Role of pinch in Argon impurity transport in ohmic discharges of Aditya-U Tokamak.

We present experimental results of the trace argon impurity puffing in the ohmic plasmas of Aditya-U tokamak performed to study the argon transport behaviour. Argon line emissions in visible and Vacuum Ultra Violet (VUV) spectral ranges arising from the plasma edge and core respectively are measured simultaneously. During the experiments, space resolved brightness profile of Ar1+ line emissions at 472.69 nm (3p44s 2P3/2-3p44p 2D3/2), 473.59 nm (3p44s 4P5/2-3p44p 4P3/2), 476.49 nm (3p44s 2P1/2-3p44p 2P3/2), 480.60 nm (3p44s 4P5/2-3p44p 4P5/2) are recorded using a high resolution visible spectrometer. Also, a VUV spectrometer has been used to simultaneously observe Ar13+ line emission at 18.79 nm (2s22p 2P3/2-2s2p2 2P3/2) and Ar14+ line emission at 22.11 nm (2s2 1S0-2s2p 1P1). The diffusivity and convective velocity of Ar are obtained by comparing the measured radial emissivity profile of Ar1+ emission and the line intensity ratio of Ar13+ and Ar14+ ions, with those simulated using the impurity transport code, STRAHL. Argon diffusivities ~ 12 m2/s and ~ 0.3 m2/s have been observed in the edge (ρ > 0.85) and core region of the Aditya-U, respectively. The diffusivity values both in the edge and core region are found to be higher than the neo-classical values suggesting that the argon impurity transport is mainly anomalous in the Aditya-U tokamak. Also, an inward pinch of ~ 10 m/s mainly driven by Ware pinch is required to match the measured and simulated data. The measured peaked profile of Ar density suggests impurity accumulation in these discharges.

Initial results from near-infrared spectroscopy on ADITYA-U tokamak.

Spectroscopy in vacuum ultraviolet (VUV) and visible ranges plays an important role in the investigation and diagnosis of tokamak plasmas. However, under harsh environmental conditions of fusion grade devices, such as ITER, VUV-visible systems encounter many issues due to the degradation of optical components used in such systems. Here, near-infrared (NIR) spectroscopy has become an effective tool in understanding the edge plasma dynamics. Considering its importance, a NIR spectroscopic diagnostic has been developed and installed on the ADITYA-U tokamak. The system consists of a 0.5 m spectrometer having three gratings with different groove densities, and it is coupled with a linear InGaAs photodiode array. Radiation from the ADITYA-U edge plasma has been collected using a collimating lens and optical fiber combination and transported to the spectrometer. The spectrum in the NIR range from the ADITYA-U plasma has been recorded using this system, in which Paß and Paγ along with many spectral lines from neutral and singly ionized impurities have been observed. The influxes of H and C have been estimated from measurements. The H influx value is found to be 2.8 × 1016 and 1.9 × 1016 particles cm-2 s-1 from neutral hydrogen lines Hα and Paß, respectively, and the C influx value is found to be 3.5 × 1015 and 2.9 × 1015 particles cm-2 s-1 from the neutral carbon and singly ionized carbon, respectively. A good agreement is seen between these results and the results obtained by using a routine photomultiplier tube based diagnostic.

Impurity toroidal rotation profile measurement using upgraded high-resolution visible spectroscopic diagnostic on ADITYA-U tokamak.

A high-resolution spectroscopic diagnostic for the measurement of spatial profiles of impurity ion toroidal rotation velocities on the ADITYA-U tokamak has been upgraded to cover the complete plasma minor radius. Earlier, the coverage of diagnostics toward the plasma edge was restricted due to the placement of collection optics on the tangential port outside the vacuum vessel. The coverage of the full plasma minor radius, from 0 to 24 cm, has been achieved using the newly designed and developed collection optics that have seven lines of sight to view the tokamak plasma mounted inside a customized re-entrant view port which is installed in the shadow of the limiter inside the vacuum vessel. The upgraded diagnostic also includes a faster charged coupled device detector with a smaller pixel size for the detection of a small wavelength shift. The complete spatial profile has been measured using the Doppler shifted passive change exchange spectral line at 529.0 nm from the C5+ ion. In this article, we present the collection optics' design, installation, calibration, and results obtained using the upgraded diagnostic.

