Extragonadal Germ Cell Tumor with Hepatic Infiltration in a Child: Aberrant Somatostatin Receptors and the Diagnostic Conundrum.

Extragonadal germ cell tumors (GCTs) are challenging to diagnose. We present a case of suprarenal GCT, with hepatic infiltration where differential diagnosis included neuroblastoma and hepatoblastoma. The positive positron emission tomography scan further obfuscated the situation. The diagnosis was clinched by fine-needle aspiration cytology and cell block immunohistochemistry.

[68Ga]Ga-Pentixafor PET/CT imaging for in vivo CXCR4 receptor mapping in different lung cancer histologic sub-types: correlation with quantitative receptors' density by immunochemistry techniques.

PURPOSE: In vivo CXCR4 receptor quantification in different lung cancer (LC) sub-types using [68Ga]Ga-Pentixafor PET/CT and to study correlation with quantitative CXCR4 receptors' tissue density by immunochemistry analyses. METHODS: [68Ga]Ga-Pentixafor PET/CT imaging was performed prospectively in 94 (77 M: 17F, mean age 60.1 ± 10.1 years) LC patients. CXCR4 receptors' expression on lung mass in all the patients was estimated by immunohistochemistry (IHC) and fluorescence-activated cell sorting (FACS) analyses. SUVmax on PET, intensity score on IHC, and mean fluorescence index (MFI) on FACS analyses were measured. RESULTS: A total of 75/94 (79.8%) cases had non-small cell lung cancer (NSCLC), 14 (14.9%) had small cell lung cancer (SCLC), and 5 (5.3%) had lung neuroendocrine neoplasm (NEN). All LC types showed increased CXCR4 expression on PET (SUVmax) and FACS (MFI). However, both these parameters (mean SUVmax = 10.3 ± 5.0; mean MFI = 349.0 ± 99.0) were significantly (p = 0.005) higher in SCLC as compared to those in NSCLC and lung NEN. The mean SUVmax in adenocarcinoma (n = 16) was 8.0 ± 1.9 which was significantly (p = 0.003) higher than in squamous cell carcinoma (n = 54; 6.2 ± 2.1) and in not-otherwise specified (NOS) sub-types (n = 5; 5.8 ± 1.5) of NSCLC. A significant correlation (r = 0.697; p = 001) was seen between SUVmax and MFI values in squamous cell NSCLC as well as in NSCLC adenocarcinoma (r = 0.538, p = 0.031) which supports the specific in vivo uptake of [68Ga]Ga-Pentixafor by CXCR4 receptors. However, this correlation was not significant in SCLC (r = 0.435, p = 0.121) and NEN (r = 0.747, p = 0.147) which may be due to the small sample size. [68Ga]Ga-Pentixafor PET/CT provided good sensitivity (85.7%) and specificity (78.1%) for differentiating SCLC from NSCLC (ROC cutoff SUVmax = 7.2). This technique presented similar sensitivity (87.5%) and specificity (71.4%) (ROC cutoff SUVmax = 6.7) for differentiating adenocarcinoma and squamous cell variants of NSCLC. CONCLUSION: The high sensitivity and specificity of [68Ga]Ga-Pentixafor PET/CT for in vivo targeting of CXCR4 receptors in lung cancer can thus be used effectively for the response assessment and development of CXCR4-based radioligand therapies in LC.

Primary leiomyosarcoma of the parotid gland: Aspiration cytology with emphasis on differential diagnosis.

Most salivary gland neoplasms are of epithelial origin. Sarcomas of the parotid gland, including leiomyosarcoma, are exceedingly rare mesenchymal tumours. A definitive diagnosis of leiomyosarcoma is challenging on cytomorphology alone. We herein describe a case of a 41-year-old woman who presented with parotid gland swelling. The patient was previously diagnosed with leiomyosarcoma of the parotid gland on histopathology. Fine needle aspiration cytology was done from this recurrent swelling. Cytomorphology combined with cell block immunocytochemistry was fruitful in confirming the tumour recurrence. Primary and recurrent/metastatic leiomyosarcoma of the parotid gland is a rarity and cannot be distinguished on cytology. Such a distinction is based on the known history of prior malignancy, which was forthcoming in the present case, or after an exhaustive work-up. Pertinent clinical history and radiology provide leads for the cytopathologist. They must be sought so that immunocytochemistry can be applied judiciously and a precise/nearly precise cytological diagnosis rendered, as it guides patient management. The diagnosis is challenging on cytology as the spindle cell lesions of the parotid gland range from reactive to benign to malignant tumours.

