Immune checkpoint inhibition in advanced colorectal cancer with inherited and acquired microsatellite instability: Current state and future directions

OBJECTIVE

This paper reviews comprehensively the most relevant data on single-agent and combination therapies for advanced colorectal cancer with inherited and acquired microsatellite instability (MSI).

DATA SOURCES

We performed a systematic search on PubMed and MEDLINE articles published from inception to December 2022. We have also searched independent websites including U.S. Food and Drug Administration and ClinicalTrials.gov.

DATA SUMMARY

Performing microsatellite stability testing, tumor mutational burden (TMB), and germline mutation analysis could identify patients with metastatic colorectal cancer that benefit from immune checkpoint inhibitor (ICI) therapy. Single-agent pembrolizumab has proven superiority over traditional chemotherapy in these patients. The nivolumab-ipilimumab is the only combination ICI therapy approved in this space. Recently, the anti-PD-1 antibody dostarlimab was granted Food and Drug Administration approval in refractory tissue-agnostic advanced solid cancers with deficient mismatch repair (dMMR). ICIs are also being studied in the adjuvant/neoadjuvant setting in colon cancer patients with dMMR. Newer agents are being scrutinized in this space as well. More solid data on biomarkers predicting responses in patients with MSI-high or TMB-H to various therapies are needed. Given its both clinical and financial toxicity, it is imperative to determine the optimal duration of ICI therapy in individual patients.

CONCLUSIONS

Overall, the outlook in advanced colorectal cancer patients with MSI appears optimistic as new and efficacious ICI drugs and combinations are being added to the existing therapeutic armamentarium.

Advanced uterine papillary serous cancer: Could there be a role for newer targeted therapeutic approaches or immune checkpoint inhibitors?

BACKGROUND

Although now available in oncology clinics, comprehensive germline mutation testing is being performed only in a minority of patients with advanced uterine papillary serous cancer (UPSC). Some of these patients might harbor various targetable mutations, either heritable or acquired.Data sources: We conducted a retrospective cohort study involving all consecutive patients with UPSC treated at our institution from 2009-2019. Data on epidemiology, with an accent on personal and family history of cancer, clinical presentation, disease stage, employed treatment modalities and cancer-specific survival (CSS) was sought.

FINDINGS

Thirteen patients were seventy years of age or younger (≤70) while 15 were older than seventy (>70), and the two arbitrary patient cohorts were well-balanced for the TNM stage. Four UPSC patients >70 had a personal history of metachronous breast cancer. We also identified five cases of breast cancer, two cases of colon cancer, and one of each ovarian and uterine cancer in the first-degree relatives of UPSC patients >70. More than 90% of patients had surgical excision/debulking, and nearly half of the patients in each group received systemic chemotherapy. The most common chemotherapy regimen was carboplatin-paclitaxel every three weeks. Compared to patients ≤70, the UPSC patients >70 were less likely to undergo postoperative radiation therapy (6% vs 61.5%; p = 0.001) and had a worse CSS (21.8 vs. 27.4 months; HR 0.61, p = 0.03).

CONCLUSIONS

Personal and family history in a cohort of older UPSC patients identified an excess of second primary cancers, and these patients displayed a shorter CSS. Comprehensive germline and tumor mutation analysis might identify optimal candidates for various targeted agents and immune checkpoint inhibitors, and ultimately improve survival. This may represent an unmet need in the UPSC patients, and further studies are needed to confirm the significance of our findings.

Merkel cell carcinoma: long-term follow-up of a single institution series and clinical outcomes by immunological status

Merkel cell carcinoma (MCC) usually arises in sun-exposed areas of older patients and might be more aggressive in the immunocompromised. We performed a retrospective chart review of 40 consecutive MCC patients treated at our institution between the years 2006-2017. Clinical and epidemiologic data were utilized and therapy and survival were analyzed. Compared to Surveillance, Epidemiology, and End Results (SEER) data, our population was entirely Caucasian (100% versus 95%; P=0.11) and male predominant (75% versus 63%; P=0.11). The median age was 76. The patients more often had Tumor-Node-Metastasis (TNM) stage I disease (50% versus 39%; P=0.00003) and a primary tumor size <2cm (57.5% versus 34%; P<0.01). They received more frequently lymph node dissection (70% versus 63%, P=0.002) compared with the SEER findings. We identified a subset of immunocompromised patients (n=10) who presented with more stage III disease (40% versus 33%; P=0.021). Time to death averaged 290.1 days in this subset versus 618.2 days (P<0.001) in immunocompetent patients and their likelihood of death was 5 times higher. As clinical outcomes in MCC patients vary by immunological status, a multidisciplinary tumor-board approach may better optimize individual patient management.

Severe left atrial enlargement due to carfilzomib use in multiple myeloma

Several cardiovascular effects have been attributed to carfilzomib in the recent literature. These side effects must be recognized promptly by treating physicians and pharmacists. Special attention is required in patients with pre-existing cardiac conditions, liver function abnormalities and/or advanced age. This is the first report of a severe left atrial enlargement due to carfilzomib use in the setting of multiple myeloma. This condition improved dramatically seven months after cessation of carfilzomib. The authors discuss further various cardiac and vascular abnormalities linked with carfilzomib in the medical literature. Prompt withdrawal of this agent is essential in these cases as it may prevent dismal outcomes.

Bevacizumab in refractory higher-grade and atypical meningioma: the current state of affairs

INTRODUCTION

Historically, systemic agents had shown limited efficacy in meningioma, at the expense of significant pharmacologic and/or financial toxicity. As meningiomas are highly vascularized, they might derive benefit from antiangiogenic therapy.

AREAS COVERED

This review summarizes the literature regarding bevacizumab pharmacology, safety and efficacy in patients with refractory meningioma. We have searched PubMed/Medline database for pertinent articles published from inception to 1 September 2018.