Observations of visible argon line emissions and its spatial profile from Aditya-U tokamak plasma.

The spectroscopic studies of medium and high Z impurities have been the subject of interest in fusion research due to their role in mitigating plasma disruption and reducing heat load on the plasma facing components. Line emissions from these impurities provide the rotation velocity and ion temperature measurements along with the understanding of the overall impurity behavior in plasma. In the Aditya-U tokamak, the spatially resolved Ar II line emissions have been observed using a high resolution multi-track spectroscopic diagnostic consisting of a 1 m Czerny-Turner spectrometer coupled with a charge coupled device (CCD) detector using seven lines of sight viewing plasma tangentially along the toroidal direction. The spatially resolved Ar II lines at 458.96 nm have been observed. The singly ionized Ar emission peaks at the radial location of ρ = 0.8 of the plasma having a minor radius of 25 cm. Moreover, a 0.5 m UV-visible spectrometer coupled with a CCD detector and having a line of sight passing through the plasma midplane from the radial port was used to record visible Ar survey spectra within the 670-810 nm wavelength range, and all these lines have been identified for further analysis.

Clinical and imaging features in adult patients with bone marrow haemophagocytosis with and without haemophagocytic lymphohistiocytosis: a single-institution experience.

AIM: To evaluate clinical, laboratory, imaging findings, and outcomes of adult patients with bone marrow haemophagocytosis (BMH) who meet the diagnostic criteria for haemophagocytic lymphohistiocytosis (HLH) with those who do not meet the criteria. MATERIALS AND METHODS: A pathology database search was performed from 2009 to 2019 to identify adult patients with BMH. Electronic medical records of 41 patients were reviewed to distinguish those who fulfil the HLH-2004 diagnostic guidelines, which identified 22 patients (11 men; mean age, 53.5 years) who met the criteria (HLH+) and 19 patients (13 men; mean age, 54.7 years) who did not meet the criteria (HLH-). Multi-modality imaging was reviewed to record imaging features. Clinical, laboratory, imaging findings, and outcomes were compared between the two groups using Fisher's exact test and Wilcoxon test. RESULTS: Malignancy (non-Hodgkin's lymphoma) was the major trigger for both groups. 86% of HLH+ and 31% of HLH- patients presented with fever. Compared to the HLH- group, the HLH+ group exhibited higher serum ferritin, triglycerides, and lower fibrinogen levels (p<0.05). Alveolar opacities and hepatosplenomegaly were the most common imaging findings identified in both groups. Median overall survival of HLH+ and HLH- were 123.5 (interquartile range [IQR]: 40.7-681.7 days) and 189 days (IQR: 52-1680 days), respectively. Distribution of imaging features and overall survival did not differ between the groups. CONCLUSION: Malignancy is the major trigger for BMH in both HLH+ and HLH- groups. HLH+ and HLH- groups have similar imaging manifestations or clinical outcomes. Therefore, presence of BMH alone is correlated with high morbidity and mortality.

Tyrosine Kinase Inhibitor Therapy for Brain Metastases in Non-Small-Cell Lung Cancer: A Primer for Radiologists.

Treatment options for patients who develop brain metastases secondary to non-small-cell lung cancer have rapidly expanded in recent years. As a key adjunct to surgical and radiation therapy options, systemic therapies are now a critical component of the oncologic management of metastatic CNS disease in many patients with non-small-cell lung cancer. The aim of this review article was to provide a guide for radiologists, outlining the role of systemic therapies in metastatic non-small-cell lung cancer, with a focus on tyrosine kinase inhibitors. The critical role of the blood-brain barrier in the development of systemic therapies will be described. The final sections of this review will provide an overview of current imaging-based guidelines for therapy response. The utility of the Response Assessment in Neuro-Oncology criteria will be discussed, with a focus on how to use the response criteria in the assessment of patients treated with systemic and traditional therapies.

