Differentiation of HIV-associated lymphoma from HIV-associated reactive adenopathy using quantitative FDG PET and symmetry

Human immunodeficiency virus-associated Lymphomas: EHA-ESMO Clinical Practice Guideline for diagnosis, treatment and follow-up

This EHA-ESMO Clinical Practice Guideline provides key recommendations for managing HIV-associated lymphomas.The guideline covers clinical, imaging and pathological diagnosis; staging and risk assessment; treatment and follow-up.The author group encompasses a multidisciplinary group of experts from different institutions and countries in Europe.Recommendations are based on available scientific data and the authors' collective expert opinion.

Association between cardiovascular inflammation and alterations in immune system induced by HIV infection detected on [18F]FDG PET/MRI

OBJECTIVE

To assess by [18F]FDG PET/MR the biomarkers of HIV-induced inflammation at baseline and 1 year post-antiretroviral therapy (ART).

METHODS

Prospective study, 14 patients, newly diagnosed HIV-positive, asymptomatic. [18F]FDG PET/MRI (PET/MR-3.0T, Signa.GE) whole body and heart was performed, baseline and 1 year post-ART. Qualitative vascular assessment (hepatic reference). Quantitative assessment (SUVmax) of the whole body. T1 and T2 value estimation in 16 myocardial segments.

RESULTS

Baseline CMR showed in 3 (21.4%) a decreased LVEF, normalising post-TAR. Fibrosis was ruled out (T1), with no signs of myocardial oedema (T2) at baseline or post-TAR. Four (28.6%) showed baseline vascular [18F]FDG uptake, two in ascending thoracic aorta and two in ascending and descending thoracic aorta, normalising post-TAR. All (100%) showed basal lymph-nodes activity; supra (n:14) and infradiaphragmatic (n:13), laterocervical (n:14) and inguinal (n:13), with variable number of territories (9 patients >6;64.3%). Post-ART, 7 patients (50%) showed resolution and the other 7 reduction in extension (0 patients >5): 7 supra (100%) and 2 infradiaphragmatic (28.6%), 5 in the axilla and 2 in the groin. All (100%) had persistent basal adenoid uptake post-ART, 9 (64.3%) splenic all resolved post-ART and 7 (50.5%) gastric, persistent 3 post-ART.

CONCLUSIONS

Cardiovascular biomarkers by [18F]FDG PET/MR have shown baseline 28.6% of patients with large vessel activity and 21.4% with low LVEF, normalising post-ART. Inflammatory/immune biomarkers showed baseline activity in 100% of lymph-nodes, 100% adenoids, 64.3% splenic and 50.5% gastric. Post-TAR the reduction was 50% lymph-nodes, 0% adenoid, 100% splenic and 57.1% gastric.

Recent advancements in 18F-FDG PET/CT for the diagnosis, staging, and treatment management of HIV-related lymphoma

Infection with the Human Immunodeficiency Virus (HIV) is one of the most pressing issues facing public health on a worldwide scale. Currently, HIV-related lymphoma is the most common cause of death among people living with HIV, and warrants more attention. The unique challenges associated with HIV-related lymphoma management derive from the underlying HIV infection and its immunosuppressive effects. 18F-fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDG PET/CT) has gained significant prominence in the past few years as a valuable diagnostic and therapeutic instrument for the treatment of HIV-related lymphoma. This review will start with an overview of the subtypes, risk factors, and therapeutic choices for individuals with HIV-related lymphoma. We will then briefly discuss the current application of 18F-FDG PET/CT in the medical management of HIV-related lymphoma patients, followed by the initial staging of the disease, the evaluation of therapeutic response, the prediction of prognostic outcomes, the decision-making process for radiotherapy guided by PET findings, and the distinguishing of various diagnoses.

Four-dimensional quantitative analysis using FDG-PET in clinical oncology

Positron emission tomography (PET) with F-18 fluorodeoxyglucose (FDG) has been commonly used in many oncological areas. High-resolution PET permits a three-dimensional analysis of FDG distributions on various lesions in vivo, which can be applied for tissue characterization, risk analysis, and treatment monitoring after chemoradiotherapy and immunotherapy. Metabolic changes can be assessed using the tumor absolute FDG uptake as standardized uptake value (SUV) and metabolic tumor volume (MTV). In addition, tumor heterogeneity assessment can potentially estimate tumor aggressiveness and resistance to chemoradiotherapy. Attempts have been made to quantify intratumoral heterogeneity using radiomics. Recent reports have indicated the clinical feasibility of a dynamic FDG PET-computed tomography (CT) in pilot cohort studies of oncological cases. Dynamic imaging permits the assessment of temporal changes in FDG uptake after administration, which is particularly useful for differentiating pathological from physiological uptakes with high diagnostic accuracy. In addition, several new parameters have been introduced for the in vivo quantitative analysis of FDG metabolic processes. Thus, a four-dimensional FDG PET-CT is available for precise tissue characterization of various lesions. This review introduces various new techniques for the quantitative analysis of FDG distribution and glucose metabolism using a four-dimensional FDG analysis with PET-CT. This elegant study reveals the important role of tissue characterization and treatment strategies in oncology.

Clinical value of 18F-FDG PET/CT in the management of HIV-associated lymphoma

HIV is still a major public health problem. At present, HIV-associated lymphoma remains the leading cause of deaths among people living with HIV, which should be paid more attention to. ¹⁸F-fluorodeoxglucose (FDG) PET/CT has been recommended in the initial staging, restaging, response assessment and prognostic prediction of lymphomas in general population. HIV-associated lymphoma is, however, a different entity from lymphoma in HIV-negative with a poorer prognosis. The ability to accurately risk-stratify HIV-infected patients with lymphoma will help guide treatment strategy and improve the prognosis. In the review, the current clinical applications of ¹⁸F-FDG PET/CT in HIV-associated lymphoma will be discussed, such as diagnosis, initial staging, response evaluation, prognostic prediction, PET-guided radiotherapy decision, and surveillance for recurrence. Moreover, future perspectives will also be presented.