EXPERT COMMENTARY

Results of two prospective phase II trials, supported by several retrospective cohorts, suggest a clinical benefit for the vascular endothelial growth factor inhibitor bevacizumab in meningiomas refractory to surgery and radiation therapy. This agent has a tolerable toxicity profile and seems more effective in higher-grade histologies and atypical meningioma, although responses in low-grade meningiomas have also been documented. Our conclusions are restricted due to a small size and lack of control in the prospective trials as well as the retrospective design of other studies. Further study of bevacizumab in refractory higher-grade meningiomas seems warranted.

Systemic therapy for relapsed/refractory meningioma: Is there potential for antiangiogenic agents?

Effective therapies for relapsed/refractory meningioma after surgery and radiation therapy represent an unmet need. Most meningiomas are highly vascularized tumors and, therefore, potentially amenable to antiangiogenic therapy. Herein, we review comprehensively the scientific literature on systemic therapy options for relapsed, persistent or metastatic meningioma, not amenable to local therapy. Also, this review offers insights into the function of vascular endothelial growth factor/receptor pathway both in health and disease. Further, we address the current status of the preclinical and clinical studies targeting vascular endothelial growth factor/receptor signaling in meningioma. Most relevant publications were identified through searching the PubMed/Medline database for articles published from inception to 1 February 2018. Vascular endothelial growth factor pathway activation might represent the primary driver of angiogenesis in meningioma. Positive findings of two prospective phase II trials, supported by the results of several retrospective cohorts, suggest a clinical benefit for the vascular endothelial growth factor inhibitor bevacizumab in refractory meningioma. Bevacizumab causes both peritumoral brain edema reduction and true meningioma shrinkage. Patients with WHO grades II-III meningioma appear to benefit more than patients with grade I disease. Similarly, responses have been documented with certain oral targeted anti-vascular endothelial growth factor/receptor agents. Further exploration of the role of vascular endothelial growth factor/receptor inhibitors in refractory meningioma seems warranted.

Inferior outcomes in immunocompromised Merkel cell carcinoma patients: Can they be overcome by the use of PD1/PDL1 inhibitors?

Cases of Merkel cell carcinoma have become increasingly more common in the last two decades, and its incidence has been predicted to climb further. Immunosenescence might explain in part the higher Merkel cell carcinoma prevalence in seniors aged 70 and older. This cancer might also be more aggressive in immunocompromised patients. In a subset of immunocompromised Merkel cell carcinoma patients, we identified significant lymphopenia and a more advanced disease stage compared with their immunocompetent counterparts. Time to death in this cohort was much shorter than in immunocompetent subjects, and their likelihood of death from Merkel cell carcinoma was five times higher. Avelumab approval in 2017 represents an important step forward in the therapy of Merkel cell carcinoma. Hopefully, PD1/PDL1 inhibitors will improve survival in immunocompromised Merkel cell carcinoma hosts, traditionally linked with inferior clinical outcomes.

Local Fibrinolysis in Spontaneous Supratentorial Hematomas: Comparison with Surgical and Medical Treatment

OBJECTIVE

To evaluate the effectiveness of minimally invasive craniopuncture with local fibrinolysis in the management of supratentorial spontaneous intracerebral hemorrhage (SICH).

METHODS

The study included 218 consecutive patients with supratentorial SICH who were assigned to one of three groups: treated with minimally invasive craniopuncture with local fibrinolysis, treated with craniotomy or other minimally invasive techniques without local fibrinolysis, or receiving conservative management alone.

RESULTS

Minimally invasive craniopuncture with local fibrinolysis was associated with a lower rate of assisted ventilation, a shorter period of in-hospital stay, a more frequent initiation of early rehabilitation, and a lower mortality rate at all periods of assessment. The overall mortality at 12 months was 19.4% (vs. 50.0 and 33.3% in the two other therapy groups). Lobar (subcortical and cortical) SICHs treated with local fibrinolysis had an overall mortality of 4.8% (vs. 43.5 and 41.7% in the two other therapy groups). On the other hand, SICHs having mixed (basal ganglia and lobar) locations treated with medical therapy alone had an overall mortality of 28.6%, while associated surgery with or without local fibrinolysis increased the overall mortality to over 65%.

CONCLUSIONS

The study demonstrated the applicability of minimally invasive craniopuncture with local fibrinolysis for the management of supratentorial SICHs and the advantages it may have in certain categories of patients. The method proved particularly useful in lobar SICHs, being associated with the lowest mortality. Mixed SICHs do not represent a predilection for surgical interventions; however, the results related to mixed supratentorial locations need confirmation in larger cohorts.

Application of partial volume effect correction and 4D PET in the quantification of FDG avid lung lesions

PURPOSE

The aim of this study is to assess a software-based method with semiautomated correction for partial volume effect (PVE) to quantify the metabolic activity of pulmonary malignancies in patients who underwent non-gated and respiratory-gated 2-deoxy-2-[(18)F]fluoro-D-glucose (FDG)-positron emission tomography (PET)/x-ray computed tomography(CT).

PROCEDURES

The study included 106 lesions of 55 lung cancer patients who underwent respiratory-gated FDG-PET/CT for radiation therapy treatment planning. Volumetric PET/CT parameters were determined by using 4D PET/CT and non-gated PET/CT images. We used a semiautomated program employing an adaptive contrast-oriented thresholding algorithm for lesion delineation as well as a lesion-based partial volume effect correction algorithm. We compared respiratory-gated parameters with non-gated parameters by using pairwise comparison and interclass correlation coefficient assessment. In a multivariable regression analysis, we also examined factors, which can affect quantification accuracy, including the size of lesion and the location of tumor.