Head-to-head comparison of prostate MRI using an endorectal coil versus a non-endorectal coil: meta-analysis of diagnostic performance in staging T3 prostate cancer.

AIM: To compare the diagnostic performance of prostate magnetic resonance imaging (MRI) with an endorectal coil (ERC) to performance without an ERC using either body-array (BAC) or pelvic phased-array coil (PAC) in staging T3 prostate cancer. MATERIALS AND METHODS: An electronic search of the PUBMED and EMBASE databases was performed until 10 October 2018 to identify studies performing a head-to-head comparison of prostate MRI using a 1.5 or 3 T magnet with an ERC and with a BAC/PAC for staging T3 prostate cancer. Pooled sensitivity and specificity of all studies were plotted in a hierarchical summary receiver operating characteristic plot. The diagnostic performance of the two techniques in staging T3 disease was evaluated using bivariate random-effects meta-analysis. RESULTS: Eight studies comparing head-to-head prostate MRI with an ERC and with a BAC/PAC were identified of which six studies compared the diagnostic performance. The pooled sensitivity and specificity of MRI with an ERC for detecting T3a, T3b and T3a+b was 53% and 95%; 52% and 92%; 72% and 65% respectively. For MRI with a BAC/PAC these were 34%, and 95%; 45% and 94%; 70% and 66%. There was no statistical difference between an ERC and a BAC/PAC in terms of sensitivity (p=0.41) and specificity (p=0.63) for T3a. The area under the receiver operating characteristic (AUROC) curve for T3a, T3b and T3a+b was 0.830, 0.901, 0.741 for an ERC and 0.790, 0.645, 0.711 for BAC, respectively. CONCLUSION: There is no significant difference in the diagnostic performance of MRI of prostate with an ERC and with a BAC/PAC in staging T3 prostate cancer.

Imaging surveillance of gastrointestinal stromal tumour: current recommendation by National Comprehensive Cancer Network and European Society of Medical Oncology-European Reference Network for rare adult solid cancers.

Imaging plays an active role in the surveillance of gastrointestinal stromal tumours (GISTs). Risk stratification schemes, based on size, mitotic count, and anatomical site of origin of the GIST, help in planning preoperative and postoperative imaging strategies especially in determining the frequency and duration of surveillance; however, there is no clear consensus on the optimal imaging strategies in patients with GISTs who are completely cured by surgery and patients who are at risk of recurrence. In addition, current surveillance protocols depend on the resectability of the primary tumour and presence of metastatic disease. The objective of this article is to provide a comprehensive review of the role of the different imaging methods for surveillance of GISTs, focusing on the guidelines recommended by National Comprehensive Cancer Network and European Society of Medical Oncology - European Network for Rare adult solid Cancers, and to propose practical guidelines for surveillance of GISTs for various risk categories.

Improved visualization of hypodense liver lesions in virtual monoenergetic images from spectral detector CT: Proof of concept in a 3D-printed phantom and evaluation in 74 patients.

OBJECTIVES: The well-known boost of iodine associated-attenuation in low-keV virtual monoenergetic images (VMI_low) is frequently used to improve visualization of lesions and structures taking up contrast media. This study aimed to evaluate this concept in reverse. Hence to investigate if increased attenuation within the liver allows for improved visualization of little or not-enhancing lesions. METHODS: A 3D-printed phantom mimicking the shape of a human liver exhibiting a lesion in its center was designed and printed. Both, parenchyma- and lesion-mimic were filled with different solutions exhibiting 80/100/120HU and 0/15/40/60HU, respectively. Further, a total of 74 contrast-enhanced studies performed on a spectral detector CT scanner (SDCT) were included in this retrospective study. Patients had MRI or follow-up proven cysts and/or hypodense metastases. VMI of 40-200 keV as well as conventional images (CI) were reconstructed. ROI were placed in lesion and parenchyma(-mimics) on CI and transferred to VMI. Signal- and contrast-to-noise ratio were calculated (S-/CNR). Further, two radiologists independently evaluated image quality. Data was statistically assessed using ANOVA or Wilcoxon-test. RESULTS: In phantoms, S/CNR was significantly higher in VMI_low. The cyst-mimic in highly attenuating parenchyma-mimic on CI yielded a CNR of 6.4 ± 0.8; using VMI_40 keV, mildly hypodense lesion-mimic in poorly attenuating parenchyma-mimic exhibited a similar CNR (5.8 ± 0.9; p ≤ 0.05). The same tendency was observed in patients (cyst in CI/metastasis in VMI_40 keV: 4.4 ± 1.2/3.9 ± 1.8; p ≤ 0.05). Qualitative analysis indicated a benefit of VMI_40 keV (p ≤ 0.05). CONCLUSIONS: VMI_low from SDCT allow for an improved visualization of hypodense focal liver lesions exploiting the concept of contrast blooming in reverse.