Safety and Diagnostic Yield of 68Ga Prostate-specific Membrane Antigen PET/CT-guided Robotic-assisted Transgluteal Prostatic Biopsy.

Background Transrectal US-guided biopsy with or without MRI fusion is performed for diagnosing prostate cancer (PCa) but has limitations. Gallium 68 (68Ga) prostate-specific membrane antigen (PSMA) PET/CT-guided targeted biopsy has the potential to improve diagnostic yield of PCa. Purpose To evaluate the safety and diagnostic yield of 68Ga PSMA PET/CT-guided, robotic-arm assisted transgluteal prostatic biopsy. Materials and Methods In this single-center nonrandomized prospective trial, participants with a clinical suspicion of PCa (serum prostate-specific antigen level > 4 ng/mL) were recruited from January 2019 to September 2020. After whole-body 68Ga PSMA PET/CT, participants with PSMA-avid intraprostatic lesions underwent PET-guided transgluteal biopsy by using an automated robotic arm. To assess safety and diagnostic yield, procedure-related complications and histopathologic results were documented. Pain during the procedure was scored by a visual analog scale. Descriptive statistics were applied; qualitative variables were reported in percentages. Results Seventy-eight participants (mean age, 66 years ± 7 [standard deviation]; 36 participants [46%] with prior negative results at transrectal US-guided biopsy) were enrolled. Fifty-six (72%) participants had PSMA-avid lesions (prior negative results at transrectal US-guided biopsy in 22 of 56 [39%]) and underwent targeted biopsy. PCa was confirmed in 54 of 56 (96%) participants, and clinically significant PCa (Gleason score ≥ 7) was confirmed in 24 of 54 (44%). Two participants had nonrepresentative samples that required rebiopsy. All participants experienced pain during the procedure, mild (median visual analog scale score, 1; interquartile range, 1-2) in 36 of 56 (64%) and moderate (median visual analog scale score, 5; interquartile range, 5-6) in 20 of 56 (36%). Postprocedure complications were noted in five of 56 (9%) participants and were minor (hematuria, four participants; hematospermia, one participant; and gluteal pain, two participants). No participant developed a postprocedural infection. Conclusion Transgluteal prostate-specific membrane antigen (PSMA) PET/CT-guided, robotic-targeted prostatic biopsy is safe with a high diagnostic yield of prostate cancer for PSMA-avid lesions. Clinical trial registration no. NCT05022576 © RSNA, 2022.

Differentiating benign and malignant pancreatic masses: Ga-68 PSMA PET/CT as a new diagnostic avenue.