Clinical features and 18F-FDG PET/CT for distinguishing of malignant lymphoma from inflammatory lymphadenopathy in HIV-infected patients

Background

It is vital to distinguish between inflammatory and malignant lymphadenopathy in human immunodeficiency virus (HIV) infected individuals. The purpose of our study was to differentiate the variations in the clinical characteristics of HIV patients, and apply ¹⁸F-FDG PET/CT parameters for distinguishing of malignant lymphoma and inflammatory lymphadenopathy in such patients.

Methods

This retrospective cross-sectional study included 59 consecutive HIV-infected patients who underwent whole-body ¹⁸F-FDG PET/CT. Of these patients, 37 had biopsy-proven HIV-associated lymphoma, and 22 with HIV-associated inflammatory lymphadenopathy were used as controls. The determined parameters were the maximum of standard uptake value (SUV_max), SUV_max of only lymph nodes (SUV_LN), the most FDG-avid lesion-to-liver SUV_max ratio (SUR_max), laboratory examinations and demographics. The optimal cut-off of ¹⁸F-FDG PET/CT value was analyzed by receiver operating characteristic curve (ROC).

Results

Considering the clinical records, the Karnofsky Performance Status (KPS) scores in patients with inflammatory lymphadenopathy were obviously higher than those in patients with malignant lymphoma (P = 0.015), whereas lymphocyte counts and lactate dehydrogenase (LDH) were obviously lower (P = 0.014 and 0.010, respectively). For the ¹⁸F-FDG PET/CT imaging, extra-lymphatic lesions, especially digestive tract and Waldeyer’s ring, occurred more frequently in malignant lymphoma than inflammatory lymphadenopathy. Furthermore, the SUR_max and SUV_LN in malignant lymphoma were markedly higher than those in inflammatory lymphadenopathy (P = 0.000 and 0.000, respectively). The cut-off point of 3.1 for SUR_max had higher specificity (91.9%) and relatively reasonable sensitivity (68.2%) and the cut-off point of 8.0 for the SUV_LN had high specificity (89.2%) and relatively reasonable sensitivity (63.6%).

Conclusion

Our study identified the distinctive characteristics of the clinical manifestations, the SUR_max, SUV_LN and detectability of extra-lymphatic lesions on ¹⁸F-FDG PET, and thus provides a new basis for distinguishing of malignant lymphoma from inflammatory lymphadenopathy in HIV-infected patients.

First Extensive Analysis of 18F-Labeled Fluorodeoxyglucose Positron Emission Tomography-Computed Tomography in a Large Cohort of Patients With HIV-Associated Hodgkin Lymphoma: Baseline Total Metabolic Tumor Volume Affects Prognosis

PURPOSE

¹⁸F-labeled fluorodeoxyglucose positron emission tomography with computed tomography (¹⁸F-FDG PET-CT) data in HIV-associated Hodgkin lymphoma (HIV-HL) are scarcely reported. In addition to the description of the characteristics of both baseline and interim ¹⁸F-FDG PET-CT examinations (PET1 and iPET, respectively), the aim of this study was to assess the prognostic value of PET1 and previously identified clinical parameters in this population.

PATIENTS AND METHODS

PET1 of 109 patients with HIV-HL, treated with doxorubicin, bleomycin, vinblastine, and dacarbazine chemotherapy regimen since 2007, and 104 iPET were centrally reviewed. All the patients were enrolled in an ongoing prospective single-center cohort of HIV-associated lymphoma.

RESULTS

Most patients had a disseminated disease according to the Ann Arbor classification (30% stage III and 43% stage IV), with especially bone marrow and liver as extranodal localizations. After a median follow-up of 6.7 years, 12 patients relapsed (11%) and 13 died (12%). Five-year progression-free survival (PFS) was 75.1%, and 5-year overall survival was 86.1%. Median total metabolic tumor volume (TMTV) was 121.4 cm³. The optimal TMTV cutoff identified for prognostic analysis was 527 cm³, with a 2-year PFS of 71% in the 20 patients with TMTV > 527 cm³, compared with 91% in the 89 patients with TMTV ≤ 527 cm³ (P = .004). On multivariate analysis, a high TMTV was the only parameter independently associated with PFS.

CONCLUSION

In this large series of HIV-HL patients with a homogeneous management, high TMTV on PET1 examination was associated with a poor prognosis.

Contribution of 18F-FDG PET/CT imaging in the diagnosis and management of HIV-positive patients

INTRODUCTION AND OBJECTIVES

The human immunodeficiency virus [HIV] is a lentevirus, primarily infects certain cells of the immune system, thereby greatly weakens the body's own defenses against diseases. This study was aimed to explore the value and significance of ¹⁸F-FDG PET/CT in the assessment of patients with HIV infection and to examine the presence of quantitative alterations in ¹⁸F-FDG uptake among patients with HIV-related infections or malignant diseases in HIV-positive patients.

PATIENTS AND METHODS

Forty patients with HIV infection were scanned on PET/CT system. The data were registered according to immune status, antiretroviral therapy, and definitive diagnosis. All pathologic lesions and disease related areas were described, ¹⁸F-FDG uptake patterns were evaluated. Semiquantitative analysis of ¹⁸F-FDG uptake was performed and SUVmax were calculated.

RESULTS

Twenty-eight patients [70%] were diagnosed with HIV-related infection or malignant diseases. The sensitivity of PET/CT was shown to be 100% and the specificity 92% for concomitant diseases requiring additional treatment to antiretroviral therapy. The SUVmax and CD4 counts were not statistically different between HIV-related reactive lymphadenopathy, HIV-related malignancy, and HIV-related infections.

CONCLUSIONS

The pattern of distribution of nodal/extranodal uptake on ¹⁸F-FDG PET/CT may facilitate distinction between HIV-related generalized lymphadenopathies, HIV-related opportunistic infections, and malignancies. In this context, ¹⁸F-FDG PET/CT should be preferred for routine use in the management of patients infected with HIV.