RESULTS

This study showed that quantification of volumetric parameters of 4D PET/CT images using an adaptive contrast-oriented thresholding algorithm and 3D lesion-based partial volume correction is feasible. We observed slight increase in FDG uptake by using PET/CT volumetric parameters in comparison of highest respiratory-gated values with non-gated values. After correction for partial volume effect, the mean standardized uptake value (SUVmean) and total lesion glycolysis (TLG) increased substantially (p value <0.001). However, we did not observe a clinically significant difference between partial volume corrected parameters of respiratory-gated and non-gated PET/CT scans. Regression analysis showed that tumor volume was the main predictor of quantification inaccuracy caused by partial volume effect.

CONCLUSIONS

Based on this study, assessment of volumetric PET/CT parameters and partial volume effect correction for accurate quantification of lung malignant lesions by using respiratory non-gated PET images are feasible and it is comparable to gated measurements. Partial volume correction increased both the respiratory-gated and non-gated values significantly and appears to be the dominant source of quantification error of lung lesions.

Oral Coenzyme Q10 supplementation does not prevent cardiac alterations during a high altitude trek to everest base cAMP

Exposure to high altitude is associated with sustained, but reversible, changes in cardiac mass, diastolic function, and high-energy phosphate metabolism. Whilst the underlying mechanisms remain elusive, tissue hypoxia increases generation of reactive oxygen species (ROS), which can stabilize hypoxia-inducible factor (HIF) transcription factors, bringing about transcriptional changes that suppress oxidative phosphorylation and activate autophagy. We therefore investigated whether oral supplementation with an antioxidant, Coenzyme Q10, prevented the cardiac perturbations associated with altitude exposure. Twenty-three volunteers (10 male, 13 female, 46±3 years) were recruited from the 2009 Caudwell Xtreme Everest Research Treks and studied before, and within 48 h of return from, a 17-day trek to Everest Base Camp, with subjects receiving either no intervention (controls) or 300 mg Coenzyme Q10 per day throughout altitude exposure. Cardiac magnetic resonance imaging and echocardiography were used to assess cardiac morphology and function. Following altitude exposure, body mass fell by 3 kg in all subjects (p<0.001), associated with a loss of body fat and a fall in BMI. Post-trek, left ventricular mass had decreased by 11% in controls (p<0.05) and by 16% in Coenzyme Q10-treated subjects (p<0.001), whereas mitral inflow E/A had decreased by 18% in controls (p<0.05) and by 21% in Coenzyme Q10-treated subjects (p<0.05). Coenzyme Q10 supplementation did not, therefore, prevent the loss of left ventricular mass or change in diastolic function that occurred following a trek to Everest Base Camp.

Prevalence and Pattern of Autoimmune Conditions in Patients with Marginal Zone Lymphoma: A Single Institution Experience

BACKGROUND

Increased risk of B-cell non-Hodgkin lymphoma (NHL) in patients with autoimmune diseases is a known fact. An association may exist between marginal zone lymphoma (MZL) and certain autoimmune conditions and vice-versa.

METHODS

Herein, we present the analysis of a series of consecutive patients (n = 24) diagnosed with MZL at our institution between 2008-2014. Our series, analyzed both retrospectively and prospectively, consisted of a blend of nodal, extranodal and splenic MZL. The median age was 71.8 years; M/F ratio was 2:1. The presence of autoimmune conditions was compared to their documented prevalence in the general population and tested for statistical significance using both chi-square test (χ2) and Fisher test for small number of observations (95% confidence). A P-value < 0.05 was considered significant.

FINDINGS

A total of 50% of MZL patients had documented autoimmune conditions. In addition, 3 of 24 patients presented with more than one autoimmune disease. Statistically significant differences in our MZL patients were recorded for immune thrombocytopenia [ITP] (P < 0.01), autoimmune hemolytic anemia [AIHA] (P < 0.01), Hashimoto thyroiditis (P = 0.037) and rheumatoid arthritis [RA] (P = 0.021). The difference did not reach statistical significance for systemic lupus erythematosus (SLE) and psoriasis. ITP and AIHA in our cohort were synchronous with MZL diagnosis in all patients, while all non-hematologic autoimmune conditions were metachronous and diagnosed prior to MZL.

CONCLUSIONS

In the course of caring for patients with MZL, a number of associated autoimmune disorders are recognized. Knowing these entities is important not only for making a correct diagnosis, but also for being able to recognize certain clinical events occurring during the course of the disease. A catalogue of autoimmune disorders associated with this type of NHL is important as they can pose formidable clinical problems for the MZL patients and their physicians.

Growing applications of FDG PET-CT imaging in non-oncologic conditions

As the number of clinical applications of 2-[fluorine 18]fluoro-2-deoxy-D-glucose (FDG) positron emission tomography/computed tomography (PET-CT) grows, familiarity with the conditions that can be diagnosed by this modality and when relevant pieces of additional information can be obtained becomes increasingly important for both requesting physicians and nuclear medicine physicians or radiologists who interpret the findings. Apart from its heavy use in clinical oncology, FDG PET-CT is widely used in a variety of non-oncologic conditions interconnecting to such disciplines as general internal medicine, infectious diseases, cardiology, neurology, surgery, traumatology, orthopedics, pediatrics, endocrinology, rheumatology, psychiatry, neuropsychology, and cognitive neuroscience. The aim of this review was to summarize the current evidence of FDG PET-CT applications in evaluating non-oncologic pathologies and the relevant information it can add to achieve a final diagnosis.

Operated bronchial carcinoids: clinical outcomes and long-term follow-up of a single institution series of 30 patients

BACKGROUND

Bronchial carcinoids (BCs) are infrequent neoplasms that account for only 1% to 2% of all lung tumors. We reviewed the outcomes and long-term follow-up data of all patients diagnosed with BC and treated surgically at our institution between the years 2002-2009.