OBJECTIVE: Differentiation of malignant and benign pancreatic lesions on anatomical imaging is difficult in some cases with overlapping features. Prostate-specific membrane antigen (PSMA) is overexpressed during angioneogenesis in many tumors. We aimed to evaluate the PSMA expression in pancreatic lesions to differentiate these lesions and explore the performance of Ga-68 PSMA-PET/CT vis-a-vis F-18 FDG-PET/CT. METHODS: Patients with pancreatic lesions on conventional imaging were prospectively recruited. All the patients underwent a whole-body F-18 FDG-PET/CT and a regional abdominal Ga-68 PSMA-PET/CT. Focal tracer uptake (FDG or PSMA) on PET images was considered positive. Histopathology and/or cytopathology were considered the reference standard. RESULTS: A total of forty patients (27 males, mean age 55.3 ± 9.8, range 37-71 years) were enrolled. Of these, 19 were diagnosed as malignant on histopathology/cytology. Patients with benign lesions showed no worsening of symptoms for at least 6 months on follow-up. FDG-PET/CT revealed 17 true-positive (TP), 9 false-positive (FP), 12 true-negative (TN), and 2 false-negative (FN) findings, whereas PSMA-PET/CT had 18 TP, 2 FP, 19 TN, and 1 FN finding. The sensitivity, specificity, PPV, NPV, and accuracy for FDG-PET/CT were 89.5%, 57.1%, 65.4%, 85.7%, and 72.5%, respectively, while for PSMA-PET/CT were 94.7%, 90.5%, 90%, 95%, and 92.5%, respectively. ROC curve analysis showed that the SUVmax value of 4.8 on PSMA-PET/CT could predict the malignant potential of a lesion with a specificity of 90.5% and a sensitivity of 84.2%. CONCLUSIONS: Ga-68 PSMA-PET/CT imaging helped in establishing a non-invasive pre-operative diagnosis of primary pancreatic malignancy with a higher degree of specificity and accuracy compared with FDG-PET/CT. KEY POINTS: • Conventional imaging such as CT and MRI are unable to reliably differentiate localized malignant pancreatic lesion from benign lesions mimicking malignancy such as mass-forming pancreatitis. • FDG PET/CT helps in detecting malignant foci in view of their increased glucose metabolism. However, it may be falsely positive in inflammatory lesions which may occasionally hinder its ability to differentiate between benign and malignant lesions. • Apart from prostatic malignancy, PSMA is overexpressed in neovasculature of many non-prostatic malignancies. The present study highlights that Ga68 PSMA PET/CT performed better in diagnosing malignancy non-invasively than FDG-PET/CT with a higher PPV (90.5% vs. 65.4%) and accuracy (92.5% vs. 72.5%).

Diagnostic Accuracy of 68Ga-PSMA PET/CT for Initial Detection in Patients With Suspected Prostate Cancer: A Systematic Review and Meta-Analysis.

BACKGROUND. Early diagnosis is important in the overall management of prostate cancer (PCa). Gallium-68-labeled prostate-specific membrane antigen (PSMA) PET/CT has an established role in the detection of recurrent disease and staging of patients with intermediate- to high-risk PCa. However, only a small number of studies have evaluated its role in the initial diagnosis of PCa. OBJECTIVE. This systematic review was conducted to evaluate the diagnostic performance of 68Ga-PSMA PET/CT in the initial detection of PCa in patients with clinical or biochemical findings suspicious for PCa. EVIDENCE ACQUISITION. This systematic review followed PRISMA guidelines. Searches in PubMed, Scopus, and Embase were conducted using relevant keywords, and articles published through April 30, 2020, were included. Using histopathology results as the reference standard, the numbers of true- and false-positives and true- and false-negatives were extracted. Pooled estimates of diagnostic test accuracy-including sensitivity, specificity, positive likelihood ratio, negative likelihood ratio, and summary ROC (SROC) curve-were generated using bivariate random-effects meta-analysis. EVIDENCE SYNTHESIS. Seven studies comprising 389 patients were included in the systematic review and meta-analysis. The pooled sensitivity, specificity, positive likelihood ratio, and negative likelihood ratio for the initial diagnosis of PCa using 68Ga-PSMA PET/CT were 0.97 (95% CI, 0.90-0.99), 0.66 (95% CI, 0.52-0.78), 2.86 (95% CI, 1.95-4.20), and 0.05 (95% CI, 0.01-0.15), respectively. The test had high accuracy; the area under the SROC curve was 0.91 (95% CI, 0.88-0.93). CONCLUSION. Gallium-68-labeled PSMA PET/CT had excellent sensitivity and negative likelihood ratio in the initial diagnosis of PCa in patients with clinical or biochemical findings suspicious for PCa. CLINICAL IMPACT. Gallium-68-labeled PSMA PET/CT had high diagnostic accuracy for the initial detection of PCa in patients with clinical or biochemical findings suspicious for PCa and has potential utility as a rule-out test for these patients.