Yield of bone scintigraphy for the detection of metastatic disease in treatment-naive prostate cancer: a systematic review and meta-analysis.

AIM: To evaluate the yield of staging bone scintigraphy in patients with treatment-naive prostate cancer. MATERIALS AND METHODS: A computerised search of the MEDLINE and EMBASE databases was performed to find relevant original literature. Studies that investigated the positivity of a staging bone scintigraphy according to prostate-specific antigen (PSA) levels and/or Gleason score in patients with treatment-naive prostate cancer were eligible for inclusion. Meta-analytic pooling was performed using the inverse variance method for calculating weights. RESULTS: Fifty-four eligible studies, which included a total sample size of 20,421 patients, were included. The pooled proportions of the positive bone scintigraphy in patients with PSA ≤10, 10 20 were 3.5% (95% confidence interval [CI]: 2.4-5%), 6.9% (95% CI: 4.5-10.3%), and 41.8% (95% CI: 36.3-47.6%). The pooled proportions of the positive bone scintigraphy examinations in patients with Gleason score ≤6, 7, and ≥8 were 4.1% (95% CI: 2-8%), 10% (95% CI: 6.1-15.8%), and 28.7% (95% CI: 21.8-36.8%). Meta-regression analysis revealed that the Gleason score was a significant factor affecting study heterogeneity in patients with PSA ≤10 (p = 0.04). Pooled proportions of positive bone scintigraphy examinations showed 3.4% in patients with a PSA of ≤10 and 3.3% in patients with 10

Imaging of hepatic toxicity of systemic therapy in a tertiary cancer centre: chemotherapy, haematopoietic stem cell transplantation, molecular targeted therapies, and immune checkpoint inhibitors.

The purpose of this review is to familiarise radiologists with the spectrum of hepatic toxicity seen in the oncology setting, in view of the different systemic therapies used in cancer patients. Drug-induced liver injury can manifest in various forms, and anti-neoplastic agents are associated with different types of hepatotoxicity. Although chemotherapy-induced liver injury can present as hepatitis, steatosis, sinusoidal obstruction syndrome, and chronic parenchymal damages, molecular targeted therapy-associated liver toxicity ranges from mild liver function test elevation to fulminant life-threatening acute liver failure. The recent arrival of immune checkpoint inhibitors in oncology has introduced a new range of immune-related adverse events, with differing mechanisms of liver toxicity and varied imaging presentation of liver injury. High-dose chemotherapy regimens for haematopoietic stem cell transplantation are associated with sinusoidal obstruction syndrome. Management of hepatic toxicity depends on the clinical scenario, the drug in use, and the severity of the findings. In this article, we will (1) present the most common types of oncological drugs associated with hepatic toxicity and associated liver injuries; (2) illustrate imaging findings of hepatic toxicities and the possible differential diagnosis; and (3) provide a guide for management of these conditions.

Prognostic significance of supradiaphragmatic lymph nodes at initial presentation in patients with stage III high-grade serous ovarian cancer.