PATIENTS AND METHODS

We analyzed the records of all patients with BC treated between January 1, 2002 and December 31st, 2009. The results were subsequently compared with the previously published data.

RESULTS

Our records identified a total of 28 patients with typical carcinoids (TC) and two patients with atypical carcinoids (AC). Of these, 22 were women and eight were men with a median age of 62 (range, 23-91 years). About two-thirds of patients were symptomatic at presentation. Central and peripheral tumor location was encountered with equal frequency, with 63.3% of tumors being located in the right lung. Bronchoscopic biopsy revealed the diagnosis in 92.3% of cases. Twenty percent of patients underwent lung sparing procedures, 73.3% underwent lobectomies, and 6.7% had pneumonectomies. Mediastinal lymphadenectomy was performed in all patients. Two patients had positive nodal metastases, one of whom survived for only 10 months. Tumor recurrence was noted in two patients with TC (7.14%) and in one patient with AC. The overall five-year survival was 90% (27/30) for the entire cohort.

CONCLUSIONS

Histological characteristics and nodal status probably represent the most important prognostic factors in persons with operated BCs. The female prevalence recorded in our cohort appears to contrast with previously reported almost equal gender distribution. The slightly lower percentage of lung-sparing procedures in our patients could be explained by their more advanced disease state, with tumor extension to more than one lung lobe.

Minimal lymphatic leakage in an infant with chylothorax detected by lymphoscintigraphy SPECT/CT

A 7-month-old girl with history of persistent left chylous pleural effusion was referred for lymphoscintigraphy. A previous chest computed tomography (CT) scan demonstrated a small to moderate-sized left pleural effusion but could not identify the lymphatic leakage site. Lymphoscintigraphy using filtered (99m)Tc sulfur colloid showed minimal focal activity in the lower chest. A correlative single-photon emission computed tomography (SPECT)/CT localized this activity to distal paraesophageal region, being highly suggestive of the site of lymphatic leakage. Subsequent lymphangiography confirmed these findings, revealing an abnormal lymphatic branch at the level of T10 and T11 vertebrae with retrocrural extravasation toward the left hemithorax. Thoracic duct embolization was accomplished at and proximal to the site of chyle leak using a platinum coil and n-Butyl cyanoacrylate glue. The patient was followed up for >24 months and demonstrated no recurrence of pleural effusion. No ascites or other complications related to the procedure were noted. The case demonstrates that (99m)Tc sulfur colloid lymphoscintigraphy SPECT/CT can be a useful modality for detecting the chyle leakage site in children with chylothorax even when the amount of leakage is minimal.

Details of left ventricular radial wall motion supporting the ventricular theory of the third heart sound obtained by cardiac MR

OBJECTIVE

Obtaining new details of radial motion of left ventricular (LV) segments using velocity-encoding cardiac MRI.

METHODS

Cardiac MR examinations were performed on 14 healthy volunteers aged between 19 and 26 years. Cine images for navigator-gated phase contrast velocity mapping were acquired using a black blood segmented κ-space spoiled gradient echo sequence with a temporal resolution of 13.8 ms. Peak systolic and diastolic radial velocities as well as radial velocity curves were obtained for 16 ventricular segments.

RESULTS

Significant differences among peak radial velocities of basal and mid-ventricular segments have been recorded. Particular patterns of segmental radial velocity curves were also noted. An additional wave of outward radial movement during the phase of rapid ventricular filling, corresponding to the expected timing of the third heart sound, appeared of particular interest.

CONCLUSION

The technique has allowed visualization of new details of LV radial wall motion. In particular, higher peak systolic radial velocities of anterior and inferior segments are suggestive of a relatively higher dynamics of anteroposterior vs lateral radial motion in systole. Specific patterns of radial motion of other LV segments may provide additional insights into LV mechanics.

ADVANCES IN KNOWLEDGE

The outward radial movement of LV segments impacted by the blood flow during rapid ventricular filling provides a potential substrate for the third heart sound. A biphasic radial expansion of the basal anteroseptal segment in early diastole is likely to be related to the simultaneous longitudinal LV displacement by the stretched great vessels following repolarization and their close apposition to this segment.

Effects of ventricular insertion sites on rotational motion of left ventricular segments studied by cardiac MR

OBJECTIVE

Obtaining new details for rotational motion of left ventricular (LV) segments using velocity encoding cardiac MR and correlating the regional motion patterns to LV insertion sites.

METHODS

Cardiac MR examinations were performed on 14 healthy volunteers aged between 19 and 26 years. Peak rotational velocities and circumferential velocity curves were obtained for 16 ventricular segments.

RESULTS

Reduced peak clockwise velocities of anteroseptal segments (i.e. Segments 2 and 8) and peak counterclockwise velocities of inferoseptal segments (i.e. Segments 3 and 9) were the most prominent findings. The observations can be attributed to the LV insertion sites into the right ventricle, limiting the clockwise rotation of anteroseptal LV segments and the counterclockwise rotation of inferoseptal segments as viewed from the apex. Relatively lower clockwise velocities of Segment 5 and counterclockwise velocities of Segment 6 were also noted, suggesting a cardiac fixation point between these two segments, which is in close proximity to the lateral LV wall.

CONCLUSION

Apart from showing different rotational patterns of LV base, mid ventricle and apex, the study showed significant differences in the rotational velocities of individual LV segments. Correlating regional wall motion with known orientation of myocardial aggregates has also provided new insights into the mechanisms of LV rotational motions during a cardiac cycle.

ADVANCES IN KNOWLEDGE

LV insertion into the right ventricle limits the clockwise rotation of anteroseptal LV segments and the counterclockwise rotation of inferoseptal segments adjacent to the ventricular insertion sites. The pattern should be differentiated from wall motion abnormalities in cardiac pathology.