Impact of broad-spectrum antibiotic exposures and multidrug-resistant gram-negative bacteremia on hematopoietic cell transplantation outcomes.

INTRODUCTION: There is a close association between the use of broad-spectrum antibiotics, gut microbiome alteration, multidrug resistant (MDR) gram-negative bacilli (GNB) bacteremia, graft versus host disease (GVHD), and mortality post-allogeneic hematopoietic cell transplantation (allo-HCT). This study reports the impact of the high use of carbapenems and colistin and MDR bacteremia pre- and post-HCT on HCT outcomes. METHODS: This was a single-center, partial retrospective, and prospective study from 2016 to 2020. Both pre- and post-HCT antibiotic exposures and blood culture/sensitivity were recorded. MDR GNB was defined as either non-susceptibility to third-generation cephalosporin or carbapenems. In the absence of positive cultures, the treating physician escalated antibiotics from third-generation cephalosporins to carbapenem and/or colistin as per clinical discretion. De-escalation policy was not strictly enforced. RESULTS: MDR GNB bacteremia was seen in 29 of 76 (38%) of patients peri-HCT. The utilization rates for carbapenems and colistin was significantly higher in the cohort with MDR GNB bacteremia pre-HCT (70% vs. 32%, p = 0.002 and 31% vs. 6.4%, p = 0.007, respectively) and post-HCT (100% vs. 74.5%, p = 0.002, and 55.2% vs. 8.5%, p < 0.0001, respectively). The cohort with MDR GNB bacteremia had significantly more severe acute GVHD at day+100 (45% vs. 17.5%, p = 0.009). The median survival was 204 days compared to not reached in the cohort without any MDR GNB bacteremia (p = 0.005). CONCLUSION: This study shows pre- and post-HCT MDR GNB bacteremia is associated with an increased risk of severe acute GVHD and mortality. Patients with MDR GNB bacteremia had higher exposure to pre- and post-HCT carbapenems and colistin.

Physical activity levels among the adults of Majha region of Punjab, India: A cross-sectional study.

OBJECTIVES: To construct a physical activity profile of the adult population of the Majha region of the Indian Punjab. METHODS: The study included a total of 1130 adult participants aged 18 to 64 years comprising both genders, from rural, urban, and different sociodemographic backgrounds from the four districts of the Majha region of Punjab. The WHO's STEPwise approach to Surveillance instrument for noncommunicable diseases was used to collect data for the selected variables such as physical activity levels, demographic characteristics, behavioral parameters (daily screen time, fruit intake/week, and vegetable intake/week), physical characteristics and self-reported history of cardiovascular diseases, raised blood pressure, diabetes, and raised cholesterol. The likelihood of physical inactivity was predicted based on independent variables using logistic regression analysis. RESULTS: Overall, 56.81% (95% confidence interval [CI]: 53.9-59.7) of participants were not sufficiently active as per WHO's moderate- to vigorous-intensity recommendations. Obesity and overweight were observed among 40.2% of the participants. Mean minutes/day of smartphone screen time was 86.11 (CI: 79.48-92.71). Mean fruit (4.69 CI: 4.42-4.95) and vegetable (15.35 CI: 15.08-15.62) weekly consumption was lower than the WHO's recommendations. Work status, residence, annual household income, smartphone screen time, history of raised blood pressure, history of diabetes, and history of raised cholesterol were significant predictors of insufficient physical activity. CONCLUSIONS: Our study found a high prevalence of physical inactivity. Being a government employee, being an urban resident, having a middle-level annual household income, high smartphone screen time and having a history of raised blood pressure, diabetes, and raised cholesterol were all significant predictors of physical inactivity.

Ultrasound-Guided Peripheral Nerve Stimulation of Cervical, Thoracic, and Lumbar Spinal Nerves for Dermatomal Pain: A Case Series.