Prognostic nomogram incorporating radiological features for predicting overall survival in patients with AIDS-related non-Hodgkin lymphoma

BACKGROUND

Acquired immune deficiency syndrome (AIDS)-related non-Hodgkin lymphoma (AR-NHL) is a high-risk factor for morbidity and mortality in patients with AIDS. This study aimed to determine the prognostic factors associated with overall survival (OS) and to develop a prognostic nomogram incorporating computed tomography imaging features in patients with acquired immune deficiency syndrome-related non-Hodgkin lymphoma (AR-NHL).

METHODS

A total of 121 AR-NHL patients between July 2012 and November 2019 were retrospectively reviewed. Clinical and radiological independent predictors of OS were confirmed using multivariable Cox analysis. A prognostic nomogram was constructed based on the above clinical and radiological factors and then provided optimum accuracy in predicting OS. The predictive accuracy of the nomogram was determined by Harrell C-statistic. Kaplan-Meier survival analysis was used to determine median OS. The prognostic value of adjuvant therapy was evaluated in different subgroups.

RESULTS

In the multivariate Cox regression analysis, involvement of mediastinal or hilar lymph nodes, liver, necrosis in the lesions, the treatment with chemotherapy, and the CD4 ≤100 cells/μL were independent risk factors for poor OS (all P < 0.050). The predictive nomogram based on Cox regression has good discrimination (Harrell C-index = 0.716) and good calibration (Hosmer-Lemeshow test, P = 0.620) in high- and low-risk groups. Only patients in the high-risk group who received adjuvant chemotherapy had a significantly better survival outcome.

CONCLUSION

A survival-predicting nomogram was developed in this study, which was effective in assessing the survival outcomes of patients with AR-NHL. Notably, decision-making of chemotherapy regimens and more frequent follow-up should be considered in the high-risk group determined by this model.

State of the art of 18F-FDG PET/CT application in inflammation and infection: a guide for image acquisition and interpretation

AIM

The diagnosis, severity and extent of a sterile inflammation or a septic infection could be challenging since there is not one single test able to achieve an accurate diagnosis. The clinical use of 18F-fluorodeoxyglucose ([18F]FDG) positron emission tomography/computed tomography (PET/CT) imaging in the assessment of inflammation and infection is increasing worldwide. The purpose of this paper is to achieve an Italian consensus document on [18F]FDG PET/CT or PET/MRI in inflammatory and infectious diseases, such as osteomyelitis (OM), prosthetic joint infections (PJI), infective endocarditis (IE), prosthetic valve endocarditis (PVE), cardiac implantable electronic device infections (CIEDI), systemic and cardiac sarcoidosis (SS/CS), diabetic foot (DF), fungal infections (FI), tuberculosis (TBC), fever and inflammation of unknown origin (FUO/IUO), pediatric infections (PI), inflammatory bowel diseases (IBD), spine infections (SI), vascular graft infections (VGI), large vessel vasculitis (LVV), retroperitoneal fibrosis (RF) and COVID-19 infections.

METHODS

In September 2020, the inflammatory and infectious diseases focus group (IIFG) of the Italian Association of Nuclear Medicine (AIMN) proposed to realize a procedural paper about the clinical applications of [18F]FDG PET/CT or PET/MRI in inflammatory and infectious diseases. The project was carried out thanks to the collaboration of 13 Italian nuclear medicine centers, with a consolidate experience in this field. With the endorsement of AIMN, IIFG contacted each center, and the pediatric diseases focus group (PDFC). IIFG provided for each team involved, a draft with essential information regarding the execution of [18F]FDG PET/CT or PET/MRI scan (i.e., indications, patient preparation, standard or specific acquisition modalities, interpretation criteria, reporting methods, pitfalls and artifacts), by limiting the literature research to the last 20 years. Moreover, some clinical cases were required from each center, to underline the teaching points. Time for the collection of each report was from October to December 2020.

RESULTS

Overall, we summarized 291 scientific papers and guidelines published between 1998 and 2021. Papers were divided in several sub-topics and summarized in the following paragraphs: clinical indications, image interpretation criteria, future perspectivess and new trends (for each single disease), while patient preparation, image acquisition, possible pitfalls and reporting modalities were described afterwards. Moreover, a specific section was dedicated to pediatric and PET/MRI indications. A collection of images was described for each indication.

CONCLUSIONS

Currently, [18F]FDG PET/CT in oncology is globally accepted and standardized in main diagnostic algorithms for neoplasms. In recent years, the ever-closer collaboration among different European associations has tried to overcome the absence of a standardization also in the field of inflammation and infections. The collaboration of several nuclear medicine centers with a long experience in this field, as well as among different AIMN focus groups represents a further attempt in this direction. We hope that this document will be the basis for a "common nuclear physicians' language" throughout all the country.

SUPPLEMENTARY INFORMATION

The online version contains supplementary material available at 10.1007/s40336-021-00445-w.

18F-FDG PET/CT imaging features of patients with multicentric Castleman disease

OBJECTIVE

The aim of this study is to investigate the role of 18F-fluorodeoxyglucose (FDG) PET/computed tomography (CT) in the evaluation of multicentric Castleman disease (MCD).

METHODS

Thirty-five patients with pathologically confirmed MCD who underwent 18F-FDG PET/CT were retrospectively included. The FDG uptake and CT findings of lymph nodes, pulmonary involvement, spleen, and bone marrow were assessed and the maximum standardized uptake value (SUVmax) of each lesion was measured. The locations of lymph nodes were also evaluated.

