Objective: The aim of the study was to evaluate the potential role of fludeoxyglucose (FDG)-positron emission tomography (PET)/CT in the detection of bone/bone marrow disease in patients with Hodgkin's lymphoma (HL). Methods: We retrospectively reviewed ( Results: There were 122 patients in total-81 (66.4%) were male and 41 (33.6%) were female. The age range was from 6 years to 78 years (mean 35.70 years). PET/CT was reported as negative for bone/bone marrow involvement in 85 (69.7%) patients, while the remaining 37 showed abnormal FDG uptake. The sensitivity of FDG-PET/CT was calculated to be 100%, the specificity was 76.57%, the negative predictive value was 76.57%, the positive predictive value was 29.72% and the diagnostic accuracy was 78.62%. Conclusion:18 F-FDG-PET/CT and BMB are complementary in the evaluation of bone marrow disease.

Introduction There are no previous published reports on primary pediatric tumors of the central nervous system (CNS) in Qatar. We undertook this retrospective cohort study to review the diagnosis of CNS tumors in children in Qatar to analyze the presentation characteristics including symptoms, referral pathways, and time to diagnosis. Methods All children registered with Pediatric Neuro-Oncology service (PNOS) were included in the study. Data from the time of diagnosis (October 2007 to February 2020) were reviewed retrospectively. Presenting symptoms were recorded and prediagnosis symptom interval (PSI) was calculated from the onset of the first symptom to the date of diagnostic imaging. Results Of the 61 children registered with PNOS during the study period, 51 were included in the final analysis. Ten children were excluded because they were either diagnosed outside Qatar (n = 7) or were asymptomatic at the time of diagnosis (n = 3). The median age was 45 (range 1-171) months. Common tumor types included low-grade glioma (LGG) (47.1%) and medulloblastoma/primitive neuroectodermal tumors (PNET) (23.5%). Nine children had an underlying neurocutaneous syndrome. Thirty-eight patients (74.5%) had at least one previous contact with healthcare (HC) professional, but 27 (52%) were still diagnosed through the emergency department (ED). Presenting symptoms included headache, vomiting (36.2%), oculo-visual symptoms (20.6%), motor weakness (18.9%), seizures, ataxia (17.2% each), irritability, cranial nerve palsies (12% each), and endocrine symptoms (10.3%). Median PSI was 28 days (range 1-845 days) for all CNS tumors. Longest PSI was seen with germ cell tumors (median 146 days), supratentorial location (39 days), and age above 3 years (30 days). Tumor characteristics of biological behavior (high-grade tumor) and location (infratentorial) were significantly associated with shorter PSI, as were presenting symptoms of ataxia, head tilt, and altered consciousness. Conclusions Although overall diagnostic times were acceptable, some tumor types were diagnosed after a significant delay. The awareness campaign, such as the "HeadSmart" campaign in the United Kingdom (UK), can improve diagnostic times in Qatar. Further research is required to better understand the reasons for the delay.

Late presentation with advanced disease, poor nutritional status and high risk of exposure to infective agents all contribute to the high mortality in patients treated with intensive protocols in resource-poor countries.

Background Large immunogenomic analyses have demonstrated the prognostic role of the functional orientation of the tumor microenvironment in adult solid tumors, this variable has been poorly explored in the pediatric counterpart. Methods We performed a systematic analysis of public RNAseq data (TARGET) for five pediatric tumor types (408 patients): Wilms tumor (WLM), neuroblastoma (NBL), osteosarcoma (OS), clear cell sarcoma of the kidney (CCSK) and rhabdoid tumor of the kidney (RT). We assessed the performance of the Immunologic Constant of Rejection (ICR), which captures an active Th1/cytotoxic response. We also performed gene set enrichment analysis (ssGSEA) and clustered more than 100 well characterized immune traits to define immune subtypes and compared their outcome. Results A higher ICR score was associated with better survival in OS and high risk NBL without MYCN amplification but with poorer survival in WLM. Clustering of immune traits revealed the same five principal modules previously described in adult tumors (TCGA). These modules divided pediatric patients into six immune subtypes (S1-S6) with distinct survival outcomes. The S2 cluster showed the best overall survival, characterized by low enrichment of the wound healing signature, high Th1, and low Th2 infiltration, while the reverse was observed in S4. Upregulation of the WNT/Beta-catenin pathway was associated with unfavorable outcomes and decreased T-cell infiltration in OS. Conclusions We demonstrated that extracranial pediatric tumors could be classified according to their immune disposition, unveiling similarities with adults’ tumors. Immunological parameters might be explored to refine diagnostic and prognostic biomarkers and to identify potential immune-responsive tumors.

Background: Low-and middle-income countries sustain the majority of pediatric cancer burden, with significantly poorer survival rates compared to high-income countries.Collaboration between institutions in low-and middle-income countries and highincome countries is one of the ways to improve cancer outcomes.Methods: Patient characteristics and effects of a pediatric neuro-oncology twinning program between the Hospital for Sick Children in Toronto, Canada and several hospitals in Karachi, Pakistan over 7 years are described in this article.Results: A total of 460 patients were included in the study. The most common primary central nervous system tumors were low-grade gliomas (26.7%), followed by medulloblastomas (18%), high-grade gliomas (15%), ependymomas (11%), and craniopharyngiomas (11.7%). Changes to the proposed management plans were made in consultation with expert physicians from the Hospital for Sick Children in Toronto, Canada. On average, 24% of the discussed cases required a change in the original management plan over the course of the twinning program. However, a decreasing trend in change in management plans was observed, from 36% during the first 3.5 years to 16% in the last 3 years. This program also led to the launch of a national pediatric neuro-oncology telemedicine program in Pakistan.