OBJECTIVES: With the development of percutaneously inserted devices, peripheral nerve stimulation (PNS) has been gaining attention within chronic pain literature as a less invasive neurostimulation alternative to spinal column and dorsal root ganglion stimulation. A majority of current PNS literature focuses on targeting individual distal nerves to treat individual peripheral mononeuropathies, limiting its applications. This article discusses our experience treating dermatomal pain with neurostimulation without needing to access the epidural space by targeting the proximal spinal nerve with peripheral nerve stimulation under ultrasound-guidance. MATERIALS AND METHODS: A temporary, percutaneous PNS was used to target the proximal spinal nerve in 11 patients to treat various dermatomal pain syndromes in patients seen in an outpatient chronic pain clinic. Four patients received stimulation targeting the lumbar spinal nerves and seven patient received stimulation targeting the cervical or thoracic spinal nerves. RESULTS: The case series presents 11 cases of PNS of the proximal spinal nerve. Seven patients, including a majority of the patients with lumbar radiculopathy, had analgesia during PNS. Four patients, all of whom targeted the cervical or thoracic spinal nerves, did not receive analgesia from PNS. CONCLUSION: PNS of the proximal spinal nerve may be an effective modality to treat dermatomal pain in patients who are not candidates for other therapies that require access to the epidural space. This technique was used to successfully treat lumbar radiculopathy, post-herpetic neuralgia, and complex regional pain syndrome.

Fluorodeoxyglucose positron emission tomography/computed tomography in the diagnosis, assessment of disease activity and therapeutic response in relapsing polychondritis.

OBJECTIVE: To evaluate 18F-fluorodeoxyglucose (FDG) PET/CT in the assessment of disease activity, extent of the disease and response to therapy in relapsing polychondritis. METHODS: Twenty-five patients (9 men, 16 women) with a mean age of 38.2 years (s.d. 13.7; range 18-62), diagnosed to have relapsing polychondritis according to Damiani and Levine's modification of McAdam's criteria, who underwent PET/CT examination were included. Ten patients underwent a second PET/CT examination after therapy or during follow-up. Clinical symptoms and auxiliary examination findings were recorded. PET/CT findings were reviewed and correlated with the clinical symptoms. RESULTS: The major symptoms were aural pain (n = 21), nasal pain (n = 10), stridor (n = 5), cough (n = 9), fever (n = 8) and laryngeal tenderness (n = 8). The initial PET/CT was positive in 23/25 patients. PET/CT revealed involvement of auricular (n = 14), nasal (n = 8), laryngeal (n = 7), tracheobronchial (n = 6) and Eustachian (n = 3) cartilages with a mean maximum standardized uptake value (SUVmax) of 4.1 (s.d. 2.5; range 1.7-12.7). Fair correlation of aural/nasal pain/stridor with FDG avidity of cartilage involvement on PET/CT was noted. The key finding was detection of asymptomatic large airway involvement in seven patients (28%). Re-examination PET in 10 patients revealed complete therapeutic response (n = 5), partial response (n = 1), stable disease (n = 1), progressive disease (n = 1) and disease recurrence (n = 2). CONCLUSION: FDG PET/CT is a useful tool for the assessment of the disease activity and extent. It identified activity in clinically inaccessible sites that are of clinical significance. It is also useful in assessing treatment response and finding relapse.

Sciatic, Femoral, and Lateral Femoral Cutaneous Nerve Ultrasound-Guided Percutaneous Peripheral Nerve Stimulation.

OBJECTIVE: With advances in peripheral nerve stimulation technology, there has been an emergence of new minimally invasive techniques to provide neurostimulation therapies for chronic pain. This technical note describes the utilization of ultrasonography for percutaneous placement of peripheral nerve stimulation leads at the sciatic, femoral, and lateral femoral cutaneous nerves. METHODS: Ultrasound can be utilized to localize a specific nerve, view neighboring soft tissue anatomy, and plan a needle trajectory. Various ultrasound techniques and transducer orientations allow for multiple options for lead placement relative to the targeted nerve. CONCLUSIONS: The option of ultrasound-guided percutaneous technique for neurostimulation lead placement allows this treatment modality to be made available to more patients with chronic pain in specific nerve distributions.