RESULTS

18F-FDG PET/CT showed increased uptake in multiple nodal regions in 34 out of 35 MCD patients. The most frequently involved nodal sites were the cervical, iliac, axillary, and inguinal areas, and the least common was paraaortic and abdominal nodes. The involved lymph nodes were not confluent and presented a relatively symmetric pattern on PET/CT images. The highest SUVmax of lymph nodes per patient ranged from 2 to 19 with a mean value of 5.61 ± 3.12. Pulmonary manifestation including cysts, nodules, and interstitial lung disease were found in 10 patients, eight of whom demonstrated mild to moderate uptake in the lungs. 18F-FDG PET/CT also revealed other findings including hypermetabolic spleen (n = 8) and bone marrow (n = 23), elevated uptake in salivary glands (n = 8). Four patients also underwent follow-up PET/CT scans after therapy, and three of them displayed decreased metabolism.

CONCLUSION

18F-FDG PET/CT is a useful tool in the diagnosis, evaluation, and follow-up of MCD by providing systemic manifestations of lymphadenopathy, pulmonary involvement, and hypermetabolic spleen or bone marrow. Furthermore, the lymphadenopathy in MCD presented a predominantly peripheral distribution, relatively symmetric, moderately hypermetabolic, and not confluent pattern on 18F-FDG PET/CT.

Response-adapted therapy with infusional EPOCH chemotherapy plus rituximab in HIV-associated, B-cell non-Hodgkin's lymphoma

Four cycles of rituximab plus CHOP chemotherapy is as effective as 6 cycles in low-risk diffuse large B-cell lymphoma (DLBCL). Here we report a post-hoc analysis of a prospective clinical trial in patients with HIV-associated DLBCL and high-grade lymphoma treated with 4-6 cycles of EPOCH plus rituximab based a response-adapted treatment strategy. 106 evaluable patients with HIV-associated DLBCL or high-grade CD20-positive non-Hodgkin's lymphoma were randomized to receive rituximab (375 mg/m2) given either concurrently prior to each infusional EPOCH cycle, or sequentially (weekly for 6 weeks) following completion of EPOCH. EPOCH consisted of a 96-hour IV infusion of etoposide, doxorubicin, and vincristine plus oral prednisone followed by IV bolus cyclophosphamide every 21 days for 4 to 6 cycles. Patients received 2 additional cycles of therapy after documentation of a complete response (CR) by computerized tomography after cycles 2 and 4. 64 of 106 evaluable patients (60%, 95% CI 50%, 70%) had a CR in both treatment arms. The 2-year event-free survival (EFS) rates were similar in the 24 patients with CR who received 4 or fewer EPOCH cycles (78%, 95% confidence intervals [55%, 90%]) due to achieving a CR after 2 cycles, compared with those who received 5-6 cycles of EPOCH (85%, 95% CI 70%, 93%) because a CR was first documented after cycle 4. A response-adapted strategy may permit a shorter treatment duration without compromising therapeutic efficacy in patients with HIV-associated lymphoma treated with EPOCH plus rituximab, which merits further evaluation in additional prospective trials. Clinical Trials.gov identifier NCT00049036.

FDG-PET for Assessment of Endometrial and Vulvar Cancer

Fluorodeoxyglucose positron emission tomography computed tomography (FDG-PET/CT) provides a comprehensive whole body evaluation in patients with endometrial and vulvar cancer. Here, we discuss the role of FDG-PET/CT in defining the disease extent in patients presenting with these cancers. Detection of lymph node and distant metastases has implications for staging, treatment planning, and patient prognosis. Procedures for image acquisition and interpretation for optimum accuracy and essential elements that should be included in the PET-CT report are described. Common imaging pitfalls are presented and illustrated with examples.

Mycobacterial Lymphadenitis in a Human Immunodeficiency Virus-Infected Patient: Usefulness of 18F-Fluorodeoxyglucose Positron Emission Tomography for Diagnosis and Monitoring the Response to Treatment

Lymphadenitis, due to typical or atypical Mycobacterium, is a clinical condition frequently associated with human immunodeficiency virus (HIV) infection. Differential diagnosis between benign and malignant causes may be a challenge for clinicians. In this regard, the role of positron emission tomography (PET) with ¹⁸F-fluorodeoxyglucose (¹⁸F-FDG) has still not been fully explored. We describe a case of 30-year-old male, infected by HIV, with mycobacterial lymphadenitis, in which ¹⁸FDG-PET and PET-derived parameters resulted useful for guiding diagnosis and monitoring the response to treatment.

HIV status does not have an impact on positron emission tomography-computed tomography (PET-CT) findings or radiotherapy treatment recommendations in patients with locally advanced cervical cancer

INTRODUCTION

Positron emission tomography-computed tomography (PET-CT) imaging is commonly used to identify nodal involvement in locally advanced cervical carcinoma, but its appropriateness for that purpose among HIV-positive patients has rarely been studied. We analyzed PET-CT findings and subsequent treatment prescribed in patients with locally advanced cervical carcinoma in Cape Town, South Africa.

METHODS

We identified a cohort of consecutive cervical carcinoma patients International Federation of Gynecology and Obstetrics (FIGO) stage IIB to IIIB at our cancer center who underwent a planning 18-fluorodeoxyglucose (18FDG) PET-CT scan from January 2015 through December 2018. Demographics, PET-CT findings, and subsequent treatment prescribed were recorded. Patients were selected for PET-CT only if they had no signs of distant disease on staging chest X-ray or abdominal ultrasound; were deemed suitable for radical chemoradiation by the multi-disciplinary team; and had normal renal function. HIV-positive patients ideally had to have been established on continuous antiviral therapy for more than 3 months and to have a CD4 cell count above 150 cells/μL. Small cell and neuroendocrine carcinoma cases were excluded from the study. Differences in demographic and clinical measures between HIV-positive and HIV-negative patients were evaluated by means of t-tests for continuous variables and χ2 tests for categorical variables.

