Kaposi's sarcoma. (A) Widely distributed red-purple papules and plaques evident before treatment, and (B) complete regression of the tumors 5 weeks after treatment with intralesional vinblastine ... Fig. 2 Immunohistochemical evaluation of classic Kaposi's sarcoma specimens. (A) Endothelial cells of the abnormal vessels staining positively for cluster of differentiation 31; (B) Spindle cells staining positively for Friend leukemia virus integration-1; and ... CKS is usually indolent over many years but is not life threatening5. Consequently, clinicians have often hesitated in administering systemic therapy, which decreases quality of life, in patients with discretely scattered CKS. Our patient exhibited a dramatic response without serious side effects after a single cycle of intralesional vinblastine injections and had no additional lesions under outpatient follow-up. We conclude, therefore, that intralesional vinblastine administration is one of the most effective and useful treatment alternatives for relatively stable, discretely scattered CKS. However, the 6-month follow-up may not be sufficiently long when we consider the growth pattern of CKS and the potential for occult CKS lesions caused by hyperpigmentation, which were not histologically confirmed but need to be considered in estimating patient responses following intralesional vinblastine injections.

Metastatic Spermatic Cord Tumor From Colorectal Cancer.

Metastatic tumors of the spermatic cord are extremely rare, and the prognosis for patients is typically poor. In the majority of cases, the primary tumor occurs in the gastrointestinal tract. We report a case of a 62-year-old man with a metastatic spermatic cord tumor. The patient complained of groin discomfort with a tender mass in the right inguinal area. An excisional biopsy was performed, and the pathologic finding was a metastatic mucinous adenocarcinoma. We performed a systemic evaluation including colonoscopy, abdominal computed tomography, and total-body positron emission tomography, and the primary tumor was confirmed to involve the total colon, including the cecum, sigmoid colon, and rectum. The pathologic finding for rectum revealed a mucinous adenocarcinoma compatible with a metastatic spermatic cord tumor.

FRI0362 Contrast-enhanced ultrasound of the sovraortic arteries: the potential role in monitoring disease activity and response to treatment in large vessel vasculitis.

BackgroundPromising data has been recently published about the role of contrast-enhanced ultrasound (CEU) in the diagnosis and follow up of Takayasu arteritis (TA) -1,2-ObjectivesTo assess the role of CEU examination...

Incidence of diffuse FDG uptake in the thyroid of patients with hypothyroidism

Positron emission tomography (PET) positive lesions are common in the thyroid. The uptake can be focal or diffuse. Diffuse thyroid uptake is thought to be indicative of autoimmune thyroiditis and not for lesions of malignant potential. Hashimoto's thyroiditis as a cause for diffusely positive thyroid glands has been demonstrated. We determine the incidence of diffuse thyroid PET positivity in hypothyroid patients, presumed to have Hashimoto's thyroiditis. The study design was retrospective database and electronic medical record review. The study setting includes tertiary care and academic health sciences center. The subjects were patients at our medical center who underwent positron emission tomography. Hypothyroid patients were identified who had total body PET imaging performed for any reason. Patients were excluded if they were not taking levothyroxine, had a history of neck surgery, neck irradiation, Graves' disease, taking lithium, thalidomide, amiodarone or interleukin. Patients remaining after the application of these exclusion criteria were presumed to be hypothyroid from Hashimoto's thyroiditis. Only 9.5% of PET scans of hypothyroid patients display diffuse thyroid activity. Only a small minority of presumed Hashimoto's thyroiditis patients will display diffuse thyroid activity after PET imaging. The etiology of this effect is unknown. Diffuse thyroid activity rarely requires surgical intervention.

Reversible, PET-positive, Generalized Lymphadenopathy and Splenomegaly During High-dose Interferon-α-2b Adjuvant Therapy for Melanoma

A patient with resected stage III nodular melanoma treated with high-dose interferon-alpha-b2 adjuvant therapy went on to develop generalized lymphadenopathy and splenomegaly. The total body positron emission tomography showed a high F-fluorodeoxyglucose uptake (standardized uptake values >9), indicating possible lymph node and spleen malignancies. Histologic examinations of an axillary lymph node biopsy and an osteomedullar biopsy were negative, excluding both melanoma metastases and hematopoietic tumors. The symptoms completely regressed after suspension of treatment and a follow-up positron emission tomography was negative. It remains to be seen whether this unusual event can be ascribed to an autoimmune phenomenon linked to potential treatment efficacy and survival.

18-FDG PET in the diagnosis of laterocervical metastases from occult carcinoma

The management of patients with cervical node metastasis (CNM) from carcinoma of unknown primary (CUP) often includes several radiographic studies and invasive procedures that are only successful in detecting an occult primary tumour in less than 25% of the cases. In this prospective study we have assessed the role of total body positron emission tomography (PET) using an 18-F-fluorodesoxyglucose (FDG) in the detection of primary tumours in patients with metastases from CUP. Thirteen patients with lymph node metastases from cytologically verified CUP have undergone total body FDG PET which confirmed the possibility of lymph nodal lesion; all patients have also undergone conventional imaging with CT and/or MRI. The data obtained with the FDG-PET method have subsequently been confirmed both by the histopathological examination and by the clinical course of the disease. The current work aims at assessing and defining the effectiveness of the FDG-PET method during the diagnostic work-up of laterocervical metastasis from CUP conventionally examined with CT and/or MRI; based on our results, we recommend a flow-chart for the clinical-diagnostic management of the patient affected by laterocervical metastasis in the absence of known primary.

Prevalence and Nature of Systemic Involvement and Stage at Initial Examination in Patients With Orbital and Ocular Adnexal Lymphoma

To determine the stage at initial examination and the prevalence of systemic involvement in patients with orbital and ocular adnexal lymphoma. The medical records of all patients with orbital and ocular adnexal lymphoma treated in a recent 7-year period were reviewed for stage at initial examination, highest stage during the follow-up period, and recurrence-free survival. Forty-three patients were included. Nineteen patients had mucosa-associated lymphoid tissue, 9 had follicular, 9 had diffuse large-cell, 3 had mantle cell, 2 had small lymphocytic, and 1 had large T-cell lymphoma. The staging workup included chest radiography; orbital computed tomography or magnetic resonance imaging; computed tomography of the chest, abdomen, and pelvis; and bone marrow biopsy. Thirty-six patients had total body positron emission tomography, 7 had gallium scans, and 16 had gastrointestinal endoscopy. Lymphoma stage at diagnosis was IE in 18 patients, II in 6, and IV in 19. Six of 19 patients with mucosa-associated lymphoid tissue, 7 of 9 patients with follicular, 6 of 9 patients with diffuse large-cell, and 3 of 3 patients with mantle cell lymphoma had non-stage IE disease at initial examination. The 5-year recurrence-free survival was 64.6% for the entire cohort. Extraorbital involvement is present at diagnosis in more than half of patients with orbital and ocular adnexal lymphoma and warrants extensive systemic workup at diagnosis, continued surveillance, and consideration of systemic therapy.