Western variant of brain intravascular lymphoma displaying three distinct evolutive radiologic stages

Intravascular lymphoma is a rare type of extranodal diffuse large B-cell lymphoma characterized by proliferation of clonal lymphocytes within small- and medium-sized blood vessels and a relative sparing of surrounding tissues. It commonly affects the central nervous system (CNS), but its atypical presentation often leads to a delayed diagnosis. We report a unique case of a 53-year-old man presenting with confusion and ataxic gait. The initial magnetic resonance imaging (MRI) of the brain showed multifocal plaque-like CNS lesions suggestive of multiple sclerosis. His condition worsened rapidly, accompanied by persistent low-grade fever and further alteration in mental status. Follow-up MRI studies suggested new parenchymal brain lesions consistent with multiple evolving embolic strokes and subsequently with brain infarcts. Biopsy showed intravascular lymphomatous brain involvement. His condition continued to deteriorate, resulting in multiorgan failure and demise. To the best of our knowledge, these clear-cut MRI stages of brain intravascular lymphoma have not been previously reported in the scientific literature. Our findings are important as the diagnosis intravascular lymphoma is commonly made postmortem, given its rapidly progressive course and lack of typical symptomatology.

Normal values of regional and global myocardial wall motion in young and elderly individuals using navigator gated tissue phase mapping

The purpose of this study was to evaluate normal values for regional and global myocardial wall motion parameters in young and elderly individuals, as detected by navigator gated high temporal resolution tissue phase mapping. Radial, longitudinal and circumferential ventricular wall motion, as well as ventricular torsion and longitudinal strain rates, were assessed in two age groups of volunteers, 23 ± 3 (n = 14) and 66 ± 7 years old (n = 9), respectively. All subjects were healthy, non-smokers without known cardiac disease. An increased global left ventricular (LV) torsion rate (peak systolic torsion rate 20.6 ± 2.0 versus 14.5 ± 1.0°/s/cm, peak diastolic torsion rate -25.2 ± 1.8 versus -14.1 ± 1.3°/s/cm) and a decrease in longitudinal LV motion (peak systolic values at mid-ventricle 5.9 ± 0.5 versus 8.5 ± 0.8 cm/s, peak diastolic values -10.7 ± 0.7 versus -15.2 ± 0.9 cm/s) in the older age group were the most prominent findings. Lower peak diastolic radial velocities with a longer time-to-peak values, most pronounced at the apex, are consistent with reduced diastolic function with ageing. Lower peak clockwise and counter-clockwise velocities at all LV levels revealed limitations in resting LV rotational motions in the older group. Significant changes in the undulating pattern of the rotational motions of the left ventricle were also observed. The results demonstrate distinct changes in regional and global myocardial wall motion in elderly individuals. Increased LV torsion rate and reduced LV longitudinal motion were particularly prominent in the older group. These parameters may have a role in the assessment of global LV contractility and help differentiate age-related changes from cardiac disease.

Beta-cell imaging: call for evidence-based and scientific approach

INTRODUCTION

Advances in positron emission tomography (PET) imaging have provided opportunities to develop radiotracers specific for imaging insulin-producing pancreatic β-cells. However, a host of lingering questions should be addressed before these radiotracers are advocated for noninvasive quantification of β-cell mass (BCM) in vivo in the native pancreas.

METHOD

We provide an overview of tetrabenazine-based PET tracers developed to image and quantify BCM and discuss several theoretical, technical, and biological limitations of applying these tracers in clinical practice.

DISCUSSION

VMAT2, a transporter protein expressed on pancreatic β-cells, has been advocated as a promising target for PET imaging tracers, such as dihydrotetrabenazine. However, the lack of radiotracer specificity for these proteins hampers their clinical application. Another important argument against their use is a striking discrepancy between radiotracer uptake and BCM in subjects with type I diabetes mellitus and healthy controls. Additionally, technical issues, such as the finite spatial resolution of PET, partial volume effects, and movement of the pancreas during respiration, impede PET imaging as a viable option for BCM quantification in the foreseeable future.

CONCLUSION

The assertion that BCM can be accurately quantified by tetrabenazine derived β-cell-specific radiotracers as density per unit volume of pancreatic tissue is not justifiable at this time. The fallacy of these claims can be explained by technical as well as biological facts that have been disregarded and ignored in the literature.

Mediastinal choriocarcinoma presenting with syncope

Mediastinal choriocarcinomas are rare germ-cell tumors that occur almost exclusively in young males. These tumors grow rapidly, causing compression of mediastinal structures, and are usually associated with a poor prognosis. We report herein a unique case documenting syncope as initial clinical presentation of a mediastinal choriocarcinoma causing a superior vena cava (SVC) syndrome. The patient was treated with a standard chemotherapy triplet, with normalization of the tumor markers after the first chemotherapy cycle. He remains with no evidence of disease relapse 18 months later. Clinicians should consider the diagnosis of a mediastinal germ-cell tumor in a younger male patient presenting with a syncopal episode.

Gastrointestinal stromal tumor of small intestine and synchronous bilateral papillary renal cell carcinoma

Association of gastrointestinal stromal tumors (GISTs) with other primary malignant neoplasms has previously been reported. In addition, coexistence of unilateral renal cell cancer and a GIST of the stomach has been documented in the literature. We report herein a unique case of a GIST of the small intestine and bilateral papillary renal cell carcinomas in a patient presenting with melena and dizziness. Literature shows that GIST arising from the small intestine is the most common location of GIST accompanied by a second primary neoplasm. However, a unique feature in our GIST patient is the presence of synchronous (bilateral) papillary renal cell carcinomas.