RESULTS

Over a 4 year period, 278 patients-192 HIV-negative (69.1%) and 86 HIV-positive (30.9%)-met the inclusion criteria. HIV-positive patients had a median CD4 count of 475 cells/µL (IQR 307-612 cells/µL). More than 80% of patients had pelvic nodal involvement, and more than 40% had uptake in common iliac and/or para-aortic nodes. Nodal involvement was not associated with HIV status. Fifty-four patients (19.4%) had at least one site of distant metastatic disease. Overall, 235 patients (84.5%) were upstaged following PET-CT staging scan. Upstaging was not associated with HIV status (HIV-negative 83.9% vs HIV-positive 87.2%; p=0.47). Ten patients who did not return for radiotherapy were excluded from the analysis. Following their PET-CT scan, treatment intent changed for 124 patients (46.3%): 53.6% of HIV-positive patients and 42.9% of HIV-negative patients (p=0.11).

CONCLUSION

We found no differences between HIV-positive or HIV-negative patients in nodal involvement or occult metastases, and PET-CT imaging did not lead to, or justify, treatment differences between the two groups. Future studies will evaluate survival and correlation of upstaging with outcome.

Subclinical Atherosclerosis Imaging in People Living with HIV

In many, but not all studies, people living with HIV (PLWH) have an increased risk of coronary artery disease (CAD) events compared to the general population. This has generated considerable interest in the early, non-invasive detection of asymptomatic (subclinical) atherosclerosis in PLWH. Ultrasound studies assessing carotid artery intima-media thickness (CIMT) have tended to show a somewhat greater thickness in HIV+ compared to HIV-, likely due to an increased prevalence of cardiovascular (CV) risk factors in PLWH. Coronary artery calcification (CAC) determination by non-contrast computed tomography (CT) seems promising to predict CV events but is limited to the detection of calcified plaque. Coronary CT angiography (CCTA) detects calcified and non-calcified plaque and predicts CAD better than either CAC or CIMT. A normal CCTA predicts survival free of CV events over a very long time-span. Research imaging techniques, including black-blood magnetic resonance imaging of the vessel wall and 18F-fluorodeoxyglucose positron emission tomography for the assessment of arterial inflammation have provided insights into the prevalence of HIV-vasculopathy and associated risk factors, but their clinical applicability remains limited. Therefore, CCTA currently appears as the most promising cardiac imaging modality in PLWH for the evaluation of suspected CAD, particularly in patients <50 years, in whom most atherosclerotic coronary lesions are non-calcified.

Computed tomography textural analysis for the differentiation of chronic lymphocytic leukemia and diffuse large B cell lymphoma of Richter syndrome

OBJECTIVE

To test the hypothesis that both indolent and aggressive chronic lymphocytic leukemia (CLL) can be differentiated from diffuse large B cell lymphoma (DLBCL) of Richter syndrome (RS) by CT texture analysis (CTTA) of involved lymph nodes.

MATERIAL AND METHODS

We retrospectively included 52 patients with indolent CLL (26/52), aggressive CLL (8/52), and DLBCL of RS (18/52), who underwent standardized contrast-enhanced CT. In main lymphoma tissue, VOIs were generated from which CTTA features including first-, second-, and higher-order textural features were extracted. CTTA features were compared between the entire CLL group, the indolent CLL subtype, the aggressive CLL subtype, and DLBCL using a Kruskal-Wallis test. All p values were adjusted after the Bonferroni correction. ROC analyses for significant CTTA features were performed to determine cut-off values for differentiation between the groups.

RESULTS

Compared with DLBCL of RS, CTTA of the entire CLL group showed significant differences of entropy heterogeneity (p < 0.001), mean intensity (p < 0.001), mean average (p = 0.02), and number non-uniformity gray-level dependence matrix (NGLDM) (p = 0.03). Indolent CLL significantly differed for entropy (p < 0.001), uniformity of heterogeneity (p = 0.02), mean intensity (p < 0.001), and mean average (p = 0.01). Aggressive CLL showed significant differences in mean intensity (p = 0.04). For differentiation between CLL and DLBCL of RS, cut-off values for mean intensity and entropy of heterogeneity were defined (e.g., 6.63 for entropy heterogeneity [aggressive CLL vs. DLBCL]; sensitivity 0.78; specificity 0.63).

CONCLUSIONS

CTTA features of ultrastructure and vascularization significantly differ in CLL compared with that in DLBCL of Richter syndrome, allowing complementary to visual features for noninvasive differentiation by contrast-enhanced CT.

KEY POINTS

• Richter transformation of CLL into DLBCL results in structural changes in lymph node architecture and vascularization that can be detected by CTTA. • First-order CT textural features including intensity and heterogeneity significantly differ between both indolent CLL and aggressive CLL and DLBCL of Richter syndrome. • CT texture analysis allows for noninvasive detection of Richter syndrome which is of prognostic value.

CT Texture Analysis of Cervical Lymph Nodes on Contrast-Enhanced [18F] FDG-PET/CT Images to Differentiate Nodal Metastases from Reactive Lymphadenopathy in HIV-Positive Patients with Head and Neck Squamous Cell Carcinoma

BACKGROUND AND PURPOSE

Differentiating nodal metastases from reactive adenopathy in HIV-infected patients with [¹⁸F] FDG-PET/CT can be challenging because lymph nodes in HIV-positive patients often show increased [¹⁸F] FDG uptake. The purpose of this study was to assess CT textural analysis characteristics of HIV-positive and HIV-negative lymph nodes on [¹⁸F] FDG-PET/CT to differentiate nodal metastases from disease-specific nodal reactivity.

MATERIALS AND METHODS

Nine HIV-positive patients with head and neck squamous cell carcinoma (7 men, 2 women; 29-62 years of age; median age, 48 years) with 22 lymph nodes (≥1 cm) who underwent contrast-enhanced CT with [¹⁸F] FDG-PET followed by pathologic evaluation of cervical lymph nodes were retrospectively reviewed. Twenty-six HIV-negative patients with head and neck squamous cell carcinoma with 61 lymph nodes were evaluated as a control group. Each lymph node was manually segmented, and an in-house-developed Matlab-based texture analysis program extracted 41 texture features from each segmented volume. A mixed linear regression model was used to compare the pathologically proved malignant lymph nodes with benign nodes in the 2 enrolled groups.