PURPOSE: To identify the optimal size threshold and to assess the prognostic significance of supradiaphragmatic lymph nodes at initial presentation of patients with high-grade serous ovarian cancer (HGSC). METHODS: This IRB-approved, HIPAA-compliant retrospective study included baseline pretreatment staging abdominal CTs of 88 women (mean age 62 years, SD 10.4, range 29-85) with FIGO stage III HGSC. Patients with stage IV disease were excluded due to worse prognosis and management guided by distant metastases. Two fellowship-trained radiologists independently reviewed abdominal CTs to record the presence of supradiaphragmatic nodes, abdominal lymphadenopathy, peritoneal carcinomatosis, and ovarian mass. Progression-free survival (PFS) and overall survival (OS) were recorded after median 79 months follow-up (IQR 58-115, range 13-144). The optimal short-axis size threshold for supradiaphragmatic lymphadenopathy was determined by correlating 3, 4, 5, 6, 7, and 10 mm thresholds with PFS and OS using Log-rank test. Prognostic significance of supradiaphragmatic lymphadenopathy was assessed using Cox proportional hazards models. RESULTS: There was good interobserver agreement for presence (κ = 0.65, 95%CI 0.51-0.79) and size (ICC = 0.77, 95%CI 0.66-0.86) of supradiaphragmatic nodes. 5 mm short-axis size threshold was associated with significantly shorter PFS (median 14 months, IQR 11-17 vs. 23 months, IQR 12-59; p = 0.02) and OS (median 44 months, IQR 27-69 vs. 65 months, IQR 45-96; p = 0.03). Total 38/88 (43%) patients had supradiaphragmatic lymphadenopathy. On Cox proportion hazards analysis, supradiaphragmatic lymphadenopathy was significantly associated with shorter PFS (p = 0.02; HR 1.81, 95%CI 1.11-2.96) and OS (p = 0.008; HR 2.11, 95%CI 1.21-3.65). CONCLUSION: In patients with stage III HGSC, supradiaphragmatic lymphadenopathy is associated with shorter PFS and OS. Further studies would help determine its implications on staging, decision regarding neoadjuvant therapy, and surgical technique.

Patterns of metastasis and recurrence in thymic epithelial tumours: longitudinal imaging review in correlation with histological subtypes.

AIM: To determine the patterns of metastasis and recurrence in thymic epithelial tumours based on longitudinal imaging studies, and to correlate the patterns with World Health Organization (WHO) histological classifications. MATERIALS AND METHODS: Seventy-seven patients with histopathologically confirmed thymomas (n=62) and thymic carcinomas (n=15) who were followed with cross-sectional follow-up imaging after surgery were retrospectively studied. All cross-sectional imaging studies during the disease course were reviewed to identify metastasis or recurrence. The sites of involvement and the time of involvement measured from surgery were recorded. RESULTS: Metastasis or recurrence was noted in 24 (31%) of the 77 patients. Patients with metastasis or recurrence were significantly younger than those without (median age: 46 versus 60, respectively; p=0.0005), and more commonly had thymic carcinomas than thymomas (p=0.002). The most common site of involvement was the pleura (17/24), followed by the lung (9/24), and thoracic nodes (9/24). Abdominopelvic involvement was noted in 12 patients, most frequently in the liver (n=8). Lung metastasis was more common in thymic carcinomas than thymomas (p=0.0005). Time from surgery to the development of metastasis or recurrence was shortest in thymic carcinoma, followed by high-risk thymomas, and was longest in low-risk thymoma (median time in months: 25.1, 68.8, and not reached, respectively; p=0.0015). CONCLUSIONS: The patterns of metastasis and recurrence of thymic epithelial tumours differ significantly across histological subgroups, with thymic carcinomas more commonly having metastasis with shorter length of time after surgery. The knowledge of different patterns of tumour spread may contribute to further understanding of the biological and clinical behaviours of these tumours.

Assessment of metastatic risk of gastric GIST based on treatment-naïve CT features.