Prevalence of autoimmune conditions in patients with Waldenstrom macroglobulinemia: Exploratory analysis of a series of consecutive patients

e19514

Background: Literature suggests association between Waldenström macroglobulinemia (WM) and autoimmune conditions which may share the same pathogenesis. We identified the prevalence of autoimmune phenomena in WM patients and compared it with the general population. Methods: We conducted retrospective and prospective analyses in a series of patients (n=12) with WM followed in outpatient setting. The median age was 74 years. The charts were reviewed for autoimmune abnormalities; length of prospective analysis segment was circa 24 months. The prevalence of autoimmune disorders was compared with the general population. Statistical analysis: Findings were tested for statistical significance using Fisher’s exact test for small number of observations (95% confidence); p value < 0.05 considered significant. Results: Circa 58.3% patients had autoimmune disorders (Table). These include Hashimoto thyroiditis, pernicious anemia, immune thrombocytopenia (ITP), autoimmune hemolytic anemia (AIHA), chronic inflammatory demyelinating polyneuropathy (CIDP), pure red cell aplasia (PRCA), polymyalgia rheumatica (PMR), temporal arteritis, and ANA positivity. The Table summarizes the statistical analysis of each autoimmune condition with their respective p values. Conclusions: More than 50% of patients had autoimmune conditions, significantly exceeding overall prevalence in general population. Statistically significant differences noted for pernicious anemia, Hashimoto thyroiditis, ITP, AIHA, CIDP, PRCA, and temporal arteritis. The difference was not significant for PMR and ANA positivity. However, analysis of larger cohorts is needed to confirm our observations. [Table: see text]

Effects of the frame acquisition rate on the sensitivity of gastro-oesophageal reflux scintigraphy

OBJECTIVE

To compare the sensitivity of gastro-oesophageal reflux (GOR) scintigraphy at 5-s and 60-s frame acquisition rates.

METHODS

GOR scintigraphy of 50 subjects (1 month-20 years old, mean 42 months) were analysed concurrently using 5-s and 60-s acquisition frames. Reflux episodes were graded as low if activity was detected in the distal half of the oesophagus and high if activity was detected in its upper half or in the oral cavity. For comparison purposes, detected GOR in any number of 5-s frames corresponding to one 60-s frame was counted as one episode.

RESULTS

A total of 679 episodes of GOR to the upper oesophagus were counted using a 5-s acquisition technique. Only 183 of such episodes were detected on 60-s acquisition images. To the lower oesophagus, a total of 1749 GOR episodes were detected using a 5-s acquisition technique and only 1045 episodes using 60-s acquisition frames (these also included the high-level GOR on 5-s frames counted as low level on 60-s acquisition frames). 10 patients had high-level GOR episodes that were detected only using a 5-s acquisition technique, leading to a different diagnosis in these patients. No correlation between the number of reflux episodes and the gastric emptying rates was noted.

CONCLUSION

The 5-s frame acquisition technique is more sensitive than the 60-s frame acquisition technique for detecting both high- and low-level GOR.

ADVANCES IN KNOWLEDGE

Brief GOR episodes with a relatively low number of radioactive counts are frequently indistinguishable from intense background activity on 60-s acquisition frames.

Neuroblastoma with a solitary intraventricular brain metastasis visualized on I-123 MIBG scan

BACKGROUND

Although metastatic skull lesions of neuroblastoma are not uncommon, brain involvement is infrequent and prompt diagnosis is of utmost importance in such cases. Previous studies have shown that Meta-Iodo-Benzyl-Guanidine (MIBG) scans were not always reliable in detecting central nervous system metastases, however most published reports referred to the Iodine-131 ((131)I)-MIBG scans. Herein, we report an intraventricular metastasis of neuroblastoma diagnosed using an Iodine-123 ((123)I)-MIBG scan, which is increasingly being used in clinical practice and reported as a more accurate method for detecting metastatic lesions.

CASE DESCRIPTION

An unusual case of metastatic neuroblastoma to the left lateral ventricle of the brain is presented. Planar (123)I-MIBG scintigraphy showed faint tracer activity close to the midline without asymmetric extensions or abnormal activity in the skull bones. A subsequent brain MR scan revealed an enhancing mass within the left frontal horn consistent with a metastatic lesion. The patient underwent tumor resection with pathology showing neuroblastoma.

CONCLUSIONS

Our case shows that (123) I-MIBG scintigraphy can be useful in detecting intraventricular brain metastases of neuroblastoma. Although the (123)I-MIBG scintigraphy has been reported to have a significantly superior sensitivity in monitoring asymptomatic patients with neuroblastoma compared with (131)I-MIBG scans, bone marrow histology, bone scan, CT, and urinary catecholamine levels, further studies may be necessary to evaluate its sensitivity in detecting brain lesions.

Brain single-photon emission computed tomography in fetal alcohol syndrome: a case report and study implications

The indications of brain single-photon emission computed tomography (SPECT) in fetal alcohol syndrome are not clearly defined, even though the condition is recognized as one of the most common causes of mental retardation. This article reports a case of a 9-year-old adopted girl with developmental delay, mildly dysmorphic facial features, and behavioral and cognitive abnormalities. Extensive investigations including genetic studies and brain magnetic resonance imaging (MRI) revealed no abnormalities, and a diagnosis of fetal alcohol syndrome was considered since official diagnostic criteria were met. A brain SPECT was requested and showed severely decreased tracer activity in the thalami, basal ganglia, and temporal lobes on both sides, the overall findings being consistent with the established diagnosis of fetal alcohol syndrome. With increasing availability of functional brain imaging, the study indications and possible ethical implications in suspected prenatal alcohol exposure or even before adoption need further consideration. In this patient, SPECT was the only test to yield positive results.