RESULTS

Thirteen (59%) lymph nodes in the HIV-positive group and 22 (36%) lymph nodes in the HIV-negative control group were confirmed as positive for metastases. There were 7 histogram features (P = .017-0.032), 3 gray-level co-occurrence features (P = .009-.025), and 9 gray-level run-length features (P < .001-.033) that demonstrated a significant difference in HIV-positive patients with either benign or malignant lymph nodes.

CONCLUSIONS

CT texture analysis may be useful as a noninvasive method of obtaining additional quantitative information to differentiate nodal metastases from disease-specific nodal reactivity in HIV-positive patients with head and neck squamous cell carcinoma.

HIV-related Malignancies and Mimics: Imaging Findings and Management

The risk of developing malignancy is higher in patients with human immunodeficiency virus (HIV) infection than in non-HIV-infected patients. Several factors including immunosuppression, viral coinfection, and high-risk lifestyle choices lead to higher rates of cancer in the HIV-infected population. A subset of HIV-related malignancies are considered to be acquired immunodeficiency syndrome (AIDS)-defining malignancies, as their presence confirms the diagnosis of AIDS in an HIV-infected patient. The introduction of highly active antiretroviral therapy (HAART) has led to a significant drop in the rate of AIDS-defining malignancies, including Kaposi sarcoma, non-Hodgkin lymphoma, and invasive cervical carcinoma. However, non-AIDS-defining malignancies (eg, Hodgkin lymphoma, lung cancer, hepatocellular carcinoma, and head and neck cancers) now account for an increasing number of cancer cases diagnosed in HIV-infected patients. Although the number has decreased, AIDS-defining malignancies account for 15%-19% of all deaths in HIV-infected patients in the post-HAART era. Most HIV-related malignancies in HIV-infected patients manifest at an earlier age with a more aggressive course than that of non-HIV-related malignancies. Understanding common HIV-related malignancies and their specific imaging features is crucial for making an accurate and early diagnosis, which impacts management. Owing to the weakened immune system of HIV-infected patients, other entities such as various infections, particularly opportunistic infections, are prevalent in these patients. These processes can have confounding clinical and imaging manifestations that mimic malignancy. This article reviews the most common AIDS-defining and non-AIDS-defining malignancies, the role of imaging in their diagnosis, and the imaging mimics of malignancies in HIV-infected patients. ^©RSNA, 2018.

Incidence and risk factors for relapses in HIV-associated non-Hodgkin lymphoma as observed in the German HIV-related lymphoma cohort study

Outcome of HIV-infected patients with AIDS-related lymphomas has improved during recent years. However, data on incidence, risk factors, and outcome of relapses in AIDS-related lymphomas after achieving complete remission are still limited. This prospective observational multicenter study includes HIV-infected patients with biopsy- or cytology-proven malignant lymphomas since 2005. Data on HIV infection and lymphoma characteristics, treatment and outcome were recorded. For this analysis, AIDS-related lymphomas patients in complete remission were analyzed in terms of their relapse- free survival and potential risk factors for relapses. In total, 254 of 399 (63.7%) patients with AIDS-related lymphomas reached a complete remission with their first-line chemotherapy. After a median follow up of 4.6 years, 5-year overall survival of the 254 patients was 87.8% (Standard Error 3.1%). Twenty-nine patients relapsed (11.4%). Several factors were independently associated with a higher relapse rate, including an unclassifiable histology, a stage III or IV according to the Ann Arbor Staging System, no concomitant combined antiretroviral therapy during chemotherapy and R-CHOP-based compared to more intensive chemotherapy regimens in Burkitt lymphomas. In conclusion, complete remission and relapse rates observed in our study are similar to those reported in HIV-negative non-Hodgkin lymphomas. These data provide further evidence for the use of concomitant combined antiretroviral therapy during chemotherapy and a benefit from more intensive chemotherapy regimens in Burkitt lymphomas. Modifications to the chemotherapy regimen appear to have only a limited impact on relapse rate.

Tuberculosis

Tuberculosis (TB) is currently the world's leading cause of infectious mortality. Imaging plays an important role in the management of this disease. The complex immune response of the human body to Mycobacterium tuberculosis results in a wide array of clinical manifestations, making clinical and radiological diagnosis challenging. ¹⁸F-FDG-PET/CT is very sensitive in the early detection of TB in most parts of the body; however, the lack of specificity is a major limitation. ¹⁸F-FDG-PET/CT images the whole body and provides a pre-therapeutic metabolic map of the infection, enabling clinicians to accurately assess the burden of disease. It enables the most appropriate site of biopsy to be selected, stages the infection, and detects disease in previously unknown sites. ¹⁸F-FDG-PET/CT has recently been shown to be able to identify a subset of patients with latent TB infection who have subclinical disease. Lung inflammation as detected by ¹⁸F-FDG-PET/CT has shown promising signs that it may be a useful predictor of progression from latent to active infection. A number of studies have identified imaging features that might improve the specificity of ¹⁸F-FDG-PET/CT at some sites of extrapulmonary TB. Other PET tracers have also been investigated for their use in TB, with some promising results. The potential role and future perspectives of PET/CT in imaging TB is considered. Literature abounds on the very important role of ¹⁸F-FDG-PET/CT in assessing therapy response in TB. The use of ¹⁸F-FDG for monitoring response to treatment is addressed in a separate review.

Monitoring Response to Therapy

Monitoring response to treatment is a key element in the management of infectious diseases, yet controversies still persist on reliable biomarkers for noninvasive response evaluation. Considering the limitations of invasiveness of most diagnostic procedures and the issue of expression heterogeneity of pathology, molecular imaging is better able to assay in vivo biologic processes noninvasively and quantitatively. The usefulness of ¹⁸F-FDG-PET/CT in assessing treatment response in infectious diseases is more promising than for conventional imaging. However, there are currently no clinical criteria or recommended imaging modalities to objectively evaluate the effectiveness of antimicrobial treatment. Therapeutic effectiveness is currently gauged by the patient's subjective clinical response. In this review, we present the current studies for monitoring treatment response, with a focus on Mycobacterium tuberculosis, as it remains a major worldwide cause of morbidity and mortality. The role of molecular imaging in monitoring other infections including spondylodiscitis, infected prosthetic vascular grafts, invasive fungal infections, and a parasitic disease is highlighted. The role of functional imaging in monitoring lipodystrophy associated with highly active antiretroviral therapy for human immunodeficiency virus is considered. We also discuss the key challenges and emerging data in optimizing noninvasive response evaluation.