OBJECTIVE: To study whether the CT features of treatment-naïve gastric GIST may be used to assess metastatic risk. METHODS: In this IRB approved retrospective study, with informed consent waived, contrast enhanced CT images of 143 patients with pathologically confirmed treatment-naïve gastric GIST (74 men, 69 women; mean age 61 years, SD ± 14) were reviewed in consensus by two oncoradiologists blinded to clinicopathologic features and clinical outcome and morphologic features were recorded. The metastatic spread was recorded using available imaging studies and electronic medical records (median follow up 40 months, interquartile range, IQR, 21-61). The association of maximum size in any plane (≤10 cm or >10 cm), outline (smooth or irregular/lobulated), cystic areas (≤50% or >50%), exophytic component (≤50% or >50%), and enhancing solid component (present or absent) with metastatic disease were analyzed using univariate (Fisher's exact test) and multivariate (logistic regression) analysis. RESULTS: Metastatic disease developed in 42 (29%) patients (28 at presentation, 14 during follow-up); 23 (16%) patients died. On multivariate analysis, tumor size >10 cm (p = 0.0001, OR 9.9), irregular/lobulated outline (p = 0.001, OR 5.6) and presence of a enhancing solid component (p < 0.0001, OR 9.1) were independent predictors of metastatic disease. On subgroup analysis, an irregular/lobulated outline and an enhancing solid component were more frequently associated with metastases in tumors ≤5 cm and >5-≤10 cm (p < 0.05). CONCLUSION: CT morphologic features can be used to assess the metastatic risk of treatment-naïve gastric GIST. Risk assessment based on pretreatment CT is especially useful for patients receiving neoadjuvant tyrosine kinase inhibitors and those with tumors <5 cm in size.

Imaging yield from 133 consecutive patients with prostate cancer and low trigger PSA from a single institution.

AIM: To investigate the yield of imaging in patients with relapsed prostate cancer (PC) with a low trigger prostate-specific antigen (PSA). MATERIALS AND METHODS: This institutional review board (IRB)-approved, Health Insurance Portability and Accountability Act (HIPAA)-compliant retrospective study included all 133 patients (mean age 68 years; range 45-88; median 69 months since original diagnosis; interquartile range [IQR]: 32-139) with hormone-sensitive PC (HSPC, n=28) or castration-resistant PC (CRPC, n=105) and trigger PSA <4 ng/ml, who underwent same-day bone scintigraphy and computed tomography (CT; total 224 time points) at Dana-Farber Cancer Institute from January to December 2013. Clinical and pathological data were obtained by manual review of the electronic medical records. All the included bone scintigraphs and CT images were reviewed by a fellowship-trained oncoradiologist to record the metastatic pattern and any clinically significant non-metastatic findings. RESULTS: Ninety-four of the 133 (71%) patients had metastatic disease (18/28 [64%] with HSPC, 76/105 [72%] with CRPC). Forty-one of the 133 (31%) patients developed new metastatic disease and 23/133 (17%) developed new clinically significant non-metastatic findings. The incidence of osseous, nodal, and visceral metastases, and clinically significant non-metastatic findings was similar across the HSPC and CRPC groups (p>0.05 for all). Fifty-seven of the 133 (43%) patients had findings seen only at CT, of which 37 had new extra-osseous findings. Only 2/133 (2%) had findings at bone scintigraphy not seen at CT, both in areas not covered on CT. CONCLUSION: Imaging frequently demonstrated new metastatic and non-metastatic findings in patients with a low trigger PSA. CT is valuable in these patients because extra-osseous findings not visible at bone scintigraphy are frequently seen.

MDCT and clinicopathological features of small bowel gastrointestinal stromal tumours in 102 patients: a single institute experience.