Monostotic Paget's disease involving the calcaneus encountered incidentally on bone scintigraphy

Isolated involvement of calcaneus with Paget's disease of bone is highly unusual, with very few cases reported in the world literature. We present herein a unique 69-year-old male patient with monostotic Paget's disease of the left calcaneus discovered incidentally during a whole body bone scintigraphy. Since most bone scans are performed for evaluating osseous metastases, differentiating Paget's disease from overlapping metastases may be of significant clinical value. We discuss further the importance of whole body bone scan and other imaging modalities in establishing the correct diagnoses in such cases.

Prevalence of autoimmune conditions in patients with marginal zone lymphoma: Exploratory analysis of a series of consecutive patients

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Background: Recent literature suggests that an association exists between marginal zone lymphoma (MZL) and certain autoimmune conditions. Furthermore, MZL and autoimmune diseases may share same pathogenesis in these patients. The present study was set to identify the prevalence of autoimmune phenomena in MZL patients and compare it with same in general population. Methods: We conducted both retrospective and prospective analyses in a series of consecutive patients (n=24) with MZL that had been followed in outpatient setting. Median age was 71.8 years (range, 50-96). Records were reviewed for the presence of autoimmune abnormalities; length of the prospective analysis segment was ~24 months. Prevalence of autoimmune disorders in our cohort was compared to their respective prevalence in general population. Statistical analysis: The obtained values were tested for statistical significance using Fisher’s exact test for small number of observations (95% confidence); a p-value < 0.05 was considered significant. Results: A total of 50% patients included in our study had documented autoimmune conditions. Identified autoimmune disorders included Hashimoto thyroiditis (n=5), immune thrombocytopenia [ITP] (n=4), rheumatoid arthritis [RA] (n=1), Raynaud's phenomena (n=1), psoriasis (n=1), and autoimmune hemolytic anemia [AIHA] (n=1). Statistical analysis showed the following significance: Hashimoto thyroiditis (p=0.037), ITP (p<0.01), AIHA (p<0.01), RA(p=0.351), psoriasis (p=0.479), and Raynaud's phenomena (p=0.666). Conclusions: Circa half of MZL patients also have autoimmune conditions, thus significantly exceeding the overall prevalence in general population. Statistically significant differences in our MZL patients were recorded for Hashimoto thyroiditis, ITP, and AIHA. When compared to the prevalence in general population, the difference did not reach statistical significance for RA, psoriasis, and Raynaud's phenomena. However, this may be related to the relatively small size of the analyzed cohort. Therefore, larger studies would be useful before definitive conclusions can be drawn.

Prevalence of autoimmune manifestations in patients with large granular lymphocytic leukemia: Exploratory analysis of a series of consecutive patients

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Background: Review of literature suggests certain autoimmune abnormalities to accompany LGL leukemia. The present study was set to identify the prevalence of autoimmune phenomena in LGL leukemia patients and compare it with same in general population. Methods: We conducted both retrospective and prospective analyses in a series of consecutive patients (n=11) with LGL leukemia that had been followed in outpatient setting. Median age was 71 years ( ± 14 years). The presence of associated autoimmune disorders in our cohort was compared to the published prevalence of these conditions in general population. Statistical analysis: The obtained values were tested for statistical significance using Fisher’s exact test for small number of observations (95% confidence); a p value < 0.05 was considered significant. Results: A total of 45% patients in our study were diagnosed with autoimmune conditions. Identified autoimmune disorders included rheumatoid arthritis [RA] (n=3), Hashimoto thyroiditis (n=3), Felty syndrome (n=1), aplastic anemia (n=1), pernicious anemia (n=1), and leukocytoclastic vasculitis (n=1). Statistical analysis showed the following significance: Hashimoto thyroiditis (p=0.044), RA (p=0.003), Felty syndrome (p<0.001), aplastic anemia (p<0.001), pernicious anemia (p<0.001), and leukocytoclastic vasculitis (p<0.001). Statistical difference was also noted for autoimmune serologic abnormalities, with ANA positivity present in 63.6% of the cases (p< 0.001) and RF present in 50% of the patients (p=0.005). Conclusions: Nearly half of LGL leukemia patients in our cohort had autoimmune conditions, thus significantly exceeding the overall prevalence in general population. Statistically significant differences were recorded for RA, Hashimoto thyroiditis, Felty syndrome, aplastic anemia, pernicious anemia, leukocytoclastic vasculitis, ANA and RF positive serologies. The prevalence of Hashimoto thyroiditis and ANA positivity in our patient cohort was significantly higher than the one in existing literature. Given the relatively small size of the analyzed cohort, larger studies are expected to confirm our findings.

Persistent polyclonal B-cell lymphocytosis in chronic smokers: more than meets the eye

BACKGROUND

Persistent neutrophiliais awell-recognized phenomenon in some chronic cigarette smokers. In contrast, persistent polyclonal B-cell lymphocytosis (PPBL) is considered a rare entity affecting this patient population.

METHODS

We analyzed a cohort of 21 patients with chronic smoking histories presenting with persistent leukocytosis. None of the patients was on steroids, lithium preparations, or other medications known to increase the white blood cell (WBC) counts. We excluded any myeloproliferative or lymphoproliferative conditions in our patient cohort. WBC differential was obtained during repeated visits and the mean values calculated. The results were subsequently compared to known upper normal limits and tested for statistical significance.

RESULTS

The absolute leukocyte count in our cohort was 17.8 +/- 3.2 x 10(9)/L and the absolute neutrophil count was 12.0 +/- 2.8 x 10(9)/L. The difference proved statistically significant for both values when compared to upper normal limits (P < 0.001). Six patients (five females and one male) were also found to have a significant and persistent lymphocytosis at 5.1 +/- 0.5 x 10(9)/L (P < 0.001).