Extraforaminal Thoracic and Lumbar Spinal Nerve Ultrasound-Guided Percutaneous Peripheral Nerve Stimulation.

OBJECTIVE: Peripheral nerve stimulation provides targeted stimulation and pain relief within a specific nerve distribution. This technical case report provides a method to perform selective nerve root stimulation of thoracic and lumbar spinal nerves using ultrasonography. METHODS: Ultrasound-guided peripheral nerve stimulation of thoracic and lumbar spinal nerves allows better visualization of soft tissue anatomy and planning of needle trajectory. CONCLUSIONS: Ultrasound-guided peripheral nerve stimulation procedures may provide a safer method for neurostimulation lead placement when compared with fluoroscopic-guided techniques.

Mechanism of Peripheral Nerve Stimulation in Chronic Pain.

INTRODUCTION: With the advancement of technology, peripheral nerve stimulation (PNS) has been increasingly used to treat various chronic pain conditions. Its origin is based on the gate control theory postulated by Wall and Melzack in 1965. However, the exact mechanism behind PNS' analgesic effect is largely unknown. In this article, we performed a comprehensive literature review to overview the PNS mechanism of action. DESIGN: A comprehensive literature review on the mechanism of PNS in chronic pain. METHODS: Comprehensive review of the available literature on the mechanism of PNS in chronic pain. Data were derived from database searches of PubMed, Scopus, and the Cochrane Library and manual searches of bibliographies and known primary or review articles. RESULTS: Animal, human, and imaging studies have demonstrated the peripheral and central analgesic mechanisms of PNS by modulating the inflammatory pathways, the autonomic nervous system, the endogenous pain inhibition pathways, and involvement of the cortical and subcortical areas. CONCLUSIONS: Peripheral nerve stimulation exhibits its neuromodulatory effect both peripherally and centrally. Further understanding of the mechanism of PNS can help guide stimulation approaches and parameters to optimize the use of PNS.

Meclizine ameliorates memory deficits in streptozotocin-induced experimental dementia in mice: role of nuclear pregnane X receptors.

Pregnane X receptors (PXRs) regulate the expression of ATP-binding cassette proteins transporters and organic anion transporting polypeptides responsible for influx/efflux of xenobiotics across the brain. Ligand activation of PXR augments the expression of P-gp and promotes amyloid-ß clearance across the blood-brain barrier. Dementia was induced in mice by intacerebroventricular administration of streptozotocin (STZ) followed by treatment with meclizine, a PXR agonist, and subsequently exposed to the Morris water maze test and biochemical and histopathological analysis to evaluate the effect on cognition. STZ-treated mice exhibited significant enhancement in brain thiobarbituric acid reactive species, interleukin-1ß, tumour necrosis factor-α, myeloperoxidase, and acetylcholinestrase activity in addition to diminution in glutathione levels and superoxide dismutase activity in comparison to untreated mice. Administration of meclizine to STZ mice recuperated cognition and biochemical alterations. Concomitant administration of ketoconazole, a PXR antagonist, with meclizine prevented the protective effects. The upshots of our study proclaim that meclizine protects cognitive deficits by virtue of its antioxidant, anticholinesterase, and antiinflammatory properties. Results also signify the potential of PXR in neuroprotective actions of meclizine in dementia.

Diagnostic performance of real-time robotic arm-assisted 18F-FDG PET/CT-guided percutaneous biopsy in metabolically active abdominal and pelvic lesions.