OBJECTIVE: Small bowel (SB) is the second most common site of gastrointestinal stromal tumours (GISTs). We evaluated clinical presentation, pathology, imaging features and metastatic pattern of SB GIST. METHODS: Imaging and clinicopathological data of 102 patients with jejunal/ileal GIST treated at Dana-Farber Cancer Institute and Brigham and Women's Hospital (Boston, MA) between 2002 and 2013 were evaluated. Imaging of treatment-naive primary tumour (41 patients) and follow-up imaging in all patients was reviewed. RESULTS: 90/102 patients were symptomatic at presentation, abdominal pain and lower gastrointestinal blood loss being the most common symptoms. On pathology, 21 GISTs were low risk, 17 were intermediate and 64 were high risk. The mean tumour size was 8.5 cm. On baseline CT (n = 41), tumours were predominantly well circumscribed, exophytic and smooth/mildly lobulated in contour. Of 41 tumours, 16 (39%) were homogeneous, whereas 25 (61%) were heterogeneous. Of the 41 tumours, cystic/necrotic areas (Hounsfield units < 20) were seen in 16 (39%) and calcifications in 9 (22%). CT demonstrated complications in 13/41 (32%) patients in the form of tumour-bowel fistula (TBF) (7/41), bowel obstruction (4/41) and intraperitoneal rupture (2/41). Amongst 102 total patients, metastases developed in 51 (50%) patients (27 at presentation), predominantly involving peritoneum (40/102) and liver (32/102). 7/8 (87%) patients having intraperitoneal rupture at presentation developed metastases. Metastases elsewhere were always associated with hepatic/peritoneal metastases. At last follow-up, 28 patients were deceased (median survival, 65 months). CONCLUSION: SB GISTs were predominantly large, well-circumscribed, exophytic tumours with or without cystic/necrotic areas. Complications such as TBF, bowel obstruction and intraperitoneal perforation were visualized at presentation, with patients with perforation demonstrating a high risk of metastatic disease. Exophytic eccentric bowel wall involvement and lack of associated adenopathy are useful indicators to help differentiate GISTs from other SB neoplasms. ADVANCES IN KNOWLEDGE: SB GISTs are predominantly large, well-circumscribed, exophytic tumours, and may present with complications. They often are symptomatic at presentation, are high risk on pathology and metastasize to the peritoneum more commonly than the liver.

Is there a difference in post-transplant lymphoproliferative disorder in adults after solid organ and haematologic stem cell transplantation? Experience in 41 patients.

OBJECTIVE: To determine if there is a difference in post-transplant lymphoproliferative disorder (PTLD) in adults after solid organ transplantation (SOT) and haematologic stem cell transplantation (HST). METHODS: In this institutional review board-approved Health Insurance Portability and Accountability Act-compliant study, we reviewed clinical data and imaging at the time of diagnosis in 41 patients (26 SOT and 15 HST) (31 males and 10 females; mean age 51 years) with histopathology-confirmed PTLD seen at our institution from 2004 through 2013. Statistical analysis was performed to assess difference in distribution and survival between SOT and HST cohorts. RESULTS: SOT: 17 lung/cardiac, 8 renal and 1 liver transplant recipients. HST: 13 leukaemia/lymphoma and 2 patients with aplastic anaemia. Median time to diagnosis: SOT 3.0 years; HST 6 months (Fisher's exact test; p = 0.0011). There was no statistically significant difference in distribution of PTLD after SOT and HST with nodes (15/26; 8/15), lung (10/26; 5/15) and bowel (6/26; 4/15) being the most common sites. Hepatic (3/26) and neurologic (2/26) involvement occurred in only SOT cohort while splenic PTLD (5/15) occurred more often in HST cohort. Death occurred earlier in HST (9/15; 2 weeks) than SOT cohort (12/26; 11 months) (Wilcoxon test; p = 0.0188). CONCLUSION: PTLD did not differ significantly in distribution between SOT and HST cohorts. PTLD after HST occurred early and had shorter survival. ADVANCES IN KNOWLEDGE: The most common sites of PTLD were the nodes, lung and bowel. Distribution of PTLD does not differ significantly between patients with SOT and HST. PTLD after HST occurs early and has poor survival compared with PTLD after SOT.

Metastasis in dedifferentiated liposarcoma: Predictors and outcome in 148 patients.