CONCLUSIONS

We have identified the presence of -29% PPBL cases in a series of consecutive patients with persistent leukocytosis/neutrophilia related to chronic cigarette smoking. Similar to the results obtained by other investigators, our PPBL patients showed a younger female predominance. Given the findings in our cohort, we believe that PPBL might be more common than previously thought and discuss further its potential implications for general and specialty practice.

Fluorodeoxyglucose-induced allergic reaction: A case report

The number of diagnostic positron emission tomography/computed tomography (PET/CT) procedures performed in the USA and worldwide is rapidly increasing. Although the benefits of these procedures are obvious, the increasing use of radiopharmaceuticals requires a better understanding of potential adverse affects and their proper management. We present herein the first report of an allergic reaction to fluorodeoxyglucose in the setting of repeated PET/CT scans for restaging purposes in a patient with pyriform sinus cancer.

Details of left ventricular remodeling and the mechanism of paradoxical ventricular septal motion after coronary artery bypass graft surgery

OBJECTIVE

The purpose of this study was to obtain new details of three-dimensional left ventricular wall motion related to ventricular remodeling in patients undergoing coronary artery bypass graft (CABG) surgery.

METHODS

Cardiac-gated, phase-contrast measurements using navigator-gated, high temporal resolution, tissue phase mapping were obtained on 19 patients (66 ± 7 years old) before and after CABG. Left ventricular motion patterns and myocardial velocities were recorded for radial, circumferential and longitudinal motion. Radial, circumferential and longitudinal velocity curves were obtained separately for 16 ventricular segments. Ventricular torsion rate and longitudinal strain rate were also derived pre- and post-surgery.

RESULTS

After CABG, there was a significant improvement in apical contraction, with an apparent paradoxical decrease in the radial inward motion of the septal segments at the left ventricular base. Despite improved ventricular contractility during systole, peak longitudinal and rotational velocities decreased or showed no significant changes. An altered pattern of rotational motion with decreased initial counter-clockwise rotation at the beginning of systole and subsequent lower amplitude of reversed motions in diastole was also noted in most left ventricular segments. Lower peak clockwise rotational velocities were recorded in the basal anteroseptal segment with relatively higher values in the rest of the basal segments.

CONCLUSION

Our results suggest that post-operative changes after CABG are limiting ventricular rotational and longitudinal motions, despite an increase in ventricular contractility due to revascularization. At the ventricular base, the restrained rotational motion of basal anteroseptal segment, located proximally to the right ventricular insertion, and higher rotational velocities of the rest of the segments are pushing the septum toward the right ventricle during ventricular twisting. At the ventricular apex, the restrain in rotational motion caused by post-operative adhesions is affecting all apical segments due to a much smaller left ventricular diameter at this level. The rotating apex and the apical septum are similarly displaced toward the right ventricle during ventricular twisting.

Chasing the reflected wave back into the heart: a new hypothesis while the jury is still out

Background:

Arterial stiffness directly influences cardiac function and is independently associated with cardiovascular risk. However, the influence of the aortic reflected pulse pressure wave on left ventricular function has not been well characterized. The aim of this study was to obtain detailed information on regional ventricular wall motion patterns corresponding to the propagation of the reflected aortic wave on ventricular segments.

Methods:

Left ventricular wall motion was investigated in a group of healthy volunteers (n = 14, age 23 ± 3 years), using cardiac magnetic resonance navigator-gated tissue phase mapping. The left ventricle was divided into 16 segments and regional wall motion was studied in high temporal detail.

Results:

Corresponding to the expected timing of the reflected aortic wave reaching the left ventricle, a characteristic “notch” of regional myocardial motion was seen in all radial, circumferential, and longitudinal velocity graphs. This notch was particularly prominent in septal segments adjacent to the left ventricular outflow tract on radial velocity graphs and in anterior and posterior left ventricular segments on circumferential velocity graphs. Similarly, longitudinal velocity graphs demonstrated a brief deceleration in the upward recoil motion of the entire ventricle at the beginning of diastole.

Conclusion:

These results provide new insights into the possible influence of the reflected aortic waves on ventricular segments. Although the association with the reflected wave appears to us to be unambiguous, it represents a novel research concept, and further studies enabling the actual recording of the pulse wave are required.

Normobaric hypoxia impairs human cardiac energetics

Hypoxia causes left ventricular dysfunction in the human heart, but the biochemical mechanism is poorly understood. Here, we tested whether short-term normobaric hypoxia leads to changes in cardiac energetics and early cardiac dysfunction. Healthy male volunteers (n=12, age 24 ± 2 yr) were exposed to normobaric hypoxia in a purpose-built hypoxic chamber. The partial pressure of oxygen during end-tidal expiration (P(ET)o₂) was kept between 50 and 60 mmHg, and peripheral oxygen saturation (Sao₂) was kept above 80%. Cardiac morphology and function were assessed using magnetic resonance imaging and echocardiography, both before and after 20 h of hypoxic exposure, and high-energy phosphate metabolism [measured as the phosphocreatine (PCr)/ATP ratio] was measured using ³¹P magnetic resonance spectroscopy. During hypoxia, P(ET)o₂ and Sao₂ averaged 55 ± 1 mmHg and 83.6 ± 0.4%, respectively. Hypoxia caused a 15% reduction in cardiac PCr/ATP (from 2.0 ± 0.1 to 1.7 ± 0.1, P<0.01) and reduced diastolic function (measured as E/E', rising from 6.1 ± 0.4 to 7.5 ± 0.7, P<0.01). Normobaric hypoxia causes a rapid decrease in high-energy phosphate metabolism in the human cardiac left ventricle, which may lead to a decline in diastolic function. These findings are important in understanding the response of normal individuals to environmental hypoxia, and to situations in which disease reduces cardiac oxygen delivery.