Clinical implications of the interaction between HPV and HIV infections

HIV-related immunodeficiency has complex effects on female genital HPV, which include increased risks of infection, multiple types, persistence, reactivation and the risk to develop pre-invasive and invasive disease. Reconstitution of immunity with anti-viral drugs improves cellular immunity, but the risk of HPV-related malignancy remains higher than background incidences and presents at younger ages. Early initiation of antiretroviral therapy (ART) allows improved retention of immune memory through existing antibodies and T-cell clones and improves long-term outcomes. Suggestions of a higher risk to contract HIV if there is existing genital HPV infection are supported and explained by pathophysiological cervical changes, including inflammation. HIV-HPV interactions should influence public health decisions towards prioritising large-scale prepubertal HPV-vaccine roll-out, secondary cervical cancer prevention and early detection programmes for HIV-infected women and early initiation of ART. This chapter will also focus on special considerations for the management of women with co-infection with these two viruses and genital HPV-related diseases.

Cervical cancer control in HIV-infected women: Past, present and future

Since the initial recognition of acquired immunodeficiency syndrome (AIDS) in 1981, an increased burden of cervical cancer was identified among human immunodeficiency virus (HIV)-positive women. Introduction of antiretroviral therapy (ART) decreased risks of opportunistic infections and improved overall survival. HIV-infected women are living longer. Introduction of the human papillomavirus (HPV) vaccine, cervical cancer screening and early diagnosis provide opportunities to reduce cervical cancer associated mortality. In line with 2030 Sustainable Development Goals to reduce mortality from non-communicable diseases, increased efforts need to focus on high burden countries within sub-Saharan Africa (SSA). Despite limitations of resources in SSA, opportunities exist to improve cancer control. This article reviews advancements in cervical cancer control in HIV-positive women.

The role of F-18 FDG PET/CT in evaluating the impact of HIV infection on tumor burden and therapy outcome in patients with Hodgkin lymphoma

BACKGROUND

To evaluate the impact of HIV infection on tumor burden and therapy outcome following treatment with chemotherapy in patients with Hodgkin lymphoma.

METHODS

A total of 136 patients with classical Hodgkin lymphoma were studied (mean age ± SD = 32.31 ± 1.39 years, male = 86, female = 50). Advanced disease (stage III and IV) was present in 64% of patients. HIV infection was present in 57 patients while 79 patients were HIV-negative. Baseline F-18 FDG PET/CT was obtained in all patients. SUVmax, MTV and TLG were determined on the baseline scan to evaluate for tumor burden. All patients completed a standard regimen of adriamycin, bleomycin, vinblastine and dacarbazine (ABVD). After a median period of 8 weeks (range = 6 to 17 weeks), a repeat F-18 FDG PET/CT scan was obtained to evaluate response to therapy using Deauville 5-point scoring system.

RESULTS

The HIV-positive and HIV-negative groups were similar with regards to age and disease stage. The groups were heterogeneous with respect to gender (p = 0.029). The SUVmax, MTV and TLG of lesions were not significant different between the two groups. Complete response was seen in 72.8% of the study population. Presence of HIV infection was associated with higher rate of treatment failure with 40.4% of the HIV-positive patients having treatment failure while only 17.7% of the HIV-negative patients had treatment failure (p = 0.0034). HIV infection was a significant predictor of response to chemotherapy. Effects of SUVmax, MTV, TLG and Ann Arbor stage of the disease were not statistically significant as predictors of therapy outcome. In a multiple logistic regression, presence of HIV infection still remained an independent predictor of therapy outcome in the presence of other factors such as SUVmax, MTV, TLG and the Ann Arbor stage of the disease.

CONCLUSIONS

HIV infection is not associated with a higher tumor burden in patients with Hodgkin lymphoma. HIV infection is, however, a strong predictor of poor therapy outcome in patients treated with standard regimen of ABVD.

CT-based texture analysis potentially provides prognostic information complementary to interim fdg-pet for patients with hodgkin's and aggressive non-hodgkin's lymphomas

OBJECTIVES

The purpose of this study was to investigate the ability of computed tomography texture analysis (CTTA) to provide additional prognostic information in patients with Hodgkin's lymphoma (HL) and high-grade non-Hodgkin's lymphoma (NHL).

METHODS

This retrospective, pilot-study approved by the IRB comprised 45 lymphoma patients undergoing routine 18F-FDG-PET-CT. Progression-free survival (PFS) was determined from clinical follow-up (mean-duration: 40 months; range: 10-62 months). Non-contrast-enhanced low-dose CT images were submitted to CTTA comprising image filtration to highlight features of different sizes followed by histogram-analysis using kurtosis. Prognostic value of CTTA was compared to PET FDG-uptake value, tumour-stage, tumour-bulk, lymphoma-type, treatment-regime, and interim FDG-PET (iPET) status using Kaplan-Meier analysis. Cox regression analysis determined the independence of significantly prognostic imaging and clinical features.

RESULTS

A total of 27 patients had aggressive NHL and 18 had HL. Mean PFS was 48.5 months. There was no significant difference in pre-treatment CTTA between the lymphoma sub-types. Kaplan-Meier analysis found pre-treatment CTTA (medium feature scale, p=0.010) and iPET status (p<0.001) to be significant predictors of PFS. Cox analysis revealed that an interaction between pre-treatment CTTA and iPET status was the only independent predictor of PFS (HR: 25.5, 95% CI: 5.4-120, p<0.001). Specifically, pre-treatment CTTA risk stratified patients with negative iPET.