OBJECTIVE: To describe the pattern of dedifferentiated liposarcoma (DDLPS) metastases and to analyze their predictors and outcome. MATERIALS AND METHODS: In this retrospective study, we reviewed the imaging and clinical records of all consenting patients with histopathology-confirmed DDLPS seen from 2000 through 2012. The predictive value of clinical and histopathologic parameters for metastasis later in the disease course was analyzed using univariate and multivariate analyses. Survival of patients with and without metastasis was compared using Log-rank test. RESULTS: Records of 148 patients (57 women, 91 men; mean age 59 years, range 30-87 years) were reviewed. Distant metastases were observed in 44/148 patients (29.7%), 9/44 (20.5%) at presentation and 35/44 (79.5%) developing them later at a median interval of 8 months (IQR = 0.80-26 months). Median duration of follow-up was 38 months (IQR = 18-74 months) with 77/148 patients (31 with metastases) deceased at the time of analysis. Median survival was 28 months (IQR = 10-56 months) for patients with metastases and 38 months (IQR, 17-65 months) for patients without metastases (p = 0.0123, Log-Rank test; Hazard ratio 1.79 [95% confidence interval 1.11-2.84]). Lung was the most common site of metastases (33 patients, 22.3%). On univariate analysis, grade and local recurrence were associated with subsequent risk of metastasis where as age, tumor size, site, de novo dedifferentiation, number of previous surgical resections, margin positivity and chemoradiation were not. On multivariate analysis, high tumor grade (p-value = 0.0005, OR 5.05; 95% CI 2.01-13.48) and local recurrence (p-value = 0.0025, OR 4.46; 95% CI 1.67-13.40) predicted metastasis. CONCLUSION: Lung was most frequent site of DDLPS metastases. Risk of developing metastatic disease was statistically associated with tumor grade and local recurrence. Metastatic disease was associated with decreased survival.

Multimodality imaging and clinical features in Castleman disease: single institute experience in 30 patients.

OBJECTIVE: To analyse imaging features of subtypes of Castleman disease (CD), emphasizing differentiating features from lymphoma. METHODS: Institutional review board-approved, Health Insurance Portability and Accountability Act compliant, retrospective study examined 30 patients with CD. 30 patients (females, 20; mean age, 46 years; range, 22-87 years) with histopathologically confirmed CD and pre-treatment imaging formed the analytic cohort. Imaging at presentation in all patients [CT, 30; positron emission tomography (PET)/CT, 5; MR, 4; ultrasound, 3] and subsequent imaging in three cases that developed lymphoma was reviewed by two radiologists in consensus. RESULTS: Subtypes: hyaline-vascular (n = 18); multicentric not otherwise specified (NOS) (n = 6); human herpesvirus 8 associated (n = 2); mixed unicentric (n = 2); pure plasma-cell variant (n = 1); and unicentric NOS (n = 1). Distribution: unicentric (n = 17); and multicentric (n = 13). Nodal sites-unicentric: 13 thoracic, 3 abdominal and 1 cervical; multicentric: 9 abdominal, 8 thoracic, 6 cervical, 5 inguinal, 4 axillary and 4 supraclavicular. On CT, differentiating features from lymphoma were calcification (n = 8; 26.7%) and heterogeneous enhancement (n = 5; 19.2%). No association between CD subtype, degree or enhancement pattern, or calcification was noted. On PET/CT (n = 5), nodes were typically fluorine-18 fludeoxyglucose avid (n = 4). On ultrasound (n = 3), nodes were hypoechoic, homogeneous with posterior acoustic enhancement. On MR (n = 4), nodes were hypointense (n = 2) to isointense (n = 2) on T1 weighted images and isointense (n = 1) to hyperintense (n = 3) on T2 weighted images. All (n = 4) demonstrated homogeneous enhancement. Three cases developed non-Hodgkin's lymphoma, two of the three had larger spleens, and these cases had effusions/ascites. CONCLUSION: CD can be unicentric or multicentric and involve nodes above and below the diaphragm. Patients with CD can develop lymphoma. ADVANCES IN KNOWLEDGE: Assessing individual risk of developing lymphoma in patients with CD is difficult, although the findings of splenomegaly, pleural effusion and ascites may be suggestive.