PURPOSE: To evaluate the feasibility and diagnostic performance of 18F-FDG PET/CT-guided biopsy of abdominal and pelvic lesions with automated robotic arm (ARA) assistance. METHODS: This prospective study included 114 patients (75 men, 39 women; mean age 51.3 ± 14.7 years, range: 18-90 years) who underwent PET/CT-guided biopsy of FDG-avid abdominal and pelvic lesions from October 2014 to December 2017. Of these patients, 54 had a prior inconclusive CT-guided biopsy. The biopsies were done with ARA assistance, and a real-time sample was obtained after confirming the position of the needle tip within the target lesion on PET/CT. Histopathology reports were reviewed to evaluate the diagnostic performance of the procedure. Clinical or imaging follow-up was done to confirm negative results. RESULTS: The lesions were successfully targeted in 110 of the 114 patients (96.5%) and yielded a pathological diagnosis. Pathological diagnoses were confirmed in 50 of the 54 patients with a prior inconclusive biopsy. Of the 110 lesions, 82 were malignant, 20 were benign, and 8 showed minimal residual FDG uptake at the end of treatment and had no active disease even on clinical and imaging follow-up of at least 3 months. Findings were true-positive in 102 lesions, false-positive in none, true-negative in eight and false-negative in four. The procedure showed sensitivity, specificity, positive predictive value, negative predictive value and accuracy of 96.2%, 100%, 100%, 66.7 and 96.5%, respectively. No immediate complications or delayed life-threatening events were observed. CONCLUSION: Percutaneous biopsy of metabolically active abdominal and pelvic lesions with ARA assistance is a technically feasible, safe and accurate method for pathological diagnosis with high diagnostic performance. PET-guided biopsy is highly practical and useful in patients, especially in those with a previous inconclusive biopsy.

18F-FDG PET/CT-Guided Real-Time Automated Robotic Arm-Assisted Needle Navigation for Percutaneous Biopsy of Hypermetabolic Bone Lesions: Diagnostic Performance and Clinical Impact.

OBJECTIVE: The purpose of this study is to establish the feasibility, safety, diagnostic performance, and clinical impact of real-time intraprocedural 18F-FDG PET/CT-guided automated robotic arm-assisted biopsy of hypermetabolic marrow or bone lesions. SUBJECTS AND METHODS: This prospective study included 73 patients (47 male patients and 26 female patients) who underwent PET/CT-guided biopsy of accessible hypermetabolic marrow or bone lesions. The biopsy needle was inserted into the target lesion with automated robotic arm assistance, and tissue sampling was performed at the site with the highest metabolic activity, after the needle position was confirmed using PET/CT. The results of histopathologic examination and clinical and imaging follow-up examinations were reviewed. The referring physicians were interviewed to assess the clinical impact of interventions on treatment planning. RESULTS: Of the 73 patients assessed, 34 were oncology patients with suspected metastasis or residual disease. The pathologic diagnosis was not known for 38 patients with clinically suspected benign (n = 7) or malignant (n = 31) disease. The remaining patient was suspected of having skeletal sarcoidosis. Thirty-nine marrow lesions and 34 bone lesions were targeted. All procedures were technically successful and safe, and no major complication was observed. Pathologic diagnosis was confirmed for 72 patients, for a diagnostic yield of 98.6%. The sensitivity, specificity, positive predictive value, negative predictive value, and accuracy for the detection of malignancy (n = 54) were 98.2%, 100%, 100%, 94.7%, and 98.6%, respectively. The procedure was helpful in determining the treatment plan for 91.7% of patients. CONCLUSION: Automated robotic arm-assisted FDG PET/CT-guided real-time bone biopsy is a feasible and safe intervention with a very high diagnostic yield. It had a major clinical impact on patients with minimal residual FDG uptake on end-of-treatment PET/CT and isolated suspected metastatic lesions.

Comparison of left ventricular systolic function and mechanical dyssynchrony using equilibrium radionuclide angiography in patients with right ventricular outflow tract versus right ventricular apical pacing: A prospective single-center study.