CONCLUSION

CTTA can potentially provide prognostic information complementary to iPET for patients with HL and aggressive NHL.

KEY POINTS

• CT texture-analysis (CTTA) provides prognostic information complementary to interim FDG-PET in Lymphoma. • Pre-treatment CTTA and interim PET status were significant predictors of progression-free survival. • Patients with negative interim PET could be further stratified by pre-treatment CTTA. • Provide precision surveillance where additional imaging reserved for patients at greatest recurrence-risk. • Assists in risk-adapted treatment strategy based on interim PET and CTTA.

18F-fluorodeoxyglucose Positron Emission Tomography in Kaposi Sarcoma Herpesvirus-Associated Multicentric Castleman Disease: Correlation With Activity, Severity, Inflammatory and Virologic Parameters

BACKGROUND

Kaposi sarcoma herpesvirus (KSHV)-associated multicentric Castleman disease (MCD) is a lymphoproliferative inflammatory disorder commonly associated with human immunodeficiency virus (HIV). Its presentation may be difficult to distinguish from HIV and its complications, including lymphoma. Novel imaging strategies could address these problems.

METHODS

We prospectively characterized (18)F-fluorodeoxyglucose positron emission tomography (PET) findings in 27 patients with KSHV-MCD. Patients were imaged with disease activity and at remission with scans evaluated blind to clinical status. Symptoms, C-reactive protein level, and HIV and KSHV loads were assessed in relation to imaging findings.

RESULTS

KSHV-MCD activity was associated with hypermetabolic symmetric lymphadenopathy (median maximal standardized uptake value [SUVmax], 6.0; range, 2.0-8.0) and splenomegaly (3.4; 1.2-11.0), with increased metabolism also noted in the marrow (2.1; range, 1.0-3.5) and salivary glands (3.0; range, 2.0-6.0). The (18)F-fluorodeoxyglucose PET abnormalities improved at remission, with significant SUVmax decreases in the lymph nodes (P = .004), spleen (P = .008), marrow (P = .004), and salivary glands (P = .004). Nodal SUVmax correlated with symptom severity (P = .005), C-reactive protein level (R = 0.62; P = .004), and KSHV load (R = 0.54; P = .02) but not HIV load (P = .52).

CONCLUSIONS

KSHV-MCD activity is associated with (18)F-FDG PET abnormalities of the lymph nodes, spleen, marrow, and salivary glands. These findings have clinical implications for the diagnosis and monitoring of KSHV-MCD and shed light on its pathobiologic mechanism.

Current knowledge on HIV-associated Plasmablastic Lymphoma

HIV-associated PBL is an AIDS-defining cancer, classified by WHO as a distinct entity of aggressive DLBCL. To date less than 250 cases have been published, of them 17 are pediatric. The pathogenesis of this rare disease is related to immunodeficiency, chronic immune stimulation and EBV. Clinically is a rapid growing destructive disease mainly involving the oral cavity even if extraoral and extranodal sites are not infrequent. The diagnosis requires tissue mass or lymph node biopsy and core needle or fine needle biopsy is acceptable only for difficult access sites. Classically immunophenotype is CD45, CD20, CD79a negative and CD38, CD138, MUM1 positive, EBER and KI67 is >80%. Regarding the therapy, standard treatment is, usually, CHOP or CHOP-like regimens while more intensive regimens as CODOX-M/IVAC or DA-EPOCH are possible options. Use of cART is recommended during chemotherapy, keeping in mind the possible overlapping toxicities. Rituximab is not useful for this CD20 negative disease and CNS prophylaxis is mandatory. Intensification with ABMT in CR1 may be considered for fit patients. For refractory/relapsed patients, therapy is, usually, considered palliative, however, in chemo-sensitive disease, intensification + ABMT or new drugs as Bortezomib may be considered. Factors affecting outcome are achieving complete remission, PS, clinical stage, MYC, IPI score. Reported median PFS ranges between 6-7 months and median OS ranges between 11-13 months. Long term survivors are reported but mostly in pediatric patients. Finally, due to the scarcity of data on this subtype of NHL we suggest that the diagnosis and the management of HIV-positive PBL patients should be performed in specialized centers.

A semi-automated technique determining the liver standardized uptake value reference for tumor delineation in FDG PET-CT

BACKGROUND

18F-fluorodeoxyglucose (FDG) positron emission tomography (PET)-computed tomography (CT) has been an essential modality in oncology. We propose a semi-automated algorithm to objectively determine liver standardized uptake value (SUV), which is used as a threshold for tumor delineation.

METHODS

A large spherical volume of interest (VOI) was placed manually to roughly enclose the right lobe (RL) of the liver. For each voxel in this VOI, a coefficient of variation of voxel values (CVv) was calculated for neighboring voxels within a radius of d/2. The voxel with the minimum CVv was then selected, where a 30-mm spherical VOI was placed at that voxel in accordance with PERCIST criteria. Two nuclear medicine physicians independently defined 30-mm VOIs manually on 124 studies in 62 patients to generate the standard values, against which the results from the new method were compared.

RESULTS

The semi-automated method was successful in determining the liver SUV that was consistent between the two physicians in all the studies (d = 80 mm). The liver SUV threshold (mean +3 SD within 30-mm VOI) determined by the new semi-automated method (3.12±0.61) was not statistically different from those determined by the manual method (Physician-1: 3.14±0.58, Physician-2: 3.15±0.58). The semi-automated method produced tumor volumes that were not statistically different from those by experts' manual operation. Furthermore, the volume change in the two sequential studies had no statistical difference between semi-automated and manual methods.

CONCLUSIONS

Our semi-automated method could define the liver SUV robustly as the threshold value used for tumor volume measurements according to PERCIST. The method could avoid possible subjective bias of manual liver VOI placement and is thus expected to improve clinical performance of volume-based parameters for prediction of cancer treatment response.