BACKGROUND: Chronic ventricular pacing is known to adversely affect left ventricular (LV) function. Studies comparing right ventricular outflow tract (RVOT) pacing with RV apical (RVA) pacing have shown heterogeneous outcomes. Our aim was to objectively assess LV function and mechanical dyssynchrony in patients with RVOT and RVA pacing using equilibrium radionuclide angiography (ERNA). METHODS: Fifty-one patients who underwent permanent pacemaker implantation and had normal LV function were prospectively included. Twenty-nine patients had pacemaker lead implanted in the RVOT and 22 at the RVA site. All patients underwent ERNA within 5 days post-pacemaker implantation and follow-up studies at 6 and 12 months. Standard deviation of LV mean phase angle (SD LV mPA) expressed in degrees, which was derived by Fourier first harmonic analysis of phase images, was used to quantify left intraventricular dyssynchrony. RESULTS: No significant difference was observed between the two groups with respect to indication (P = .894), Type/mode (P = .985), and percentage of ventricular pacing (P = .352). Paced QRS duration was significantly longer in RVA group than RVOT group (P = .05). There was no statistically significant difference between the RVA and RVOT groups at baseline with respect to LVEF (P = .596) and SD LV mPA (P = .327). Within the RVA group, a significant decline in LVEF was observed over 12-month follow-up (from 57.3% ± 5.32% to 55.6% ± 6.25%; P = .012). In the RVOT group, the change in LVEF was not statistically significant (from 56.7% ± 4.08% to 54.3% ± 6.63%; P = .159). No significant change in SD LV mPA was observed over 12-month follow-up within the RVA group (from 10.5 ± 2.58° to 10.4 ± 3.54°; P = 1.000) as well as in the RVOT group (from 9.7 ± 3.28° to 9.4 ± 2.85°; P = .769). However, between the RVA and RVOT groups, no significant difference was observed at 12-month follow-up in terms of LVEF and dyssynchrony (LVEF P = .488; SD LV mPA P = .296). CONCLUSION: No significant difference was observed between RVOT and RVA groups with regard to LV function and synchrony over a 12-month follow-up. RVOT pacing offers may lead to better preservation of LV function on longer follow-up.

Does perfusion pattern influence stress-induced changes in left ventricular mechanical dyssynchrony on thallium-201-gated SPECT myocardial perfusion imaging?

BACKGROUND: The relationship between perfusion pattern and stress-induced changes in left ventricular mechanical dyssynchrony (LVMD) on stress-rest thallium-201-gated SPECT myocardial perfusion imaging (Tl-201 SPECT MPI) is not clear. The aim of the study is to assess the relation of perfusion pattern with stress-induced changes in LVMD on Tl-201 MPI. METHODS: Data of 194 patients who underwent exercise-rest Tl-201 MPI between January to December 2012 at our institute was retrospectively evaluated. Institute Ethical committee approval was obtained. Fifty patients who underwent Tl-201 MPI for suspected CAD and had normal LV perfusion and function on MPI were taken as normal group. Patients with perfusion abnormalities (n = 144) were divided into three groups: ischemia (n = 66), infarct (n = 32), and mixed group (n = 46; ischemia and infarct both). Summed stress score, summed rest score, summed difference score (SDS), and LV ejection fraction (EF) were evaluated. Two LVMD parameters, phase standard deviation (PSD) and phase histogram bandwidth (PHB), were assessed in post-stress and rest MPI images. ΔPSD (post-stress PSD - rest PSD) and ΔPHB (post-stress PHB - rest PHB) were calculated to measure stress-induced changes in LVMD. RESULTS: In all the groups, mean post-stress LVMD parameters were lower as compared to LVMD parameters at rest. Post-stress PSD was significantly lower than rest PSD in all groups. Similar trend was noted with PHB values also, but it was statistically significant in the normal and ischemia group only. Post-stress worsening of at least one of the LVMD parameters was noted in 28 patients and all these patients had perfusion abnormalities. But on subgroup analysis, no difference was found in proportion of patients showing post-stress worsening of LVMD between ischemia (13.6%), infarct (25%), and mixed (23.6%) groups. No significant correlation was found between ΔPSD/ΔPHB and ΔLVEF/SDS in any group. CONCLUSION: LV mechanical dyssynchrony parameters are smaller in post-exercise stress as compared to rest on Tl-201 MPI, regardless of perfusion pattern. Stress-induced worsening of LV dyssynchrony was observed only in patients with perfusion abnormalities, but this is not related to the type of perfusion abnormality.